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Papers by Richard Wilder

Research paper thumbnail of Primary bladder preservation treatment for urothelial bladder cancer

Cancer Control Journal of the Moffitt Cancer Center, Jul 1, 2013

BACKGROUND: Significant advancements have occurred in surgical procedures and chemoradiation ther... more BACKGROUND: Significant advancements have occurred in surgical procedures and chemoradiation therapy for bladder preservation.METHODS: This review addresses primary treatment options for bladder cancer, including an overview of bladder-sparing strategies.RESULTS: Surgical series demonstrate that highly selected patients with cT2N0M0 urothelial bladder cancers can be managed with partial cystectomy and bilateral pelvic lymphadenectomy. For patients with cT2N0M0 to cT4aN0M0 urothelial bladder cancers, neoadjuvant chemotherapy followed by radical cystectomy or maximal transurethral resection of the bladder tumor (TURBT) followed by chemoradiation therapy results in equivalent survival rates. However, each treatment option has a different impact on quality of life. Current chemoradiation therapy trials are evaluating novel approaches to improve outcomes.CONCLUSIONS: Maximal TURBT followed by chemoradiation therapy demonstrated equivalent survival with radical cystectomy while preserving bladder function in the majority of patients. Future efforts will be directed toward improving survival and quality of life.

Research paper thumbnail of European Organization for Research and Treatment of Cancer and Groupe d'Etude des Lymphomes de l'Adulte very favorable and favorable, lymphocyte-predominant Hodgkin disease

Research paper thumbnail of OC3MON: flexible, affordable, high performance statistics collection

... This level of security is equivalent to that provided by most SNMP implementations. ... to th... more ... This level of security is equivalent to that provided by most SNMP implementations. ... to the analysis of packet trace and flows data and the web interface to the data are limited ... We have described the design, implementation, and use of a high performance yet affordable Internet ...

Research paper thumbnail of OC3MON: Flexible, Affordable, High Performance Staistics Collection

USENIX Systems Administration Conference, 1996

this paper. Initial tests with timeouts as large as 10minutes did not significantly increase the ... more this paper. Initial tests with timeouts as large as 10minutes did not significantly increase the number of flows, but we have not yet tested it under heavierdata streams.This timeout-based flow definition allows flexibility in how one further specifies a flow. There are otheraspects that structure a flow specification: directionality, one sided vs. two sided, endpoint granularity,and functional layer.flow directionality: one

Research paper thumbnail of Kidney cancer, version 3.2015

Journal of the National Comprehensive Cancer Network : JNCCN, 2015

The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for the clinical ... more The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for the clinical management of patients with clear cell and non-clear cell renal carcinoma. These NCCN Guidelines Insights highlight the recent updates/changes in these guidelines, and updates include axitinib as first-line treatment option for patients with clear cell renal carcinoma, new data to support pazopanib as subsequent therapy for patients with clear cell carcinoma after first-line treatment with another tyrosine kinase inhibitor, and guidelines for follow-up of patients with renal cell carcinoma.

Research paper thumbnail of Preliminary Results in 185 Patients Treated with Accelerated Partial Breast Irradiation for Early-stage Breast Cancer

International Journal of Radiation Oncology*Biology*Physics, 2008

Results: Median follow-up time was 34 months. There was considerable variation in maximum skin do... more Results: Median follow-up time was 34 months. There was considerable variation in maximum skin dose among patients with a common skin distance (mean standard deviation of 40 cGy). A significant correlation was found between incidence of acute moist desquamation and a maximum skin dose .410 cGy (120% prescription dose, p = 0.014) or a skin distance \8 mm (p = 0.025). Correlations were found between a maximum skin dose .400 cGy and incidence of chronic induration (p = 0.042) and chronic erythema (borderline significant, p = 0.051). Incidence of telangiectasia was found to increase continuously with closer skin distance (p = 0.0006) and maximum skin dose (p = 0.0003) with no threshold found #10 mm or .210 cGy. Conclusions: Maximum planned skin dose was found to correlate with incidence of acute moist desquamation, telangiectasia, chronic erythema, and chronic induration resulting from MammoSite APBI. This correlation supports the empirically validated use of minimum balloon-to-skin distance as a predictor of toxicity from MammoSite treatment. We expect that as more sophisticated brachytherapy dose calculation methods evolve, calculated maximum skin dose will improve correspondingly as a predictor for morbidity.

Research paper thumbnail of An Analysis of Intrafraction Prostate Motion in the Prone vs. Supine Treatment Positions for Intensity-Modulated Radiation Therapy

International Journal of Radiation Oncology*Biology*Physics, 2008

Research paper thumbnail of Early Diagnosis and Treatment of Cancer: Prostate Cancer

International Journal of Radiation Oncology*Biology*Physics, 2011

Research paper thumbnail of Impact of collimator leaf width on stereotactic radiosurgery and 3D conformal radiotherapy treatment plans

International Journal of Radiation Oncology*Biology*Physics, 1999

Purpose: The authors undertook a study to analyze the impact of collimator leaf width on stereota... more Purpose: The authors undertook a study to analyze the impact of collimator leaf width on stereotactic radiosurgery and 3D conformal radiotherapy treatment plans. Methods and Materials: Twelve cases involving primary brain tumors, metastases, or arteriovenous malformations that had been planned with BrainLAB's conventional circular collimator-based radiosurgery system were re-planned using a ␤-version of BrainLAB's treatment planning software that is compatible with MRC Systems' and BrainLAB's micro-multileaf collimators. These collimators have a minimum leaf width of 1.7 mm and 3.0 mm, respectively, at isocenter. The clinical target volumes ranged from 2.7-26.1 cc and the number of static fields ranged from 3-5. In addition, for 4 prostate cancer cases, 2 separate clinical target volumes were planned using MRC Systems' and BrainLAB's micro-multileaf collimators and Varian's multileaf collimator: the smaller clinical target volume consisted of the prostate gland and the larger clinical target volume consisted of the prostate and seminal vesicles. For the prostate cancer cases, treatment plans were generated using either 6 or 7 static fields. A "PITV ratio," which the Radiation Therapy Oncology Group defines as the volume encompassed by the prescription isodose surface divided by the clinical target volume, was used as a measure of the quality of treatment plans (a PITV ratio of 1.0 -2.0 is desirable). Bladder and rectal volumes encompassed by the prescription isodose surface, isodose distributions and dose volume histograms were also analyzed for the prostate cancer patients. Results: In 75% of the cases treated with radiosurgery, a PITV ratio between 1.0 -2.0 could be achieved using a micro-multileaf collimator with a leaf width of 1.7-3.0 mm at isocenter and 3-5 static fields. When the clinical target volume consisted of the prostate gland, the micro-multileaf collimator with a minimum leaf width of 3.0 mm allowed one to decrease the median volume of bladder and rectum within the prescription isodose surface by 26% and 17%, respectively, compared to the multileaf collimator with a leaf width of 10 mm. Use of the 1.7 mm leaf width micro-multileaf collimator allowed one to decrease the median volume of bladder and rectum within the prescription isodose surface by 48% and 39%, respectively, compared to the multileaf collimator with a leaf width of 10 mm. Conclusions: For most lesions treated with radiosurgery, the use of a micro-multileaf collimator with a leaf width of 1.7-3.0 mm at isocenter and 3-5 static fields allows one to meet the Radiation Therapy Oncology Group guidelines for treatment planning. Both planning and treatment are relatively straightforward with a micromultileaf collimator, allowing for efficient treatment of non-spherical targets with either stereotactic radiosurgery or fractionated stereotactic radiotherapy. When the clinical target volume consists of the prostate gland, micro-multileaf collimators with a minimum leaf width of 1.7-3.0 mm allow one to spare more bladder and rectum than one can with a multileaf collimator that has a 10-mm leaf width based on an analysis of PITV ratios, isodose distributions, and dose volume histograms.

Research paper thumbnail of Results with chemotherapy comprised of cyclophosphamide, doxorubicin, vincristine, and prednisone followed by radiotherapy with or without prechemotherapy surgical debulking for patients with bulky, aggressive lymphoma

Cancer, 2002

The authors performed a case-control analysis of local control, progression free survival, and ov... more The authors performed a case-control analysis of local control, progression free survival, and overall survival in patients with Stage I-II aggressive lymphomas measuring Ն 7 cm in greatest dimension who were treated initially with or without surgical debulking: All patients then received cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-based chemotherapy followed by involved-field radiotherapy.

Research paper thumbnail of A Dosimetric Comparison in Prostate Cancer Patients Treated with HDR Brachytherapy ± IMRT ± Polyethylene Glycol Gel

Research paper thumbnail of Radiation Therapy for Squamous Cell Carcinoma of the Supraglottic Larynx

American Journal of Clinical Oncology, 1989

Sixty-five patients with invasive squamous cell carcinoma of the supraglottic larynx received irr... more Sixty-five patients with invasive squamous cell carcinoma of the supraglottic larynx received irradiation with curative intent between 1975 and 1984, with a 5-year actuarial survival of 48% and a local control rate of 70%. Five-year survivals for clinical Stages I, II, and III + IV were 60, 53, and 52%, respectively; local control rates were 88, 76, and 63%, respectively. These patients included one treated with preoperative irradiation, 35 treated with surgery followed by postoperative irradiation, and 29 treated with radiation therapy alone. In the surgery plus irradiation group, 5-year local control was 93% for clinical Stages I + II (14 patients), and 61% for clinical Stages III + IV (21 patients). Three patients had pathologic Stage II disease, with the remainder demonstrating a higher pathologic than clinical stage. Multiple positive nodes predisposed to local/regional recurrence, while no relationship could be established between recurrence and extracapsular nodal spread, positive margins, emergency tracheostomy, total versus less-than-total laryngectomy, radiation field size, radiation dose, or delay until radiation therapy, probably because of patient numbers. Six patients, five with positive nodes, developed distant metastases, and three developed second primary tumors outside the head and neck region. In the radiation therapy alone group, 5-year local control rates were 86, 59, and 53% for clinical Stages I (7 patients), II (11 patients), and III + IV (11 patients), respectively. However, three of four Stage II local/regional failures were surgically salvaged for periods greater than 30 months, for an ultimate Stage II local control of 89%. No relationship could be established between local control and radiation dose or field size, again probably because of small patient numbers. Three patients developed distant metastases, and eight developed second malignancies, one within the irradiated volume. Fifteen patients developed acute toxicity during irradiation, and there were eight chronic complications, five requiring surgery; toxicity was more common in the group treated with radiation alone. Radiation therapy alone with surgical salvage is an effective, function-preserving treatment for clinical Stages I and II carcinoma of the supraglottic larynx, and appears to yield local control and survival comparable with that of combined irradiation and surgery in more advanced disease.

Research paper thumbnail of A PROSPECTIVE STUDY OF INTRAFRACTION PROSTATE MOTION IN THE PRONE VS. SUPINE POSITION

To prospectively analyze prostate intrafraction motion in the prone vs. supine position and to as... more To prospectively analyze prostate intrafraction motion in the prone vs. supine position and to assess patient satisfaction with these two positions. Fifteen prostate cancer patients underwent implantation of five fiducial gold seeds in their prostate for localization. Patients were treated with high-dose-rate brachytherapy to 2,200 cGy followed by intensity-modulated radiation therapy (IMRT) to 5,040 cGy. Patients underwent computed tomography simulation and IMRT in the prone position. For the first five IMRT treatments, an electronic portal imaging system was used to acquire anteroposterior (AP) and lateral images pretreatment and posttreatment. We then repositioned each patient supine and repeated the process, resulting in 600 images. Mean +/- standard deviation intrafraction prostate motion was 2.1 +/- 1.2 mm and 1.7 +/- 1.4 mm (AP, p = 0.47), 2.2 +/- 2.0 mm and 1.6 +/- 1.8 mm (superoinferior, p = 0.16), and 1.0 +/- 1.2 mm and 0.6 +/- 0.9 mm (left-right, p = 0.03) in the prone and supine positions, respectively. Eighty percent of patients stated that they were more comfortable in the supine position (p = 0.02). Prone and supine positions resulted in a similar magnitude of AP and superoinferior intrafraction prostate motion (2 mm). Because there was no significant difference in the magnitude of AP and superoinferior prostate motion prone vs. supine and patients were more comfortable in the supine position, patients now undergo IMRT to the prostate and seminal vesicles at our center in the supine position.

Research paper thumbnail of Recurrent basal cell carcinoma treated with radiation therapy

Archives of Dermatology, Nov 1, 1991

A retrospective study was performed of 61 recurrent basal cell carcinomas treated with radiation ... more A retrospective study was performed of 61 recurrent basal cell carcinomas treated with radiation therapy between 1974 and 1990 at the University of Arizona College of Medicine or at Southwestern Radiation Oncology, Tucson, Arizona. The median length of follow-up was 57 months. Applying the American Joint Committee on Cancer staging system to these recurrent tumors, 36 were stage I, 19 were stage II, five were stage III, and one was stage IV. Kaplan-Meier methods were used to estimate the 5-year complete remission rates. The Mantel-Haenszel Test and the Cox Proportional Hazards Model were used to determine if tumor size, stage, histologic subtype, anatomic site, age, sex, dose, number of radiation therapy treatments, length of time over which the radiation therapy was administered, or type of radiation beam used (orthovoltage x-rays vs megavoltage electrons) affected the 5-year complete remission rates. Only tumor size and stage had a statistically significant effect on the complete remission rates. The Kaplan-Meier estimates of the 5-year complete remission rates for 0.5- to 1.0-cm tumors vs tumors larger than 1.0 cm were 96% (95% confidence interval, 88% to 100%) and 81% (95% confidence interval, 64% to 99%), respectively. The Kaplan-Meier estimates of the 5-year complete remission rates for stage I/II tumors vs stage III/IV tumors were 93% (95% confidence interval, 85% to 100%) and 42% (95% confidence interval, 8% to 84%), respectively. Functional and cosmetic results were frequently good to excellent at 5 years. Soft-tissue necrosis developed in two of 61 cases, and was successfully managed in both. This article, combined with a review of the literature, suggests that radiation therapy is an effective method of treating recurrent basal cell carcinomas.

Research paper thumbnail of Treatment of unicentric and multicentric Castleman disease and the role of radiotherapy

Research paper thumbnail of Packet-based Approaches to ATM Cell Policing and Their Effects on Internet Traffic

Proceedings of the Ifip Tc 6 Eigth International Conference on High Performance Networking, Sep 21, 1998

Research paper thumbnail of A preliminary cell kinetics model of thrombocytopenia after radioimmunotherapy

Journal of Nuclear Medicine, Jul 1, 1998

The cumulative data in this study showed a strong correlation between L/B ratios calculated on at... more The cumulative data in this study showed a strong correlation between L/B ratios calculated on attenuation-corrected and uncorrected images . However, there was no correlation between SUR values calculated on both types of images. This is probably due to the fact that the background activity, an important variable in these calculations, is not considered in SUR calculations. Moreover, absolute counts are required for the original definition of SUR. For the same reasons, SUR and LIB values calculated on uncorrected images also did not show a significant correlation ). This indicates that the L/B ratio is the only index that can be used for semiquantitative evaluation of uncorrected images.

Research paper thumbnail of Dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with high-dose-rate brachytherapy for large prostate volumes

International braz j urol : official journal of the Brazilian Society of Urology

To evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with H... more To evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes. One hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL) were treated with high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38%) unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4. Median follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3%) patients developed Grade 2 acute proctitis. No variables were s...

Research paper thumbnail of Stage IIA and IIB testicular seminoma treated postorchiectomy with radiation therapy versus other approaches: a population-based analysis of 241 patients

International braz j urol : official journal of the Brazilian Society of Urology

To evaluate post-orchiectomy utilization of radiation therapy (RT) versus other management approa... more To evaluate post-orchiectomy utilization of radiation therapy (RT) versus other management approaches in stage IIA and IIB testicular seminoma patients. Two hundred and forty-one patients with stage IIA and IIB testicular seminoma were identified between 1988 and 2003 using the Surveillance, Epidemiology, and End Results (SEER) database. Median follow-up was 10 years. Patients with stage IIA disease underwent RT more frequently than those with stage IIB disease (72 % vs. 46 %, respectively; P < 0.001). There was no significant change in RT utilization for stage IIA or IIB disease between 1988 and 2003 (P = 0.89). Between 1988 and 2003, stage IIA patients underwent RT more often than stage IIB patients in the United States. There was no significant change in RT utilization for stage IIA or IIB disease during this time period. Based on reports describing excellent progression-free survival with cisplatin-based chemotherapy, this approach has increased in popularity since 2003 and m...

Research paper thumbnail of Quality of life after high-dose-rate brachytherapy monotherapy for prostate cancer

International braz j urol, 2015

There is little information in the literature on health-related quality of life (HRQOL) changes d... more There is little information in the literature on health-related quality of life (HRQOL) changes due to high-dose-rate (HDR) brachytherapy monotherapy for prostate cancer. We conducted a prospective study of HRQOL changes due to HDR brachytherapy monotherapy for low risk or favorable intermediate risk prostate cancer. Sixty-four of 84 (76 %) patients who were treated between February 2011 and April 2013 completed 50 questions comprising the Expanded Prostate Cancer Index Composite (EPIC) before treatment and 6 and/or 12 months after treatment. Six months after treatment, there was a significant decrease (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) in EPIC urinary, bowel, and sexual scores, including urinary overall, urinary function, urinary bother, urinary irritative, bowel overall, bowel bother, sexual overall, and sexual bother scores. By one year after treatment, EPIC urinary, bowel, and sexual scores had increased and only the bowel overall and bowel bother scores remained significantly below baseline values. HDR brachytherapy monotherapy is well-tolerated in patients with low and favorable intermediate risk prostate cancer. EPIC urinary and sexual domain scores returned to close to baseline 12 months after HDR brachytherapy.

Research paper thumbnail of Primary bladder preservation treatment for urothelial bladder cancer

Cancer Control Journal of the Moffitt Cancer Center, Jul 1, 2013

BACKGROUND: Significant advancements have occurred in surgical procedures and chemoradiation ther... more BACKGROUND: Significant advancements have occurred in surgical procedures and chemoradiation therapy for bladder preservation.METHODS: This review addresses primary treatment options for bladder cancer, including an overview of bladder-sparing strategies.RESULTS: Surgical series demonstrate that highly selected patients with cT2N0M0 urothelial bladder cancers can be managed with partial cystectomy and bilateral pelvic lymphadenectomy. For patients with cT2N0M0 to cT4aN0M0 urothelial bladder cancers, neoadjuvant chemotherapy followed by radical cystectomy or maximal transurethral resection of the bladder tumor (TURBT) followed by chemoradiation therapy results in equivalent survival rates. However, each treatment option has a different impact on quality of life. Current chemoradiation therapy trials are evaluating novel approaches to improve outcomes.CONCLUSIONS: Maximal TURBT followed by chemoradiation therapy demonstrated equivalent survival with radical cystectomy while preserving bladder function in the majority of patients. Future efforts will be directed toward improving survival and quality of life.

Research paper thumbnail of European Organization for Research and Treatment of Cancer and Groupe d'Etude des Lymphomes de l'Adulte very favorable and favorable, lymphocyte-predominant Hodgkin disease

Research paper thumbnail of OC3MON: flexible, affordable, high performance statistics collection

... This level of security is equivalent to that provided by most SNMP implementations. ... to th... more ... This level of security is equivalent to that provided by most SNMP implementations. ... to the analysis of packet trace and flows data and the web interface to the data are limited ... We have described the design, implementation, and use of a high performance yet affordable Internet ...

Research paper thumbnail of OC3MON: Flexible, Affordable, High Performance Staistics Collection

USENIX Systems Administration Conference, 1996

this paper. Initial tests with timeouts as large as 10minutes did not significantly increase the ... more this paper. Initial tests with timeouts as large as 10minutes did not significantly increase the number of flows, but we have not yet tested it under heavierdata streams.This timeout-based flow definition allows flexibility in how one further specifies a flow. There are otheraspects that structure a flow specification: directionality, one sided vs. two sided, endpoint granularity,and functional layer.flow directionality: one

Research paper thumbnail of Kidney cancer, version 3.2015

Journal of the National Comprehensive Cancer Network : JNCCN, 2015

The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for the clinical ... more The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for the clinical management of patients with clear cell and non-clear cell renal carcinoma. These NCCN Guidelines Insights highlight the recent updates/changes in these guidelines, and updates include axitinib as first-line treatment option for patients with clear cell renal carcinoma, new data to support pazopanib as subsequent therapy for patients with clear cell carcinoma after first-line treatment with another tyrosine kinase inhibitor, and guidelines for follow-up of patients with renal cell carcinoma.

Research paper thumbnail of Preliminary Results in 185 Patients Treated with Accelerated Partial Breast Irradiation for Early-stage Breast Cancer

International Journal of Radiation Oncology*Biology*Physics, 2008

Results: Median follow-up time was 34 months. There was considerable variation in maximum skin do... more Results: Median follow-up time was 34 months. There was considerable variation in maximum skin dose among patients with a common skin distance (mean standard deviation of 40 cGy). A significant correlation was found between incidence of acute moist desquamation and a maximum skin dose .410 cGy (120% prescription dose, p = 0.014) or a skin distance \8 mm (p = 0.025). Correlations were found between a maximum skin dose .400 cGy and incidence of chronic induration (p = 0.042) and chronic erythema (borderline significant, p = 0.051). Incidence of telangiectasia was found to increase continuously with closer skin distance (p = 0.0006) and maximum skin dose (p = 0.0003) with no threshold found #10 mm or .210 cGy. Conclusions: Maximum planned skin dose was found to correlate with incidence of acute moist desquamation, telangiectasia, chronic erythema, and chronic induration resulting from MammoSite APBI. This correlation supports the empirically validated use of minimum balloon-to-skin distance as a predictor of toxicity from MammoSite treatment. We expect that as more sophisticated brachytherapy dose calculation methods evolve, calculated maximum skin dose will improve correspondingly as a predictor for morbidity.

Research paper thumbnail of An Analysis of Intrafraction Prostate Motion in the Prone vs. Supine Treatment Positions for Intensity-Modulated Radiation Therapy

International Journal of Radiation Oncology*Biology*Physics, 2008

Research paper thumbnail of Early Diagnosis and Treatment of Cancer: Prostate Cancer

International Journal of Radiation Oncology*Biology*Physics, 2011

Research paper thumbnail of Impact of collimator leaf width on stereotactic radiosurgery and 3D conformal radiotherapy treatment plans

International Journal of Radiation Oncology*Biology*Physics, 1999

Purpose: The authors undertook a study to analyze the impact of collimator leaf width on stereota... more Purpose: The authors undertook a study to analyze the impact of collimator leaf width on stereotactic radiosurgery and 3D conformal radiotherapy treatment plans. Methods and Materials: Twelve cases involving primary brain tumors, metastases, or arteriovenous malformations that had been planned with BrainLAB's conventional circular collimator-based radiosurgery system were re-planned using a ␤-version of BrainLAB's treatment planning software that is compatible with MRC Systems' and BrainLAB's micro-multileaf collimators. These collimators have a minimum leaf width of 1.7 mm and 3.0 mm, respectively, at isocenter. The clinical target volumes ranged from 2.7-26.1 cc and the number of static fields ranged from 3-5. In addition, for 4 prostate cancer cases, 2 separate clinical target volumes were planned using MRC Systems' and BrainLAB's micro-multileaf collimators and Varian's multileaf collimator: the smaller clinical target volume consisted of the prostate gland and the larger clinical target volume consisted of the prostate and seminal vesicles. For the prostate cancer cases, treatment plans were generated using either 6 or 7 static fields. A "PITV ratio," which the Radiation Therapy Oncology Group defines as the volume encompassed by the prescription isodose surface divided by the clinical target volume, was used as a measure of the quality of treatment plans (a PITV ratio of 1.0 -2.0 is desirable). Bladder and rectal volumes encompassed by the prescription isodose surface, isodose distributions and dose volume histograms were also analyzed for the prostate cancer patients. Results: In 75% of the cases treated with radiosurgery, a PITV ratio between 1.0 -2.0 could be achieved using a micro-multileaf collimator with a leaf width of 1.7-3.0 mm at isocenter and 3-5 static fields. When the clinical target volume consisted of the prostate gland, the micro-multileaf collimator with a minimum leaf width of 3.0 mm allowed one to decrease the median volume of bladder and rectum within the prescription isodose surface by 26% and 17%, respectively, compared to the multileaf collimator with a leaf width of 10 mm. Use of the 1.7 mm leaf width micro-multileaf collimator allowed one to decrease the median volume of bladder and rectum within the prescription isodose surface by 48% and 39%, respectively, compared to the multileaf collimator with a leaf width of 10 mm. Conclusions: For most lesions treated with radiosurgery, the use of a micro-multileaf collimator with a leaf width of 1.7-3.0 mm at isocenter and 3-5 static fields allows one to meet the Radiation Therapy Oncology Group guidelines for treatment planning. Both planning and treatment are relatively straightforward with a micromultileaf collimator, allowing for efficient treatment of non-spherical targets with either stereotactic radiosurgery or fractionated stereotactic radiotherapy. When the clinical target volume consists of the prostate gland, micro-multileaf collimators with a minimum leaf width of 1.7-3.0 mm allow one to spare more bladder and rectum than one can with a multileaf collimator that has a 10-mm leaf width based on an analysis of PITV ratios, isodose distributions, and dose volume histograms.

Research paper thumbnail of Results with chemotherapy comprised of cyclophosphamide, doxorubicin, vincristine, and prednisone followed by radiotherapy with or without prechemotherapy surgical debulking for patients with bulky, aggressive lymphoma

Cancer, 2002

The authors performed a case-control analysis of local control, progression free survival, and ov... more The authors performed a case-control analysis of local control, progression free survival, and overall survival in patients with Stage I-II aggressive lymphomas measuring Ն 7 cm in greatest dimension who were treated initially with or without surgical debulking: All patients then received cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-based chemotherapy followed by involved-field radiotherapy.

Research paper thumbnail of A Dosimetric Comparison in Prostate Cancer Patients Treated with HDR Brachytherapy ± IMRT ± Polyethylene Glycol Gel

Research paper thumbnail of Radiation Therapy for Squamous Cell Carcinoma of the Supraglottic Larynx

American Journal of Clinical Oncology, 1989

Sixty-five patients with invasive squamous cell carcinoma of the supraglottic larynx received irr... more Sixty-five patients with invasive squamous cell carcinoma of the supraglottic larynx received irradiation with curative intent between 1975 and 1984, with a 5-year actuarial survival of 48% and a local control rate of 70%. Five-year survivals for clinical Stages I, II, and III + IV were 60, 53, and 52%, respectively; local control rates were 88, 76, and 63%, respectively. These patients included one treated with preoperative irradiation, 35 treated with surgery followed by postoperative irradiation, and 29 treated with radiation therapy alone. In the surgery plus irradiation group, 5-year local control was 93% for clinical Stages I + II (14 patients), and 61% for clinical Stages III + IV (21 patients). Three patients had pathologic Stage II disease, with the remainder demonstrating a higher pathologic than clinical stage. Multiple positive nodes predisposed to local/regional recurrence, while no relationship could be established between recurrence and extracapsular nodal spread, positive margins, emergency tracheostomy, total versus less-than-total laryngectomy, radiation field size, radiation dose, or delay until radiation therapy, probably because of patient numbers. Six patients, five with positive nodes, developed distant metastases, and three developed second primary tumors outside the head and neck region. In the radiation therapy alone group, 5-year local control rates were 86, 59, and 53% for clinical Stages I (7 patients), II (11 patients), and III + IV (11 patients), respectively. However, three of four Stage II local/regional failures were surgically salvaged for periods greater than 30 months, for an ultimate Stage II local control of 89%. No relationship could be established between local control and radiation dose or field size, again probably because of small patient numbers. Three patients developed distant metastases, and eight developed second malignancies, one within the irradiated volume. Fifteen patients developed acute toxicity during irradiation, and there were eight chronic complications, five requiring surgery; toxicity was more common in the group treated with radiation alone. Radiation therapy alone with surgical salvage is an effective, function-preserving treatment for clinical Stages I and II carcinoma of the supraglottic larynx, and appears to yield local control and survival comparable with that of combined irradiation and surgery in more advanced disease.

Research paper thumbnail of A PROSPECTIVE STUDY OF INTRAFRACTION PROSTATE MOTION IN THE PRONE VS. SUPINE POSITION

To prospectively analyze prostate intrafraction motion in the prone vs. supine position and to as... more To prospectively analyze prostate intrafraction motion in the prone vs. supine position and to assess patient satisfaction with these two positions. Fifteen prostate cancer patients underwent implantation of five fiducial gold seeds in their prostate for localization. Patients were treated with high-dose-rate brachytherapy to 2,200 cGy followed by intensity-modulated radiation therapy (IMRT) to 5,040 cGy. Patients underwent computed tomography simulation and IMRT in the prone position. For the first five IMRT treatments, an electronic portal imaging system was used to acquire anteroposterior (AP) and lateral images pretreatment and posttreatment. We then repositioned each patient supine and repeated the process, resulting in 600 images. Mean +/- standard deviation intrafraction prostate motion was 2.1 +/- 1.2 mm and 1.7 +/- 1.4 mm (AP, p = 0.47), 2.2 +/- 2.0 mm and 1.6 +/- 1.8 mm (superoinferior, p = 0.16), and 1.0 +/- 1.2 mm and 0.6 +/- 0.9 mm (left-right, p = 0.03) in the prone and supine positions, respectively. Eighty percent of patients stated that they were more comfortable in the supine position (p = 0.02). Prone and supine positions resulted in a similar magnitude of AP and superoinferior intrafraction prostate motion (2 mm). Because there was no significant difference in the magnitude of AP and superoinferior prostate motion prone vs. supine and patients were more comfortable in the supine position, patients now undergo IMRT to the prostate and seminal vesicles at our center in the supine position.

Research paper thumbnail of Recurrent basal cell carcinoma treated with radiation therapy

Archives of Dermatology, Nov 1, 1991

A retrospective study was performed of 61 recurrent basal cell carcinomas treated with radiation ... more A retrospective study was performed of 61 recurrent basal cell carcinomas treated with radiation therapy between 1974 and 1990 at the University of Arizona College of Medicine or at Southwestern Radiation Oncology, Tucson, Arizona. The median length of follow-up was 57 months. Applying the American Joint Committee on Cancer staging system to these recurrent tumors, 36 were stage I, 19 were stage II, five were stage III, and one was stage IV. Kaplan-Meier methods were used to estimate the 5-year complete remission rates. The Mantel-Haenszel Test and the Cox Proportional Hazards Model were used to determine if tumor size, stage, histologic subtype, anatomic site, age, sex, dose, number of radiation therapy treatments, length of time over which the radiation therapy was administered, or type of radiation beam used (orthovoltage x-rays vs megavoltage electrons) affected the 5-year complete remission rates. Only tumor size and stage had a statistically significant effect on the complete remission rates. The Kaplan-Meier estimates of the 5-year complete remission rates for 0.5- to 1.0-cm tumors vs tumors larger than 1.0 cm were 96% (95% confidence interval, 88% to 100%) and 81% (95% confidence interval, 64% to 99%), respectively. The Kaplan-Meier estimates of the 5-year complete remission rates for stage I/II tumors vs stage III/IV tumors were 93% (95% confidence interval, 85% to 100%) and 42% (95% confidence interval, 8% to 84%), respectively. Functional and cosmetic results were frequently good to excellent at 5 years. Soft-tissue necrosis developed in two of 61 cases, and was successfully managed in both. This article, combined with a review of the literature, suggests that radiation therapy is an effective method of treating recurrent basal cell carcinomas.

Research paper thumbnail of Treatment of unicentric and multicentric Castleman disease and the role of radiotherapy

Research paper thumbnail of Packet-based Approaches to ATM Cell Policing and Their Effects on Internet Traffic

Proceedings of the Ifip Tc 6 Eigth International Conference on High Performance Networking, Sep 21, 1998

Research paper thumbnail of A preliminary cell kinetics model of thrombocytopenia after radioimmunotherapy

Journal of Nuclear Medicine, Jul 1, 1998

The cumulative data in this study showed a strong correlation between L/B ratios calculated on at... more The cumulative data in this study showed a strong correlation between L/B ratios calculated on attenuation-corrected and uncorrected images . However, there was no correlation between SUR values calculated on both types of images. This is probably due to the fact that the background activity, an important variable in these calculations, is not considered in SUR calculations. Moreover, absolute counts are required for the original definition of SUR. For the same reasons, SUR and LIB values calculated on uncorrected images also did not show a significant correlation ). This indicates that the L/B ratio is the only index that can be used for semiquantitative evaluation of uncorrected images.

Research paper thumbnail of Dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with high-dose-rate brachytherapy for large prostate volumes

International braz j urol : official journal of the Brazilian Society of Urology

To evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with H... more To evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes. One hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL) were treated with high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38%) unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4. Median follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3%) patients developed Grade 2 acute proctitis. No variables were s...

Research paper thumbnail of Stage IIA and IIB testicular seminoma treated postorchiectomy with radiation therapy versus other approaches: a population-based analysis of 241 patients

International braz j urol : official journal of the Brazilian Society of Urology

To evaluate post-orchiectomy utilization of radiation therapy (RT) versus other management approa... more To evaluate post-orchiectomy utilization of radiation therapy (RT) versus other management approaches in stage IIA and IIB testicular seminoma patients. Two hundred and forty-one patients with stage IIA and IIB testicular seminoma were identified between 1988 and 2003 using the Surveillance, Epidemiology, and End Results (SEER) database. Median follow-up was 10 years. Patients with stage IIA disease underwent RT more frequently than those with stage IIB disease (72 % vs. 46 %, respectively; P < 0.001). There was no significant change in RT utilization for stage IIA or IIB disease between 1988 and 2003 (P = 0.89). Between 1988 and 2003, stage IIA patients underwent RT more often than stage IIB patients in the United States. There was no significant change in RT utilization for stage IIA or IIB disease during this time period. Based on reports describing excellent progression-free survival with cisplatin-based chemotherapy, this approach has increased in popularity since 2003 and m...

Research paper thumbnail of Quality of life after high-dose-rate brachytherapy monotherapy for prostate cancer

International braz j urol, 2015

There is little information in the literature on health-related quality of life (HRQOL) changes d... more There is little information in the literature on health-related quality of life (HRQOL) changes due to high-dose-rate (HDR) brachytherapy monotherapy for prostate cancer. We conducted a prospective study of HRQOL changes due to HDR brachytherapy monotherapy for low risk or favorable intermediate risk prostate cancer. Sixty-four of 84 (76 %) patients who were treated between February 2011 and April 2013 completed 50 questions comprising the Expanded Prostate Cancer Index Composite (EPIC) before treatment and 6 and/or 12 months after treatment. Six months after treatment, there was a significant decrease (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) in EPIC urinary, bowel, and sexual scores, including urinary overall, urinary function, urinary bother, urinary irritative, bowel overall, bowel bother, sexual overall, and sexual bother scores. By one year after treatment, EPIC urinary, bowel, and sexual scores had increased and only the bowel overall and bowel bother scores remained significantly below baseline values. HDR brachytherapy monotherapy is well-tolerated in patients with low and favorable intermediate risk prostate cancer. EPIC urinary and sexual domain scores returned to close to baseline 12 months after HDR brachytherapy.