Guidelines for primary radiotherapy of patients with prostate cancer (original) (raw)
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I n the last decades the status of radiotherapy was tremendously increased in terms of conformity to the target as well as image-guided techniques in conjunction with intensity-modulated radiotherapy (IMRT). The technological improvement had a significant clinical outcome for better response and lower toxicity to the surrounding normal tissues. Nowadays the incidence of rectal toxicity has been significantly decreased, especially with image guided radiation therapy (IGRT), whereas the dose escalation to the prostate has driven the clinical practice to the fact that radical radiotherapy for low or intermediate risk prostate cancer is definitely equivalent to surgery. The treatment volume can be reduced by reducing the size of the necessary margins to count for inaccuracies in target position and patient setup. This can be achieved either by improving the daily localization of the target before treatment or by adapting the treatment in response to feedback. This is the goal of image-guided and adaptive radiotherapy, respectively. These techniques improve the accuracy of dose delivery with a significant impact on clinical outcome and toxicity.
Australasian Radiology, 2004
There is an increasing use of 3-D conformal radiotherapy (3DCRT) in the radiotherapeutic management of prostate cancer. The Faculty of Radiation Oncology Genito-Urinary Group carried out a survey of Australian and New Zealand radiotherapy centres in the preparation of a consensus workshop. Of the 19 centres that were represented, there were 24 radiation oncologists, 16 radiation therapists and 12 medical physicists. The survey collected demographic information and data on the practices undertaken at those centres when delivering curative radiotherapy in the treatment of prostate cancer. There was much variation in the delivery of treatment in the areas of patient set-up, contouring of target volumes and organs of interest during computer planning, the techniques and the dose constraints used in these techniques, the use of adjuvant androgen deprivation therapy and the quality assurance processes used in monitoring effects of treatment. This variability reflects the range of data in the published literature. Emerging trends of practices were also identified. This is a first report on a multi-disciplinary approach to the development of guidelines in 3DCRT of prostate cancer.
International Journal of Radiation Oncology*Biology*Physics, 1999
Purpose: Currently, three-dimensional conformal radiation therapy (3D-CRT) planning relies on the interpretation of computed tomography (CT) axial images for defining the clinical target volume (CTV). This study investigates the variation among multiple observers to define the CTV used in 3D-CRT for prostate cancer. Methods and Materials: Seven observers independently delineated the CTVs (prostate ؎ seminal vesicles [SV]) from the CT simulation data of 10 prostate cancer patients undergoing 3D-CRT. Six patients underwent CT simulation without the use of contrast material and serve as a control group. The other 4 had urethral and bladder opacification with contrast medium. To determine interobserver variation, we evaluated the derived volume, the maximum dimensions, and the isocenter for each examination of CTV. We assessed the reliability in the CTVs among the observers by correlating the variation for each class of measurements. This was estimated by intraclass correlation coefficient (ICC), with 1.00 defining absolute correlation. Results: For the prostate volumes, the ICC was 0.80 (95% confidence interval [CI]: 0.56 -0.96). This changed to 0.92 (95% CI: 0.75-0.99) with the use of contrast material. Similarly, the maximal prostatic dimensions were reliable and improved. There was poor agreement in defining the SV. For this structure, the ICC never exceeded 0.28. The reliability of the isocenter was excellent, with the ICC exceeding 0.83 and 0.90 for the prostate ؎ SV, respectively. Conclusions: In 3D-CRT for prostate cancer, there was excellent agreement among multiple observers to define the prostate target volume but poor agreement to define the SV. The use of urethral and bladder contrast improved the reliability of localizing the prostate. For all CTVs, the isocenter was very reliable and should be used to compare the variation in 3D dosimetry among multiple observers.
Tumori Journal, 2001
To report the technique of 3D-conformal radiation therapy (3D-CRT) currently used at our Institute for the treatment of prostate cancer with a curative intent. A critical review of the technical aspects of the technique is provided. Methods and study design: Between December 1995 and October 2000, 334 patients with biopsy-proven adenocarcinoma of the prostate were treated with 3D-CRT.All patients were treated in a prone position with 15 MV X-ray beams and a 6-field technique for all but 20 patients, who were treated with a 3-field technique. Patients were simulated with the rectum and bladder empty. To ensure reproducible positioning, custom-made polyurethane foam or thermoplastic casts were produced for each patient. Subsequently, consecutive CT scan slices were obtained. The clinical target volume and critical organs (rectum and bladder) were identified on each CT slice. The beam's eye view technique was used to spatially display these structures , and the treatment portals were manually shaped based on the images obtained. The beam apertures were initially realized by conventional Cerrobend blocks (48 patients), which were replaced in October 1997 by a computer-driven multi-leaf collimator. The total target dose prescribed at the ICRU point is 76 Gy, delivered in 38 fractions and 54 days. The seminal vesicles are excluded at 70 Gy. Dose-volume histograms were obtained for all patients. If more than 30"10 of the bladder and/or more than 20"10 of the rectum receive >95"10 of the prescribed total dose, the treatment plan is jUdged as unsatisfactory and is adjusted. The dose-volume histogram can be improved by changing the beam's arrangement and/or weights or by introducing or modifying the wedge filters. Conclusions: 3D-CRT in prostate cancer patients is a highly sophisticated and time-consuming method of dose delivery. Important technical issues remain to be clarified.
International Journal of Radiation Oncology*Biology*Physics, 1996
Purpose: To compare conformat radiotherapy using three dimensional treatment planning (3D-CRT) to conventional radiotherapy (Convert-RT) for patients with Stages T2-T4 adenocarcinoma of the prostate. Methods and Materials: A Phase III randomized study was activated in May 1993, to compare treatment toxicity and patient outcome after 78 Gy in 39 fractions using 3D-CRT to that after 70 Gy in 35 fractions using Convert-RT. The first 46 Gy were administered using the same nonconform field arrangement (fourfield) in both arms. The boost was given nonconformalty usiug four fields in the Conven-RT arm and conformally using six fields in the 3D-CRT arm. The dose was specifkd to the isocenter. The hrst 60 patients, 29 in the 3D-CRT arm and 31 in the Conven-RT arm, are the subject of this pretimtnary analysis. Results: The two treatment arms were tirst compared in terms of dosimetry by dose-volume histogram anafys~s. Using a subgroup of patients in the 3D-CRT arm (n = U), both Conven-RT and 3D-CRT plans were generated and the dose-volume histogram data compared. The mean volumes treated to doses above 60 Gy for the bladder and rectmn were 28 and 36% for the 3D-CRT plans, and 43 and 38% for the Conven-RT plans, respectively @ < 0.05 for the bladder volumes). The mean clinicat target volume (prostate and seminal vesicles) treated to 95% of the prescribed dose was 97.5% for the 3D-CRT arm, and 95.6% for the Convert-RT arm (p < 0.05). There were no signiticant differences in the acute reactions between the two arms, with the majority experiencing Grade 2 or less toxicity (92%). Moreover, no relationship was seen between acute toxicity and the volume of bladder and rectum receiving in excess of 60 Gy for those in the 3D-CRT arm. There was also no difference between the groups in terms of early biochemical response. Prostate-specific antigen levels at 3 and 6 months after completion of radiotherapy were similar in the two treatment arms. There was only one biochemical failure in the study population at the time of the analysis. Conclusions: Comparison of the Conven-RT and 3D-CRT treatment plans revealed that signiticantty less bladder was in the high dose volume iu the 3D-CRT plans, white the volume of rectum receiving doses over 60 Gy was equivalent. There were no differences between the two treatment arms in terms of acute toxicity or early biochemical response. Longer follow-up is needed to determine the impact of 3D-CRT on long-term patient outcome and late reactions.
Australasian Radiology, 2004
Three-dimensional conformal radiation therapy (3DCRT) has been shown to reduce normal tissue toxicity and allow dose escalation in the curative treatment of prostate cancer. The Faculty of Radiation Oncology Genito-Urinary Group initiated a consensus process to generate evidence-based guidelines for the safe and effective implementation of 3DCRT. All radiation oncology departments in Australia and New Zealand were invited to complete a survey of their prostate practice and to send representatives to a consensus workshop. After a review of the evidence, key issues were identified and debated. If agreement was not reached, working parties were formed to make recommendations. Draft guidelines were circulated to workshop participants for approval prior to publication. Where possible, evidence-based recommendations have been made with regard to patient selection, risk stratification, simulation, planning, treatment delivery and toxicity reporting. This is the first time a group of radiation therapists, physicists and oncologists representing professional radiotherapy practice across Australia and New Zealand have worked together to develop best-practice guidelines. These guidelines should serve as a baseline for prospective clinical trials, outcome research and quality assurance.
Journal of Radiotherapy in Practice, 2010
Background and Purpose:Intensity-modulated radiation therapy (IMRT) is considered by many to be the standard of care in the delivery of external-beam radiotherapy treatments to the prostate. The purpose of this study is to assess the validity of the purported benefits of IMRT.Materials and Methods:Treatment plans were produced for 10 patients using both 3D conformal radiation therapy (3D-CRT) and IMRT, utilising the dose constraints recommended by the Radiation Therapy Oncology Group (RTOG) 0415 protocol. Three IMRT modalities used in this study were linear accelerator based IMRT, helical tomotherapy, and serial tomotherapy. The prescription to the target, 76 Gy, was the same for all plans.Results:In general the 3D-CRT plans satisfied the RTOG criteria for planning target volume (PTV) coverage, and met or bettered the dose criteria for the organs at risk. PTV coverage was more homogeneous for the IMRT plans than the 3D-CRT plans but not significantly improved.Conclusions:Technically...