Samuel Ngan - Academia.edu (original) (raw)

Papers by Samuel Ngan

Research paper thumbnail of The Role of Intraoperative Radiotherapy in Solid Tumors

Annals of Surgical Oncology, 2009

Research paper thumbnail of A phase I trial of Capecitabine+Gemcitabine with radical radiation for locally advanced pancreatic cancer

British journal of cancer, Jan 13, 2009

Standard chemoradiotherapy with infusional 5FU for locally advanced pancreatic cancer (LAPC) has ... more Standard chemoradiotherapy with infusional 5FU for locally advanced pancreatic cancer (LAPC) has limited efficacy in this disease. The combination of Capecitabine (Cap) and Gemcitabine (Gem) are synergistic and are potent radiosensitisers. The aim of this phase I trial was thus to determine the highest administered dose of the Cap plus Gem combination with radical radiotherapy (RT) for LAPC. Patients had LAPC, adequate organ function, ECOG PS 0-1. During RT, Gem was escalated from 20-50 mg m(-2) day(-1) (twice per week), and Cap 800-2000 mg m(-2) day(-1) (b.i.d, days 1-5 of each week). Radiotherapy 50.4 Gy/28 fractions/5.5 weeks, using 3D-conformal techniques. Three patients were entered to each dose level (DL). Dose-limiting toxicity(s) (DLTs) were based on treatment-related toxicities. Twenty patients were accrued. Dose level (DL) 1: Cap/Gem; 800/20 mg m(-2) day(-1) (3 patients), DL2: 1000/20 (12 patients), DL3: 1300/30 (5 patients). Dose-limiting toxicities were observed in DL3; ...

Research paper thumbnail of A phase I trial of preoperative radiotherapy and capecitabine for locally advanced, potentially resectable rectal cancer

British journal of cancer, Jan 13, 2004

The purpose of the study was to determine the maximum-tolerated dose (MTD) of oral capecitabine, ... more The purpose of the study was to determine the maximum-tolerated dose (MTD) of oral capecitabine, combined with concurrent, standard preoperative pelvic radiotherapy, when given twice daily, from Monday to Friday throughout the course of radiotherapy, for locally advanced potentially resectable rectal cancer. Maximum-tolerated dose was defined as the total (given in two equally divided doses) oral dose of capecitabine that caused treatment-related grade 3 or 4 toxicity in one-third or more of the patients treated. Radiotherapy involved 50.4 Gy given in 28 fractions in 5 weeks and 3 days. Eligible patients had a newly diagnosed clinical stage T3-4 N0-2 M0 rectal adenocarcinoma located within 12 cm of the anal verge suitable for curative resection. Surgery was performed 4-6 weeks from completion of preoperative chemoradiotherapy. In all, 28 patients were enrolled in the study at predefined dose levels: 850 mg m(-2) day(-1) (n=3), 1000 mg m(-2) day(-1) (n=6), 1250 mg m(-2) day(-1) (n=3)...

Research paper thumbnail of Characterising atherothrombosis in Hong Kong: results of the Hong Kong data from a global atherothrombosis epidemiological survey

Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine, 2005

To describe the characteristics of patients in Hong Kong with or at risk of atherothrombosis, to ... more To describe the characteristics of patients in Hong Kong with or at risk of atherothrombosis, to determine the proportion of symptomatic patients with more than one vascular bed affected, and to assess the relationship between ankle brachial index and disease severity. Local participation in an international prevalence study. Five centres in Hong Kong. A total of 210 subjects were recruited (105 women and 105 men). Patients were divided into the symptomatic group (with current or previous atherothrombotic symptoms, n=101) and at-risk group (with no current or previous symptoms, but aged over 55 years with at least two specified risk factors, n=109). Patient characteristics were described, including the number of arterial beds affected, ankle brachial index, presence of risk factors, and medications taken. Of the symptomatic patients, 30% had more than one arterial bed involved. A total of 55.4% of the symptomatic group and 18.4% of the at-risk group had abnormal ankle brachial index...

Research paper thumbnail of 3008 ORAL Acute adverse events in a randomised trial of short course versus long course preoperative radiotherapy for T3 adenocarcinoma of rectum: a Trans-Tasman Radiation Oncology Group trial (TROG 01.04)

Research paper thumbnail of Comparison of four 3D conformal treatment techniques to optimise radiotherapy treatment for anal cancer

Journal of Medical Radiation Sciences, 2014

Research paper thumbnail of Oxaliplatin combined with infusional 5-fluorouracil and concomitant radiotherapy in inoperable and metastatic rectal cancer: a phase I trial

Research paper thumbnail of Post-radiation sarcoma of the neck treated with re-irradiation followed by wide excision

Research paper thumbnail of 3D Conformal radiotherapy for gastric cancer—results of a comparative planning study

Radiotherapy and Oncology, 2005

Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arr... more Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116). Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance. 3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity.

Research paper thumbnail of 3543 POSTER Phase I trial of capecitabine and gemcitabine with concurrent radical radiotherapy in locally advanced pancreatic cancer: final results

European Journal of Cancer Supplements, 2007

Research paper thumbnail of A prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer

Radiotherapy and Oncology, 2006

This prospective study sought to determine how the use of combined PET/CT for radiotherapy treatm... more This prospective study sought to determine how the use of combined PET/CT for radiotherapy treatment planning of oesophageal cancer would alter the delineation of tumour volumes compared to CT alone if PET/CT is assumed to more accurately represent true disease extent. All patients underwent FDG-PET/CT scanning in the radiotherapy treatment position. For each patient, two separate gross tumour volumes (GTV) were defined, one based on CT images alone (GTV-CT) and another based on combined PET/CT data (GTV-PET). Corresponding planning target volumes (PTV) were generated, and separate treatment plans were then produced. For each patient, volumetric analysis of GTV-CT, PTV-CT and GTV-PET was performed to quantify the proportion of PET-avid disease that was not included in the GTV and PTV (geographic miss) if CT data alone were used for radiotherapy planning. Assessment of the cranial and caudal extent of the primary oesophageal tumour as defined by CT alone vs PET/CT was also compared. The addition of PET information altered the clinical stage in 8 of 21 eligible patients enrolled on the study (38%); 4 patients had distant metastatic disease and 4 had unsuspected regional nodal disease. Sixteen patients proceeded to the radiotherapy planning phase of the study and received definitive chemoradiation planned with the PET/CT data set. The GTV based on CT information alone excluded PET-avid disease in 11 patients (69%), and in five patients (31%) this would have resulted in a geographic miss of gross tumour. The discordance between CT and PET/CT was due mainly to differences in defining the longitudinal extent of disease in the oesophagus. The cranial extent of the primary tumour as defined by CT vs PET/CT differed in 75% of cases, while the caudal extent differed in 81%. This study demonstrates that if combined PET/CT is used for radiotherapy treatment planning, there may be alterations to the delineation of tumour volumes when compared to CT alone, with the potential to avoid a geographic miss of tumour.

Research paper thumbnail of Primary anal adenocarcinoma: a caution for conservative treatment

Journal of Radiotherapy in Practice, 2006

Research paper thumbnail of Accrediting radiation technique in a multicentre trial of chemoradiation for pancreatic cancer

Journal of Medical Imaging and Radiation Oncology, 2008

Before a multicentre trial of 3-D conformal radiotherapy to treat cancer of the pancreas, partici... more Before a multicentre trial of 3-D conformal radiotherapy to treat cancer of the pancreas, participating clinicians were asked to complete an accreditation exercise. This involved planning two test cases according to the study protocol, then returning hard copies of the plans and dosimetric data for review. Any radiation technique that achieved the specified constraints was allowed. Eighteen treatment plans were assessed. Seven plans were prescribed incorrect doses and two of the planning target volumes did not comply with protocol guidelines. All plans met predefined normal tissue dose constraints. The identified errors were attributable to unforeseen ambiguities in protocol documentation. They were addressed by feedback and corresponding amendments to protocol documentation. Summary radiobiological measures including total weighted normal tissue equivalent uniform dose varied significantly between centres. This accreditation exercise successfully identified significant potential sources of protocol violations, which were then easily corrected. We believe that this process should be applied to all clinical trials involving radiotherapy. Due to the limitations of data analysis with hard-copy information only, it is recommended that complete planning datasets from treatment-planning systems be collected through a digital submission process.

Research paper thumbnail of Acute vascular embolus resulting from metastatic endocardial involvement with synovial sarcoma: Report of a case and review of the literature

Australasian Radiology, 1997

A rare case of metastatic soft tissue sarcoma (STS) involving the endocardium of the left ventric... more A rare case of metastatic soft tissue sarcoma (STS) involving the endocardium of the left ventricle of the heart is described. A 57-year-old man with a previously resected synovial sarcoma of the anterior abdominal wall presented 5 years later with an acute ischaemic arm resulting from tumour embolus. The treatment and outcome of the patient are outlined. Metastatic STS cardiac involvement and management of this complication are reviewed.

Research paper thumbnail of Postoperative radiotherapy for DukesB ‘ and C rectal cancer: Peter MacCallum Cancer Institute experience

Australasian Radiology, 1996

SUMMARY This retrospective study reviews the outcome of patients with DukesB 'and C rectal c... more SUMMARY This retrospective study reviews the outcome of patients with DukesB 'and C rectal cancer treated with adjuvant postoperative pelvic radiotherapy at the Peter MacCallum Cancer Institute from 1981 to 1990. Sixty-one patients (22 DukesB ', 36 DukesC 'and 3 ...

Research paper thumbnail of A phase I/II trial of celecoxib with chemotherapy and radiotherapy in the treatment of patients with locally advanced oesophageal cancer

Investigational New Drugs, 2006

The study's aim was to determine the maxi... more The study's aim was to determine the maximum tolerated dose (MTD) of celecoxib combined with chemoradiotherapy (CRT) for locally advanced oesophageal cancer (OC). CRT comprised of 5FU (1000 mg/m(2)/day, days 1-4, weeks 1 & 5), cisplatin (75 mg/m(2), days 1 & 29) and radiotherapy (50 Gy in 25 fractions or 50.4 Gy in 28 fractions). Celecoxib was given daily during CRT at one of five doses (200 mg bd to 600 mg bd). Three to six patients were assigned per dose. Thirteen patients were recruited before trial closure due to external safety concerns regarding celecoxib. Median follow up was 17 months (95% CI 9 - >39). The highest administered dose was 400 mg bd (n=4) with one dose-limiting toxicity at this level: grade 3 rash. Five (38%) and 8(62%) patients had grade 3 non-haematological and haematological toxicities respectively. No grade 4 toxicities occurred. Radiological response rate was 54% (n=7: all CR). Six patients had resection with one pathological CR. Median progression-free and overall survival were 8.8 (95% CI 5.1 - >24.8) and 19.6 months (95% CI 7.3 - >39) respectively. A MTD was not reached. The regimen was tolerable, indicating that celecoxib can be safely administered with CRT for locally advanced OC.

Research paper thumbnail of Twenty-Five-Year Experience with Radical Chemoradiation for Anal Cancer

International Journal of Radiation Oncology*Biology*Physics, 2011

To evaluate the prognostic factors, patterns of failure, and late toxicity in patients treated wi... more To evaluate the prognostic factors, patterns of failure, and late toxicity in patients treated with chemoradiation (CRT) for anal cancer. Consecutive patients with nonmetastatic squamous cell carcinoma of the anus treated by CRT with curative intent between February 1983 and March 2008 were identified through the institutional database. Chart review and telephone follow-up were undertaken to collect demographic data and outcome. Two hundred eighty-four patients (34% male; median age 62 years) were identified. The stages at diagnosis were 23% Stage I, 48% Stage II, 10% Stage IIIA, and 18% Stage IIIB. The median radiotherapy dose to the primary site was 54 Gy. A complete clinical response to CRT was achieved in 89% of patients. With a median follow-up time of 5.3 years, the 5-year rates of locoregional control, distant control, colostomy-free survival, and overall survival were 83% (95% confidence interval [CI] 78-88), 92% (95% CI, 89-96), 73% (95% CI, 68-79), and 82% (95% CI, 77-87), respectively. Higher T stage and male sex predicted for locoregional failure, and higher N stage predicted for distant metastases. Locoregional failure occurred most commonly at the primary site. Omission of elective inguinal irradiation resulted in inguinal failure rates of 1.9% and 12.5% in T1N0 and T2N0 patients, respectively. Pelvic nodal failures were very uncommon. Late vaginal and bone toxicity was observed in addition to gastrointestinal toxicity. CRT is a highly effective approach in anal cancer. However, subgroups of patients fare relatively poorly, and novel approaches are needed. Elective inguinal irradiation can be safely omitted only in patients with Stage I disease. Vaginal toxicity and insufficiency fractures of the hip and pelvis are important late effects that require prospective evaluation.

Research paper thumbnail of 3D Radiotherapy Can Be Safely Combined With Sandwich Systemic Gemcitabine Chemotherapy in the Management of Pancreatic Cancer: Factors Influencing Outcome

International Journal of Radiation Oncology*Biology*Physics, 2008

The aim of this Phase II study was to examine whether concurrent continuous infusion 5-fluorourac... more The aim of this Phase II study was to examine whether concurrent continuous infusion 5-fluorouracil (CI 5FU) plus three-dimensional conformal planning radiotherapy sandwiched between gemcitabine chemotherapy is effective, tolerable, and safe in the management of pancreatic cancer. Patients were enrolled in two strata: (1) resected pancreatic cancer at high risk of local relapse (postsurgery arm, n = 22) or (2) inoperable pancreatic cancer in head or body without metastases (locally advanced arm, n = 41). Gemcitabine was given at 1,000 mg/m(2) weekly for 3 weeks followed by 1 week rest then 5-6 weeks of radiotherapy and concurrent CI 5FU (200 mg/m(2)/day). After 4 weeks' rest, gemcitabine treatment was reinitiated for 12 weeks. For the two arms combined, treatment-related Grade 3 and 4 toxicities were reported by 25 (39.7%) and 7 (11.1%) patients, respectively. No significant late renal or hepatic toxicity was observed. In the postsurgery arm (R1 54.5%), median time to progressive disease from surgery was 11.0 months, median time to failure of local control was 32.9 months, and median survival time was 15.6 months. The 1- and 2-year survival rates were 63.6% and 31.8%. No significant associations between outcome and mutations in K-ras or TP53 or microsatellite instability were identified. Post hoc investigation of cancer antigen 19-9 levels found baseline levels and increases postbaseline were associated with shorter survival (p = 0.0061 and p < 0.0001, respectively). This three-dimensional chemoradiotherapy regimen is safe and promising, with encouraging local control for a substantial proportion of patients, and merits testing in a randomized trial.

Research paper thumbnail of Impact of treatment interruption on outcome of chemoradiation for carcinoma of anus

International Journal of Radiation Oncology*Biology*Physics, 1998

Research paper thumbnail of Primary adenocarcinoma of the anus: a retrospective analysis

International Journal of Radiation Oncology*Biology*Physics, 1999

Research paper thumbnail of The Role of Intraoperative Radiotherapy in Solid Tumors

Annals of Surgical Oncology, 2009

Research paper thumbnail of A phase I trial of Capecitabine+Gemcitabine with radical radiation for locally advanced pancreatic cancer

British journal of cancer, Jan 13, 2009

Standard chemoradiotherapy with infusional 5FU for locally advanced pancreatic cancer (LAPC) has ... more Standard chemoradiotherapy with infusional 5FU for locally advanced pancreatic cancer (LAPC) has limited efficacy in this disease. The combination of Capecitabine (Cap) and Gemcitabine (Gem) are synergistic and are potent radiosensitisers. The aim of this phase I trial was thus to determine the highest administered dose of the Cap plus Gem combination with radical radiotherapy (RT) for LAPC. Patients had LAPC, adequate organ function, ECOG PS 0-1. During RT, Gem was escalated from 20-50 mg m(-2) day(-1) (twice per week), and Cap 800-2000 mg m(-2) day(-1) (b.i.d, days 1-5 of each week). Radiotherapy 50.4 Gy/28 fractions/5.5 weeks, using 3D-conformal techniques. Three patients were entered to each dose level (DL). Dose-limiting toxicity(s) (DLTs) were based on treatment-related toxicities. Twenty patients were accrued. Dose level (DL) 1: Cap/Gem; 800/20 mg m(-2) day(-1) (3 patients), DL2: 1000/20 (12 patients), DL3: 1300/30 (5 patients). Dose-limiting toxicities were observed in DL3; ...

Research paper thumbnail of A phase I trial of preoperative radiotherapy and capecitabine for locally advanced, potentially resectable rectal cancer

British journal of cancer, Jan 13, 2004

The purpose of the study was to determine the maximum-tolerated dose (MTD) of oral capecitabine, ... more The purpose of the study was to determine the maximum-tolerated dose (MTD) of oral capecitabine, combined with concurrent, standard preoperative pelvic radiotherapy, when given twice daily, from Monday to Friday throughout the course of radiotherapy, for locally advanced potentially resectable rectal cancer. Maximum-tolerated dose was defined as the total (given in two equally divided doses) oral dose of capecitabine that caused treatment-related grade 3 or 4 toxicity in one-third or more of the patients treated. Radiotherapy involved 50.4 Gy given in 28 fractions in 5 weeks and 3 days. Eligible patients had a newly diagnosed clinical stage T3-4 N0-2 M0 rectal adenocarcinoma located within 12 cm of the anal verge suitable for curative resection. Surgery was performed 4-6 weeks from completion of preoperative chemoradiotherapy. In all, 28 patients were enrolled in the study at predefined dose levels: 850 mg m(-2) day(-1) (n=3), 1000 mg m(-2) day(-1) (n=6), 1250 mg m(-2) day(-1) (n=3)...

Research paper thumbnail of Characterising atherothrombosis in Hong Kong: results of the Hong Kong data from a global atherothrombosis epidemiological survey

Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine, 2005

To describe the characteristics of patients in Hong Kong with or at risk of atherothrombosis, to ... more To describe the characteristics of patients in Hong Kong with or at risk of atherothrombosis, to determine the proportion of symptomatic patients with more than one vascular bed affected, and to assess the relationship between ankle brachial index and disease severity. Local participation in an international prevalence study. Five centres in Hong Kong. A total of 210 subjects were recruited (105 women and 105 men). Patients were divided into the symptomatic group (with current or previous atherothrombotic symptoms, n=101) and at-risk group (with no current or previous symptoms, but aged over 55 years with at least two specified risk factors, n=109). Patient characteristics were described, including the number of arterial beds affected, ankle brachial index, presence of risk factors, and medications taken. Of the symptomatic patients, 30% had more than one arterial bed involved. A total of 55.4% of the symptomatic group and 18.4% of the at-risk group had abnormal ankle brachial index...

Research paper thumbnail of 3008 ORAL Acute adverse events in a randomised trial of short course versus long course preoperative radiotherapy for T3 adenocarcinoma of rectum: a Trans-Tasman Radiation Oncology Group trial (TROG 01.04)

Research paper thumbnail of Comparison of four 3D conformal treatment techniques to optimise radiotherapy treatment for anal cancer

Journal of Medical Radiation Sciences, 2014

Research paper thumbnail of Oxaliplatin combined with infusional 5-fluorouracil and concomitant radiotherapy in inoperable and metastatic rectal cancer: a phase I trial

Research paper thumbnail of Post-radiation sarcoma of the neck treated with re-irradiation followed by wide excision

Research paper thumbnail of 3D Conformal radiotherapy for gastric cancer—results of a comparative planning study

Radiotherapy and Oncology, 2005

Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arr... more Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116). Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance. 3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity.

Research paper thumbnail of 3543 POSTER Phase I trial of capecitabine and gemcitabine with concurrent radical radiotherapy in locally advanced pancreatic cancer: final results

European Journal of Cancer Supplements, 2007

Research paper thumbnail of A prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer

Radiotherapy and Oncology, 2006

This prospective study sought to determine how the use of combined PET/CT for radiotherapy treatm... more This prospective study sought to determine how the use of combined PET/CT for radiotherapy treatment planning of oesophageal cancer would alter the delineation of tumour volumes compared to CT alone if PET/CT is assumed to more accurately represent true disease extent. All patients underwent FDG-PET/CT scanning in the radiotherapy treatment position. For each patient, two separate gross tumour volumes (GTV) were defined, one based on CT images alone (GTV-CT) and another based on combined PET/CT data (GTV-PET). Corresponding planning target volumes (PTV) were generated, and separate treatment plans were then produced. For each patient, volumetric analysis of GTV-CT, PTV-CT and GTV-PET was performed to quantify the proportion of PET-avid disease that was not included in the GTV and PTV (geographic miss) if CT data alone were used for radiotherapy planning. Assessment of the cranial and caudal extent of the primary oesophageal tumour as defined by CT alone vs PET/CT was also compared. The addition of PET information altered the clinical stage in 8 of 21 eligible patients enrolled on the study (38%); 4 patients had distant metastatic disease and 4 had unsuspected regional nodal disease. Sixteen patients proceeded to the radiotherapy planning phase of the study and received definitive chemoradiation planned with the PET/CT data set. The GTV based on CT information alone excluded PET-avid disease in 11 patients (69%), and in five patients (31%) this would have resulted in a geographic miss of gross tumour. The discordance between CT and PET/CT was due mainly to differences in defining the longitudinal extent of disease in the oesophagus. The cranial extent of the primary tumour as defined by CT vs PET/CT differed in 75% of cases, while the caudal extent differed in 81%. This study demonstrates that if combined PET/CT is used for radiotherapy treatment planning, there may be alterations to the delineation of tumour volumes when compared to CT alone, with the potential to avoid a geographic miss of tumour.

Research paper thumbnail of Primary anal adenocarcinoma: a caution for conservative treatment

Journal of Radiotherapy in Practice, 2006

Research paper thumbnail of Accrediting radiation technique in a multicentre trial of chemoradiation for pancreatic cancer

Journal of Medical Imaging and Radiation Oncology, 2008

Before a multicentre trial of 3-D conformal radiotherapy to treat cancer of the pancreas, partici... more Before a multicentre trial of 3-D conformal radiotherapy to treat cancer of the pancreas, participating clinicians were asked to complete an accreditation exercise. This involved planning two test cases according to the study protocol, then returning hard copies of the plans and dosimetric data for review. Any radiation technique that achieved the specified constraints was allowed. Eighteen treatment plans were assessed. Seven plans were prescribed incorrect doses and two of the planning target volumes did not comply with protocol guidelines. All plans met predefined normal tissue dose constraints. The identified errors were attributable to unforeseen ambiguities in protocol documentation. They were addressed by feedback and corresponding amendments to protocol documentation. Summary radiobiological measures including total weighted normal tissue equivalent uniform dose varied significantly between centres. This accreditation exercise successfully identified significant potential sources of protocol violations, which were then easily corrected. We believe that this process should be applied to all clinical trials involving radiotherapy. Due to the limitations of data analysis with hard-copy information only, it is recommended that complete planning datasets from treatment-planning systems be collected through a digital submission process.

Research paper thumbnail of Acute vascular embolus resulting from metastatic endocardial involvement with synovial sarcoma: Report of a case and review of the literature

Australasian Radiology, 1997

A rare case of metastatic soft tissue sarcoma (STS) involving the endocardium of the left ventric... more A rare case of metastatic soft tissue sarcoma (STS) involving the endocardium of the left ventricle of the heart is described. A 57-year-old man with a previously resected synovial sarcoma of the anterior abdominal wall presented 5 years later with an acute ischaemic arm resulting from tumour embolus. The treatment and outcome of the patient are outlined. Metastatic STS cardiac involvement and management of this complication are reviewed.

Research paper thumbnail of Postoperative radiotherapy for DukesB ‘ and C rectal cancer: Peter MacCallum Cancer Institute experience

Australasian Radiology, 1996

SUMMARY This retrospective study reviews the outcome of patients with DukesB 'and C rectal c... more SUMMARY This retrospective study reviews the outcome of patients with DukesB 'and C rectal cancer treated with adjuvant postoperative pelvic radiotherapy at the Peter MacCallum Cancer Institute from 1981 to 1990. Sixty-one patients (22 DukesB ', 36 DukesC 'and 3 ...

Research paper thumbnail of A phase I/II trial of celecoxib with chemotherapy and radiotherapy in the treatment of patients with locally advanced oesophageal cancer

Investigational New Drugs, 2006

The study's aim was to determine the maxi... more The study's aim was to determine the maximum tolerated dose (MTD) of celecoxib combined with chemoradiotherapy (CRT) for locally advanced oesophageal cancer (OC). CRT comprised of 5FU (1000 mg/m(2)/day, days 1-4, weeks 1 & 5), cisplatin (75 mg/m(2), days 1 & 29) and radiotherapy (50 Gy in 25 fractions or 50.4 Gy in 28 fractions). Celecoxib was given daily during CRT at one of five doses (200 mg bd to 600 mg bd). Three to six patients were assigned per dose. Thirteen patients were recruited before trial closure due to external safety concerns regarding celecoxib. Median follow up was 17 months (95% CI 9 - >39). The highest administered dose was 400 mg bd (n=4) with one dose-limiting toxicity at this level: grade 3 rash. Five (38%) and 8(62%) patients had grade 3 non-haematological and haematological toxicities respectively. No grade 4 toxicities occurred. Radiological response rate was 54% (n=7: all CR). Six patients had resection with one pathological CR. Median progression-free and overall survival were 8.8 (95% CI 5.1 - >24.8) and 19.6 months (95% CI 7.3 - >39) respectively. A MTD was not reached. The regimen was tolerable, indicating that celecoxib can be safely administered with CRT for locally advanced OC.

Research paper thumbnail of Twenty-Five-Year Experience with Radical Chemoradiation for Anal Cancer

International Journal of Radiation Oncology*Biology*Physics, 2011

To evaluate the prognostic factors, patterns of failure, and late toxicity in patients treated wi... more To evaluate the prognostic factors, patterns of failure, and late toxicity in patients treated with chemoradiation (CRT) for anal cancer. Consecutive patients with nonmetastatic squamous cell carcinoma of the anus treated by CRT with curative intent between February 1983 and March 2008 were identified through the institutional database. Chart review and telephone follow-up were undertaken to collect demographic data and outcome. Two hundred eighty-four patients (34% male; median age 62 years) were identified. The stages at diagnosis were 23% Stage I, 48% Stage II, 10% Stage IIIA, and 18% Stage IIIB. The median radiotherapy dose to the primary site was 54 Gy. A complete clinical response to CRT was achieved in 89% of patients. With a median follow-up time of 5.3 years, the 5-year rates of locoregional control, distant control, colostomy-free survival, and overall survival were 83% (95% confidence interval [CI] 78-88), 92% (95% CI, 89-96), 73% (95% CI, 68-79), and 82% (95% CI, 77-87), respectively. Higher T stage and male sex predicted for locoregional failure, and higher N stage predicted for distant metastases. Locoregional failure occurred most commonly at the primary site. Omission of elective inguinal irradiation resulted in inguinal failure rates of 1.9% and 12.5% in T1N0 and T2N0 patients, respectively. Pelvic nodal failures were very uncommon. Late vaginal and bone toxicity was observed in addition to gastrointestinal toxicity. CRT is a highly effective approach in anal cancer. However, subgroups of patients fare relatively poorly, and novel approaches are needed. Elective inguinal irradiation can be safely omitted only in patients with Stage I disease. Vaginal toxicity and insufficiency fractures of the hip and pelvis are important late effects that require prospective evaluation.

Research paper thumbnail of 3D Radiotherapy Can Be Safely Combined With Sandwich Systemic Gemcitabine Chemotherapy in the Management of Pancreatic Cancer: Factors Influencing Outcome

International Journal of Radiation Oncology*Biology*Physics, 2008

The aim of this Phase II study was to examine whether concurrent continuous infusion 5-fluorourac... more The aim of this Phase II study was to examine whether concurrent continuous infusion 5-fluorouracil (CI 5FU) plus three-dimensional conformal planning radiotherapy sandwiched between gemcitabine chemotherapy is effective, tolerable, and safe in the management of pancreatic cancer. Patients were enrolled in two strata: (1) resected pancreatic cancer at high risk of local relapse (postsurgery arm, n = 22) or (2) inoperable pancreatic cancer in head or body without metastases (locally advanced arm, n = 41). Gemcitabine was given at 1,000 mg/m(2) weekly for 3 weeks followed by 1 week rest then 5-6 weeks of radiotherapy and concurrent CI 5FU (200 mg/m(2)/day). After 4 weeks' rest, gemcitabine treatment was reinitiated for 12 weeks. For the two arms combined, treatment-related Grade 3 and 4 toxicities were reported by 25 (39.7%) and 7 (11.1%) patients, respectively. No significant late renal or hepatic toxicity was observed. In the postsurgery arm (R1 54.5%), median time to progressive disease from surgery was 11.0 months, median time to failure of local control was 32.9 months, and median survival time was 15.6 months. The 1- and 2-year survival rates were 63.6% and 31.8%. No significant associations between outcome and mutations in K-ras or TP53 or microsatellite instability were identified. Post hoc investigation of cancer antigen 19-9 levels found baseline levels and increases postbaseline were associated with shorter survival (p = 0.0061 and p < 0.0001, respectively). This three-dimensional chemoradiotherapy regimen is safe and promising, with encouraging local control for a substantial proportion of patients, and merits testing in a randomized trial.

Research paper thumbnail of Impact of treatment interruption on outcome of chemoradiation for carcinoma of anus

International Journal of Radiation Oncology*Biology*Physics, 1998

Research paper thumbnail of Primary adenocarcinoma of the anus: a retrospective analysis

International Journal of Radiation Oncology*Biology*Physics, 1999