- Email: [email protected]
Does the Revised FIGO Staging for Endometrial Cancer Lead to Increased Discrimination in Patient Outcomes?
I. J. Radiation Oncology d Biology d Physics
S144
Volume 78, Number 3, Supplement, 2010
CT-based Gross Tumor Volume (GTV-CT) was delineated by two independent observers while the PET data remained obscured. The Planning Target Volume (PTV) was obtained by adding a 1.5 cm margin around the GTV. The same volumes were recontoured using PET/CT data and termed GTV-ABC and PTV-ABC, respectively. The mean values of GTV-CT and GTV-ABC and the absolute differences between the two observers were analyzed. In addition, nineteen of these patients had PET/CT performed 2 to 3 months after treatment. The anatomic biologic value (ABV) was calculated using the product of maximum diameter and mean SUV of the cervical tumor (max. diameter (cm) x mean SUV). The post-treatment ABV was compared with pre-treatment ABV. Patients were also stratified for partial and complete response and their ABV’s were analyzed. Results: A halo was observed around areas of maximal SUV uptake. The mean halo SUV level was 2.04 ± 0.81 (SD). The mean halo thickness was 2.5 ± 1.23 (SD) mm. A clinically significant ($ 25%) modification of GTV was observed in 10 patients. Interobserver GTV variability decreased from a mean volume difference of 24.1 cm3 +/- 26.2 (SD) in CT-based planning to 7 cm3 +/- 5.6 (SD) in PET/CT-based planning with a respective decrease in standard deviation (SD) from 26.2 to 5.6 (p \ 0.001). Comparison of mean pre-treatment and post-treatment ABVs revealed a decrease of ABV from 48.2 to 7.8 (p \ 0.001). Patients with complete response (no residual tumor and no SUV uptake) had a mean pre-treatment ABV of 40.8 compared to 56.3 in those with partial response (p = 0.3). Conclusions: PET/CT is a valuable tool in radiation therapy planning and evaluation of treatment response for cervical cancer. A clearly visualized halo was successfully implemented in GTV contouring in cervical cancer, resulting in decreased inter-observer variability in radiation therapy planning. PET/CT has the ability to quantify treatment response using anatomic biologic value. Anatomical Biological value can be used to identify those patients that have a lesser likelihood of achieving a complete response. Author Disclosure: A. Tejwani, None; A. Lavaf, None; U. Swamy, None; J. Emmolo, None; A. Guirguis, None; B. Mokhtar, None; K. Parikh, None; H. Ashamalla, None.
1009
Differences in Uptake and Distribution of 64Cu-ATSM and 18F-FDG in Primary Tumors of Patients with Squamous Cell Carcinoma of the Cervix
A. J. Chang1 P. W. Grigsby2 1 Washington University in St. Louis, St. Louis, MO, 2Department of Radiation Oncology, Mallinckrodt Institute of Radiology, Washington University in St. Louis and the Alvin J. Siteman Cancer Center, St. Louis, MO
Purpose/Objective(s): Tumor hypoxia measured by positron emission tomography (PET) with Cu-labeled diacetyl-bis (N (4)methylthiosemicarbazone (Cu-ATSM) has been demonstrated to be a predictor of outcome in patients undergoing chemoradiation for cervical cancer. PET with 18F-fluorodeoxyglucose (FDG) is performed for initial staging and provides prognostic information. Metabolic tumor volume defined by the 40% threshold of the maximum standardized uptake value (SUVmax) has been correlated with cervical tumor size as determined by pathology, MRI, and CT. To characterize the relationships between Cu-ATSM and FDGPET, this study compares the intratumoral uptake and distribution of 64Cu-ATSM and FDG in patients with squamous cell carcinoma of the cervix. Materials/Methods: Ten patients with squamous cell carcinoma (SCC) of the cervix enrolled on a prospective trial underwent 64 Cu-ATSM and FDG PET/CT at diagnosis. After image reconstruction, 64Cu-ATSM-PET and FDG-PET/CT images were co-registered utilizing MIM version 4.2.2 software. At the level of the tumor epicenter, metabolic tumor volumes were auto-contoured at 9 different thresholds on the 64Cu-ATSM-PET and also on the FDG-PET/CT set of images: SUVmax 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, and 10%. To determine a relationship between metabolic tumor volumes autocontoured on the 64Cu-ATSM-PET and FDG-PET/CT images, regression lines were determined between the different threshold volumes. To determine if there were differences in the regions of highest intratumoral distribution of the tracers, concordance indexes were generated between the 64 Cu-ATSM-PET and FDG-PET/CT metabolic tumor volumes. The concordance index describes the spatial relationship between the volumes and is calculated by dividing the volume of overlap with volume of the tumor. Results: SUVmax for 64Cu-ATSM-PET (range, 3.2 - 6.5) were lower than those for FDG-PET (range, 8.2 - 20.0). A strong correlation (R2 = 0.757) was observed between the metabolic tumor volumes generated using the 30% threshold value on the 64 Cu-ATSM-PET images and the 40% threshold value on the FDG-PET images. A low concordance index (0.20) was observed between the metabolic tumor volumes of greatest intensity for each isotope (65% threshold value on the 64Cu-ATSM-PET and the 70% threshold value on the FDG-PET images) showing a significant difference in the regions of maximal uptake and intratumoral distribution of 64Cu-ATSM and FDG uptake. Conclusions: Metabolic tumor volume of 64Cu-ATSM and FDG correlates well; however, the intratumoral distribution patterns of the regions of maximal 64Cu-ATSM and FDG uptake were discordant indicating that intratumoral regions of hypoxia and glucose metabolism are not the same. Supported by 1R01 CA136931-01A2. Author Disclosure: A.J. Chang, None; P.W. Grigsby, None.
1010
Does the Revised FIGO Staging for Endometrial Cancer Lead to Increased Discrimination in Patient Outcomes?
E. W. Cooke, L. Pappas, D. K. Gaffney University of Utah Huntsman Cancer Hospital, Salt Lake City, UT Purpose/Objective(s): The International Federation of Gynecology and Obstetrics (FIGO) recently updated the 1988 endometrial cancer staging system. The objective of our study was to compare survival outcomes in a large cohort of patients with endometrial adenocarcinoma when staged using the 1988 versus 2009 FIGO staging systems. Materials/Methods: Data were obtained from the Surveillance, Epidemiology, and End Results Program (SEER) for the years 1998-2006. Patients with a diagnosis of adenocarcinoma of the uterus with complete staging information were included. Patients were staged according to both the 1988 and 2009 staging systems, and Kaplan-Meier survival estimates were derived for cause
Proceedings of the 52nd Annual ASTRO Meeting specific survival (CSS) comparing the two groups. Univariate and multivariate analysis using Cox Proportional Hazards models were generated. Results: A total of 47,284 patients were included. The median follow-up time was 37 months. The 5-year CSS of 2009 stage IA and IB were 96.6% and 89.9%, respectively (p \ 0.0001). After accounting for age (. or \/ = 60), tumor grade, and race, this survival difference remained significant (HR, 1.97; 95% CI, 1.74-2.24; p \0.0001). There was no survival difference shown between 1988 stage IA and IB disease in the multivariate model (HR, 0.93; 95% CI, 0.80-1.08; p = 0.36). Patients with 1988 stage IIA disease had similar CSS outcomes to patients with 1988 stage IC disease, with 5-year CSS of 88.6% versus 89.9%, respectively (p = 0.09). Patients with positive pelvic washings had 5-year CSS similar to patients staged as IIIA with the 2009 system, with five-year CSS estimates of 74.2% versus 72.1% (p = 0.37). No difference was shown in CSS between patients with positive washings and 2009 stage IIIA disease in the multivariate model (HR, 0.98; 95% CI, 0.81-1.20; p = 0.87). CSS of patients staged as IIIC1 was significantly improved compared with patients staged as IIIC2. Five year estimates were 68.2% versus 57.3%, respectively (p \ 0.0001). In the multivariate model, the survival difference between stage IIIC1 and IIIC2 remained after adjusting for age, tumor grade and race (HR, 1.49; 95% CI, 1.26-1.76; p \ 0.0001). Conclusions: Recent recommendations for changes to the endometrial cancer staging system are validated in this dataset. For patients with involved lymph nodes, positive pelvic nodes portend a better survival outcome than involvement of the paraaortic chain. In this dataset of over 47,000 patients with endometrial adenocarcinoma, the 2009 staging system produced better discrimination in CSS outcomes compared with the old system. Author Disclosure: E.W. Cooke, None; L. Pappas, None; D.K. Gaffney, None.
1011
Survival Analysis of FIGO Stage IIIC Endometrial Cancer Patients
A. P. Brown1, D. K. Gaffney2, M. K. Dodson2,1, A. P. Soisson2,1, W. T. Sause1 1
Intermountain Medical Center, Murray, UT, 2Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT
Purpose/Objective(s): Approximately 1 in 40 women will be diagnosed with endometrial cancer in their lifetime. Most endometrial cancers are diagnosed when the disease is localized and only approximately 7% of patients have nodal involvement at the time of diagnosis (FIGO stage IIIC disease). These patients with locally advanced disease have a substantially worse prognosis. There is a lack of consensus about appropriate adjuvant therapy for stage IIIC patients. This study seeks to provide data to guide future clinical trials and patient care. Materials/Methods: This multi-institution, IRB approved, study is a retrospective review of surgically staged IIIC endometrial cancer patients treated at hospitals within the Intermountain Health Care system and the University of Utah/Huntsman Cancer Hospital from 1995 to 2008. Of 1875 patients evaluated, 118 patients had stage IIIC disease. Five patients were excluded from analysis for previously diagnosed cancers within five years of endometrial cancer diagnosis and one patient was excluded because of death at the time of surgery, leaving 112 patients for analysis. The study cohort was evaluated using Kaplan-Meier estimates and proportional hazards modeling. Results: The median age at diagnosis was 65 with a range of 26 to 88. Five-year survival was 45% for patients treated with surgery alone (n = 25, 22%), 60% for patients treated with surgery and adjuvant radiation therapy (n = 43, 38%), 33% for patients treated with surgery and adjuvant chemotherapy (n = 6, 5%) and 54% for patients treated with adjuvant radiation therapy and chemotherapy (n = 38, 34%). Patients who received adjuvant radiation therapy (n = 81) had a 5-year survival of 57% compared to 43% for patients who did not get adjuvant radiation (n = 31; p = 0.002). Patients who had adjuvant chemotherapy (n = 44) had a 5-year survival of 51% compared to 54% for patients who did not get adjuvant chemotherapy (n = 68) (p = 0.525). After controlling for age at diagnosis, grade, and the presence of a recurrence on multivariate analysis, the administration of adjuvant radiation therapy resulted in a trend toward improved overall survival, although the difference was not statistically significant (p = 0.087). Conclusions: This multicenter study reviewed a large population of node-positive endometrial cancer patients. Univariate analysis showed that administration of adjuvant radiation therapy improves 5 year survival of stage IIIC endometrial cancer. However, after controlling for covariates, the survival benefit of adjuvant radiation does not achieve statistical significance. This study is subject to the limitations of any retrospective review of data collected in a clinical context. Further work is being done to define the role of adjuvant therapies in stage IIIC endometrial cancer and to identify subpopulations that may benefit from specific adjuvant therapies. Author Disclosure: A.P. Brown, None; D.K. Gaffney, None; M.K. Dodson, None; A.P. Soisson, None; W.T. Sause, None.
1012
Epithelial Ovarian Cancer: Definitive Radiotherapy for Limited Recurrence after Complete Remission 1
K. Yahara , T. Ohguri1, H. Imada2, S. Moon1, S. Yamaguchi1, H. Narisada1, Y. Matsuura3, N. Toki3, T. Hachisuga3, Y. Korogi1 1
Department of Radiology, University of Occupational and Environmental Health, Kitakyushu, Japan, 2Cancer Therapy Center, Tobata Hospital, Kitakyushu, Japan, 3Department of Obstetrics and Gynecology, University of Occupational and Environmental Health, Kitakyushu, Japan Purpose/Objective(s): The high complete response rates have been achieved after aggressive front-line therapy, including surgery and chemotherapy, for epithelial ovarian cancer. However, the response rate of the second-line chemotherapy for recurrent ovarian cancer is still low, and the clinical indication for secondary surgery is limited. The purpose of this study was to assess the efficacy and toxicity of definitive radiotherapy for the recurrence of epithelial ovarian cancer, which was limited in one or two regions, after complete remission achieved with aggressive front-line therapy. Materials/Methods: Twenty-seven patients with one or two gross recurrent lesions were treated with definitive radiotherapy and were retrospectively analyzed. The time from the front-line therapy to radiotherapy was median 22 months. The sites of the irradiated lesion were as follows; the pelvic lesion alone (n = 12), the extrapelvic lymph node lesion alone (n = 8), the pelvic lesion plus extrapelvic lymph node lesion (n = 5), the pelvic lesion plus liver (n = 1) and the pelvic lesion plus spleen (n = 1). The median tumor
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S144
Volume 78, Number 3, Supplement, 2010
CT-based Gross Tumor Volume (GTV-CT) was delineated by two independent observers while the PET data remained obscured. The Planning Target Volume (PTV) was obtained by adding a 1.5 cm margin around the GTV. The same volumes were recontoured using PET/CT data and termed GTV-ABC and PTV-ABC, respectively. The mean values of GTV-CT and GTV-ABC and the absolute differences between the two observers were analyzed. In addition, nineteen of these patients had PET/CT performed 2 to 3 months after treatment. The anatomic biologic value (ABV) was calculated using the product of maximum diameter and mean SUV of the cervical tumor (max. diameter (cm) x mean SUV). The post-treatment ABV was compared with pre-treatment ABV. Patients were also stratified for partial and complete response and their ABV’s were analyzed. Results: A halo was observed around areas of maximal SUV uptake. The mean halo SUV level was 2.04 ± 0.81 (SD). The mean halo thickness was 2.5 ± 1.23 (SD) mm. A clinically significant ($ 25%) modification of GTV was observed in 10 patients. Interobserver GTV variability decreased from a mean volume difference of 24.1 cm3 +/- 26.2 (SD) in CT-based planning to 7 cm3 +/- 5.6 (SD) in PET/CT-based planning with a respective decrease in standard deviation (SD) from 26.2 to 5.6 (p \ 0.001). Comparison of mean pre-treatment and post-treatment ABVs revealed a decrease of ABV from 48.2 to 7.8 (p \ 0.001). Patients with complete response (no residual tumor and no SUV uptake) had a mean pre-treatment ABV of 40.8 compared to 56.3 in those with partial response (p = 0.3). Conclusions: PET/CT is a valuable tool in radiation therapy planning and evaluation of treatment response for cervical cancer. A clearly visualized halo was successfully implemented in GTV contouring in cervical cancer, resulting in decreased inter-observer variability in radiation therapy planning. PET/CT has the ability to quantify treatment response using anatomic biologic value. Anatomical Biological value can be used to identify those patients that have a lesser likelihood of achieving a complete response. Author Disclosure: A. Tejwani, None; A. Lavaf, None; U. Swamy, None; J. Emmolo, None; A. Guirguis, None; B. Mokhtar, None; K. Parikh, None; H. Ashamalla, None.
1009
Differences in Uptake and Distribution of 64Cu-ATSM and 18F-FDG in Primary Tumors of Patients with Squamous Cell Carcinoma of the Cervix
A. J. Chang1 P. W. Grigsby2 1 Washington University in St. Louis, St. Louis, MO, 2Department of Radiation Oncology, Mallinckrodt Institute of Radiology, Washington University in St. Louis and the Alvin J. Siteman Cancer Center, St. Louis, MO
Purpose/Objective(s): Tumor hypoxia measured by positron emission tomography (PET) with Cu-labeled diacetyl-bis (N (4)methylthiosemicarbazone (Cu-ATSM) has been demonstrated to be a predictor of outcome in patients undergoing chemoradiation for cervical cancer. PET with 18F-fluorodeoxyglucose (FDG) is performed for initial staging and provides prognostic information. Metabolic tumor volume defined by the 40% threshold of the maximum standardized uptake value (SUVmax) has been correlated with cervical tumor size as determined by pathology, MRI, and CT. To characterize the relationships between Cu-ATSM and FDGPET, this study compares the intratumoral uptake and distribution of 64Cu-ATSM and FDG in patients with squamous cell carcinoma of the cervix. Materials/Methods: Ten patients with squamous cell carcinoma (SCC) of the cervix enrolled on a prospective trial underwent 64 Cu-ATSM and FDG PET/CT at diagnosis. After image reconstruction, 64Cu-ATSM-PET and FDG-PET/CT images were co-registered utilizing MIM version 4.2.2 software. At the level of the tumor epicenter, metabolic tumor volumes were auto-contoured at 9 different thresholds on the 64Cu-ATSM-PET and also on the FDG-PET/CT set of images: SUVmax 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, and 10%. To determine a relationship between metabolic tumor volumes autocontoured on the 64Cu-ATSM-PET and FDG-PET/CT images, regression lines were determined between the different threshold volumes. To determine if there were differences in the regions of highest intratumoral distribution of the tracers, concordance indexes were generated between the 64 Cu-ATSM-PET and FDG-PET/CT metabolic tumor volumes. The concordance index describes the spatial relationship between the volumes and is calculated by dividing the volume of overlap with volume of the tumor. Results: SUVmax for 64Cu-ATSM-PET (range, 3.2 - 6.5) were lower than those for FDG-PET (range, 8.2 - 20.0). A strong correlation (R2 = 0.757) was observed between the metabolic tumor volumes generated using the 30% threshold value on the 64 Cu-ATSM-PET images and the 40% threshold value on the FDG-PET images. A low concordance index (0.20) was observed between the metabolic tumor volumes of greatest intensity for each isotope (65% threshold value on the 64Cu-ATSM-PET and the 70% threshold value on the FDG-PET images) showing a significant difference in the regions of maximal uptake and intratumoral distribution of 64Cu-ATSM and FDG uptake. Conclusions: Metabolic tumor volume of 64Cu-ATSM and FDG correlates well; however, the intratumoral distribution patterns of the regions of maximal 64Cu-ATSM and FDG uptake were discordant indicating that intratumoral regions of hypoxia and glucose metabolism are not the same. Supported by 1R01 CA136931-01A2. Author Disclosure: A.J. Chang, None; P.W. Grigsby, None.
1010
Does the Revised FIGO Staging for Endometrial Cancer Lead to Increased Discrimination in Patient Outcomes?
E. W. Cooke, L. Pappas, D. K. Gaffney University of Utah Huntsman Cancer Hospital, Salt Lake City, UT Purpose/Objective(s): The International Federation of Gynecology and Obstetrics (FIGO) recently updated the 1988 endometrial cancer staging system. The objective of our study was to compare survival outcomes in a large cohort of patients with endometrial adenocarcinoma when staged using the 1988 versus 2009 FIGO staging systems. Materials/Methods: Data were obtained from the Surveillance, Epidemiology, and End Results Program (SEER) for the years 1998-2006. Patients with a diagnosis of adenocarcinoma of the uterus with complete staging information were included. Patients were staged according to both the 1988 and 2009 staging systems, and Kaplan-Meier survival estimates were derived for cause
Proceedings of the 52nd Annual ASTRO Meeting specific survival (CSS) comparing the two groups. Univariate and multivariate analysis using Cox Proportional Hazards models were generated. Results: A total of 47,284 patients were included. The median follow-up time was 37 months. The 5-year CSS of 2009 stage IA and IB were 96.6% and 89.9%, respectively (p \ 0.0001). After accounting for age (. or \/ = 60), tumor grade, and race, this survival difference remained significant (HR, 1.97; 95% CI, 1.74-2.24; p \0.0001). There was no survival difference shown between 1988 stage IA and IB disease in the multivariate model (HR, 0.93; 95% CI, 0.80-1.08; p = 0.36). Patients with 1988 stage IIA disease had similar CSS outcomes to patients with 1988 stage IC disease, with 5-year CSS of 88.6% versus 89.9%, respectively (p = 0.09). Patients with positive pelvic washings had 5-year CSS similar to patients staged as IIIA with the 2009 system, with five-year CSS estimates of 74.2% versus 72.1% (p = 0.37). No difference was shown in CSS between patients with positive washings and 2009 stage IIIA disease in the multivariate model (HR, 0.98; 95% CI, 0.81-1.20; p = 0.87). CSS of patients staged as IIIC1 was significantly improved compared with patients staged as IIIC2. Five year estimates were 68.2% versus 57.3%, respectively (p \ 0.0001). In the multivariate model, the survival difference between stage IIIC1 and IIIC2 remained after adjusting for age, tumor grade and race (HR, 1.49; 95% CI, 1.26-1.76; p \ 0.0001). Conclusions: Recent recommendations for changes to the endometrial cancer staging system are validated in this dataset. For patients with involved lymph nodes, positive pelvic nodes portend a better survival outcome than involvement of the paraaortic chain. In this dataset of over 47,000 patients with endometrial adenocarcinoma, the 2009 staging system produced better discrimination in CSS outcomes compared with the old system. Author Disclosure: E.W. Cooke, None; L. Pappas, None; D.K. Gaffney, None.
1011
Survival Analysis of FIGO Stage IIIC Endometrial Cancer Patients
A. P. Brown1, D. K. Gaffney2, M. K. Dodson2,1, A. P. Soisson2,1, W. T. Sause1 1
Intermountain Medical Center, Murray, UT, 2Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT
Purpose/Objective(s): Approximately 1 in 40 women will be diagnosed with endometrial cancer in their lifetime. Most endometrial cancers are diagnosed when the disease is localized and only approximately 7% of patients have nodal involvement at the time of diagnosis (FIGO stage IIIC disease). These patients with locally advanced disease have a substantially worse prognosis. There is a lack of consensus about appropriate adjuvant therapy for stage IIIC patients. This study seeks to provide data to guide future clinical trials and patient care. Materials/Methods: This multi-institution, IRB approved, study is a retrospective review of surgically staged IIIC endometrial cancer patients treated at hospitals within the Intermountain Health Care system and the University of Utah/Huntsman Cancer Hospital from 1995 to 2008. Of 1875 patients evaluated, 118 patients had stage IIIC disease. Five patients were excluded from analysis for previously diagnosed cancers within five years of endometrial cancer diagnosis and one patient was excluded because of death at the time of surgery, leaving 112 patients for analysis. The study cohort was evaluated using Kaplan-Meier estimates and proportional hazards modeling. Results: The median age at diagnosis was 65 with a range of 26 to 88. Five-year survival was 45% for patients treated with surgery alone (n = 25, 22%), 60% for patients treated with surgery and adjuvant radiation therapy (n = 43, 38%), 33% for patients treated with surgery and adjuvant chemotherapy (n = 6, 5%) and 54% for patients treated with adjuvant radiation therapy and chemotherapy (n = 38, 34%). Patients who received adjuvant radiation therapy (n = 81) had a 5-year survival of 57% compared to 43% for patients who did not get adjuvant radiation (n = 31; p = 0.002). Patients who had adjuvant chemotherapy (n = 44) had a 5-year survival of 51% compared to 54% for patients who did not get adjuvant chemotherapy (n = 68) (p = 0.525). After controlling for age at diagnosis, grade, and the presence of a recurrence on multivariate analysis, the administration of adjuvant radiation therapy resulted in a trend toward improved overall survival, although the difference was not statistically significant (p = 0.087). Conclusions: This multicenter study reviewed a large population of node-positive endometrial cancer patients. Univariate analysis showed that administration of adjuvant radiation therapy improves 5 year survival of stage IIIC endometrial cancer. However, after controlling for covariates, the survival benefit of adjuvant radiation does not achieve statistical significance. This study is subject to the limitations of any retrospective review of data collected in a clinical context. Further work is being done to define the role of adjuvant therapies in stage IIIC endometrial cancer and to identify subpopulations that may benefit from specific adjuvant therapies. Author Disclosure: A.P. Brown, None; D.K. Gaffney, None; M.K. Dodson, None; A.P. Soisson, None; W.T. Sause, None.
1012
Epithelial Ovarian Cancer: Definitive Radiotherapy for Limited Recurrence after Complete Remission 1
K. Yahara , T. Ohguri1, H. Imada2, S. Moon1, S. Yamaguchi1, H. Narisada1, Y. Matsuura3, N. Toki3, T. Hachisuga3, Y. Korogi1 1
Department of Radiology, University of Occupational and Environmental Health, Kitakyushu, Japan, 2Cancer Therapy Center, Tobata Hospital, Kitakyushu, Japan, 3Department of Obstetrics and Gynecology, University of Occupational and Environmental Health, Kitakyushu, Japan Purpose/Objective(s): The high complete response rates have been achieved after aggressive front-line therapy, including surgery and chemotherapy, for epithelial ovarian cancer. However, the response rate of the second-line chemotherapy for recurrent ovarian cancer is still low, and the clinical indication for secondary surgery is limited. The purpose of this study was to assess the efficacy and toxicity of definitive radiotherapy for the recurrence of epithelial ovarian cancer, which was limited in one or two regions, after complete remission achieved with aggressive front-line therapy. Materials/Methods: Twenty-seven patients with one or two gross recurrent lesions were treated with definitive radiotherapy and were retrospectively analyzed. The time from the front-line therapy to radiotherapy was median 22 months. The sites of the irradiated lesion were as follows; the pelvic lesion alone (n = 12), the extrapelvic lymph node lesion alone (n = 8), the pelvic lesion plus extrapelvic lymph node lesion (n = 5), the pelvic lesion plus liver (n = 1) and the pelvic lesion plus spleen (n = 1). The median tumor
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