Benefit Of Adjuvant Radiotherapy Research Articles

The Case Of The Missing Target: Comparison of RTOG CTV To “Prostate Cancer Maps” and Preoperative MRI

Despite the benefit of adjuvant radiotherapy (XRT) 50% of prostate cancer patients (pts) relapse with the predominant site of failure being local (SWOG 8794). 4 consensus guides have been published defining Clinical Target Volume (CTV) for prostate cancer in the post-op setting. Previous work from our institution has demonstrated that these guides do not adequately cover the prostate bed/gross tumor based on pre-op MRI (ASTRO 2010). The current research focuses on detailed pathology maps and their implications for CTV definition.

The Case of the Missing Target: Mystery Solved

Despite the benefit of adjuvant radiotherapy (RT) in high risk prostate cancer 50% of patients relapse with the primary site of failure being local (SWOG 8794). Four consensus guidelines define postoperative CTV. Previous work from our institution demonstrated the 4 guidelines do not adequately cover the prostate bed/gross tumor based on preoperative MRI. On average, 38% of prostate volume and 41% of gross tumor volume were missed (ASTRO 2010). To improve target coverage, a modified CTV (CTV TOH) was created using pre-op MRI.

Breast Cancer in Men

The aim of this study was to review the clinical presentation and to evaluate prognostic factors, treatment modalities, outcome, and second malignancy in male breast cancer patients. A chart review was conducted of all men treated for breast cancer between January 1991 and December 2007. Cox proportional hazards regression model and Kaplan-Meier curve were used to determine prognostic factors and plot survival probabilities. Invasive carcinoma was diagnosed in 22 patients and ductal carcinoma in situ in 7 patients. With mortality as the endpoint, tumor size indicated hazard ratio (HR) of 1.5 for each 1-cm increase in tumor size (p = .03). Overall stage and increased age were associated with increased risk of mortality (HR = 2.1, p = .055; HR = 1.09 for a 1-year increase in age, p = .08, respectively). Adjuvant radiation therapy yielded an HR of 0.1 (p = .058), indicating a favorable association with the survival. Advanced age, higher stage, and increasing tumor size were unfavorable to survival in male breast carcinoma. The benefit of adjuvant radiation therapy should be addressed in future collaborative studies.

Long Term Benefits of Post-surgical Adjuvant Radiotherapy Among Sub-population of Patients with Stage IB Grade 2 Endometrial Cancer

Present study was designed to evaluate potential risks and benefits of adjuvant radiotherapy in selected patients with inter- mediate-risk endometrial cancer. A total of 100 patients with stage IB grade II endometrial cancer followed up in Radiation Oncology Clinic at Dr. Lutfi Kirdar Training and Research Hospital were evaluated retrospectively to determine the influence of postsurgical adjuvant radiotherapy on disease-free survival, local recurrences and locally-relaps free survival. Side effects related to adjuvant radiotherapy were also evaluated. Forty-seven (47%) patients were determined to undergo total abdo- minal hysterectomy + bilateral salphingo-oopherectomy and 53 (53%) patients, total abdominal hysterectomy + bilateral salphingo-oopherectomy + pelvic lymph node dissection. Postsurgical adjuvant radiotherapy was administered in 77 pati- ents (77%), while the surgery was the sole medical intervention for 23 patients (23%). The median follow-up period was 40.5 months (range: 6-139) Five-year disease-free survival (96.6% vs. 80.5%; p< 0.01) and local control (98.6% vs. 80.5%; p<0.05) were better in patients who were administered postoperative radiotherapy compared to patients without postope- rative radiotherapy. In conclusion, while our results concerning homogenous sub-population of patients with stage IB grade II endometrial can- cer seem to support the use of postoperative adjuvant radiotherapy, larger and more detailed prospective studies are requ- ired for determination of its exact prognostic value.

Carcinoma of the ampulla of Vater: Patterns of failure after resection and benefit of adjuvant radiotherapy.

254 Background: Ampullary carcinoma is a rare malignancy. Despite radical resection, survival rates remain low with high rates of local failure. To define the role of radiation therapy and chemotherapy with surgery, we performed a single institution analysis of treatment- related outcomes. Methods: A retrospective analysis was performed of all patients undergoing potentially curative therapy for adenocarcinoma of the ampulla of Vater at Duke University Hospitals between 1975 and 2009. Local control (LC), overall survival (OS), disease-free survival (DFS), and metastases-free survival (MFS) were estimated using the Kaplan-Meier Method. Results: One hundred thirty-seven patients with ampullary carcinoma underwent potentially curative pancreaticoduodenectomy. Sixty-one patients undergoing resection received adjuvant (n= 43) or neoadjuvant (n=18) radiation therapy with concurrent chemotherapy (CRT). Patients receiving radiotherapy were more likely to have poorly differentiated tumors. Median radiation dose was 50 Gy. Median follow up was 8.8 years. Of patients receiving neoadjuvant therapy, 67% were downstaged on final pathology with 28% achieving pathologic complete response. Three-year local control was significantly improved in patients receiving CRT (88% vs. 55% p= 0.001) with trend toward a 3-year OS benefit in patients receiving CRT (62% vs. 46% p=0.074). Despite this, there was no significant difference in 3-year DFS (66% CRT vs 48% surgery alone p=0.09) or MFS (69% CRT vs 63% surgery alone p=0.337). Conclusions: Long term survival rates are low. Local failure rates are high following radical resection alone and improved with CRT. Despite more adverse pathologic features in patients receiving CRT, survival outcomes were at least equivalent with a trend toward statistical significance. Given the patterns of relapse with surgery alone and local control benefit in patients receiving CRT, the use of chemoradiotherapy in selected patients should be considered. No significant financial relationships to disclose.

Recommendations for Post-Prostatectomy Radiation Therapy in the United States Before and After the Presentation of Randomized Trials

The EORTC 22911 and the SWOG 8794 studies, presented in 2004 and 2005, showed that adjuvant radiation therapy after prostatectomy improved biochemical disease-free survival in men with adverse pathological features. In this study we evaluated the use of post-prostatectomy radiation therapy following the presentation of these results, and the impact of margin involvement, pathological tumor stage, Gleason score and sociodemographic factors on post-prostatectomy radiation therapy recommendations. The SEER cancer registry was used to identify 21,917 men who underwent radical prostatectomy for N0M0 prostate cancer with adverse pathological features (pT3 or margin positive pT2 disease) from 2000 through 2007. After adjusting for age, diagnosis year, race, SEER region and county education level in a multivariable regression model, decreasing age, margin involvement and Gleason 8 to 10 cancer were associated with receiving post-prostatectomy radiation therapy (all p < 0.001). Men with pT3a (AOR 2.95, CI 2.64-3.29) and pT3b disease (AOR 6.77, CI 5.75-7.97) were more likely to receive post-prostatectomy radiation therapy than those with pT2 disease. The use of post-prostatectomy radiation therapy did not increase after the presentation of study results (p = 0.166). While men with involved margins and more aggressive pathological disease features were more likely to receive post-prostatectomy radiation therapy, recommendations for post-prostatectomy radiation did not increase after the initial reports from the randomized trials, perhaps because these studies initially reported improved biochemical disease-free survival but not overall survival. Whether the recent report of a survival benefit from adjuvant radiation therapy in the SWOG trial will impact patterns of care requires further followup.

Survival Outcomes in Resected Extrahepatic Cholangiocarcinoma: Effect of Adjuvant Radiotherapy in a Surveillance, Epidemiology, and End Results Analysis

The benefit of adjuvant radiotherapy (RT) after surgical resection for extrahepatic cholangiocarcinoma has not been clearly established. We analyzed survival outcomes of patients with resected extrahepatic cholangiocarcinoma and examined the effect of adjuvant RT. Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) program between 1973 and 2003. The primary endpoint was the overall survival time. Cox regression analysis was used to perform univariate and multivariate analyses of the following clinical variables: age, year of diagnosis, histologic grade, localized (Stage T1-T2) vs. regional (Stage T3 or greater and/or node positive) stage, gender, race, and the use of adjuvant RT after surgical resection. The records for 2,332 patients were obtained. Patients with previous malignancy, distant disease, incomplete or conflicting records, atypical histologic features, and those treated with preoperative/intraoperative RT were excluded. Of the remaining 1,491 patients eligible for analysis, 473 (32%) had undergone adjuvant RT. After a median follow-up of 27 months (among surviving patients), the median overall survival time for the entire cohort was 20 months. Patients with localized and regional disease had a median survival time of 33 and 18 months, respectively (p<.001). The addition of adjuvant RT was not associated with an improvement in overall or cause-specific survival for patients with local or regional disease. Patients with localized disease had significantly better overall survival than those with regional disease. Adjuvant RT was not associated with an improvement in long-term overall survival in patients with resected extrahepatic bile duct cancer. Key data, including margin status and the use of combined chemotherapy, was not available through the SEER database.

Does the Benefit of Adjuvant Radiotherapy following Radical Prostatectomy for Pathologic T3 or Margin-positive Prostate Cancer Extend to All Pathologic Subgroups? A Meta-analysis of the Randomized Trials

Does the Benefit of Adjuvant Radiotherapy following Radical Prostatectomy for Pathologic T3 or Margin-positive Prostate Cancer Extend to All Pathologic Subgroups? A Meta-analysis of the Randomized Trials

Carcinoma of the Ampulla of Vater: Patterns of Failure after Resection and Possible Benefit of Adjuvant Radiotherapy

Carcinoma of the Ampulla of Vater: Patterns of Failure after Resection and Possible Benefit of Adjuvant Radiotherapy

Postoperative Radiotherapy in Prostate Cancer: The Case of the Missing Target

Postoperative radiotherapy increases survival in high-risk (pT3/margin positive) prostate cancer patients (pts). Despite the benefit of adjuvant radiotherapy (XRT) approximately 50% of pts in long-term follow-up relapse with the primary site of failure being local (SWOG 8794). Potential reasons for recurrence include inadequate XRT dose and inadequate clinical target volume (CTV) delineation. There are four published consensus guidelines (EORTC, FROGG, PMH, and RTOG) defining postoperative CTV in prostate cancer. We explore the possibility that inadequate CTV coverage is an important cause of local failure. This study evaluates the utility of preoperative MRI in defining postoperative prostate bed CTV. Twenty prostate cancer pts at The Ottawa Hospital receiving post-op XRT who also had pre-op staging MRI were identified. Pts underwent CT Simulation and the 4 CTV consensus definitions were applied. CTVs were expanded by 1 cm to create respective Planning Target Volumes (PTVs). Pre-op MRIs were fused with the post-op planning CT scans. MRI based prostate and gross visible tumor were contoured. 3DCRT plans were developed and Dose Volume Histograms (DVH) analyzed. Subtraction analysis was conducted to assess the adequacy of prostate and gross tumor coverage. Mean pre-op prostate volume was 45cc (range, 25-79 cc) and gross tumor was visible in 17 cases. In all 20 cases, the consensus CTVs did not fully cover the pre-resection extent of the prostate seen on the MRI. On average, 38% of the prostate volume was missed by the CTVs (mean and range, CTV-RTOG 29% [5-65%], CTV-PMH 27% [4-61%], CTV-FROGG 43% [17-67%], CTV-EORTC 52% [23-77%]). In only 1 case, the entire gross tumor was completely covered. On average, 41% of the visible gross tumor volume was missed (mean and range: CTV-RTOG 35% [0-67%], CTV-PMH 33% [0-64%], CTV-FROGG 48% [18-92%], and CTV-EORTC 46% [9-88%]). Furthermore, the PTVs did not cover the prostate in 50% of cases. On average, 7% of the prostate volume was missed by PTVs (mean and range: PTV-RTOG 3% [0-13%], PTV-PMH 3% [0-13%], PTV-FROGG 8% [0-27%], PTV-EORTC 14% [0-36%]).The prostate base and mid-zones were the predominant site of inadequate coverage. CTV-PMH and CTV-RTOG were similar with respect to prostate and tumor coverage and yielded the best overall results. CTV-EORTC provided the least overall coverage. Data on anatomic shifts of bladder and rectum associated with radical prostatectomy will also be presented. Current CTV consensus definitions do not adequately cover the prostate bed and/or gross tumor based on pre-op MRI. Additionally, the PTVs do not fully cover the prostate bed in 50% of cases. CTV definitions should be modified to incorporate pre-op imaging. Improved CTV definition should result in further increases in survival for high risk prostate cancer.

Adjuvant radiotherapy following total mesorectal excision for stage IIA rectal cancer: is it beneficial?

The benefit of adjuvant radiotherapy in patients with stage IIA (T3N0) rectal cancer following total mesorectal excision (TME) is controversial. We evaluated the effect of adjuvant chemoradiotherapy (CRT) versus chemotherapy (CT) alone on the local recurrence and survival of patients with stage IIA rectal cancer after TME. Between 1996 and 2004, patients with stage IIA rectal cancer who received adjuvant CT (n = 29) or CRT (n = 122) following TME were enrolled. Oncologic outcomes were compared between groups, and risk factors for local recurrence and overall survival rates were analyzed. The median follow-up period was 78 months. No significant differences were observed in the 5-year local recurrence (3.4% versus 9.0%; P = 0.348) or 5-year overall survival rates (86.2% versus 80.3%; P = 0.924) between CT and CRT. However, involvement of the circumferential resection margin and age >60 years were associated with adverse oncologic outcomes. Additional postoperative radiotherapy did not alter local recurrence or survival after TME in patients with stage IIA rectal cancer. Postoperative radiation may be an overtreatment as an adjuvant therapy in patients with stage IIA rectal cancer if they had no other risk factors. However, randomized controlled trials are warranted to confirm this suggestion.

A national propensity‐adjusted analysis of adjuvant radiotherapy in the treatment of resected pancreatic adenocarcinoma

The benefit of adjuvant radiotherapy (RT) for resected pancreatic adenocarcinoma remains controversial after randomized clinical trials. In this national-level US study, a propensity score (conditional probability of receiving RT) was used to adjust for potential confounding in nonrandomized designs from treatment group differences. Patients were identified from the Surveillance, Epidemiology, and End Results (SEER) registry (1988-2005 dataset). Multivariate analyses to determine the effect of RT on overall survival were performed using propensity-adjusted Cox proportional hazards and Kaplan-Meier analyses. In total, 5676 patients with resected pancreatic adenocarcinoma were identified, and 40.8% of those patients had received adjuvant RT. Univariate predictors of survival included age, race, marital status, disease stage, tumor size, tumor extension, tumor grade, lymph node status, year of diagnosis, type of resection, and receipt of RT (all P < .002). In a Cox model, independent predictors of improved survival included white race, married status, earlier stage, smaller tumors, well differentiated tumors, negative lymph node (N0) status, recent diagnosis, and receipt of RT (all P < .05). In a propensity-adjusted proportional hazards regression, the benefit of adjuvant treatment that included RT remained significant after adjusting for the likelihood of receiving RT (hazard ratio, 0.773; 95% confidence interval, 0.714-0.836; P < .0001). Within all 5 propensity strata, Kaplan-Meier survival differed significantly (P < .0001 [lowest and highest probability strata] and P = .0165 [middle stratum with a "pseudorandom" probability of RT]). Adjuvant RT for resected pancreatic adenocarcinoma was associated with a significant survival advantage in a large national database, even after using propensity score methods to adjust for differences between treatment groups. The authors concluded that adjuvant RT should be considered for all appropriate patients who have resected pancreatic adenocarcinoma.

The benefits of adjuvant radiation therapy after therapeutic lymphadenectomy for clinically advanced, high‐risk, lymph node‐metastatic melanoma

The objective of this study was to evaluate the impact of adjuvant radiation therapy (RT) on regional recurrence and survival after therapeutic lymphadenectomy (TL) for clinically advanced, lymph node-metastatic melanoma. Six hundred fifteen patients who had clinically advanced, regional lymph node-metastatic disease underwent TL. All patients were appropriate potential candidates for adjuvant RT (enlarged or multiple positive lymph nodes, extracapsular extension) because of a high risk for regional recurrence regardless of whether or not they received RT. Patient-related, tumor-related, and treatment-related variables that were associated with recurrence, survival, and treatment-related morbidity with and without RT were analyzed. The median follow-up was 5 years. The actuarial 5-year regional lymph node basin control rate was 81%. On multivariate analysis, the number of positive lymph nodes, the number of lymph nodes removed, and the use of adjuvant RT were associated with improved regional control. Treatment-related morbidity, particularly lymphedema, was increased with the use of adjuvant RT and an inguinal site of lymph node metastases. At last follow-up, 268 patients were alive with actuarial 5-year distant metastasis-free survival (DMFS) and disease-specific survival (DSS) rates of 40% and 48%, respectively. On multivariate analysis, DMFS and DSS both were influenced by the number of positive lymph nodes and the number of lymph nodes removed. In addition, DSS was influenced by primary tumor thickness and the receipt of adjuvant RT. Adjuvant RT was associated with improved regional lymph node basin control compared with TL alone in patients with high-risk, clinically advanced, lymph node-metastatic melanoma. Although it is a regional therapy, adjuvant RT also may have an impact on DSS.

A study of meningiomas in South Africa: Investigating a correlation between clinical presentation, histopathology and genetic markers

Objective. To determine whether there are certain genetic markers which correlate with particular clinical characteristics of meningiomas including multiplicity, recurrence and calvarial erosion.Methods. Thirty-eight South African-born patients with meningiomas were recruited for this study. At surgery, blood and tumour specimens were obtained for histopathological, cytogenetic and molecular analysis. Loss of heterozygosity (LOH) on chromosomes 1p and 22q were investigated and the NF2 gene on 22q12.2 was screened for disease-causing mutations.Results. The commonest tumour locations were convexity (25%) and parasagittal (21%). The histology results showed that 86.8% of the patients had Grade I tumours and the remainder had Grade II tumours. A pathogenic nonsense mutation, R341X in the NF2 gene was found in only one patient. LOH on each of chromosomes 1p and 22q was observed in 44.7% of patients, but in different individuals. Significant associations were found between having specific tumour characteristics and both male gender (p-value = 0.0059) and 22q LOH (p-value = 0.0425). We estimated that having 22q LOH makes an individual approximately four times more likely to develop a tumour that exhibits multiplicity, recurrence or calvarial erosion (OR = 4.8; 95% CI: 1.2–23.4). Adjusting for gender strengthened this effect (OR = 6.1; 95% CI: 1.1–48.7).Conclusions. Our data indicate that male patients and patients with a meningioma that has 22q LOH are more likely to develop tumours exhibiting multiplicity, recurrence or calvarial erosion. We recommend that this subset of patients should be followed up more closely. Further study is needed to determine the benefit of adjuvant radiation therapy in this scenario.

Determining the survival benefit of adjuvant radiotherapy in patients with node-positive head and neck cancer

Whether postoperative radiotherapy improves survival compared with surgery alone in patients with head and neck cancer remains unclear. This Practice Point commentary discusses the findings of a study by Kao et al. who used the Surveillance, Epidemiology, and End Results database to look for evidence of improved overall survival in patients with node-positive head and neck cancer. The analysis included 5,297 eligible patients who were treated with first-line surgery, of whom 4,307 (81%) received adjuvant radiotherapy. On multivariate analysis, adjuvant radiotherapy, age, primary tumor site, tumor and nodal stage were significant predictors of overall survival. While these results show an association between the use of adjuvant radiotherapy and improved overall survival in a selected group of patients, several aspects of the study limit its interpretation. Whether there is a causal relationship between postoperative radiotherapy and the observed overall survival benefit remains undetermined.

PT3R1-Prostatakarzinom

Approximately 50-60% of patients with tumor stage pT3R1 after radical prostatectomy (RP) who do not receive adjuvant therapy develop biochemical progression. At present it is unclear whether these patients should undergo immediate adjuvant irradiation or whether a wait and see approach should be adopted while monitoring PSA until the PSA level rises from zero and then initiate salvage radiotherapy (SRT).Three randomized trials showed that an absolute improvement of 20% in the 5-year biochemical no evidence of disease (bNED) could be achieved by administering adjuvant radiotherapy with 60 Gy in patients with tumor stage pT3R1, even with a PSA level around zero after RP. The rate of serious late effects is low. On the other hand, there are numerous, albeit retrospective studies, which provide evidence that SRT after an increase in PSA above zero is an effective treatment, but with higher total doses of 66-70 Gy and a higher rate of late effects. Prognostic factors such as the PSA level before radiotherapy is started, PSA doubling time, R1 resection, PSA velocity, and the Gleason score have a significant impact on both the return of the PSA level to zero and the bNED. Depending on the risk factor, between 20 and 70% of patients again achieve PSA levels around zero after SRT. Retrospective comparative studies suggest a benefit of adjuvant radiotherapy; prospective randomized trials do not exist.Adjuvant radiotherapy after RP in stage pT3R1 tumor and SRT in cases of PSA rising above zero or persistent PSA levels are valid options for the management of high-risk patients after RP. SRT requires higher total doses and thus carries a higher risk of late complications. A benefit has been demonstrated for bNED, but not for survival. The approach should be discussed with the individual patient.

Carcinoma of the Ampulla of Vater: Patterns of Failure after Resection and Possible Benefit of Adjuvant Radiotherapy

Carcinoma of the Ampulla of Vater: Patterns of Failure after Resection and Possible Benefit of Adjuvant Radiotherapy

Stage-specific survival differences associated with postoperative radiotherapy for gastrointestinal cancers

15504 Background: The benefit of adjuvant radiotherapy (RT) for resected gastrointestinal (GI) cancers remains controversial. This study evaluates the frequency and effect of postoperative RT in pa...

Adjuvant intraoperative electron radiotherapy and external beam radiotherapy for locally advanced transitional cell carcinoma of the ureter

Objective Surgery is the mainstay treatment for transitional cell carcinoma (TCC) of the ureter; however, local recurrence remains a common cause of treatment failure for locally advanced disease after surgery, and the benefit of adjuvant radiotherapy has not been completely determined. The objective of this analysis was to evaluate the outcome of postsurgical high dose radiotherapy consisting of intraoperative electron beam radiotherapy (IOERT) and external beam radiotherapy (EBRT) in locally advanced transitional cell carcinoma of the ureter. Methods Seventeen patients with pathologically diagnosed TCC of ureter were treated with nephroureterectomy and adjuvant radiation consisted of IOERT and EBRT according to an institutional research protocol. The dose of IOERT ranged between 10 to 20 Gy (median 14 Gy). Conventional EBRT given with the total dose ranged between 36 and 45 Gy (median 42 Gy). Chemotherapy was utilized in 10 of the 17 patients at the discretion of their primary oncologist. Results The median follow-up for all patients was 48 months (range, 10–91 months). The overall survivals of the entire group of patients at 1, 3, and 5 years were 82%, 65%, and 46%, respectively. The estimated locoregional control rates at 1, 3, and 5 year were 82%, 64%, and 51%, respectively. Depth of invasion (pT), histological grade, and presence of residual disease were significant prognostic factors in univariate analysis. Multivariate analysis revealed that independent prognostic factors for survival included histological grade (grade 1 + 2 vs. grade 3 + 4; P = 0.03) and presence of residual disease after surgery (R0 vs. R1 or R2 resection; P = 0.053). Acute and long-term adverse effects rated grade 3 or higher were seen in 4 and 2 patients, respectively. No grade 5 toxicity occurred. Conclusion IOERT and EBRT following surgery produced a 51% local control and 46% overall survival rate for locally advanced TCC of ureter at 5 years of follow-up, with acceptable rates of acute and late toxicity. Adjuvant IOERT appears to permit dose escalation safely in patients who received conventional adjuvant EBRT and chemotherapy. This strategy deserves to be optimized and then tested in a prospective trial to learn if it can further improve outcome.

The impact of adjuvant radiation therapy on survival in women with uterine carcinosarcoma

Background and purpose Uterine carcinosarcoma is an aggressive neoplasm and the benefit of adjuvant radiation therapy (RT) is unclear. This retrospective study analyzes the influence of RT on survival using a large population database. Materials and methods Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) program of the US National Cancer Institute. Women with uterine carcinosarcoma who underwent primary surgery were eligible. Survival rates and multivariate analyses were performed by standard methods. Results Of the 2461 women in the analysis, 890 received adjuvant RT. Five-year rates of overall survival were 41.5% and 33.2% ( P < 0.001) and uterine-specific survival were 56.0% and 50.8% ( P = 0.005), for women receiving RT compared to those who did not. Women with stages I–III disease experienced a benefit in overall survival (HR 0.87, P = 0.03) while women with stage IV disease experienced benefits in overall (HR 0.63, P < 0.001) and uterine-specific survival (HR 0.63, P = 0.004) with RT. Conclusions RT predicted for improved overall and disease specific survival in women with uterine carcinosarcoma within the SEER database. The benefit in disease specific survival was restricted to stage IV disease. These benefits may indicate a role for adjuvant RT in future prospective trials in the treatment of uterine carcinosarcoma.