PORTEC-2 trial suggested that isolated brachytherapy (BT) is equivalent when compared to external beam radiotherapy for intermediate-high risk patients.
S494
International Journal of Radiation Oncology " Biology " Physics
PORTEC-2 trial suggested that isolated brachytherapy (BT) is equivalent when compared to external beam radiotherapy for intermediate-high risk patients. Moreover, BT was associated to less gastro-intestinal toxicity. Our aim was to analyze local failure (LF) and toxicity of BT for intermediate risk stage I endometrial cancer in a series of patients treated in a single institution. We also conduct a toxicity analysis. Materials/Methods: One hundred and twenty four patients treated between 2009 and 2013 were retrospectively analyzed. The intermediatehigh risk group (IHR) was defined by PORTEC-2 eligibility criteria. Seven patients were excluded because they were retrospectively considered high risk (n Z 6) or low risk (n Z 1). BT was delivered with cylinder (94%) or ovoids (6%). The total dose was 24Gy (4 x 6Gy), prescribed 5mm in depth. The ICRU38 bladder point dose was calculated. LF and survival were done by Kaplan-Meier and Log-rank test was used for subgroup analysis. Student t test compared de mean doses between the groups with and without urinary toxicity. The toxicity was graded according to Common Terminology Criteria for Adverse Events (CTCAE v4.0). Results: After a median follow up of 26 months, there were 2 vaginal failures (both at 18 month of follow-up) and 2 deaths not related to endometrial cancer. In a subgroup analysis, IHR did not increase the risk of LF, when compared to intermediate-low risk (p Z 0.869). The 3-years LF rate was 2.7%. Two patients (1.6%) developed grade 1 gastro-intestinal toxicity and 10 patients (8%) developed grades 1-2 urinary toxicity. The mean bladder point dose was 46.9% (11.25Gy) for the asymptomatic group and 49.8% (11.95Gy) for the symptomatic group (p Z 0.69). Three patients with urinary toxicities had urinary infection that required oral antibiotics, probably due the bladder catheterization. Conclusions: BT alone is an efficient adjuvant treatment for intermediate risk (high or low) stage I endometrial cancer. The 3-years local control, cancer specific and overall survivals were 97.3%, 100% and 97.1%, respectively. The favorable toxicity profile of the treatment (less than 10% G1-2 acute reactions), could not be previewed by the ICRU38 bladder evaluation point. Moreover, bladder catheterization may be responsible for 30% of the urinary toxicity, questioning the value of the ICRU 38 bladder point in this scenario. Author Disclosure: L. Sapienza: None. B.C. Almeida: None. A. Aiza: None. M.J. Chen: None. R.C. Fogaroli: None. A.C. Pellizzon: None. G. Baiocchi: None.
98.3% for D0.1cc D1cc and D2cc respectively. The corresponding figures for the bladder were 96.8%, 80.1% and 73.4% respectively. Obese patients were more frequently treated with large cylinders (p Z 0.037). BMI did not show any significant association with rectal doses on univariate linear regression analysis. BMI showed a significant association with all evaluated bladder dose metrics (D0.1cc, R2 Z 0.1338, p Z 0.044; D1cc, R2 Z 0.2065, p Z 0.0003; D2cc, R2 Z 0.2034, p Z 0.0003). BMI was not among the predictors on multiple linear regressions for rectal dose metrics. When the analysis was carried out for bladder dose metrics BMI took part in the models (D0.1cc, adj-R2 Z 0.1186, p Z 0.0044; D1cc, adj-R2 Z 0.2354, p Z 0.0002; D2cc, adj-R2 Z 0.3154; p Z 0.0001). Conclusions: BMI in our group of overweight and moderately obese patients was associated to lower bladder dose values and failed to be associated with rectal dose metrics. Considering the present results we could hypothesize that patients with WHO BMI class II and III can have a worse relationship than in the population described herein that should be demonstrated in other studies. The impact on late toxicity of these findings should be tested in clinical practice. Author Disclosure: S. Sabater: None. R. Berenguer: None. I. Andres: None. M. Sevillano: None. A. Rovirosa: None. E. Jimenez: None. A. Martos: None. M. Arenas: None.
2715 Body Mass Index and Doses at Organs at Risk Evaluated by CT in a Mediterranean Postoperative Vaginal Cuff Brachytherapy (VCB) Cancer Population S. Sabater,1 R. Berenguer,1 I. Andres,1 M. Sevillano,1 A. Rovirosa,2 E. Jimenez,1 A. Martos,1 and M. Arenas3; 1Complejo Hospitalario Universario de Albacete (CHUA), Albacete, Spain, 2Hospital Clinic Barcelona, Barcelo, Spain, 3Hospital Universitari Sant Joan, Reus, Spain Purpose/Objective(s): Body mass index (BMI) has been related with higher rectal doses on permanent prostate brachytherapy, but such data are lacking in postoperative VBT treatments. Our aim was to analyze the impact of BMI on the dose delivered to bladder and rectum during highdose-rate VCB using CT scans for planning treatment at every fraction. Materials/Methods: 220 CT sets derived from 59 patients treated with VCB were re-segmented and re-planned for this study purpose under the same parameters. Planning CTs were performed with a bladder Foley catheter. Rectum and bladder DVH values (D0.1cc, D1cc and D2cc) were extracted and evaluated as the percent dose prescribed to 5 mm. Variables studied were: cylinder diameter, cylinder angle placement related to the cranio-caudal patient axis, rectum and bladder volume and, BMI. The mean values of all applications per patient were calculated and correlated to BMI and WHO BMI categories. Univariate and stepwise multiple regression analysis were performed. Results: Patients underwent a mean of 3.7 fractions. Mean patient BMI 32.3 (!5.2). According to WHO class 6.8% of patients were normal, 35.6% overweight and, 57.6% obese class I. Mean cylinder angle was 3.9o (!6.3o) toward rectum. Mean rectal doses were 133.2%, 109.6% and
2716 Tolerability of Concurrent Chemotherapy and Vaginal Brachytherapy for Treatment of Early-Stage High-Grade Endometrial Cancer H. Nagar, D. Boothe, A. Parikh, M. Yondorf, B. Parashar, D. Gupta, K. Holcomb, T. Caputo, K. Chao, D. Nori, and A. Wernicke; New York Presbyterian Hospital/Weill Cornell Medical College, New York, NY Purpose/Objective(s): Evaluate tolerability and toxicity of concurrent chemotherapy and vaginal brachytherapy (VB) compared to the sequential approach for patients with early stage high grade endometrial cancer. Materials/Methods: A retrospective analysis of 102 surgically staged patients with endometrial cancer AJCC 2009 Stages IA-IB treated with adjuvant postoperative vaginal brachytherapy (VB) at our institution from 2001-2012 was conducted. All patients received VB + 6 cycles of adjuvant carboplatin and paclitaxel based chemotherapy. VB mean dose was 20.78 Gy (range, 20 - 21 Gy) with 3-4 weekly applications. Hematologic, gastrointestinal (GI), and genitourinary (GU) toxicities were assessed by Common Toxicity Criteria (CTC) and compared between sequential and concurrent chemotherapy and VB schedules. Results: Among patients that received VB and adjuvant chemotherapy, 62/ 102 patients (61%) received VB sandwiched between cycles 3 and 4 of chemotherapy. A separate group of 40 patients (39%) were treated with VB during the first 3 cycles of chemotherapy with a weekly application on non-chemotherapy days. Patients treated with VB during chemotherapy had a decreased overall treatment time by 4 weeks (p 0.05). CTC grade 3 or 4 hematologic, GI, and GU toxicities were zero. Conclusions: Vaginal brachytherapy during chemotherapy is well tolerated, decreases overall treatment time, and does not render more toxicity than the sequential regimen. Author Disclosure: H. Nagar: None. D. Boothe: None. A. Parikh: None. M. Yondorf: None. B. Parashar: None. D. Gupta: None. K. Holcomb: None. T. Caputo: None. K. Chao: None. D. Nori: None. A. Wernicke: None.
2717 Single-Institution Comparison of “Sandwich” Versus Sequential Adjuvant Chemotherapy and Radiation for Stage III Endometrioid Uterine Carcinoma S.M. Lu, C. Chang-Halpenny, E.C. White, and J. Hwang-Graziano; Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA
