Abstract Book

S819

ESTRO 37

Material and Methods Patients affected by oligometastatic ovarian carcinoma of any histology were treated with SBRT. Toxicities were graded according to Common Terminology Criteria for Adverse Events version 4.0. Tumor response was evaluated by CT/ PET and/or MRI, according to Response Evaluation Criteria in Solid Tumors (version 1.1). Results Twenty-six patients with 44 metastatic lesions (lymph nodes 63.6%, liver 31.8% and lung 4.5%) treated with to SBRT between January 2011 and May 2017 were analyzed. Lymph-nodal lesions received a median total dose of 45 Gy (range 36-60); the median dose per fraction was 7.5 Gy (range,6-12) and the median number of fractions was 6 (range, 4-8). For hepatic lesions the median dose per fraction and number of fractions were 25 Gy (range,7.5- 25) and 3 fractions (range, 3-6), respectively and a median total dose of 75 Gy (range 45-75) was delivered. Both lung metastases were treated with 48 Gy in 4 fractions. Complete radiologic response, partial response, stable disease and progressive disease were observed in 26 (59.1%), 9 (20.5%), 6 (13.6%) and 3 cases (6.8%), respectively. An objective clinical response (CR+PR) was observed in 35 (79.6%). The overall clinical benefit (CR+PR+SD) was 93.2%. After a median follow-up period of 28.5 months (range 6-86), 17 patients (65.4%) were still alive at time of analysis: 6 are without evidence of disease, 11 experienced a disease progression. Eight patients died of disease, one died because of an heart attack while being without disease. The median LC was not reached. One year- two year- and 5year-LC were 92.9%. Median PFS was 19 months, with one year- PFS of 69.3% and 38% at two year, 19% at 5 years. Median OS was 64.5 months, with all patients alive after one year, 92.7% at two year, 61.7% at 5 years. Cox proportional hazard regression showed no significant impact of factors such as platinum sensitivity (p=0.78), number of lines of chemotherapy before SBRT (p=0.45), number of lesions treated (p=0.70) on local control. Five cases (11.3%) experienced G2 toxicity; most common adverse effect was nausea and vomiting (3 cases, 6.8%) followed by abdominal pain (2 cases, 4.5%). None of the patients had grade 3 /4 acute or late toxicity. No patients developed RILD, chest pain or rib fracture. Conclusion In conclusion, SBRT is a feasible and safe approach for selected cases of oligometastatic ovarian cancer, with satisfactory results in terms of LC and DFS. EP-1512 Radiotherapy at pelvis region in menopausal cervix cancer induce osteopenia/osteoporosis C. Klaitong 1 , E. Meannuch 1 , U. Kaewbunperm 1 , P. Klaiphibule 1 , T. Sinthusek 1 1 Maha Vajiralongkorn Thanyaburi Hospital, Radiotherapy, Pathumthani, Thailand Purpose or Objective Osteopenia and osteoporosis is the most common in women after menopause but may develop in other condition such as hormonal disorder, chronic disease or as a result of medications, specifically glucocorticoids. In premenopausal women who received radiotherapy at pelvic region for gynecologic cancer that induced early post menopause. There occur developed osteopenia and/or osteoporosis as same as postmenopausal women. This retrospective study is conducted to demonstrated radiotherapy at pelvic region in premenopausal female induce osteopenia and/or osteoporosis.

(and paraórtic if present). A boost of 50-60 Gy (Stage IIIB-IV) was given to PTV2: cervix, parametria and macroscopic lymph nodes (pelvic or paraortic), using simultaneous integrated boost (IMRT-SIB) technique. Image guidance was performed weekly with cone beam CT. The treatment was administrated in 25 fractions with IMRT, or in 32 fractions with 3DCRT. All patients were treated with intracavitary brachytherapy (BT) Higth Dose Rate (HDR), Fletcher System, and Computed Tomography (CT) planning. The Kaplan-Meier method was used to estimate recurrence-free survival (RFS) and overal survival (OS). The log-rank test and multivariable Cox proportional hazards modeling were used to evaluate the effect of technique and length of full treatment: RTC3D vs. IMRT and ≤55 days vs. > 55 days on RFS and OS. Results A total of 58 patients were included. Median age was 53 and 54% were stage IIIB/IV. 35% patients had pelvic and 10% had paraaortic metastases. All of the patients who had parametrial infiltration or lymph node metastases received escalated dose with 3DCRT or IMRT-SIB and CP more BT (median 4 fractions). 36(68%) patients were treated with RTC3D and 22(38%) with IMRT-SIB. The length of treatment was ≤55 days in 28(48%), of which 21(75%) were treated with IMRT-SIB, and was >55 days in 30(52%) of which 29(95%) were treated with 3DCRT. All patients had a RMN or PET-CT for response evaluation and were 52(89%) complete and 6(11%) partial response, of which 5 were surgically rescued. Local relapse was observed in 11(19%), and distant metastases in 5(8%) patients. With a median follow up of 21 months (12–68 months) estimated two, four and five year RFS and OS were 91,3%, 77,5% and 72,4%. %, and 89,5%, 77,5% and 70,6%. Among the 22 patients who were treated with IMRT-SIB, 3 of them received in field recurrence. None of the patients experienced ≥grade 3 toxicity. On multivariable analysis, the hazard ratio for technique of treatment was: 0.34, 95% confidence interval (CI) 0,04 e 2,84, P Z ,417. The hazard ratio for length treatment was 0,47, 95% CI 0,07 e 2,90, P Z 0,423. Conclusion IMRT-SIB combined with HDR brachytherapy and length of all treatment od ≤55 days for locally advanced cervical cancer seem to have a positive impact on overall survival. EP-1511 SBRT In Oligometastatic Ovarian Cancer: A Promising Therapeutic Approach C. Iftode 1 , A. Tozzi 1 , G.R. D'Agostino 1 , T. Comito 1 , D. Franceschini 1 , L. Di Brina 1 , E. Clerici 1 , G.A. Carta 1 , P. Mancosu 1 , M. Scorsetti 1 1 Istituto Clinico Humanitas, Radiotherapy and Radiosurgery, Rozzano Milan, Italy Purpose or Objective Ovarian cancer is the gynecological malignancy characterized by the worst prognosis for its tendency to metastasize despite aggressive systemic therapies. SBRT has been successfully used to treat oligometastases of several primary tumors, but few experiences have been described in patients with gynecological oligometastatic cancer, particularly in ovarian neoplasm. The aim of this study was to evaluate the role of this new radiotherapy modality in a series of oligometastatic ovarian cancer patients.