ESTRO 38 Abstract book

S1183 ESTRO 38

squamous cell carcinoma and 15 (37.5%) had an adenocarcinoma. Eight patients (20%) had LVI, eight (20%) had a tumor size more than 3 cm and one (2.5%) had close resection margins (<2mm). Median follow-up time was 39.5 months. A total of four patients experienced tumor relapse (10%), all in the peritoneal cavity, associated with synchronous external iliac lymph node in one patient. No patient had vaginal relapse and no isolated pelvic nodal failure was reported. The median overall survival time was 42 months. The Kaplan-Meier estimated five-year probability of survival was 84% (CI95%:68%-100%). In univariate analysis, probability of relapse was significantly higher in patients with tumor size > 3cm (p=0.004). Presence of LVI, margin distance, or histology (adenocarcinoma versus squamous cell) was not significant. No toxicity more than grade 1 was reported. During their follow-up, five patients (12.5%) presented telangiectasia grade 1, 2 (5%) had vaginal stenosis grade 1, 2 (5%) had vaginal bleeding grade 1, 1 (2.5%) had vaginal dryness grade 1. One patient had rectal bleeding and two had urinary toxicity. No bowel morbidity was reported. Conclusion This study suggests that adjuvant BT is an appropriate option for decreasing vaginal relapses in selected patients with pT1b pN0 cervical cancer with one or two of the following risk factors: size > 2cm and LVI. EP-2140 HDR Brachytherapy in Reirradiation of Local Nasopharyngeal Recurrence M. Ait Erraisse 1 , W. Hassani 1 , T. Bouhafa 1 , K. Hassouni 1 1 CHU Hassan II, Radiothérapie, Fez, Morocco Purpose or Objective pharyngeal carcinoma (NPC) is a most cancer of head and neck in North Africa and South East Asia. Reirradiation of loca recuurence is limited by the dose constraints. Brachytherapy alone or in combination with EBRT can be a good compromise. The aim of this study was to determine the role of brachytherapy in safety reirradiation of recurrent NPC. Material and Methods This is a retrospective study of 8 patients with nasopharyngeal cancer recurrence collected in the radiotherapy department of the University hospital Hassan II in Fez between January 2014 and December 2017. Results The average age of our patients is 42 years old. the average time to onset of relapse is 29 months. All patients received external radiation therapy at 70 Gy on macroscopic tumor volume (tumor and lymphadenopathy) during initial irradiation with or without chemotherapy. relapse was localized in 5 patients and associated with lymph node involvement in 3 patients. 2 patients received exclusive high-dose rate brachytherapy and 6 received external radiation radiotherapy followed by brachytherapy. The total radiation dose EQD2 was 60 to 66 Gy. With an average follow-up of 20 months, 37.5% of patients are alive and in complete remission. Conclusion Brachytherapy alone or after EBRT could play an important role in reirradiation of locally recurrent NPC with acceptable toxicity. Electronic Poster: Brachytherapy: Head and neck

proportions and Kaplan Meier for survival analysis and log- rank for curve comparison. Toxicity was evaluated according to CTCAE v.4.0 criteria. Results After a median follow-up of 30 months, 3-year overall survival (OS), 3-year disease-free survival (DFS) and 3-year local relapse-free survival (LRFS) were 83.7%, 58% and 84.2%, respectively. The mean D 2cc in rectum and bladder were: 66.2Gy (47.8-87.9) and 76.3Gy (54.9-96), respectively. Rectal morbidity (diarrhea, proctitis and/or bleeding), was observed in 22p: G1: 13p (20%) and G2-3: 9p (14%). One patient presented with sigmoid perforation. Two-year G2-3 rectal toxicity-free survival (RTFS) and G2- 3 rectal bleeding-free survival (RBFS) were 82.6% and 84.2%, respectively. In relation to dosimetric parameters, there were more rectal toxicity in patients with D 2cc >65Gy, although differences were not significatives (2y G2-3 RTFS of 65% vs 93%). A D 2cc >65Gy was associated with more incidence of G2-3 proctitis (0% vs 100%, p 0.05). Urinary morbidity (urgency, incontinence, cystitis and/or hematuria) was observed in 17p (G2-3 cystitis: 2p and G2- 3 hematuria: 6p). Two-year G2-3 hematuria-free survival was 91%. The probability of G2-3 hematuria was not related with D 2cc >80Gy. G2-3 vaginal stenosis was observed in 25p (39.6%). Sacrum fracture was observed in 12p (19%). Two-year sacrum fracture-free survival was 84%. Conclusion Rectal complications remain as the main toxicity in modern brachytherapy. Efforts should be made to maintain rectal D 2cc below 65 Gy. Based in our results , early evaluation and intervention are recommended to detect and prevent sacral fractures. EP-2139 Adjuvant brachytherapy for T1b1N0 cervical cancer: an alternative to postoperative EBRT E. Bronsart 1 , C. Petit 1 , I. Fumagalli 1 , S. Gouy 2 , P. Morice 2 , C. Haie-Meder 1 , C. Chargari 1 1 Gustave Roussy, Radiation oncology, Paris, France; 2 Gustave Roussy, Gynecologic Surgery, Paris, France Purpose or Objective Generally the treatment in early stage cervical cancer is upfront surgery. An adjuvant external bream radiation therapy (EBRT) is delivered according to histopathological risk factors (lymph node involvement, lymphovascular invasion, tumor > 4cm, deep stroma invasion, positive surgical margins, parametrial spread). In a Gynecologic Oncology Group (GOG) study, adjuvant EBRT was shown to reduce the risk of locoregional relapse by 46%, at the expanse of an increase in severe morbidities. 1 We report our institutional experience of adjuvant vaginal wall brachytherapy as an alternative to EBRT in selected patient treated with upfront surgery for pT1b1N0 tumors. Material and Methods Medical records of consecutive patients treated for an early stage cervical by upfront radical colpohysterectomy and pelvic lymph node dissection for a pT1bN0 cervical cancer between 1991 and 2018 were examined. Patients were proposed adjuvant vaginal wall brachytherapy because of the following risk factors: tumor size >= 2cm and/or lymphovascular involvement. Patients with parametrial spread, positive margins, or with nodal metastases were excluded and received adjuvant EBRT. Patients received a dose of 60 Gy and the dose was prescribed at 5 mm depth from the vaginal wall and the upper third of vagina was included in the target volume. The vaginal mould technique was used in all cases. Organ at risk point doses or dose/volume parameters followed ICRU dose constraints guidelines. Patients were followed clinically and toxicities were scored according to CTCAEv3. Results 40 patients were included, mean age 50.3 years (range: 28.8-80.6 years). A total of 25 patients (62,5%) had a

Electronic Poster: Brachytherapy: Physics

EP-2141 Recommendations for reporting the rectal dose during image guided HDR brachytherapy of prostate