ESTRO 36 Abstract Book

S375 ESTRO 36 _______________________________________________________________________________________________

Conclusion The ΔADC and %ADC values may be useful for predicting the prognosis of patients with stage IIIB cervical cancer treated with CCRT. Furthermore, the %ADC value of <30% may be an important factor for selecting a stronger treatment strategy in patients receiving radiotherapy after mid-treatment MRI. PO-0714 Toxicity and Clinical Outcome of IMRT versus Conventional Radiation Therapy for Endometrial Cancer L. Vaalavirta 1 , S. Larjavaara 1 , P. Arponen-Esteves 1 , A. Leminen 2 , J. Collan 1 , M. Harrela 1 , M. Kouri 1 , M. Tenhunen 1 , H. Joensuu 3 1 Comprehensive Cancer Center- Helsinki University Hospital, Deparment of Radiation Oncology, Helsinki, Finland 2 Helsinki University Hospital and University of Helsinki, Department of Gynaecologic Oncology, Helsinki, Finland 3 Comprehensive Cancer Center- Helsinki University Hospital, University of Helsinki, Helsinki, Finland Purpose or Objective To evaluate toxicity as primary objective and clinical outcome as secondary objective in patients with endometrial cancer (EC) treated with whole pelvic intensity modulated radiation therapy (IMRT) versus whole pelvic conventional radiation therapy (CRT). Material and Methods Between 9/2005 and 6/2008 40 eligible patients with EC were stratified according to stage into two groups: (stage I-II and stage III-IV) and then randomly assigned to receive adjuvant IMRT (n=20) or CRT (n=20).The treatment consisted of 50.4 Gy at 28 fractions. A self-administered symptom scale questionnaire (based on the Common Toxicity Criteria (CTC) v3.0), was being used for patient- reported symptoms with different entities for gastrointestinal (GI), gynecological and urological (GU) symptoms. The questionnaire was filled by the patients prior and after RT course, and at 3, 6, 9, 12, 16, 20, 24, 30, 36, 48 and finally at 60 months after RT. In addition, a physician-reported toxicity questionnaire (based on CTCv3.0) was collected in the beginning, at end of RT, as well as at 3 and 6 months after RT. When evaluating the differences in physician-reported toxicity between the two arms, Fisher’s exact test was being used. Hazard ratios (HRs) were estimated for relapse-free survival (RFS) and EC-specific mortality for CRT arm relative to the IMRT arm using Cox proportional hazard model. All statistical analyses were performed using Stata software version 14.2(StataCorp). Results The most noticeable differences between the two study arms were seen for urological symptoms at the end of the given RT, for GI symptoms at 12 months and for gynecological symptoms at 12 months, even though seen throughout the 60-month study period. However the differences remained moderate: patient-reported mean score for urological symptoms at the end of RT was 4.8 (95% CI, 3.0-6.6) with CRT and 2.8 (95% CI, 1.3-4.2) for IMRT, p=0.067; for GI symptoms 1.5 (95% CI, -0.16-3.3) for CRT and 0.4 (95% CI, -0.0080-0.81) for IMRT, p = 0.110 at 12 months; and for gynecological symptoms 1.5 (95% CI, 0.68-2.4) for CRT and 0.2 (95% CI, -0.11-0.51) for IMRT, p=0.0014 at 12 months. Based on the physician-reported toxicity, grade ≥2 symptoms were further divided into urological, GI and other symptoms. The differences between study groups remained statistically insignificant, even after pooling all the grade ≥2 symptoms together at each reported time. No pelvic in-field relapses were seen in either study arms in a median follow up of 9.1 years. At 9 years there was no statistically significant difference in the cancer- specific mortality between the CRT and IMRT arms. HR in favor of the IMRT was 0.50 (95% CI, 0.14-1.70), p=0.253. No statistically significant difference was found in RFS at

9 years between the study arms. HR in favor of the IMRT was 0.72 (95% CI, 0.24-2.14), p=0.551. Conclusion IMRT reduces patient reported GI and GU toxicity. Survival outcomes at 9 years were not statistically different between study arms. PO-0715 A phase II study of chemoradiation with tri- weekly cycles of nedaplatin for uterine cervical cancer. K. Okuma 1 , H. Yamashita 1 , R. Kobayashi 2 , K. Nakagawa 1 1 University of Tokyo Hospital, Radiology, Tokyo, Japan 2 NTT Medical Center Tokyo, Radiology, Tokyo, Japan Purpose or Objective Chemoradiotherapy based on cisplatin is the standard treatment for locally advanced cervical cancer. Nedaplatin an analog of cisplatin, has been shown to have similar treatment effectiveness for several cancer to cisplatin with less nephrotoxicity, myelotoxicity and gastrointestinal toxicity. This study aimed to assess the acute complication with the maximal dose of nedaplatin for carcinoma of the uterine cervix when administered tri- weekly during pelvic radiotherapy. Material and Methods Nedaplatin, 100mg/m2, was administered on days 1, 22, and 43 with a concurrent external beam radiotherapy and intracavitary or intersititial brachytherapy. External beam radiotherapy was delivered with a fraction of 1.8-2 Gy per day for 5 days a week during 5-5.6 weeks and brachytherapy of 24 Gy/ 4 fractions at point A. The efficacy and toxicity of chemoradiotherapy with 100mg/m2 nadaplatin were evaluated. Results Thirty-four patients with uterine cervical cancer in FIGO stages IB1 to IVA were enrolled in this phase II trial from April 2011 through August 2016. The median follow-up period was 15 (range, 2-56) months. Of the 34 patients enrolled for the trial, only 1 (3%) had grade 4 leukopenia and neutropenia. 18 of 34 patients (53%) developed grade 3 treatment-related hematologic toxicities within 30 days. Without one patient who had to go hospital because of grade 3 diarrhea, there were no grade ≥3 treatment- related non-hematologic toxicities. Complete response was observed in 94% (32/34) of patients. The 2-year overall survival rate and 2-year progression-free survival rate were 96.7% (95% CI, 50-59%) and 73.5% (95% CI, 27- 45%), respectively. Conclusion Chemoradiotherapy with tri-weekly cycles of nedaplatin of 100 mg/m 2 was an effective and tolerable regimen in patients for uterine cervical cancer. PO-0716 Pelvic insufficiency fracture after IMRT for gynecologic or anal cancer L. Bazire 1 , H.P. Xu 1 , M. Amessis 1 , C. Malhaire 2 , K. Cao 1 , A. De La Rochefordière 1 , Y.M. Kirova 1 1 Institut Curie, Radiation Oncology, Paris, France 2 Institut Curie, Radiology, Paris, France Purpose or Objective To summarize results for pelvic insufficiency fracture (PIF) in patients with anal or gynecological cancer treated with pelvic intensity modulated radiation therapy (IMRT). Material and Methods The clinical and morphological (CT and / or pelvic MRI) characteristics of patients treated by IMRT at the Institut Curie, between 2007 and 2014 were analyzed. The overall incidence of pelvic fractures occurred after external beam radiation and the effects of localization (gynecological or anal cancer) were calculated. A retrospective delineation of the pelvic bones (iliac bones and sacrum) was conducted in patients who had a fracture and in 60 patients free of fracture after radiotherapy. Dosimetric study was then performed to compare the patients who had a fracture in patients without fracture.