The Efficacy of Involved-field Radiation Therapy for Residual or Locoregionally Recurrent Epithelial Ovarian Cancer After Definitive Treatment; Multi-institutional Clinical Trial

1. Title: The efficacy of involved-field radiation therapy for residual or locoregionally recurrent epithelial ovarian cancer after definitive treatment; Multi-institutional phase 2 clinical trial 2. Study period: 2014.04~2018.04 3. Objective: To determine whether involved-field radiation therapy will prove to be improve 2-year progression free survival for residual or locoregionally recurrent epithelial ovarian cancer patients after definitive treatment. 4. Patient Selection: primary epithelial ovarian cancer (Required sample size: 70) 5. Planned number of patients

* YUHS database have 149 FIGO stage III patients treated with debulking surgery and adjuvant platinum-based chemotherapy 2. * Of these patients, 90 patients experienced locoregional failures, and then the investigators selected 44 patients who could be treated effectively with IFRT based on MDACC suggestion. * Median interval to failure was 9 months in these patients

* Hypothesis; IFRT reduces 44% hazard of progression compared with patients without IFRT * Sample size; two-sided, accrual time = 24 mo, f/u time= 36 mo. α= 0.05, power = 0.80 Null progression-free median survival = 9 mo Alt progression-free median survival = 16 mo Calculated sample number = total 27 patients Drop rate = 10% • Total sample number = 30 patients Estimated Enrollment : 30 participants

Drop rate = 10%

* Total sample number = 70 patients 6. Radiation therapy: Participants will receive involved-field radiotherapy (external beam radiotherapy or brachytherapy) over 45Gy with 1.8-2.0 Gy fraction, five times per week for residual or locoregionally recurrent epithelial ovarian cancer after definitive treatment * Target volume

* directed to gross disease plus a high-risk clinical target volume (CTV) that included the postoperative bed or the prechemotherapy extent of disease with a 1- to 1.5-cm margin, excluding uninvolved clinical structures * Additional CTVs were designated according to the risks of microscopic disease spread, proximity to critical structures, and other risk factors for complications. * Nodal CTVs included grossly involved lymph node sites, extending to cover adjacent uninvolved regions. * Modality; 3-dimensional conformal RT including electron, intensity-modulated RT, proton beam RT 7. Patient assessment: Participants will be followed at 1, 3, 6, 12, 18 and 24 month after radiation therapy 8. Key words: ovarian cancer, involved-field radiation therapy, progression free survival