Clinical analysis of conformal and intensity-modulated radiotherapy in patients with recurrent ovarian cancer

Abstract
We aimed to provide evidence for radiotherapy treatment regimens in patients with clinically recurrent ovarian cancer. We analyzed the survival and prognostic factors in 43 patients who were treated for recurrent ovarian cancer at 58 tumor sites using three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) during January 2006–December 2017. t years 1, 2, and 3, overall survival (OS) rate was 82.4%, 68.4%, and 57.9%; local control (LC) rate was 100%, 100% and 80%; recurrence free survival (RFS) rate was 86.8%, 66.6%, and 61.1%; and disease-free survival (DFS) rate was 79.7%, 56.7%, and 46.8%, respectively. The radiotherapy technique was determined to be an independent prognostic factor for survival; the survival rate of patients was significantly improved with IMRT compared to 3D-CRT (P = 0.035). Radiotherapy dose was an independent prognostic factor; survival rate improved when patients were treated with a radiation dose ≥ 60 Gy as compared to < 60 Gy (P = 0.046). Elective nodal prophylactic radiation therapy (ENRT) did not lead to a significant improvement in survival when compared to involved-field radiation therapy (IFRT). The toxicities of 3D-CRT and IMRT were tolerable. One patient (2.3%) had grade 3 acute gastrointestinal (GI) toxicity, 2 (4.6%) grade 3 late GI toxicity, 5 (11.6%) grade 3 hematological toxicity, and 2 (4.6%) had grade 4 hematological toxicity. IMRT improved LC and OS in patients with recurrent ovarian cancer after surgery and multiple chemotherapy; toxicities were tolerable. The IMRT technique and radiotherapy dose of ≥ 60 Gy had independent prognostic significance for the survival of such patients.