The incidence and risk factors of pelvic insufficiency fracture in patients with cervical cancer after intensity-modulated radiotherapy

Abstract

Objective To analyze the incidence and risk factors of pelvic insufficiency fractures (PIF) in patients with cervical cancer who received pelvic intensity-modulated radiotherapy. Methods This study a retrospective review of all patients was performed with cervical cancer who received pelvic intensity-modulated radiotherapy at our institution from November 2013 to December 2015, and the incidence and risk factors of insufficiency fractures were analyzed. Results Among the 104 patients, 16(with a total of 31 lesions) were diagnosed with pelvic insufficiency fracture. The occurrence rate of pelvic insufficiency was 15.4%. Ten patients (62.5%) had multiple fractures and five patients (31%) complained of pain. All patients′ pain was relieved by rest or analgesic drugs. Insufficiency fractures were detected at a median of 6.5 months (range 1-16) from radiotherapy completion. The distribution of PIFs was followed: sacral had 16 cases (51.6%), sacroiliac joint had 7 cases (22.6%), iliac had 6 cases(19.4%), femoral head had 1 case (3.2%) and pubis had 1 case(3.2%). Univariate analysis and multiple analysis showed that postmenopausal status and low body weight (≤55 kg) were thought to be risk factors for PIF(P<0.05). Subgroup analysis also confirmed that postmenopausal status was a risk factor for PIF(P<0.05) in postoperative cervical cancer patients after pelvic intensity-modulated radiation therapy. Conclusions Cervical cancer patients with menopausal status and low body weight (≤55 kg) are at some risk for the development of PIF after pelvic intensity-modulated radiotherapy. Key words: Cervical cancer; Intensity modulated radiotherapy; Pelvic insufficiency fractures