Alan McWilliam

Limitations and future directions in identifying risk factors for radiotherapy related pelvic insufficiency fractures in gynecological cancers: A scoping review

A systematic search of PubMed and EMBASE was conducted using terms such as "pelvic insufficiency fractures", "radiotherapy" and "gynecological cancers". Citations of relevant studies were also screened. Eligible studies included gynecolgical patients treated with pelvic RT, and reporting risk factors for RRIFs. Key data, including study characteristics, incidence rates, fracture definitions, imaging and dosimetry methods and statistical approaches were extracted. The Transparent Reporting of a multivariable prediction modelfor Individual Prognosis Or Diagnosis (TRIPOD) checklist was used to assess the methodological quality of the included studies. 28 studies met the inclusion criteria. RRIF incidence ranged from 1.7% to 37.4%. Commonly reported risk factors included advanced age, postmenopausal status, higher RT doses, low body weight, pre-existing osteoporosis, and concurrent chemotherapy. Imaging protocols, fracture definitions, and timing of detection varied widely. Statistical limitations, including reliance on univariable analyses, small sample sizes, and inconsistent baseline assessments, were common and limit reliable interpretation of risk factors. Anatomical targets for dose evaluation varied, with few studies correcting for biologically effective dose. Only one study developed a predictive model for RRIFs, which demonstrated moderate performance but lacked validation. Bone health assessments were inconsistently performed. Interdisciplinary approaches to improve fracture risk prediction, reduce treatment-related toxicity, and guide clinical decision-making.