Radiation-Induced Insufficiency Fractures After Pelvic Irradiation for Gynecologic Malignancies: A Systematic Review.

PURPOSE

To identify and define the incidence, risk factors, clinical characteristics, and treatment approaches to pelvic insufficiency fractures (PIFs) that develop as a consequence of pelvic radiation therapy for gynecologic malignancies.

MATERIALS AND METHODS

A systematic literature review (PubMed and Embase indexed from January 1, 1980, to May 1, 2020) of studies describing PIFs that result from radiation therapy for gynecologic malignancies. A random-effects model weighted by the inverse variance was used to calculate the pooled crude incidence, actuarial incidence, and proportion of symptomatic PIFs, and to evaluate the relationship between PIF incidence and various risk factors.

RESULTS

Thirty-eight studies describing PIFs following radiation therapy for gynecologic malignancies were reviewed. A meta-analysis of 6488 patients (37 studies) identified the crude incidence of PIF as 9.4% (95% confidence interval [CI] 6.8%-12.4%), and a meta-analysis of 2131 patients (9 studies) identified the 5-year actuarial incidence of PIF as 15.3% (95% CI 7.5%-25.0%). Factors that significantly correlated with increased risk of PIF development included evidence of osteoporosis (P < .001), postmenopausal state (P < .001), and history of diabetes mellitus (P = .005). Median time to PIF development ranged from 8 to 39 months after radiation therapy with the sacrum being the most frequent location for fracture development (60%). From 18 studies, 58.5% (95% CI 50.6%-66.2%) of PIFs were symptomatic, with pain as the most common presenting symptom of PIFs. Conservative management was used more than bone-directed therapies for treatment of PIFs (85% and 6% of patients, respectively).

CONCLUSIONS

PIFs cause significant morbidity in gynecologic cancer patients after radiation therapy. In this systematic review, we discuss the incidence and risk factors associated with PIF development as it relates to the different detection methods, radiation techniques, doses, and gynecologic cancers treated. Additional studies are needed to further define prevention and treatment approaches for insufficiency fractures.