Hip-related toxicity after prostate radiotherapy: Treatment related or coincidental?

To evaluate the incidence and predictors of hip toxicity postradiotherapy for localized prostate cancer.

4067 prostate cancer patients were treated with external beam radiotherapy (EBRT; n=2569; 63%) or brachytherapy with or without supplemental EBRT (n=1508; 27%). 43% (n=1738) were treated with neo-adjuvant and concurrent ADT and 57% (n=2329) with radiotherapy alone. Hip toxicity was defined as moderate or severe pain upon ambulation with or without the need for hip-revision surgery. Median follow-up was 7years (range, 3-21years).

One hundred twenty-one (2.7%) patients developed moderate-to-severe hip pain after radiotherapy affecting ambulation. Of these, 73 (60%) required hip replacement secondary to persistent hip pain. Among patients with baseline degenerative joint disease (DJD) changes on scans, 10-year incidence of hip-related toxicity was 11% versus 3% for those without such changes (P<.001). The only variables on multivariate analysis associated with hip-related toxicity post-radiotherapy were baseline DJD on imaging (P<.0001) and prolonged ADT for salvage therapy (P<.0001).

Prostate EBRT or brachytherapy is associated with low incidence of long-term hip-related toxicity. The only variables identified associated with hip toxicity posttherapy was the presence of baseline DJD and prolonged salvage ADT posttreatment for patients developing recurrence.

Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. 2016 Oct 15 [Epub ahead of print]

Michael J Zelefsky, Marisa A Kollmeier, Elan Gorshein, Xin Pei, Marina Torres, Sean McBride, Laura Happersett, Gil'ad N Cohen, Yoshiya Yamada

Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, USA. Electronic address: ., Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, USA., Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, USA.