Hip fractures and pain following proton therapy for management of prostate cancer.
BACKGROUND
Proton therapy (PT) for prostate cancer reduces rectal and bladder dose, but increases dose to the femoral necks. We assessed the risk of hip fracture and pain in men treated with PT for prostate cancer.


METHODS
From 2006 to 2008, 382 men were treated for prostate cancer and evaluated at six-month intervals after PT for toxicities at University of Florida Proton Therapy Institute (UFPTI). The WHO Fracture Risk Assessment Tool (FRAX) generated annual hip-fracture risk for the cohort. The WHO FRAX tool was utilized to generate the expected number of patients with hip fractures and the observed-to-expected ratio; confidence intervals and p-value were generated with the mid-P exact test. Univariate analysis of hip pain as a function of several prognostic factors was accomplished with Fisher's exact test.


RESULTS
Median follow-up was four years (range, 0.1-5.5 years). Per FRAX, 3.02 patients were expected to develop a hip fracture without PT. Three PT patients actually developed fractures for a rate of 0.21 fractures per 100 person-years of follow-up. There was an observed-expected ratio of 0.99 (p-value not significant). Forty-eight patients (13%) reported new pain in the hip during follow-up; three required prescription analgesics.


CONCLUSIONS
PT for prostate cancer did not increase hip-fractures in the first four years after PT compared to expected rates in untreated men.
University of Florida Proton Therapy Institute, University of Florida College of Medicine, Jacksonville, Florida 32206, USA.
Raul
R
Valery
Nancy P
NP
Mendenhall
Romaine C
RC
Nichols
Randal
R
Henderson
Christopher G
CG
Morris
Zhong
Z
Su
William M
WM
Mendenhall
Christopher R
CR
Williams
Zuofeng
Z
Li
Bradford S
BS
Hoppe
D000230:Adenocarcinoma / Q000453:epidemiology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017321:Clinical Trials, Phase I as Topic / Q000706:statistics & numerical data; D017322:Clinical Trials, Phase II as Topic / Q000706:statistics & numerical data; D006620:Hip Fractures / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology*; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000532:radiotherapy*; D061766:Proton Therapy / Q000009:adverse effects* / Q000706:statistics & numerical data; D011832:Radiation Injuries / Q000453:epidemiology*; D011879:Radiotherapy Dosage