Pelvic insufficiency fractures in postmenopausal woman with advanced cervical cancer treated by radiotherapy.
OBJECTIVE
To assess the predisposing factors and clinical characteristics of pelvic insufficiency fractures (PIF) in postmenopausal women with pelvic irradiation.


METHODS
A total 335 postmenopausal patients with cervical cancer of the intact uterus treated with radiation therapy between 1983 and 1998 were reviewed. Total external dose was delivered between 45 and 50.4 Gy with parallel opposed anteroposterior portals. Total brachytherapy dose at point A was delivered between 10 and 36 Gy. PIF were diagnosed by bone scintigraphy and confirmed by computed tomography. The cumulative incidence of symptomatic PIF was estimated by actuarial methods. Potential risk factors (age, weight, type II diabetes, delivery, menopause, total external dose, total brachytherapy dose) were assessed.


RESULTS
Fifty-seven (17.0%) of 335 patients were diagnosed as having PIF. Forty-seven patients were symptomatic and ten were asymptomatic. Parameters carrying a significant association with PIF were body weight 49 kg or below (P=0.044) in stepwise logistic regression analysis. The cumulative incidence of symptomatic PIF at 5 years was 17.9% calculated by the Kaplan-Meier method. A body weight of 49 kg or below and more than three deliveries were identified as having a significant effect on symptomatic PIF in univariate analysis (P=0.021, P=0.003, log-rank test) and Cox life table regression analysis (P=0.038, P=0.013). Five patients required narcotic agents and eight patients required hospital admission.


CONCLUSIONS
We should consider reducing the dose contribution to the sacrum and sacroilac joints, without underdosing the tumor, especially in postmenopausal women with many deliveries or low body weight.
Ogino
Ichiro
I
Department of Radiology, School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Yokohama, Japan.
Okamoto
Naoyuki
N
Ono
Yoshimi
Y
Kitamura
Tatsuo
T
Nakayama
Hiroki
H
D000368:Aged; D000369:Aged, 80 and over; D001835:Body Weight; D005260:Female; D005598:Fractures, Spontaneous / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008875:Middle Aged; D016017:Odds Ratio; D010298:Parity; D010384:Pelvic Bones / Q000528:radiation effects*; D017698:Postmenopause; D011832:Radiation Injuries / Q000209:etiology; D011878:Radiotherapy / Q000009:adverse effects; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D012447:Sacrum / Q000528:radiation effects; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000532:radiotherapy*