Two Cases of Avascular Necrosis of the Femur Head after Whole Pelvic Radiation Therapy for the Treatment of Cervical Cancer

Avascular necrosis (AVN) is a disease characterized by the temporary or permanent loss of the blood supply to the bones, resulting from many possible causes, including radiation therapy. The femoral head is known to be the most common site of AVN. The authors encountered two cases of AVN of the femoral head among 557 patients with cervical cancer treated with whole pelvic radiation therapy at the Samsung Medical Center. AVN of the femoral head was presented with a sclerotic density change in a plain roentgenography and a decreased signal intensity lesion on the T1 and T2 weighted phases of a magnetic resonance image (MRI). Although it is a very rare complication after whole pelvic radiation therapy, AVN of the femoral head should be considered when characteristic imaging findings appear on follow-up examinations.