A Case of Significant Fibrosis in Irradiation Field After Salvage Radiation Therapy for Postprostatectomy Biochemical Recurrence

An 80-year-old man received salvage radiation therapy for prostate-specific antigen recurrence of prostate cancer after prostatectomy. Urinary retention and edema of both legs developed 1 year and 3 months after initiation of radiation therapy. Imaging showed significant fibrosis in the radiation field. Histological findings were characteristic of ischemic changes, but not retroperitoneal fibrosis or fibrosarcoma. Development of significant fibrosis with accompanying symptoms after postoperative radiation therapy is rare in prostate cancer. The patient’s history of heavy smoking and arteriosclerotic diseases ( e.g., cerebral infarction and carotid artery stenosis ), in addition to an elevated D-dimer level confirmed by blood test, suggested the presence of underlying advanced vascular endothelial disorders and microvascular circulatory disorders. Significant fibrosis was likely caused by the patient’s underlying condition in addition to surgery and extensive radiation to the pelvis.