[Palliative radiotherapy for bone pain in hormone refractory prostate cancer]

From 1970 to 1992, 23 patients were treated with irradiation for palliation of pain caused by bone metastases from hormone refractory adenocarcinoma of the prostate at Cancer Institute Hospital. External beam irradiation was delivered to painful bony metastatic sites using linear accelerator. Numbers of irradiated sites were 1, 2, 3 in 6 patients, 4 in 3 patients and 5 or 7 in one patient. To evaluate the pain relief at the irradiated sites, severity and frequency of pain were measured quantitatively before and 1 month after the treatment. Overall efficacy of palliation was evaluated by summing up results of the irradiated sites in each patient. Pain relief was obtained in all the irradiated sites. Minimal relief, partial relief and complete relief of pain were achieved in 10%, 15% and 75% of the 60 irradiated sites, respectively. No significant dose-response relationship was observed. Complete pain relief was attained less frequently at the sites with severe and constant pain that those with moderate and intermittent pain. Minimal, partial and complete palliation of pain was attained in 9%, 17% and 74% of 23 patients, respectively. In patients with highly extensive bone metastases, many irradiated sites, or many irradiated bones, complete palliation was difficult to obtain. Recurrence of pain was observed in one site. In other 59 irradiated sites, pain relief lasted until patient's death or throughout the follow-up period (maximum 51 months, median 9 months). We concluded that external beam irradiation is an effective palliation therapy for pain of bone metastases from hormone refractory prostate cancer and will play a considerable role in the management of advanced disease.