[186Re]HEDP in the palliation of painful bone metastases from cancers other than prostate and breast.

Aim. Palliative therapy using [ 186 Re]hydroxyethylidene diphosphonate (HEDP) has been widely tested in patients with bone metastases from prostate and breast cancers. Whereas, to the best of our knowledge, only few cases of bone metastases from tumors other than prostate and breast treated with [ 186 Re]HEDP have been reported. The aim of this paper is to report our experience with 186 Re-HEDP in the palliation of painful bone metastases from tumors other than prostate and breast. Methods. In this study 41 patients (17 non-small cell lung cancer-NSCLC, 1 small cell lung cancer, 1 lung neuroendocrine tumor, 8 bladder cancer, 3 kidney cancer, 3 gastric cancer, 1 uterine carcinoma, 1 colon cancer, 1 rhinopharynx carcinoma, 1 medullary thyroid carcinoma, 1 ovarian cancer, 1 esophagus cancer, 2 carcinoma of unknown origin) are evaluated. All patients had lesions with increased [ 99m Tc]MDP uptake and none had radiological findings of mainly osteolytic lesions. A total of 46 therapeutic cycles were performed using a [ 186 Re]HEDP activity of 1 295 MBq for each administration. After treatment, patients were followed up for 3 months or to the time of pain recurrence (if longer than 3 months). Responses were evaluated using a validated method considering the modifications of pain index, analgesic intake and performance status. Results. Treatment efficacy was complete in 49% (20/41) of patients, partial in 36% (15/41) and negative in 15% (6/41). Namely, we observed 35% (6/17) complete, 41% (7/17) partial and 24% (4/17) negative responses in patients with NSCLC and 63% (5/8) complete, 25% (2/8) partial and 12% (1/8) negative responses in patients affected by bladder cancer. The median duration of pain relief in responder patients was 10 weeks. A mild platelet toxicity occurred in 32% (13/41) of patients. Conclusion. Pain palliation with [ 186 Re] HEDP seems highly effective and safe also in patients with bone metastases from cancers other than prostate and breast. Patients who can benefit from the treatment with [ 186 Re]HEDP can be selected on the basis of [ 99m Tc]MDP bone scan and radiological examination findings.