Radioisotopic treatment of bone pain from metastatic prostate cancer

Hormone-refractory prostate cancer patients with painful bony metastatic lesions are potential candidates for boneseeking radiopharmaceutical therapies. After careful assessment of symptoms and localization of pain, a bone scan is the single most useful imaging modality for the clinician to assess patients for the presence and distribution of osteoblastic lesions. Increased uptake (compatible with bony metastases) on a conventional bone scan is currently a prerequisite for treating patients with a bone-targeted therapeutic isotope. Determining whether metastatic bony involvement is focal or diffuse is also important in the clinical decision-making process. Patients with multifocal metastatic disease are excellent candidates for systemic therapies, whereas patients with unifocal metastatic disease may be more appropriate candidates for focal therapies such as external-beam radiation. Patients who are poorly tolerant of narcotics should be actively considered for alternative treatments such as systemic radiopharmaceuticals. Contraindications to administration of current boneseeking radioisotopes include substantial degrees of renal insufficiency or bone marrow suppression.