Morphine After Radiofrequency Ablation of Painful Bone Metastases in Patients With Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed cancer * Primary or unknown origin * Painful bone metastases despite radiotherapy or symptomatic relapse into previously irradiated area with no possibility of repeating radiotherapy * Bone metastases may have been treated with bisphosphonates * Osteolytic bone or joint (lytic and condensed) confirmed by CT scan and meeting the following criteria: * Lesion size ≤ 5 cm * No more than 2 painful bone metastases * If 2 lesions are to be treated, distinct anatomical locations can be treated at the same time * Metastatic bone lesions of the pelvis, sacrum (in absence of canal involvement), ribs, or long bones allowed * Pain located at the tumor or in the area * Maximum pain in the last 24 hours \> 4 points (numerical scale to 11 points) PATIENT CHARACTERISTICS: * Life expectancy \> 3 months * Platelet count \> 50,000/μL * Prothrombin \< 50% * Activated cephalin time ≤ 1.5 times normal * Not pregnant * Fertile patients must use effective contraception * No geographical, social, or psychiatric reason that would preclude follow up PRIOR CONCURRENT THERAPY: * See Disease Characteristics * At least 4 weeks since prior radiotherapy * At least 3 weeks since prior chemotherapy or bisphosphonates * At least 1 week since beginning new painkiller therapy or anticoagulation treatment * More than 30 days since participation in another drug study * More than 30 days since prior surgery