Best investigation to detect bone metastasis is-

Ans. is 'd' i.e., Bone scan * Because of increased sensitivity, radionuclide imaging (Bone scan) is usually the investigation of first choice in patients who have clinical evidence of possible bone metastases, since in most cancers a normal scan virtually excludes the presence of metastases.Metastasis to bony skeleton* A number of tumors commonly metastasize to bone, the best examples of which are breast cancerf prostate cancer and lung cancer. Other forms of malignancies may also metastasize to bone.* The presence of tumor cells in bone can result in the development of either osteolytic bone lesions, an osteoblastic disease, or a mixed osteolytic/osteoblastic lesions. In most types of tumor, however, the deposits tend to be predominantly of one type.* Prostatic carcinoma is the most common cause of osteoblastic bone metastasis.* Renal cell carcinoma and thyroid carcinoma produce expansile pulsatile bony metastasis. Other tumors which produce expansile bony metastases are melanoma and pheochromocytoma.* Bone scan is the initial investigation of choice for bone metastasis. Whole body MRI can also be used