[Spinal metastases. Value of diagnostic procedures in the initial diagnosis and follow-up]

In this retrospective study plain radiographs, radionuclide bone scans, computed tomography (CT) and magnetic resonance (MRT) examinations of 115 patients with metastatic carcinoma of the spine were analyzed. In 32 patients metastases were proven histologically and in the remainder by follow-up studies. Altogether, 513 vertebrae were evaluated. Forty-one patients had histologically proven breast cancer, 14 renal cell carcinoma, 11 prostate cancer, 8 melanoma. 8 tumors of the gastrointestinal system and 7 bronchial carcinoma. Evaluation of the plain films showed that the initial site of metastasis (n = 463) was the vertebral body in 441 cases and the pedicles in 294 cases. In CT scans most of the lesions confined to one part of the vertebral body (36 of 98) were localized in the posterior part. Twelve percent of the metastases were diagnosed with conventional radiography and 17% of those diagnosed with CT were not detected in skeletal scintigraphy. MRI was rarely used in diagnosing occult vertebral metastases (n = 37); 22% of the metastases demonstrated by MRI were not detected in skeletal scintigraphy. We concluded that only in 63.8% was the pedicle sign the initial site of metastasis on plain films. Bone scans and plain films are the most important diagnostic procedures for detecting and monitoring vertebral metastases. CT and MRI are only needed in patients with neurological symptoms and persistent pain.