Osteolytic metastatic lesions

RF ablation has been used as an alternative method for treating certain bone tumors such as painful osteolytic metastatic lesions (Callstrom et al. 2000), osteoid osteoma (Rosenthal et al. 1992,1995,2001), and chondroblastoma (Erickson et al. 2001). 

It has been reported that cement leakage is more common when PV is used for metastatic osteolytic tumors or myelomas of the spine than in osteoporotic fractures. However, Vasconcelos et al. (2002) observed no major differences, although they noted venous leaks slightly more frequently in patients with metastatic lesions. When PV was performed in osteoporotic vertebral compression fractures, leakage into the disc space was more commonly observed. Mousavi et al. (2003) reviewed post-procedural GT scans in patients with osteoporotic vertebral compression fractures and metastatic lesions of the spine and concluded that in osteoporotic vertebrae leakage occurred mainly into the disc, whereas in metastatic lesions it was found in various different locations. 

Aredia, pamidronate disodium (APD), is a bone-resorption inhibitor used to treat hypercalcemia associated with malignancy and osteolytic bone lesions associated with multiple myeloma, metastatic breast cancer, and moderate to severe Paget s disease of bone. Aredia, a member of the group of chemical compounds known as bisphosphonates, is an analog of pyrophosphate. Pamidronate disodium is designated chemically as phosphonic acid (3-amino-l-hydroxypropylidene) bis-, disodium salt, pentahydrate, (APD). 

Pamidronate is one of the first drugs that has been proven to reduce the incidence of skeletal complications of metastatic breast cancer and prostate cancer. It also relieves bone pain caused by metastatic bone lesions. Other indications include treatment of osteolytic bone lesions of multiple myeloma, moderate-to-severe hypercalcemia of malignancy, and moderate-to-severe bone lesions due to Paget s disease. 

Metastatic bone disease (MBD) is characterized by very high levels of bone turnover in regions proximal to the tumour [33]. Bone resorption inhibitors such as bisphosphonates represent the current standard of care for the treatment of bone metastases primarily due to breast or prostate cancer and multiple myeloma. It has been proposed that other strong anti-resorptives such as a Cat K inhibitor could be useful in the treatment of bone metastases. Evidence for this has been presented in the form of a preclinical MBD model in which human breast cancer cells are implanted into nude mice. Treatment with a Cat K inhibitor gave a significantly lower area of breast cancer-mediated osteolytic lesions in the tibia [34]. In a separate study, the efficacy of a Cat K inhibitor in the reduction in tumour-induced osteolysis was found to be enhanced in the presence of the bisphosphonate zolendronic acid [35,36]. When prostate cancer cells were injected into the tibia of SCID mice, treatment with a Cat K inhibitor both prevented and diminished the progression of cancer growth in bone [37]. 

Metastatic spread can occnr by local extension, lymphatic drainage, or hematogenous dissemination. Lymph node metastases are more common in patients with large, nndifferentiated tumors that invade the seminal vesicles. The pelvic and abdominal lymph node gronps are the most common sites of lymph node involvement (Fig. 128-1). Skeletal metastases from hematogenous spread are the most common sites of distant spread. Typically, the bone lesions are osteoblastic or a combination of osteoblastic and osteolytic. The most common site of bone involvement is the lumbar spine. Other sites of bone involvement include the proximal femurs, pelvis, thoracic spine,... 

To date, the mechanical properties of the metastatic spine and the mechanisms of collapse have not been fuUy elucidated. Moreover, the correlation between vertebral body coUapse and the location and extent of the metastatic tumor is not fully understood. Taneichi et al. (1997) evaluated 100 thoracic and lumbar vertebrae (53 patients) with osteolytic lesions, determined risk factors for vertebral coUapse, and estimated the probability of coUapse under various states of metastatic vertebral involvement. The most important risk factor leading to vertebral coUapse in the thoracic region was involvement of the costovertebral joint. Tumor size within the vertebral body was the second most important risk factor. In-... 

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