Cutting Edge Treatment
There have been enormous advances in improving the success and reducing the morbidity of surgery and radiation therapy thanks to computerized tomography.
The terms gamma knife, cyber knife and x-knife are used by different companies for their products. When a tumor is identified, treatment is planned so that Cobalt 60 beams will converge on a small area (usually less than 3 cm) from many directions, thereby minimizing the damage to normal tissue surrounding the tumor and maximizing the radiation dose to the tumor itself. The patient is placed in a helmet-like head holder called a collimater and then slides into the treatment machine. Usually this is a one-time outpatient treatment.
- angiogenesis inhibitors
- growth factor inhibitors
- monoclonal antibodies
- radioisotope-tagged monoclonal antibodies
The above types of therapies are under clinical investigation as part of clinical trials. Most of these therapies do not kill cells by themselves, but work with other therapies.
Radiosensitizers enhance the effect of radiotherapy. Angiogenesis inhibitors attempt to block the tumor's ability to create its own blood vessels to bring extra nourishment to the tumor. Growth factor inhibitors work in a similar manner to stop certain parts of the tumor from growing. Immunotherapy helps deliver antineoplastic agents to the tumor itself minimizing damage to surrounding normal tissue.
Systemic agents rather than chemotherapy are used because some of these drugs do not fit the registry definition of chemotherapy.
- BCNU (Carmustine)
- CCNU (Lomustine)
- CPT-11 (Camptosar)
- Procarbazine (Matulane)
- Tamoxifen (Nolvadex)
- Temodar (Temozolomide)
Standard chemotherapy has not been terribly successful due to the brain's natural blood-brain barrier which blocks large molecules from entering the vascular system in the brain.
Some drugs have proven effective against neural tumors, particularly the nitrosoureas BCNU and CCNU. Newer drugs under clinical investigation include Camptosar, Temodar, and even Tamoxifen. Older drugs like melphalan, vincristine and procarbazine have been given second opportunities to prove their effectiveness in combination therapies. Thalidomide has made a comeback as an antiangiogenesis agent in clinical trials. Tamoxifen has been used to treat recurrent meningioma.