Fractionated stereotactic radiation therapy for intracranial tumors

Article Abstract:

Radiation damages both healthy and cancerous cells. The use of radiation for the treatment of cancer relies upon the facts that some cancers are more sensitive to radiation than healthy cells, and healthy cells are often more able to recover from the potentially deadly effects of radiation. This is why the dose of radiation used to treat cancer is generally fractionated, that is, delivered as several small doses rather than as a single large dose. The schedule of smaller doses may provide better opportunities for the survival of healthy cells while maintaining effectiveness against cancer cells. Fractionation is generally not employed in stereotactic radiosurgery, however. This technique is often used for lesions that are not cancerous at all, such as blood vessel malformations in the brain. In this technique, a system of coordinates is used to locate the target within the brain, and a large dose of radiation is used for wholesale destruction of both diseased and healthy tissues within a small and precisely defined area. Researchers have now attempted to determine if stereotactic radiation therapy might be successful in the treatment of brain tumors if a fractionated dose schedule is used. For 15 patients with brain tumors or intracranial tumors, the radiation dose was fractionated for experimental treatment. A typical dose was a total of 4,200 cGy divided into six doses of 700 cGy each. (A Gy, or Gray, is a dose of radiation equivalent to one joule of energy absorbed per kilogram of tissue. It is equal to 100 rads.) At the end of the follow-up period (27 months or more for half the patients), the brain tumor had disappeared in only two patients; in most patients the tumor decreased in size but did not disappear. However, since brain tumors cause illness primarily by exerting pressure on surrounding tissue, this reduction in size resulted in significant palliation of symptoms for most patients. The present study indicates that in some patients stereotactic radiotherapy may prove useful. However, the technique must still be considered experimental, since the present study did not compare the results of the stereotactic method with conventional radiotherapy, in which the affected area within the skull is less precisely targeted. (Consumer Summary produced by Reliance Medical Information, Inc.)

Care and treatment, Usage, Gliomas, Brain tumors, Astrocytoma, Astrocytomas, Intracranial tumors, Stereotaxic techniques

---

Palliative treatment of advanced cancer using multiple nonconfluent pencil beam radiation: a pilot study

Article Abstract:

Historically, one of the main problems with radiotherapy has been delivering a dose sufficient to kill a tumor while avoiding excessive destruction of normal tissues. This is particularly true of deep tumors, which can only be irradiated through the overlying structures. In an attempt to solve this problem, the GRID technique has been given the somewhat ponderous nomenclature of multiple nonconfluent pencil beam radiation. The technique gets the name GRID simply from the fact that the radiation is passed through a metallic grid full of holes. The principle is straightforward; skin tolerates radiation better in small patches than in a large area. Therefore, delivering a lot of radiation in a number of narrow beams is more sparing of the skin than a larger beam would be. The technique has largely fallen by the wayside due to the development of new irradiation equipment with better tissue penetration and improved skin-sparing characteristics. However, the GRID technique may still have some advantageous uses. A study was conducted on 22 patients with large tumors, which had resisted all forms of treatment. While a cure of such patients would be extremely unlikely, massive irradiation may provide relief from painful symptoms. Using the GRID technique, doses of radiation were administered; 20 of 22 patients achieved some relief of their more severe symptoms. There were no acute side effects, and no unusual skin damage was observed. (Consumer Summary produced by Reliance Medical Information, Inc.)

Palliative care, Cancer, Cancer treatment

---

Similar abstracts:

• Abstracts: Rationale for different chemotherapeutic and radiation therapy strategies in cancer management. Treatment of clinical Stage I Hodgkin's disease by local radiation therapy alone: a United Kingdom Childrens Cancer Study Group study
• Abstracts: Occupational chiropractic - a glimpse into the new millennium. Hospital rotations augment clinical experience
• Abstracts: Saliva and serum CA 125 assays for detecting malignant ovarian tumors. Intraoperative radioimmunodetection of ovarian cancer using monoclonal antibody B72.3 and a portable gamma-detecting probe
• Abstracts: Concomitant cisplatin and hyperfractionated external beam irradiation for advanced malignancy of the head and neck
• Abstracts: Percutaneous ethanol injection therapy for hepatocellular carcinoma: a histopathologic study. Continuous hyperthermic peritoneal perfusion for the treatment of peritoneal dissemination in gastric cancers and subsequent second-look operation

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.