TREATMENT OF MALIGNANT TUMORS

Valley Cancer Institute, Los Angeles, CA, U.S.A

Hyperthermia has been proven to increase the response of malignant tumors to radiation therapy in both experimental animal tumors and the clinical treatment of human cancer. Based on our multi-year experience, first in re-treatment of previously radiated fields that necessitated the use of low dose radiation fractions as adjunct to the heat treatments, and then progressively applying the encouraging results obtained to areas treated "de novo" and eventually to situations allowing a potentially curative intent, treatment protocols have been devised and tested that yield positive preliminary data showing superior tumor response rates and less side effects when compared with historical controls at our Institute.

The hyperthermia part of the protocol extends the number of heat treatments to correspond to the number of radiation-fractions, as each hyperthermia treatment proceeds or follows each radiation treatment in close time proximity. The number of hyperthermia treatments therefore varies from 25-50 per course for each treated field.

The radiation protocol consists of progressively decreasing daily doses of radiation therapy combined with the daily hyperthermia treatments. Typically the treatment is started at a daily dose of 180cGy gradually reduced to 100cGy protracting a typical radiation therapy treatment course from 5000cGy in five weeks to 5000cGy given in over eight weeks; or 7000cGy in seven weeks to 7000cGy in 14 weeks. According to the ELLIS TDF formula, this results in a 15% or 25% reduction of the effective radiation dose. The total dose is of course adapted to the clinical situation.

The following Conclusions are drawn:

CONCLUSIONS

Protracted Hyperfractionation