[The use of potentiating agents in megavoltage therapy of non-resected localized carcinoma of the lung (author's transl)].
A 5 years survival of 20% without local recurrence and/or metastasis was obtained after radiation therapy alone. This figure is slightly inferior to the survival rate of surgically treated tumours. Failure is mostly due to the appearance of metastases after radical treatment in spite of additional chemotherapy and/or immunotherapy. But experience has also shown that certain cancers "locally controlled" by radiation therapy can recur 3, 5, 8 or even more years later. Two thirds of squamous cell carcinomas are sterilized with doses of 60 Gy. A dose of 80-90 Gy has a greater curative effect on tumours usually unresponsive to doses of 60 Gy. But this level of radiation results in significant damage to normal tissue with inacceptable complications. Even with such doses, quiescent cells and hypoxic cells remain unresponsive. These cell populations are both clonogenic later. Megavoltage therapy must therefore be associated with chemical and physical radiosensitizing agents (e. g. hyperthermia and drugs of the nitro-imidazole group). Treatment protocols also fully exploit the biological effect of chemotherapy recruitment, cell synchronisation and synergistic lethal effect. The biological effects to neutrons on hypoxic cells were also explored, as most of the latter respond to neither X nor kappa therapy. In all, the new treatment strategy must seek the complementarity of the specific biological effects or radiotherapy chemotherapy and radiosensitizing agents (chemical and/or physical). The goal is a 10% growth rate in the cure of squamous cell carcinomas.
D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D006358:Hot Temperature / Q000627:therapeutic use; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D009502:Neutrons; D009593:Nitroimidazoles / Q000627:therapeutic use; D011882:Radiotherapy, High-Energy / Q000009:adverse effects / Q000379:methods*
D009593:Nitroimidazoles
De la stratégie thérapeutique associant mégavoltage et sensibilisateurs dans les cancers bronchiques localisés non opérés.