Treatment of Bronchogenic Cancer with Conventional X-Rays According to a Specific Time-Dose Pattern

This is A report of 43 patients with advanced nonresectable cancer of the lung who received conventional x-ray therapy according to an abbreviated time-dose pattern and showed subjective and objective improvement. Inoperable carcinoma of the lung is essentially an incurable disease either because of its local extension to vital structures (1) or because of distant metastasis. Experience has shown that when a dose of radiation sufficient to eradicate the local disease is delivered, irreparable changes in the surrounding normal lung tissue may be produced. While the morbidity secondary to these changes is incapacitating, it would be a small price to pay were the disease cured. However, with the frequent incidence of local extension and/or distant spread, both of which mitigate against cure, one should be circumspect in delivering high dosage to the lung. There is little doubt that irradiation can induce a significant degree of palliation in a great many patients. This should be accomplished with a dose that will not inflict irreparable damage to the normal surrounding structures or debilitate the patient. The extreme debilitation which often necessitates interruption of the therapeutic cycle has been noted by many who employ curative or radical radiation therapy in lung cancer. A compromise in treatment policy has been ably expressed by Garland and Sisson (2): “If the disease is limited in extent and at all radiosensitive, moderate dosage will achieve as much as heavy dosage in the majority of cases; if it is neither limited nor sensitive, no tolerable radical dosage will be of significant benefit.” Material and Methods Forty-three consecutive patients with histologically proved cancer of the lung were treated with a uniform pattern. Treatments were given with x-rays generated at 250 kv, Thoraeus II (0.4 Sn) filter, h.v.l. 2.5 mm. Cu at 50 cm. distance, the output being 37 r/minute (air). The size of the field varied from 10 × 10 to 10 × 15 cm. All lesions received a calculated tumor dose of 3,000 r in fourteen elapsed days. Skin doses ranged approximately from 4,000 to 4,800 r, depending on the anterior-posterior diameter of the chest. Localization films were taken in each instance to verify the accuracy of the treatment portals. The choice of a tumor dose of 3,000 r in a two-week period requires explanation. Generally, a tissue dose of 6,000 r in four to six weeks is considered curative therapy for cancer. The aim was to shorten the overall treatment time, which is justifiably indicated in palliative therapy. A fourteen-day period was chosen arbitrarily, in keeping with Paterson's expression of time as, “the shortest time which will be adequate to the task on hand, yet which will not produce immediate general effects on the patient” (3).