Radiotherapy in the Treatment of Carcinoma of the Urinary Bladder
MALIGNANT tumors of the urinary bladder arise from transitional epithelium and may be expected to respond well to ionizing radiation, but this favorable response has not occurred in the past. Tumor doses with 250-kv. apparatus were necessarily inadequate and only the most advanced lesions were treated. Currently the availability of high-energy, skin-sparing sources of radiation makes it possible to deliver cancerocidal doses to the tumor volume; therapeutic technics and skill are minimizing or preventing the types of sequelae formerly encountered; and more lesions are now being treated in the early stages by radiation as the effectiveness of some surgical procedures is being challenged. An attempt will be made to review the events that have led some clinicians to reassess the position of radiotherapy in the treatment of carcinoma of the urinary bladder.
Classification of Tumors and Prognosis
Survival of patients who had undergone surgical treatment for carcinoma of the bladder was evaluated in terms of various therapeutic technics in the early years. Later some investigators began to assess survival on the basis of histologic findings. However, despite improvements in operative management, patients with ostensibly localized lesions of a favorable histologic type were dying of recurrent cancer of the bladder. It remained for Jewett1 to establish the validity of survival as a function of invasion of the muscularis. He proved conclusively that the stage (extent of tumor) and to a lesser degree the grade (cellular dedifferentiation) were the most significant prognostic indexes. This classification brought into sharper focus the limitations of . . .