Role of radiation therapy in small cell anaplastic carcinoma of the lung.

The previously established roles of radiotherapy in the management of small cell anaplastic carcinoma of the lung have changed with the development of improved chemotherapy. A group of the International Association for the Study of Lung Cancer has concluded that while there is established evidence that the addition of chemotherapy improves the results of radiation therapy, the value of the addition of loco-regional radiation therapy to chemotherapy is uncertain and more difficult to assess. No advantage in short-term (median) survival has been shown in randomized studies, but current data suggest a possible advantage in long-term control of loco-regional disease. Further results of prospective trials are needed to resolve this question. Prophylactic cranial irradiation reduces the incidence of cerebral metastases but so far has not resulted in improved survival. Pending the results of further randomized studies, its routine use in all patients is not advocated. The palliative role of radiation therapy is valuable in symptomatic treatment. Various current modifications of technique to improve the results of conventional radiation treatments with an altered fractionation schedule and use of sensitizers and large fields are not believed to show major advantages. The clear documentation of treatment details and the definition of the criteria for the assessment of results are important if further comparisons of results are to be made possible. In particular, the need for reporting long-term survival at 2 years in contrast to the more usual median survival time is stressed.