Chest radiotherapy in limited-stage small cell lung cancer: facts, questions, prospects

Limited-disease small cell lung cancer (LD-SCLC) is initially very sensitive to both radiotherapy and chemotherapy. However, the 5-year survival is generally only 10-15%, with most patients failing with therapy refractory relapses, both locally and in distant sites. The addition of chest irradiation to chemotherapy increases the absolute survival by approximately 5%. We reviewed the many controversies regarding optimal timing and irradiation technique.

No strong data support total radiation doses over 50 Gy. According to one phase III trial and several retrospective studies, increasing the volume of the radiation fields to the pre-chemotherapy tumour volume instead of the post-chemotherapy volume does not improve local control.

The total time in which the entire combined-modality treatment is delivered may be important. From seven randomized trials, it can be concluded that the timing of the radiotherapy as such is not very important. Some phase III trials support the use of accelerated chest radiation together with cisplatin-etoposide chemotherapy, delivered from the first day of treatment, although no firm conclusions can be drawn from the available data. The best results are reported in studies in which the time from the start of treatment to the end of the radiotherapy was less than 30 days. This has to be taken into consideration when treatment modalities incorporating new chemotherapeutic agents and radiotherapy are considered.