Dubaere et al. of Leuven University evaluated the effect of synchronized chemoradiotherapy (CRT) with involvement field (IF-RT) on tumor control, survival and toxicity in localized areas in patients with limited-stage small cell lung cancer. The results showed that the efficacy of combined with involvement field radiation therapy in cycle 2 of chemotherapy was better. The study included 50 patients with LD-SCLC receiving synchronized CRT between February 2002 and February 2009, with a female/male ratio of 15/38 and a median age of 58 years. m2 d1~3, q3w). Radiotherapy was administered using IFRT with measurable tumor lesions, PET-positive lymph nodes and lymph nodes with a minimum diameter >1 cm on CT scan. tumor evaluation was performed using CT after CRT. Patients who achieved (near) complete remission (nCR) underwent prophylactic brain irradiation (PCI) at a dose of 30 Gy/2 Gy within 6 weeks of completing CRT. results showed that the median time between the start of treatment and the end of radiotherapy was 59 days. 30 of the 32 patients with nCR received PCI at 30 Gy/2 Gy, including 2 at 30 Gy/3 Gy. Of the 21 patients who achieved partial remission, 10 received PCI. Of the 21 patients who achieved partial remission, 10 received PCI. 20 patients in all groups had no recurrence/progression. Of the remaining 33 patients, the first recurrence/progression was localized in 10 cases, distant metastases in 15 cases, and both in 8 cases. Of the local recurrences, 3 were within the radiotherapy area (2 were remedied by surgery) and 3 were partially within or outside the radiotherapy area. Only one patient relapsed completely outside the radiotherapy area. three patients with PR developed local progression before developing distant metastases. The median follow-up was 24 months, with median OS and PFS of 28.3 and 26 months, respectively. overall survival was 81.1%, 58.4% and 40.6% at 1, 2 and 5 years, respectively. At the same time point, the local recurrence rates were 85.5%, 63.1% and 52.6%, respectively. Dubaere concluded that the results of combining involved-field radiation therapy with chemotherapy in cycle 2 were quite impressive, partly due to the fine staging used and thus the inclusion of true limited-stage patients. The low rate of local recurrence supports the use of IF-RT and also recommends PET for the diagnosis and treatment of small cell lung cancer. The investigators also observed a relatively high proportion of patients who failed to achieve nCR, suggesting that higher doses of radiotherapy may need to be given to improve prognosis.