Radiotherapy for early-stage non-small cell lung cancer: Research in early-stage non-small cell lung cancer (NSCLC) has focused on stereotactic body radiotherapy (SBRT). SBRT is currently used as the standard of care for early-stage NSCLC that cannot tolerate surgery, with a local control rate of >90%. SBRT versus conventional dose fractionation studyAn Australian randomized study comparing the efficacy of SBRT with conventional fractionated radiotherapy (CONV) for patients with stage I NSCLC who could not tolerate surgery suggested that SBRT improved local control rates relative to CONV, with no effect on overall survival (OS). Prognostic analysis found that T1 and adenocarcinoma were the most important factors affecting OS. Another US study compared SBRT techniques with different split doses of 60 Gy/3F, 48 Gy/4 to 5F and 30 Gy/1F, among others. In SBRT for stage I NSCLC, 60Gy/3F reduced local tumor recurrence relative to other doses, without significant differences in OS. However, the ideal dose of SBRT treatment still needs to be confirmed by further randomized clinical trials. Prognostic analysis The phase II clinical study of RTOG0236 evaluated the long-term efficacy of SBRT for inoperable stage I NSCLC. This study enrolled 59 cases of stage I NSCLC (55 evaluable, including 44 T1 patients and 11 T2 patients) with a total radiotherapy dose of 54 Gy/3F/1.5 to 2 W. The median OS was 4 years and the 5-year OS rate was 40%. The local control rate was higher than CONV, and late recurrence often occurred in the untreated residual lobes. Severe radiotherapy toxicity reactions were observed at the end of the late stage. Louie (Louie) analyzed the prognostic risk factors of 676 stage I NSCLC treated with SBRT and showed that tumor diameter, size of planned target volume (PTV), biologically effective dose (BED) and age were risk factors affecting the survival of stage I NSCLC patients after SBRT. SBRT combined with radiofrequency ablation (RFA) study A phase II prospective clinical study at the University of California, Los Angeles evaluated the safety and efficacy of SBRT combined with RFA for the treatment of central lung cancer. Thirteen patients were enrolled in this study. 42 Gy/3F was given to the group with tumors 1 to 2 cm from the bronchial bifurcation (TBT) and 36 Gy/3F was given to the group within 1 cm from the TBT, and both were given RFA within 10 days. early results showed that SBRT plus RFA treatment was effective for central lung cancer with an acceptable safety profile. Since the interaction between SBRT and RFA is not yet clear, SBRT/RFA should be applied with caution outside of clinical studies. Toxic reactions With the application of SBRT technique in the treatment of lung cancer, esophageal radiation toxicity is of increasing concern. Harder (2001) reported 158 cases of SBRT-treated central lung cancer, and only 8 cases (5.1%) of grade ≥2 radiation esophagitis occurred. Further analysis revealed that esophageal 3.5 cc volume of BED ≥ 40 Gy predisposed to grade ≥ 2 esophageal radiotoxicity. In Thibault’s analysis of 239 patients treated with pulmonary SBRT (48-60Gy/4-5F), 17% (50/289) developed rib fractures, of which 56% (28/50) were asymptomatic rib fractures. Those with tumors adjacent to the chest wall were at greater risk. The chest wall is subject to observable volume. Radiotherapy for locally advanced non-small cell lung cancer: Multidisciplinary combination therapy is the standard of care for locally advanced NSCLC. Preoperative neoadjuvant therapy The investigators analyzed the efficacy of preoperative neoadjuvant radiotherapy (N-CRT) and neoadjuvant chemotherapy (N-CTX) in 1559 patients with stage III NSCLC from the National Cancer Database, and showed no significant differences in OS, complete remission rate of lymph node pathology, or positive surgical margins between the two groups, suggesting that both N-CRT and N-CTX are alternative treatment strategies. This result is at variance with current guidelines, but further analysis suggests that it may also be due to case selection bias. Another German study comparing N-CRT plus surgery after induction chemotherapy with concurrent radiotherapy (CCRT) showed improved disease-free survival for both, with the N-CRT group after induction chemotherapy improving the 5-year local recurrence-free rate. Simultaneous radiotherapy plus consolidation chemotherapy A multinational, phase III randomized trial investigated the efficacy of consolidation therapy with or without docetaxel combined with cisplatin (DP) after CCRT in patients with inoperable stage III NSCLC. In this study, 437 patients were enrolled and randomized to CCRT and CCRT+DP, with the specific regimen of CCRT being a chest radiotherapy dose of 66 Gy/33F with concurrent chemotherapy docetaxel 20 mg/m2+cisplatin 20 mg/m2qw×6 times and the specific regimen of DP being docetaxel 35 mg/m2+cisplatin 35 mg/m2qw, d1, d8, q3w×3 times. The results showed that consolidation chemotherapy with DP did not significantly prolong the progression-free survival (PFS) period in patients with stage III non-small cell lung cancer. Dosimetric study A dosimetric study from the United States performed a matched analysis of 178 patients with locally advanced (stage IIB-IIIB) NSCLC treated with high-dose (HD) (>64 Gy) and standard-dose (SD) (≤64 Gy) radiotherapy and showed that CCRT with HD had a higher OS (P=0.003) relative to SD for locally advanced NSCLC and lower distant metastasis (P=0.038). OS was significantly associated with mean cardiac dose, V20, V30, and V40. This study concluded that radiotherapy for lung cancer should be administered at as high a dose as possible. Radiotherapy for small cell lung cancer: Thoracic radiotherapy (TRT) for extensive-stage small cell lung cancer (SCLC) A study enrolled 498 patients with extensive-stage SCLC in remission after 4 to 6 cycles of standard chemotherapy, randomized to receive TRT (30 Gy/10F) and no TRT. results showed that TRT prolonged the PFS period. Although TRT did not affect the risk of death in year 1, it significantly improved two-year survival. Therefore, TRT should be offered to all patients with extensive-stage small cell lung cancer in remission after initial chemotherapy. Brain prophylaxis irradiation A study from the United States classified 283 patients with limited-stage small cell lung cancer (LS-SCLC) into stages I to IIIB according to AJCC staging (7th edition) and analyzed the effect of AJCC staging on brain metastasis (BM) and OS in LS-SCLC. The results showed that OS, BM and distant metastases were significantly different in LS-SCLC patients with different AJCC stages; whole-brain prophylactic radiotherapy (PCI) did not significantly affect BM, which may also be related to the fact that BM in this study was lower than the commonly reported proportion of BM; and PCI was associated with OS. Future studies should distinguish between early-stage (stage I/II) and locally advanced (stage III) LS-SCLC and give correspondingly different treatment regimens, especially whether there is a need for PCI at the stage with a lower risk of BM (stage I/II). A randomized, phase III clinical trial in Japan enrolled 163 patients with extensive-stage SCLC after chemotherapy remission and randomized them to receive PCI (25Gy/10F) and an observation group. The results showed that PCI can have a negative impact on the OS period of patients with extensive-stage SCLC after chemotherapy remission.