Clinical Study Of The Influence Of Prophylactic Cranial Irradiation, Single Temozolomide Maintenance Treatment And Their Combination Therapy On Survival And Preventing Brain Metastases In Small Cell Lung Cancer

Objective: 1. to compare Prophylactic Cranial Irradiation, single Temozolomide maintenance therapy and their combination Protocols to prevent brain metastases and improve survival situation in SCLC. 2.To explore the adverse reaction of Temozolomide; 3. To explore central nervous system adverse reaction of prophylactic cranial irradiation 4.To compare patients' tolerability of combination therapy and single therapy.Method: This retrospective and randomized controlled trial analyzed patients of China PLA General Hospital who confirmed as Small Cell Lung Cancer by pathological or cytological examinations. All patients received Platinum-based chemotherapy (EP/IP) and thoracic radiotherapy as first -line treatment. We also evaluated their curative effect as partial response (PR) or complete response (CR).Brain CT or MRI enhancement scan shows no evidence of brain metastases in all the patients. All patients were divided into three groups as PCI group (26), TMZ group (18) and combination group (12).In TMZ group, patients received oral single Temozlomide for 6 cycle after first-line treatment till disease progression or intolerable adverse reactions happening. In PCI group, patients received 25Gy/10F prophylactic cranial irradiation after first-line treatment till disease progression or intolerable adverse reactions happening. In combination group, patients received Temozolomide following PCI after first line therapy. The primary evaluation indexes are brain metastases positive rates in 1 year and cranial-progression-free survival.Secondary indexes are overall survival, progression-free survival and tolerability.Results: In all the 56 patients, 35 died until the last follow-up, among them 20 patients died of cranial metastatic and 15 patients died of extracranial progression. PCI group enrolled 26 patients, TMZ group enrolled 18 patients and Combination group enrolled 12 patients. 1. There were significant differences in 1 year brain metastases positive rates of combination group, PCI group and TMZ group( 0%vs34.62%vs38.89%,P<0.05),Cranial-progression-free survival (29vs22vs12 month, p<0.05) and median OS(29vs25 vs18,P<0.05). 2. Adverse events of temozolomide were hematologic and gastrointestinal toxicities, while all adverse reactions were slight and moderate. 3. Acute adverse events of PCI were dizziness and nausea, a small number of patients had long-term nervous system adverse events including hypomnesis, bradykinesia.Conclusion: 1. PCI combined with TMZ can significantly improve 1 year brain metastasis rates, Cranial-progression-free survival, and OS. 2. adverse reaction of TMZ includs gastrointestinal and hematologic reaction,all were ??? greed 3.Traditional PCI may bring acute reactions such as nausea and emesis, also long-term adverse reactions such as hypomnesis, bradykinesia.4. The combined-modality therapy was well tolerated.