3 Dimensional Conformal Radiotherapy Combined With Chemotherapy For Thymoma

Thymoma is a rare neoplasm,but it is the most common tumor of the anteriosuperior mediastinum, representing 20% of all malignant mediastinal tumors. Surgery remains the mainstay of thymoma. But patients with thymomas are usually asymptomatic,or they may complain of vague nonspecific symptoms like pressure of the chest or aches and pains,so when they were found ,they had invasived the adjacent tissue and organs, and connot be totally resected . Thymomas also have a high response rate to radiotherapy and chemotherapy, which can be used to treat these unresectable patients. ObjectiveTo investigate the short-term effective rate and toxicity of 3 dimensional conformal radiotherapy combined with chemotherapy for inoperable patients with thymomas. To evaluate the advantage and disadvantage of this combined therapy.Materials and Methods1.Clinical materialsfifty-six inoperable patients with invasive thymic epithelial tumors admitted to Oncology department of Shandong Provincial Hospital from February of 2007 to February of 2009 were divided randomly into two groups: twenty-eight patients in radio-chemotherapy group received 3 dimensional conformal radiotherapy combined with chemotherapy, while the other twenty-eight patients in simple radiotherapy group received 3 dimensional conformal radiotherapy only. There were twenty-nine male patients and twenty-seven female patients, aged from nineteen to sixty-one, averaged at 44.5 years old; twelve patients had no symptoms while forty-four had symptoms(myasthenia gravis was present in eleven cases).The staging was carried out according to the Asamura staging (stage II: six; III: thirty-nine; IV: eleven)。The pathologic type of the patients according WHO classification was found to be of type A in two, AB in thirteen,B₁ in eighteen, B₂ in thirteen, B₃ in ten. All these patients had no sign of metastasis or serious physical disease with no previous thoracic operation, radiotherapy or chemotherapy and with normal blood cell counts, hepatic and renal function, which Karfhosky score were all more than seventy.2.TreatmentAll patients were treated by 3 dimensional conformal radiotherapy , 2Gy per fraction, five times a week to a total dose of 66Gy. Radio-chemotherapy group received chemotherapy from the first day of radiotherapy, every 3 weeks as one cycle to totally 3 cycles. The patients had blood regulation examination weekly and had CT examination of thorax every two weeks and dwindled the field.3.Terminal pointsâ‘ Short-term effective rate. It was evaluated by the WHO criteria of curative effect, which was classified into complete remission (CR) , partial remission(PR), stable disease(SD)and progression disease (PD) no remission(NR) by the result of CT examination of thorax after radiotherapy.â‘¡Side effect. The toxicity of chemical drugs was evaluated by NCI criteria and the side effect of radiotherapy was evaluated by RTOG criteria.4.Statistical analysisUse the SPSS17.0 statistical software. Constitution rate was tested by Chi-square.Results1.short-term effectAll patients were sensitive to the treatments ,but the difference of the short-term effect between the radio-chemotherapy group and the simple radiotherapy group was statistically significant (χ²=4.791, P=0.029<0.05) . In radio-chemotherapy group, 53.6% (15/28) achieved complete remission and 46.4% (13/28) achieved partial remission, while in simple radiotherapy group, 25.0% (7/28) achieved complete remission and 75.0% (21/28) achieved partial remission.2.side effect:Gastrointestinal and blood toxicity in radio-chemotherapy group was more serious than chemotherapy group, which didn't affect the completion of treatment due to prompt therapy. As for acute radiation side effect, there was no significant difference between the two groups.Conclusion3 dimensional conformal radiotherapy combined with chemotherapy for invasive thymomas can improve short-term effective rate .Besides gastrointestinal and blood toxicity, other side effects were not statistically different from the radiotherapy alone and were tolerable. The value of combined treatment in long-term results needs further study in clinic.