摘要
Objective: To analyze the influencing factors for radiation-induced heart disease (RIHD) in a panel of cases with malignant thymic tumors treated by radiotherapy. Methods: 52 consecutive patients were treated by radiotherapy for malignant thymic tumor (14 at Masaoka stage II, 23 at stage III and 15 at stage IV). Treatment included radical (in 20), postoperative (in 14), preoperative (in 2) and palliative (in 16) radiotherapy. The conventional two-dimension (2D) radiation therapy was performed in forty-seven patients and three-dimension (3D) conformal radiation therapy has been used in 5 patients since October 2000. The total tumor dose ranged from 10 Gy to 84.5 Gy (median of 55 Gy). Chemotherapy was given in twenty-five patients before or after radiotherapy. The results of following-up could be obtained from the database and updated where appropriated. The dose volume histogram (DVH) of heart in radiotherapy for all patients was analyzed for the effective volume dose of heart. Result: The median following-up was 14 months (ranged from 0.6 to 111.3 months) in the study. RIHD was observed in seven patients. Cardiac toxicity of these seven patients were evaluated as SOMA grade 1-3. The median two-third effective volume dose of heart was 47.2 Gy (ranged from 8.3 Gy to 70.1 Gy) for conventional 2D radiotherapy, which correlated with thymic tumor dose (P<0.0001). The median two-third effective volume dose of heart was 35.3 Gy (ranged from 13 Gy to 38.7 Gy) for 3D conformal radiotherapy. The effective volume doses of heart were decreased by using 3D conformal radiotherapy (P=0.048). A significant association between cardiac toxicity and effective volume dose of heart was found in this study (P<0.0001). Cardiac toxicity accounted for 10.4% and 4.1% of patients receiving and not receiving adjuvant chemotherapy, respectively, and occurred earlier in radiochemotherapy group (P=0.0528). Multivariate analysis suggested that cardiac toxicity was significantly influenced by the effective volume dose of heart and chemotherapy. Conclusion: the results indicate that decreasing the effective volume dose of heart and carefully using chemotherapy drugs that have significant cardiotoxicity may reduce the probability of radiation-induced heart disease.
Objective: To analyze the influencing factors for radiation-induced heart disease (RIHD) in a panel of cases with malignant thymic tumors treated by radiotherapy. Methods: 52 consecutive patients were treated by radiotherapy for malignant thymic tumor (14 at Masaoka stage II, 23 at stage III and 15 at stage IV). Treatment included radical (in 20), postoperative (in 14), preoperative (in 2) and palliative (in 16) radiotherapy. The conventional two-dimension (2D) radiation therapy was performed in forty-seven patients and three-dimension (3D) conformal radiation therapy has been used in 5 patients since October 2000. The total tumor dose ranged from 10 Gy to 84.5 Gy (median of 55 Gy). Chemotherapy was given in twenty-five patients before or after radiotherapy. The results of following-up could be obtained from the database and updated where appropriated. The dose volume histogram (DVH) of heart in radiotherapy for all patients was analyzed for the effective volume dose of heart. Result: The median following-up was 14 months (ranged from 0.6 to 111.3 months) in the study. RIHD was observed in seven patients. Cardiac toxicity of these seven patients were evaluated as SOMA grade 1-3. The median two-third effective volume dose of heart was 47.2 Gy (ranged from 8.3 Gy to 70.1 Gy) for conventional 2D radiotherapy, which correlated with thymic tumor dose (P<0.0001). The median two-third effective volume dose of heart was 35.3 Gy (ranged from 13 Gy to 38.7 Gy) for 3D conformal radiotherapy. The effective volume doses of heart were decreased by using 3D conformal radiotherapy (P=0.048). A significant association between cardiac toxicity and effective volume dose of heart was found in this study (P<0.0001). Cardiac toxicity accounted for 10.4% and 4.1% of patients receiving and not receiving adjuvant chemotherapy, respectively, and occurred earlier in radiochemotherapy group (P=0.0528). Multivariate analysis suggested that cardiac toxicity was significantly influenced by the effective volume dose of heart and chemotherapy. Conclusion: the results indicate that decreasing the effective volume dose of heart and carefully using chemotherapy drugs that have significant cardiotoxicity may reduce the probability of radiation-induced heart disease.
