Deformable image registration (DIR) has been an important component in adaptive radiotherapy (ART). Our goal was to examine the accuracy of ART using the dice similarity coefficient (DSC) and to determine the optimal ...Deformable image registration (DIR) has been an important component in adaptive radiotherapy (ART). Our goal was to examine the accuracy of ART using the dice similarity coefficient (DSC) and to determine the optimal timing of replanning. A total of 22 patients who underwent volume modulated arc therapy (VMAT) for head and neck (H&N) cancers were prospectively analyzed. The planning target volume (PTV) was to receive a total of 70 Gy in 33 fractions. A second planning CT scan (rescan) was performed at the 15th fraction. The DSC was calculated for each structure on both CT scans. The continuous variables to predict the need for replanning were assessed. The optimal cut-off value was determined using receiver operating characteristic (ROC) curve analysis. In the correlation between body weight loss and DSC of each structure, weight loss correlated negatively with DSC of the whole face (rs = -0.45) and the face surface (rs = -0.51). Patients who required replanning tended to have experienced rapid weight loss. The threshold DSC was 0.98 and 0.60 in the whole face and the face surface, respectively. Patients who showed low DSC in the whole face and the face surface required replanning at a significantly high rate (P < 0.05 and P < 0.01). Weight loss correlated with DSC in both the whole face and the face surface (P < 0.05 and P < 0.05). The DSC values in the face predicted the need for replanning. In addition, weight loss tended to correlate with DSC. DIR during ART was found to be a useful tool for replanning.展开更多
Surgical excision and postoperative radiotherapy are widely accepted therapeutic modalities for sinonasal teratocarcinosarcoma （SNTCS）. Previous studies have shown that intensity-modulated radiation therapy （IMRT）...Surgical excision and postoperative radiotherapy are widely accepted therapeutic modalities for sinonasal teratocarcinosarcoma （SNTCS）. Previous studies have shown that intensity-modulated radiation therapy （IMRT） is safe and effective for the treatment of some sinonasal malignancies. We hypothesize that use of IMRT for SNTCS may result in clinical benefits. We report here two cases of SNTCS that were treated by IMRT. One patient was given extensive IMRT involving elective neck irradiation. Follow-up examinations revealed no recurrence and metastasis 3.5 years after IMRT. Another patient simultaneously suffered from multiple systematical diseases and was administered involved-field radiotherapy. He was found to have a marginal recurrence during the follow up and eventually died 8 months after disease diagnosis. It was suggested in this study that appropriate use of IMRT for the treatment of SNTCS may achieve excellent local control.展开更多
Radiotherapy plays a critical role in the treatment of oral cavity squamous cell carcinoma as monotherapy in early stage cancer or combined with surgery and/or chemotherapy in advances ones.Recent developments in the ...Radiotherapy plays a critical role in the treatment of oral cavity squamous cell carcinoma as monotherapy in early stage cancer or combined with surgery and/or chemotherapy in advances ones.Recent developments in the imaging of cancer and radiation technology have allowed developing more precise delivery of treatment with recent data demonstrating improvement in survival and lessening of adverse toxics effects of radiation.This review will focus in the recent advances and current state-of-the-art in radiation oncology both external beam radiotherapy and brachytherapy.As complexity of cancer treatments increases a close coordination between head-neck surgeons and radiation oncologist is needed due to a significant proportion of patients will be treated with combined modality therapy.展开更多
目的:研究基于形变配准头颈部肿瘤自适应放疗计划剂量学优势。方法:选取8例头颈部肿瘤患者行自适应放疗,每周扫描CT重新勾画靶区和危及器官并设计新的计划执行1周,直至分次治疗结束。以初始计划CT1为参考分别进行形变配准,每周实际受照...目的:研究基于形变配准头颈部肿瘤自适应放疗计划剂量学优势。方法:选取8例头颈部肿瘤患者行自适应放疗,每周扫描CT重新勾画靶区和危及器官并设计新的计划执行1周,直至分次治疗结束。以初始计划CT1为参考分别进行形变配准,每周实际受照剂量在CT1上累积得到自适应方案总受照剂量。同时计算初始计划剂量和虚拟常规放疗实际受照剂量作为对比。结果:8例患者自适应方案PTV D95剂量平均值较初始计划低45 c Gy,与初始计划剂量基本一致,剂量均匀性指数(HI)和适形指数(CI)分别提高0.002和0.031。左右腮腺Dmean分别降低24.37和127.50 c Gy,脑干和脊髓D_(max)平均降低189.87和111.37 c Gy。虚拟常规放疗PTV D95剂量较初始计划低334.87 c Gy,未达到初始计划剂量,HI和CI分别下降0.073和0.069,左右腮腺Dmean分别高出153.63和170.50 c Gy,脊髓D_(max)平均高出113.37 c Gy。结论:常规放疗方案患者靶区实际受照剂量低于计划剂量,部分危及器官受到超量照射。自适应放疗方案可使靶区受照剂量与初始计划剂量保持一致,同时降低危及器官剂量,具有显著的剂量学优势。展开更多
文摘Deformable image registration (DIR) has been an important component in adaptive radiotherapy (ART). Our goal was to examine the accuracy of ART using the dice similarity coefficient (DSC) and to determine the optimal timing of replanning. A total of 22 patients who underwent volume modulated arc therapy (VMAT) for head and neck (H&N) cancers were prospectively analyzed. The planning target volume (PTV) was to receive a total of 70 Gy in 33 fractions. A second planning CT scan (rescan) was performed at the 15th fraction. The DSC was calculated for each structure on both CT scans. The continuous variables to predict the need for replanning were assessed. The optimal cut-off value was determined using receiver operating characteristic (ROC) curve analysis. In the correlation between body weight loss and DSC of each structure, weight loss correlated negatively with DSC of the whole face (rs = -0.45) and the face surface (rs = -0.51). Patients who required replanning tended to have experienced rapid weight loss. The threshold DSC was 0.98 and 0.60 in the whole face and the face surface, respectively. Patients who showed low DSC in the whole face and the face surface required replanning at a significantly high rate (P < 0.05 and P < 0.01). Weight loss correlated with DSC in both the whole face and the face surface (P < 0.05 and P < 0.05). The DSC values in the face predicted the need for replanning. In addition, weight loss tended to correlate with DSC. DIR during ART was found to be a useful tool for replanning.
文摘Surgical excision and postoperative radiotherapy are widely accepted therapeutic modalities for sinonasal teratocarcinosarcoma （SNTCS）. Previous studies have shown that intensity-modulated radiation therapy （IMRT） is safe and effective for the treatment of some sinonasal malignancies. We hypothesize that use of IMRT for SNTCS may result in clinical benefits. We report here two cases of SNTCS that were treated by IMRT. One patient was given extensive IMRT involving elective neck irradiation. Follow-up examinations revealed no recurrence and metastasis 3.5 years after IMRT. Another patient simultaneously suffered from multiple systematical diseases and was administered involved-field radiotherapy. He was found to have a marginal recurrence during the follow up and eventually died 8 months after disease diagnosis. It was suggested in this study that appropriate use of IMRT for the treatment of SNTCS may achieve excellent local control.
文摘Radiotherapy plays a critical role in the treatment of oral cavity squamous cell carcinoma as monotherapy in early stage cancer or combined with surgery and/or chemotherapy in advances ones.Recent developments in the imaging of cancer and radiation technology have allowed developing more precise delivery of treatment with recent data demonstrating improvement in survival and lessening of adverse toxics effects of radiation.This review will focus in the recent advances and current state-of-the-art in radiation oncology both external beam radiotherapy and brachytherapy.As complexity of cancer treatments increases a close coordination between head-neck surgeons and radiation oncologist is needed due to a significant proportion of patients will be treated with combined modality therapy.
文摘目的:研究基于形变配准头颈部肿瘤自适应放疗计划剂量学优势。方法:选取8例头颈部肿瘤患者行自适应放疗,每周扫描CT重新勾画靶区和危及器官并设计新的计划执行1周,直至分次治疗结束。以初始计划CT1为参考分别进行形变配准,每周实际受照剂量在CT1上累积得到自适应方案总受照剂量。同时计算初始计划剂量和虚拟常规放疗实际受照剂量作为对比。结果:8例患者自适应方案PTV D95剂量平均值较初始计划低45 c Gy,与初始计划剂量基本一致,剂量均匀性指数(HI)和适形指数(CI)分别提高0.002和0.031。左右腮腺Dmean分别降低24.37和127.50 c Gy,脑干和脊髓D_(max)平均降低189.87和111.37 c Gy。虚拟常规放疗PTV D95剂量较初始计划低334.87 c Gy,未达到初始计划剂量,HI和CI分别下降0.073和0.069,左右腮腺Dmean分别高出153.63和170.50 c Gy,脊髓D_(max)平均高出113.37 c Gy。结论:常规放疗方案患者靶区实际受照剂量低于计划剂量,部分危及器官受到超量照射。自适应放疗方案可使靶区受照剂量与初始计划剂量保持一致,同时降低危及器官剂量,具有显著的剂量学优势。
