CyberKnife 治疗肺门肿瘤的疗效和毒性报告。

OBJECTIVE

To report clinical efficacy and toxicity of fractionated CyberKnife radiosurgery for the treatment of hilar lung tumors.

METHODS

Patients presenting with primary and metastatic hilar lung tumors, treated using the CyberKnife system with Synchrony fiducial tracking technology, were retrospectively reviewed. Hilar location was defined as abutting or invading a mainstem bronchus. Fiducial markers were implanted by conventional bronchoscopy within or adjacent to tumors to serve as targeting references. A prescribed dose of 30 to 40 Gy to the gross tumor volume (GTV) was delivered in 5 fractions. Clinical examination and PET/CT imaging were performed at 3 to 6-month follow-up intervals.

RESULTS

Twenty patients were accrued over a 4 year period. Three had primary hilar lung tumors and 17 had hilar lung metastases. The median GTV was 73 cc (range 23-324 cc). The median dose to the GTV was 35 Gy (range, 30 - 40 Gy), delivered in 5 fractions over 5 to 8 days (median, 6 days). The resulting mean maximum point doses delivered to the esophagus and mainstem bronchus were 25 Gy (range, 11 - 39 Gy) and 42 Gy (range, 30 - 49 Gy), respectively. Of the 17 evaluable patients with 3 - 6 month follow-up, 4 patients had a partial response and 13 patients had stable disease. AAT t a median follow-up of 10 months, the 1-year Kaplan-Meier local control and overall survival estimates were 63% and 54%, respectively. Toxicities included one patient experiencing grade II radiation esophagitis and one patient experiencing grade III radiation pneumonitis. One patient with gross endobronchial tumor within the mainstem bronchus developed a bronchial fistula and died after receiving a maximum bronchus dose of 49 Gy.

CONCLUSION

CyberKnife radiosurgery is an effective palliative treatment option for hilar lung tumors, but local control is poor at one year. Maximum point doses to critical structures may be used as a guide for limiting toxicities. Preliminary results suggest that dose escalation alone is unlikely to enhance the therapeutic ratio of hilar lung tumors and novel approaches, such as further defining the patient population or employing the use of radiation sensitizers, should be investigated.

目的

报告使用分割 CyberKnife 放射外科治疗肺门肿瘤的临床疗效和毒性。

方法

回顾性分析了使用 CyberKnife 系统和 Synchrony 基准跟踪技术治疗的原发性和转移性肺门肿瘤患者。肺门部位定义为紧邻或侵犯主支气管。通过常规支气管镜将基准标记物植入肿瘤内或附近，作为靶向参考。将 30 至 40Gy 的处方剂量施用于大体肿瘤体积（GTV），分 5 次进行。在 3 至 6 个月的随访期间进行临床检查和 PET/CT 成像。

结果

在 4 年的时间里共入组了 20 名患者。其中 3 名患有原发性肺门肿瘤，17 名患有肺门转移瘤。GTV 的中位数为 73cc（范围 23-324cc）。GTV 的中位数剂量为 35Gy（范围 30-40Gy），在 5 至 8 天（中位数 6 天）内分 5 次进行。食管和主支气管的最大点剂量分别为 25Gy（范围 11-39Gy）和 42Gy（范围 30-49Gy）。在 17 名可评估的 3 至 6 个月随访患者中，4 名患者有部分缓解，13 名患者病情稳定。在中位随访 10 个月时，1 年的 Kaplan-Meier 局部控制和总生存率估计值分别为 63%和 54%。毒性包括 1 名患者出现 II 级放射性食管炎和 1 名患者出现 III 级放射性肺炎。1 名主支气管内有大体支气管内肿瘤的患者在接受 49Gy 的最大支气管剂量后发生支气管瘘并死亡。