Radiation Oncology, Northwestern University, Chicago, Illinois.
Radiation Oncology, Northwestern University, Chicago, Illinois.
Int J Radiat Oncol Biol Phys. 2019 Jan 1;103(1):28-37. doi: 10.1016/j.ijrobp.2018.08.034. Epub 2018 Aug 29.
A prospective clinical trial was conducted for patients undergoing cardiac sparing (CS) whole lung irradiation (WLI) using intensity modulated radiation therapy (IMRT). The 3 trial aims were (1) to demonstrate the feasibility of CS IMRT with real-time central quality control; (2) to determine the dosimetric advantages of WLI using IMRT compared with standard anteroposterior (AP) techniques; and (3) to determine acute tolerance and short-term efficacy after a protocol-mandated minimum 2-year follow-up for all patients.
All patients underwent a 3-dimensional chest computed tomography scan and a contrast-enhanced 4-dimensional (4D) gated chest computed tomography scan using a standard gating device. The clinical target volume was the entire bilateral 3-dimensional lung volume, and the internal target volume was the 4D minimum intensity projection of both lungs. The internal target volume was expanded by 1 cm to get the planning target volume. All target volumes, cardiac contours, and treatment plans were centrally reviewed before treatment. The different cardiac volumes receiving percentages of prescribed radiation therapy (RT) doses on AP and IMRT WLI plans were estimated and compared.
The target 20 patients were accrued in 2 years. Median RT dose was 15 Gy. Real-time central quality assurance review and plan preapproval were obtained for all patients. WLI using IMRT was feasible in all patients. Compared with standard AP WLI, CS IMRT resulted in a statistically significant reduction in radiation doses to the whole heart, atria, ventricles, and coronaries. One child developed cardiac dysfunction and pulmonary restrictive disease 5.5 years after CS IMRT (15 Gy) and doxorubicin (375 mg/m). The 2- and 3-year lung metastasis progression-free survival was 65% and 52%, respectively.
We have demonstrated the feasibility of WLI using CS IMRT and confirmed the previously reported advantages of IMRT, including superior cardiac protection and superior dose coverage of 4D lung volumes. Further studies are required to establish the efficacy and safety of this irradiation technique.
对接受心脏保护（CS）全肺照射（WLI）的患者进行了前瞻性临床试验，采用调强放疗（IMRT）。该 3 期临床试验的目的是：（1）证明使用实时中心质量控制的 CS-IMRT 的可行性；（2）确定与标准前后（AP）技术相比，使用 IMRT 的 WLI 的剂量学优势；（3）在所有患者完成协议规定的至少 2 年随访后，确定急性耐受和短期疗效。
所有患者均进行了三维胸部 CT 扫描和使用标准门控装置的对比增强 4 维（4D）门控胸部 CT 扫描。临床靶区为整个双侧三维肺体积，内部靶区为双肺的 4D 最小强度投影。内部靶区向外扩展 1cm 以获得计划靶区。所有靶区、心脏轮廓和治疗计划均在治疗前进行中心审查。比较了在 AP 和 IMRT-WLI 计划中不同心脏体积接受处方放疗（RT）剂量的百分比。
2 年内入组了 20 例患者。中位 RT 剂量为 15Gy。所有患者均获得了实时中心质量保证审查和计划预批准。所有患者均可行 IMRT-WLI。与标准 AP-WLI 相比，CS-IMRT 可显著降低整个心脏、心房、心室和冠状动脉的放射剂量。1 例患儿在 CS-IMRT（15Gy）和多柔比星（375mg/m）后 5.5 年出现心脏功能障碍和肺限制性疾病。2 年和 3 年的肺转移无进展生存率分别为 65%和 52%。
我们已经证明了 CS-IMRT 用于 WLI 的可行性，并证实了之前报道的 IMRT 的优势，包括更好的心脏保护和 4D 肺体积的更好剂量覆盖。需要进一步的研究来确定这种照射技术的疗效和安全性。
