Siva S, Kirby K, Caine H, Pham D, Kron T, Te Marvelde L, Whalley D, Stevens M J, Foroudi F, MacManus M, Ball D, Eade T
Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Australia; Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Clin Oncol (R Coll Radiol). 2015 Jun;27(6):353-61. doi: 10.1016/j.clon.2015.01.004. Epub 2015 Feb 16.
To compare outcomes of single-fraction and multi-fraction stereotactic ablative body radiotherapy (SABR) for pulmonary metastases.
A retrospective review from two academic institutions of patients with one to three pulmonary metastases staged with (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans. For single-fraction SABR, 26 Gy was prescribed for peripheral targets and 18 Gy for central targets. In the multi-fraction cohort, 48 Gy/4 or 50 Gy/5 was prescribed for peripheral targets and 50 Gy/5 was prescribed for central targets. Three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans were delivered using heterogeneity corrections. Conformity indices at an intermediate dose (R50%) and at a high dose (R100%) were used to assess a relationship with the planning target volume (PTV). Overall survival, local and distant progression and toxicity rates were analysed from the date of treatment completion.
Between February 2010 and June 2013, 65 patients with 85 pulmonary metastases were reviewed. The median follow-up was 2.1 years. Metastases most commonly originated from colorectal cancer (31%), followed by non-small cell lung cancer (25%). 3D-CRT was used in 52 targets, IMRT in 21 and VMAT in 12. 3D-CRT showed a lower median R50% (P=0.01), but a higher median R100% than IMRT/VMAT (P=0.04). The R50% index was inversely correlated to the PTV with all techniques (P=0.01). Overall survival at 1 and 2 years in all patients was 93% (95% confidence interval 87-100%) and 71% (95% confidence interval 58-86%), respectively. The 2 year freedom from local and distant progression was 93% (95% confidence interval 86-100%) and 38% (95% confidence interval 27-55%), respectively. There were no significant differences between overall survival (P=0 .14), time to distant progression (P=0.06) or toxicity rates (P=0.75) between single- and multi-fraction cohorts.
We report comparable local control, overall survival and toxicity rates between single-fraction and multi-fraction SABR treatments in patients with FDG-PET-staged pulmonary oligometastases. We propose a guideline for R50% conformity incorporating 3D-CRT/IMRT/VMAT techniques with heterogeneity corrected planning algorithms.
比较单次分割与多次分割立体定向消融体部放疗（SABR）治疗肺转移瘤的疗效。
对两家学术机构中经（18）F-氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描（FDG-PET/CT）分期为1至3个肺转移瘤的患者进行回顾性研究。对于单次分割SABR，外周靶区处方剂量为26 Gy，中央靶区为18 Gy。在多次分割组中，外周靶区处方剂量为48 Gy/4或50 Gy/5，中央靶区为50 Gy/5。采用三维适形放疗（3D-CRT）、调强放疗（IMRT）和容积调强弧形放疗（VMAT）计划，并进行了不均匀性校正。使用中间剂量（R50%）和高剂量（R100%）的适形指数来评估与计划靶体积（PTV）的关系。从治疗完成日期开始分析总生存、局部和远处进展以及毒性率。
2010年2月至2013年6月，对65例有85个肺转移瘤的患者进行了回顾性研究。中位随访时间为2.1年。转移瘤最常见起源于结直肠癌（31%），其次是非小细胞肺癌（25%）。52个靶区采用3D-CRT，21个采用IMRT，12个采用VMAT。3D-CRT的中位R50%较低（P = 0.01），但中位R100%高于IMRT/VMAT（P = 0.04）。所有技术的R50%指数与PTV呈负相关（P = 0.01）。所有患者1年和2年的总生存率分别为93%（95%置信区间87 - 100%）和71%（95%置信区间58 - 86%）。2年局部和远处无进展率分别为93%（95%置信区间86 - 100%）和38%（95%置信区间27 - 55%）。单次分割组与多次分割组在总生存（P = 0.14）、远处进展时间（P = 0.06）或毒性率（P = 0.75）方面无显著差异。
我们报告了在FDG-PET分期的肺寡转移瘤患者中，单次分割与多次分割SABR治疗在局部控制、总生存和毒性率方面具有可比性。我们提出了一个R50%适形性的指南，纳入了3D-CRT/IMRT/VMAT技术以及不均匀性校正的计划算法。
