Comparison between HyperArc and conventional VMAT approach for brain metastases
Yang Bo1, Yu Lang1, Wang Zhiqun1, Wang Bei1, Li Wenbo1, Zhang Jie1, Wang Xingliu2, Zhu Hao2, Wang Xiaoshen2, Lan Maoying2, Zhu Feng2, Zhang Zhen2, Hu Ke1, Zhang Fuquan1, Qiu Jie1
1Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China; 2Varian Medical System, Beijing 100176, China
Abstract：Objective To compare the dosimetric parameters and plan complexity between newly-delicated HyperArc (HA) and conventional volumetric-modulated arc therapy (VMAT) in the treatment of brain metastases. Methods For 26 patients with brain metastases, HA, conventional coplanar (Cop) and non-coplanar (Non-cop) VMAT plans with a prescription dose of 9Gy 3fx or 6Gy 5fx were generated. The dosimetric parameters for planning target volume (PTV), RTOG conformity index (RTOG CI), Paddick CI, homogeneity index (HI), gradient index (GI), maximum dose (Dmax) of brainstem and dose-volume parameters of brain-PTV(V2Gy-V26Gy) were statisticaly compared among these three approaches. In addition, the monitor unit (MU) and the plan complexity parameters (including MCSv and AlPO) were statistically compared. Results To prevent missed targets during treatment, all plans were established with RTOG CI of greater than 1.1. For Paddick CI, HA provided significantly higher conformity (0.89±0.019) than Non-cop (0.87±0.036, P=0.001) and Cop (0.88±0.017, P=0.003) VMAT. For GI, the fastest dose fall-off was noted in HA (3.35±0.64), followed by conventional Non-cop VMAT of (3.70±0.80), and conventional Cop VMAT of (4.90±1.85)(all P<0.05). For the brainstem sparing, HA plan performed better than Non-cop plan[(604.14±531.61) cGy vs.(682.75±558.22) cGy, P<0.05)]. For normal brain tissue sparing, HA approach showed significant reduction than conventional Cop and Non-cop VMAT (both P<0.05). For MU, HA approach (2872.60 ± 566.93) was significantly lower than those of Non-cop VMAT (3771.28 ± 1022.38, P<0.05) and Cop VMAT (4494.08 ± 1323.09, P<0.05). In terms of plan complexity, the MCSv of Cop plan was the lowest, indicating that the complexity was the highest (P<0.05). The AlPO of HA was significantly higher than that of Non-cop VMAT (P<0.05), suggesting that the complexity of HA plan was lower (P<0.05). Conclusion For the treatment of brain metastases, HA provides better conformity, more rapid dose fall-off, better sparing of brainstem and normal brain tissues and less plan complexity compared with conventional VMAT.
Yang Bo,Yu Lang,Wang Zhiqun et al. Comparison between HyperArc and conventional VMAT approach for brain metastases[J]. Chinese Journal of Radiation Oncology, 2021, 30(9): 876-881.
[1] Mehta MP, Tsao MN, Whelan TJ, et al.The American Society for Therapeutic Radiology and Oncology (ASTRO) evidence-based review of the role of radiosurgery for brain metastases[J]. Int J Radiat Oncol Biol Phys, 2005, 63(1):37-46.DOI:10.1016/j.ijrobp.2005.05.023. [2] Patchell RA.The management of brain metastases[J]. Cancer Treat Rev, 2003, 29(6):533-540.DOI:10.1016/s0305-7372(03)00105-1. [3] Kocher M, Soffietti R, Abacioglu U, et al.Adjuvant whole-brain radiotherapy versus observation after radiosurgery or surgical resection of one to three cerebral metastases:results of the EORTC 22952-26001 study[J]. J Clin Oncol, 2011, 29(2):134-141.DOI:10.1200/JCO.2010.30.1655. [4] Aoyama H, Shirato H, Tago M, et al.Stereotactic radiosurgery plus whole-brain radiation therapy vs. stereotactic radiosurgery alone for treatment of brain metastases:a randomized controlled trial[J]. JAMA, 2006, 295(21):2483-2491.DOI:10.1001/jama.295.21.2483. [5] Brown PD, Jaeckle K, Ballman KV, et al.Effect of radiosurgery alone vs. radiosurgery with whole brain radiation therapy on cognitive function in patients with 1 to 3 brain metastases:a randomized clinical trial[J]. JAMA, 2016, 316(4):401-409.DOI:10.1001/jama.2016.9839. [6] Hartgerink D, Swinnen A, Roberge D, et al.LINAC based stereotactic radiosurgery for multiple brain metastases:guidance for clinical implementation[J]. Acta Oncol, 2019, 58(9):1275-1282.DOI:10.1080/0284186X.2019.1633016. [7] Wolff HA, Wagner DM, Christiansen H, et al.Single fraction radiosurgery using Rapid Arc for treatment of intracranial targets[J]. Radiat Oncol, 2010, 5(1):77-77.DOI:10.1186/1748-717X-5-77. [8] Ning ZH, Jiang JT, Li XD, et al.Coplanar VMAT vs. noncoplanar VMAT in the treatment of sinonasal cancer[J]. Strahlenther Onkol, 2015, 191(1):34-42.DOI:10.1007/s00066-014-0760-8. [9] Ohira S, Ueda Y, Akino Y, et al.HyperArc VMAT planning for single and multiple brain metastases stereotactic radiosurgery:a new treatment planning approach[J]. Radiat Oncol, 2018, 13(1):13-13.DOI:10.1186/s13014-017-0948-z. [10] Ruggieri R, Naccarato S, Mazzola R, et al.Linac-based VMAT radiosurgery for multiple brain lesions:comparison between a conventional multi-isocenter approach and a new dedicated mono-isocenter technique[J]. Radiat Oncol, 2018, 13(1):38.DOI:10.1186/s13014-018-0985-2. [11] Minniti G, Esposito V, Clarke E, et al.Multidose stereotactic radiosurgery (9Gy × 3) of the postoperative resection cavity for treatment of large brain metastases[J]. Int J Radiat Oncol Biol Phys, 2013, 86(4):623-629.DOI:10.1016/j.ijrobp.2013.03.037. [12] Ohira S, Sagawa T, Ueda Y, et al.Effect of collimator angle on HyperArc stereotactic radiosurgery planning for single and multiple brain metastases[J]. Med Dosim, 2020, 45(1):85-91.DOI:10.1016/j.meddos.2019.07.004. [13] Clark GM, Popple RA, Prendergast BM, et al.Plan quality and treatment planning technique for single isocenter cranial radiosurgery with volumetric modulated arc therapy[J]. Pract Radiat Oncol, 2012, 2(4):306-313.DOI:10.1016/j.prro.2011.12.003. [14] Paddick I, Lippitz B.A simple dose gradient measurement tool to complement the conformity index[J]. J.Neurosurg, 2006, 105 suppl (Suppl):194-201.DOI:10.3171/sup.2006.105.7.194. [15] Reynolds TA, Jensen AR, Bellairs EE, et al.Dose gradient index for stereotactic radiosurgery/radiation therapy[J]. Int J Radiat Oncol Biol Phys, 2020, 106(3):604-611.DOI:10.1016/j.ijrobp.2019.11.408. [16] McNiven AL, Sharpe MB, Purdie TG.A new metric for assessing IMRT modulation complexity and plan deliverability[J]. Med Phys, 2010, 37(2):505-515.DOI:10.1118/1.3276775. [17] Masi L, Doro R, Favuzza V, et al.Impact of plan parameters on the dosimetric accuracy of volumetric modulated arc therapy[J]. Med Phys, 2013, 40(7):071718.DOI:10.1118/1.4810969. [18] Zygmanski P, Kung JH.Method of identifying dynamic multileaf collimator irradiation that is highly sensitive to a systematic MLC calibration error[J]. Med Phys, 2001, 28(11):2220-2226.DOI:10.1118/1.1408284. [19] Korytko T, Radivoyevitch T, Colussi V, et al.12Gy gamma knife radiosurgical volume is a predictor for radiation necrosis in non-AVM intracranial tumors[J]. Int J Radiat Oncol Biol Phys, 2006, 64(2):419-424.DOI:10.1016/j.ijrobp.2005.07.980. [20] Alongi F, Fiorentino A, Gregucci F, et al.First experience and clinical results using a new non-coplanar mono-isocenter technique (HyperArcTM) for Linac-based VMAT radiosurgery in brain metastases[J]. J Cancer Res Clin Oncol, 2019, 145(1):193-200.DOI:10.1007/s00432-018-2781-7. [21] Ruggieri R, Naccarato S, Mazzola R, et al.Linac-based radiosurgery for multiple brain metastases:Comparison between two mono-isocenter techniques with multiple non-coplanar arcs[J]. Radiother Oncol, 2019, 132(1):70-78.DOI:10.1016/j.radonc.2018.11.014. [22] Slosarek K, Bekman B, Wendykier J, et al.In silico assessment of the dosimetric quality of a novel, automated radiation treatment planning strategy for linac-based radiosurgery of multiple brain metastases and a comparison with robotic methods[J]. Radiat Oncol, 2018, 13(1):41-41.DOI:10.1186/s13014-018-0997-y. [23] Vergalasova I, Liu H, Alonso-Basanta M, et al.Multi-institutional dosimetric evaluation of modern day stereotactic radiosurgery (SRS) treatment options for multiple brain metastases[J]. Front Oncol, 2019, 9:483.DOI:10.3389/fonc.2019.00483. [24] Wang SC, Wang X, He YB, et al.A dosimetric comparison of the fixed-beam IMRT plans using different leaf width of multileaf collimators for the intermediate risk prostate cancer[J]. Radiat Phys Chem, 2016, 127:210-221.DOI:10.1016/j.radphyschem.2016.07.008.
2021, Vol. 30 
