Seravalli Enrica, Kroon Petra S, Buatti John M, Hall Matthew D, Mandeville Henry C, Marcus Karen J, Onal Cem, Ozyar Enis, Paulino Arnold C, Paulsen Frank, Saunders Daniel, Tsang Derek S, Wolden Suzanne L, Janssens Geert O
Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, The Netherlands.
Departments of Radiation Oncology, University of Iowa, Iowa City, USA.
Clin Transl Radiat Oncol. 2021 Jun 4;29:71-78. doi: 10.1016/j.ctro.2021.05.008. eCollection 2021 Jul.
Magnetic resonance guided radiotherapy (MRgRT) has been successfully implemented for several routine clinical applications in adult patients. The purpose of this study is to map the potential benefit of MRgRT on toxicity reduction and outcome in pediatric patients treated with curative intent for primary and metastatic sites.
Between May and August 2020, a survey was distributed among SIOPE- and COG-affiliated radiotherapy departments, treating at least 25 pediatrics patients annually and being (candidate) users of a MRgRT system. The survey consisted of a table with 45 rows (clinical scenarios for primary (n = 28) and metastatic (n = 17) tumors) and 7 columns (toxicity reduction, outcome improvement, PTV margin reduction, target volume daily adaptation, online re-planning, intrafraction motion compensation and on-board functional imaging) and the option to answer by 'yes/no' . Afterwards, the Dutch national radiotherapy cohort was used to estimate the percentage of pediatric treatments that may benefit from MRgRT.
The survey was completed by 12/17 (71% response rate) institutions meeting the survey inclusion criteria. Responders indicated an 'expected benefit' from MRgRT for toxicity/outcome in 7% (for thoracic lymphomas and abdominal rhabdomyosarcomas)/0% and 18% (for mediastinal lymph nodes, lymph nodes located in the liver/splenic hilum, and liver metastases)/0% of the considered scenarios for the primary and metastatic tumor sites, respectively, and a 'possible benefit' was estimated in 64%/46% and 47%/59% of the scenarios. When translating the survey outcome into a clinical perspective a toxicity/outcome benefit, either expected or possible, was anticipated for 55%/24% of primary sites and 62%/38% of the metastatic sites.
Although the benefit of MRgRT in pediatric radiation oncology is estimated to be modest, the potential role for reducing toxicity and improving clinical outcomes warrants further investigation. This fits best within the context of prospective studies or registration trials.
磁共振引导放射治疗（MRgRT）已成功应用于成人患者的多种常规临床治疗。本研究旨在探讨MRgRT对接受根治性治疗的原发性和转移性病灶的儿科患者在降低毒性和改善预后方面的潜在益处。
在2020年5月至8月期间，向隶属于国际小儿肿瘤学会（SIOPE）和儿童肿瘤协作组（COG）的放射治疗科室发放了一份调查问卷，这些科室每年至少治疗25名儿科患者且是MRgRT系统的（潜在）用户。该调查问卷包含一个有45行（原发性肿瘤28种临床情况、转移性肿瘤17种临床情况）和7列（降低毒性、改善预后、计划靶体积（PTV）边界缩小、靶区体积每日调整、在线重新计划、分次内运动补偿和机载功能成像）的表格，回答选项为“是/否”。之后，利用荷兰国家放射治疗队列来估计可能从MRgRT中获益的儿科治疗的百分比。
符合调查纳入标准的17家机构中有12家（回复率71%）完成了调查。回复者表示，对于原发性和转移性肿瘤部位，分别有7%（针对胸段淋巴瘤和腹部横纹肌肉瘤）/0%和18%（针对纵隔淋巴结、位于肝/脾门的淋巴结以及肝转移瘤）的考虑场景中，MRgRT对毒性/预后有“预期益处”，在64%/46%和47%/59%的场景中估计有“可能益处”。从临床角度将调查结果转化后，预计55%/24%的原发性部位和62%/38%的转移性部位会有预期或可能的毒性/预后益处。
尽管估计MRgRT在儿科放射肿瘤学中的益处不大，但在降低毒性和改善临床结局方面的潜在作用值得进一步研究。这最适合在前瞻性研究或注册试验的背景下进行。
