Leiser Dominic, Dantonello Tobias, Krcek Reinhardt, Grawehr Leonie, Rössler Jochen, Calaminus Gabriele, Weber Damien Charles
Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen, Switzerland.
Department of Pediatrics, Division of Pediatric Hematology/Oncology, Inselspital, University of Bern, 3012 Bern, Switzerland.
Cancers (Basel). 2025 Aug 26;17(17):2771. doi: 10.3390/cancers17172771.
RMS is the most common soft tissue sarcoma in children. Pencil beam scanning proton therapy (PBS PT) enables highly conformal dose delivery with reduced exposure to surrounding healthy structures, making it particularly suited for RMS in critical anatomical regions. Long-term clinical outcome data for this new radiation technique are scarce.
This study reports long-term outcomes and quality of life after PBS PT in children and adolescents with rhabdomyosarcoma (RMS).
We retrospectively reviewed 114 children and adolescents with RMS (mostly embryonal, = 100; 87.7%) treated between 2000 and 2020. Their median age was 4.6 years (range, 0.3-18). All received systemic chemotherapy according to prospective protocols. The median total PT dose delivered was 52 Gy (RBE; range, 41.4-64.8).
After a median follow-up period of 7.1 years (range, 0.3 to 17 years), we observed 26 failures overall; 21 (80.8%) occurred in-field. The 5-year local control and overall survival were 81.2% and 81%, respectively. The composite endpoint (non-ocular grade ≥3 toxicity- and failure-free survival) counting the first occurrence of any failure (local or distant), death, or non-ocular CTCAE v5.0 grade ≥3 toxicity was 77.3% at 5 years. At the start of PT, parents and children reported a quality of life significantly worse than that of a German normative group, but during the follow-up period, their scores improved to normal values in nearly all domains within two years.
Our two decades of experience with PBS PT provide data that reflect good local control rates and minimal late non-ocular grade 3 toxicity. We also show that quality of life returned to normal scores in nearly all domains within 2 years. Children and adolescents with RMS seem to benefit from PBS PT in terms of toxicity and quality of life, but further prospective, multi-institutional comparative trials are needed.
横纹肌肉瘤（RMS）是儿童最常见的软组织肉瘤。笔形束扫描质子治疗（PBS PT）能够实现高度适形的剂量输送，减少对周围健康组织的照射，使其特别适用于关键解剖区域的RMS。关于这种新放射技术的长期临床结果数据很少。
本研究报告了接受PBS PT治疗的儿童和青少年横纹肌肉瘤（RMS）的长期结局和生活质量。
我们回顾性分析了2000年至2020年间接受治疗的114例儿童和青少年RMS患者（大多数为胚胎型，n = 100；87.7%）。他们的中位年龄为4.6岁（范围0.3 - 18岁）。所有患者均根据前瞻性方案接受全身化疗。质子治疗的中位总剂量为52 Gy（相对生物效应剂量；范围41.4 - 64.8）。
中位随访期为7.1年（范围0.3至17年），我们共观察到26例治疗失败；其中21例（80.8%）发生在射野内。5年局部控制率和总生存率分别为81.2%和81%。复合终点（非眼部3级及以上毒性和无失败生存）定义为首次出现任何失败（局部或远处）、死亡或非眼部CTCAE v5.0 3级及以上毒性，5年时为77.3%。在质子治疗开始时，家长和儿童报告的生活质量明显低于德国正常人群组，但在随访期间，他们的评分在两年内几乎所有领域都改善到了正常水平。
我们二十年的PBS PT经验提供的数据表明局部控制率良好，晚期非眼部3级毒性最小。我们还表明，生活质量在两年内几乎所有领域都恢复到了正常评分。患有RMS的儿童和青少年似乎在毒性和生活质量方面从PBS PT中获益，但需要进一步的前瞻性、多机构比较试验。
