Local Control For High-Grade Nonrhabdomyosarcoma Soft Tissue Sarcoma Assigned to Radiation Therapy on ARST0332: A Report From the Childrens Oncology Group

Million L, Hayes-Jordan A, Chi YY, Donaldson SS, Wolden S, Morris C, Terezakis S, Laurie F, Morano K, Fitzgerald TJ, Yock TI, Rodeberg DA, Anderson JR, Speights RA, Black JO, Coffin C, McCarville MB, Kao SC, Hawkins DS, Spunt SL, Randall RL. Local Control For High-Grade Nonrhabdomyosarcoma Soft Tissue Sarcoma Assigned to Radiation Therapy on ARST0332: A Report From the Childrens Oncology Group. Int J Radiat Oncol Biol Phys. 2021 Jul 1;110(3):821-830. doi: 10.1016/j.ijrobp.2021.01.051. Epub 2021 Feb 3. PubMed PMID: 33548339; PubMed Central PMCID: PMC8767764.

The ARST0332 trial for pediatric and young adults with nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) used risk-based treatment including primary resection with lower-than-standard radiation doses to optimize local control (LC) while minimizing long-term toxicity in those requiring radiation therapy (RT). RT for high-grade NRSTS was based on extent of resection (R0: negative margins, R1: microscopic margins, R2/U: gross disease/unresectable); those with >5 cm tumors received chemotherapy (CT; ifosfamide/doxorubicin). This analysis evaluates LC for patients assigned to RT and prognostic factors associated with local recurrence (LR). Patients aged <30 years with high-grade NRSTS received RT (55.8 Gy) for R1 ≤5 cm tumor (arm B); RT (55.8 Gy)/CT for R0/R1 >5 cm tumor (arm C); or neoadjuvant RT (45 Gy)/CT plus delayed surgery, CT, and postoperative boost to 10.8 Gy R0 <5 mm margins/R1 or 19.8 Gy for R2/unresected tumors (arm D).