부산대학교 도서관

The standard pre-operative radiation therapy (RT) dose of 50 Gy in 25 daily fractions for soft tissue sarcoma (STS) contributes to excellent local control and is associated with major wound complications (MWC) in approximately 35% of patients. We sought to prospectively investigate whether a radiobiologically equivalent dose given in a 3-week course of 42.75 Gy in 15 daily fractions confers a higher risk of MWC. We conducted a prospective, single-arm, non-randomized trial of hypofractionated pre-operative RT consisting of 42.75 Gy in 15 once-daily fractions followed by surgery 4-8 weeks after RT completion for adult patients with biopsy-confirmed, non-metastatic, previously un-irradiated STS of the extremity or superficial trunk. Patients (n=120) were enrolled from December 2018 to January 2021. The primary outcome of the study was to determine the rate of MWC within 120 days of surgery among patients treated with the trial regimen. Safety was monitored using a Bayesian stopping rule One-Arm Time-To-Event Simulator which compared development of MWC at 120 days post-surgery among patients on study to the historical rate of 35%. The Kaplan-Meier method was used to estimate outcomes. Median follow-up from surgery was 23 months (interquartile range [IQR] 15-29). Median age was 60 years (IQR 48-69) and median maximum tumor size was 7.6 cm (IQR 4.5-12.8). A majority of the patients had lower extremity (LE) tumors (n=78, 65%; upper extremity (UE), n=20, 17%; trunk, n=22, 18%). Tumor grade was: high in 51% (n=61), intermediate in 23% (n=27), low in 8% (n=9), or not gradable in 19% (n=23). All patients received 42.75 Gy (or CGE) in 15 once-daily fractions with either: IMRT (n=57, 48%), 3D-RT (n=55, 46%), electrons (n=5, 4%), or protons (n=3, 3%). None experienced acute skin toxicity of CTCAE v4.0 > or = grade 3. Thirty-seven (31%, 95% CI: 24-40%) patients developed MWC within 120 days of surgery (median, 37 days (IQR 25-59)). Six patients (5%) developed local recurrence at a median 16 mos (IQR 7-17); 4 in the RT field, 1 at the field margin, and 1 wide of field. Actuarial 2-year local control is 93% (95% CI: 85-97%). Our prospective non-randomized clinical trial revealed that a hypofractionated pre-operative radiotherapy dosing regimen of 42.75 Gy in 15 once-daily fractions resulted in a MWC rate that was not higher than accepted historical rates. Early analyses show rates of local recurrence that are consistent with those observed with standard fractionation. These data support that this 3-week regimen may offer a safe, effective, and more convenient alternative to 50 Gy in 25 daily fractions for patients undergoing pre-operative RT for STS. [ABSTRACT FROM AUTHOR]