(P 319) HYPO-FRACTIONATED RADIATION THERAPY FOR THE EXTREMITY SOFT TISSUE SARCOM IN ELDERLY AND DISABLED.

Objective:

Introduction:
The standards in treatment of soft tissue sarcoma are continuously evolving. The role of radiation therapy (RT) in reducing local recurrence is well established.
According to the "Executive Summary of an ASTRO Clinical Practice Guideline" , neo-adjuvant RT (NART) is preferable as opposite to postoperative RT (PORT).
The recently published phase 2 study of hypo-fractionated NART showed compatible results to standard radiation in terms of toxicity with similar survival.
Elderly or disabled patients are unable to participate in the standard RT protocol due to its length.
We have previously published our results of hypo fractionated PORT in elderly patients.
The shifting paradigm in replacement of RT before the surgery was applied to this category of
patients in our center. We, herein report on results of RT (mostly NART) in last decade.

Methods: Twenty consecutive patients with high grade soft tissue sarcoma of the extremities were treated in our tertiary center for soft-tissue sarcoma between the years 2015-2019. This is a retrospective EMR chart review looking at demographics, oncologic outcomes and complications.

Results: The median age of patients was 80.2 (62-92). Male/female ratio was 14/6. Anatomic location was upper extremity in 35% and lower extremity in 65%.
All cases were treated by hypo-fractionated doses of 39-45 Gy provided in 13-15 fractions. Nine patients were treated by NART and 11 by PORT. Mild to moderate acute toxicity developed in 2 patients (22.2%) in NART and in 1 patient (9%) in PORT. Significant wound complications including infection, dehiscence, re-hospitalization and surgery occurred in 4 (44.5%) patients in NART and 2 (18%) patients in PORT.
Long term complications such as fibrosis and joint stiffness developed in 2 (22.2%) patients who received NART and 1(9%) patient in PORT.
Local recurrence was developed in 3 patients in NART and in 2 in PORT treatment. The disease free survival was 30.3 (2-81), 30.8 (3-72) and 29.8 (2-81) month in all cohort, NART or PORT, respectively. The median survival was 38.7 (4-81), 38.3(16-72) and 39 (4-81) in all cohort, NART and PORT accordingly.

Conclusion: The standards Radiotherapy treatment of soft tissue sarcoma is hard to attain in the elderly and disabled patients.
Short course radiation therapy, neo-adjuvant or adjuvant radiation therapy for soft tissue sarcoma in elderly or disabled patients achieves similar rates of acute and long term toxicity in our study, compared to historical data.
The decreased reserves in elderly patients should always be considered in selecting the timing and fractionation of the treatment provided to the patient.
The relatively high incidence of local recurrence observed in patients with initially worst prognostic factors (in 2 patients treated for local recurrence after previous surgery, and one patient who was diagnosed with aggressive angiosarcoma). The DFS and median survival in our study are not compromised.
Our study supports results of recently published research, which shows the efficacy of preoperative hypo-fractionated radiotherapy in soft tissue sarcoma.
The use of short NART in the treatment of STS in elderly patients. Should be encouraged after careful assessment of risk factors.