(P 248) RESULTS OF A NEOADJUVANT REGIMEN USING A FIXED DOSE OF ADRIAMYCIN AS AN ELECTRON AFFINIC AGENT WITH 27GY FOLLOWED BY WIDE LOCAL RESECTION OF SOFT TISSUE SARCOMAS

Objective: There are a variety of different preoperative therapies used in the treatment of soft tissue sarcoma (STS). These include radiation alone (50-65 Gy), interstitial implants, neoadjuvant chemotherapy and chemotherapy with radiation. Most of the STS present as stage III lesions for which local control is critical for long-term survival. Wound complications arising with preoperative radiation after 55 Gy is greater than 50%. The preoperative therapies are aimed at reducing the size of the tumor and marginating the lesion to facilitate obtaining adequate margins necessary for local control. The UCLA protocol of Eilbert & Morton showed that Adriamycin used as an electron affinic agent gave adequate rates of local control in sarcomas that were irradiated with 27 Gy (35 Gy created too many wound complications, and 23 Gy had poor local control). The purpose of this study was to retrospectively look at local control, wound complication rate, and metastatic spread of STS in patients receiving Adriamycin at 30 mg IV over 3 days, followed by electron beam irradiation intent with 10 treatments of 2.7 Gy per day for 2 weeks.Methods: All patients in this cohort presented with Stage II, III, or I-B STS near vital structures. The 0- patients were staged with CT and MRIs locally, CT of the lung, Tri-phase bone scans, and underwent needle biopsies. After diagnosis, they were given 3 days of IV Adriamycin 30 mg per day followed by electron beam therapy. To perform this, radiation fields were designed to include the tumor as visualized on MRI and CT scans with 5-7 cm proximal and distal margins. Most commonly, opposed fields were used, and obliqued with blocking wedges, where appropriate. Computer dose distributions were obtained. In most recent years, a CT stimulator and intensity modulated segments have been used to reduce dose inhomogeneity. The cohort consisted of patient data from 1991-2020, allowing for 2 year follow-up. No Stage IV STS at presentation were included in this study. After receiving radiation, patients were given 2-3 weeks off prior to re-staging, followed by surgical resection. Pathology was carefully analyzed for exact surgical margins or contamination. All patients in this group had wide surgical margins qualified by gross specimen analysis and histologic examination.Results: Of the 155 patients in the cohort, there were 16 different sarcoma subtypes at 16 anatomical sites treated with STS protocol (Table 1 & 2). Following STS protocol, 5 (3.2%) recurred locally, 38 (24.5%) metastasized, and 112 (72.3%) had no recurrence. 57 (40%) had minor wound healing complications prior to using hyperbaric oxygen therapy (HBO). This complication was reduced to 30 (19%) with the use of HBO. There were 18 (11.6%) major wound complications, 1 of which required an amputation. Induction of a fibrous rind was seen 2-3 weeks after completion of the radiation histologically (Figure 1 & 2). This allowed for closer resection margins. Only 2 patients progressed with metastatic disease to the lung during the STS protocol. A total of 16 amputations were necessary in order to get wide margins.Conclusion: The use of IV Adriamycin 90 mg over 3 days coupled with 27 Gy preoperatively, followed by wide resection (STS protocol), gave adequate rates of local control (96.8%), which is comparable to or better than the use of standard radiation (50-65 Gy) which also requires an additional 4 weeks to complete. This allowed for more functional resections with preservation of vital structures in a shorter window of time. Most of the complications were wound healing and were treated conservatively but improved with HBO (19% vs 40% without HBO). Metastases for the stage III lesions were similar to other study groups at 24.5% for STS.Table 1 STS.docxTable 2 STS.docxFigure 1 STS.docxFigure 2 STS.docx