ESTRO 2020 Abstract Book

S1104 ESTRO 2020

cohort due to local infection. Minor self-limited complications presented as limited-bleeding, local infection, acute seroma or delayed wound healing, were documented in 5p (7,1%) acutely and 2p (2.8%) lately (>1month after PHDRBT or WBRT). Acute RTOG skin and subcutaneous toxicity were reported 68,6%, 28,6% and 2,8% for G0, G1 and G2 respectively. Re-operation due to positive margins was required in 1p (1,4 %). Regarding dosimetry parameters, the median CTV volume, V100 and V150 is 34,75cc (10-93,52cc), 45,73cc (7,75-106,95cc) and 5,81cc (1,9-26.6cc), the median DHI and DNR is 0,8 (0,49- 0,9) and 0,24 (0,1-0,4).Double plane were the predominant (61,4%) with a median of 11 catheters (range 7-18). The rest of GEC-ESTRO recommendation constrains were correctly full-filled. With a median follow up of 15 months (1-32m) only 1p (1,4%) developed distant metastasis on her 11 month of follow up. Early cosmetic evaluation on patients with more than one-year follow up (60% of the serie), were 54,8% excellent, 40,5% good and 4,8% fair, respectively. Conclusion Ultra-accelerated four-fractions partial breast irradiation (4fAPBI) using minimally invasive perioperative multi- cathether breast implant (FHIOMBI) is feasible and safe without acute events of G3 RTOG toxicity. Preliminary data show excellent clinical outcome and cosmesis, offering promising results although further follow-up is required. Partial or Whole Breast Irradiation after BCS: 20-year Results of a Randomized Clinical Trial

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