ESTRO 2022 - Abstract Book

S1036

Abstract book

ESTRO 2022

Conclusion Early results suggest that RSAPBI with fiducial tracking is a well-tolerated technique for the adjuvant treatment of early- stage breast cancer patients. Acute radiation dermatitis may be mitigated by further decreasing lumpectomy cavity margins and by limiting the skin Dmax to < 32 Gy.

PO-1227 Predictors of cardiac dose sparing in Deep Inspiratory Breath Hold for left breast cancer patients

P. Nagpal 1 , D.S. Pruthi 1 , M. Pandey 1

1 Action Cancer Hospital, Radiation Oncology, New Delhi, India

Purpose or Objective Radiation therapy for left breast cancer results in significant exposure to heart resulting in long term cardiac morbidity. This exposure can be reduced by performing Deep Inspiratory Breath Hold (DIBH) technique however no patient selection criteria or predictive parameters can identify patients on free breathing CT simulation, who will have significant benefit with this technique. This study intends to find some predictive parameters measured on free breathing simulation scan which can help to select such patients. Materials and Methods A total of 35 patients of left breast cancer post-surgery were recruited in the study. All patients underwent 2- 3 sessions of DIBH coaching followed by planning Computed Tomography (CT) scan in both free breathing (FB) phase and DIBH phase. Various anatomical parameters like Cardiac Contact Distance para-sagittal (CCDps), axial (CCDax), Heart Chest Distance (HCD) and D was measured on FB scan and were correlated with mean heart dose achieved in DIBH scan. Another parameter was the maximal heart distance (D)which was measured as the perpendicular distance to the farthest point on heart from a line drawn from left end of sternum to the anterior border of left latissimus dorsi at the level of the dome of right diaphragm. Results Dose to normal structures namely heart and lung were drastically reduced for DIBH scan over FB scan. V5, V10, V20 of heart also followed similar reduction. Mean dose to heart in free breathing scan was 5.34 Gy while in DIBH scan was 2.79 Gy which was statistically significant with p value of <0.0001. V20 left lung was 21.3 % in FB Scan while it was 19.5 % in DIBH scan which was also statistically significant. Mean CCDax and CCDps on FB scan were 6.67 cm and 3.88 cm respectively while mean HCD and D (maximal heart distance) were 2.17 cm and 2.88 cm. Patients who had CCDax> 7 cm and CCDps> 3.5 cm had less benefit from doing DIBH technique, although CCD ax did not correlate significantly with these results. HCD on FB scan was inversely correlated with mean heart dose in DIBH scan with a cutoff value of 2.1 cm. Amongst all the parameters measured, CCDps and D had statistically significant positive correlation with the mean heart dose in DIBH phase while HCD had negative correlation which was statistically significant. The parameter ‘D’ which we assessed had positive correlation with all heart dosimetric parameters but statistically significant results were associated with mean heart dose and V20. Conclusion Cardiac parameters on FB scan like CCDps, HCD and D predicts the patients with usual cardiac risk who will benefit most with DIBH techniques setting an arbitrarily cutoff value. In our study, all patients were benefitted with the use of DIBH technique but the benefit was most pronounced with the cutoff values suggested above. S. Dicuonzo 1 , F. Colombo 2 , L. Bergamaschi 2 , G. Piperno 1 , A. Ferrari 1 , M.C. Leonardi 1 , M. Zaffaroni 1 , M.A. Zerella 1 , D.P. Rojas 1 , M.A. Gerardi 1 , A. Morra 1 , E. Rondi 3 , S. Vigorito 3 , F. Cattani 3 , R. Orecchia 4 , B.A. Jereczek-Fossa 1 , S. Frassoni 5 , V. Bagnardi 5 1 European Institute of Oncology IRCCS, Department of Radiotherapy, Milan, Italy; 2 University of Milan/European Institute of Oncology IRCCS, Department of Oncology and Hemato-Oncology/Department of Radiotherapy, Milan, Italy; 3 European Institute of Oncology IRCCS, Unit of Medical Physic, Milan, Italy; 4 European Institute of Oncology IRCCS, Scientific Directorate, Milan, Italy; 5 University of Milan-Bicocca, Department of Statistics and Quantitative Methods, Milan, Italy Purpose or Objective Outcomes of patients with HER2-breast cancer brain metastasis (BCBM) remain suboptimal. To evaluate the effectiveness of local therapy (stereotactic radiosurgery [SRS]) we analyzed local control (LC), distant intra-cranial control (DBC) and overall survival (OS) in patients with metachronous HER2-BCBM Materials and Methods Data of consecutive patients who underwent SRS with CyberKnife (Accuray, USA) from February 2012 to November 2020 were retrospectively analysed. Parameters included demographics, histology and primary tumour characteristics, presence and control of extracranial disease, number of lesions, single and total gross target volume (GTV). Preliminary results of OS, LC and DBC at the last follow up were evaluated. This retrospective study was notified to our Ethical Committee ( IEO N93/11 ) PO-1228 Radiosurgery in her2-breast cancer brain metastasis:local control and overall survival in 32 women

Results