ESTRO 2021 Abstract Book

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ESTRO 2021

optimal adjuvant treatment in a group of very low risk breast cancer patients with basically excellent prognosis. The impact of radiotherapy, endocrine therapy, both or none, on LC, OS was analyzed. The trails are conclusive that adding radiotherapy alone or combined with ET increase LC with no OS impact. While the absolute risk reduction with the addition of therapy is low, the options of omission of radiotherapy or endocrine therapy were also proposed. A few studies explored that idea. Radiotherapy alone, endocrine therapy alone and combined therapies were analyzed in term of LR risk in BASO trial. Receipt of both therapies was significantly associated with lower LR rates than receipt of either alone but LR rates did not differ significantly between the two single therapies (BASO Trial). Significant but comparable risk reduction was observed with RT (HR=0,36 ) and ET (HR=35). In another trial there was no difference between monotherapy with either Tamoxifen or radiotherapy, compared with combined endocrine and radiotherapy. Based on these results, women who cannot tolerate or opt to omit endocrine therapy, may favor the inclusion of adjuvant radiotherapy. It is important to emphasize the possibility of alternative radiotherapy techniques with reduced overall time and risk of complications. Radiotherapy without endocrine therapy may have similar clinical results while providing an alternative option to ET, but this option is not currently supported by guidelines. We must not forget that the patients' preference plays an important role: some women still opt to receive RT to minimize the risk of local relapse, despite the lack of survival benefit; other patients refuse ET as long-term medication, mainly because they do not tolerate the potential side effects and prefer RT alone. Some authors suggested, that women aged plus 70 with low-risk hormone receptor-positive early breast cancer, treated with surgery, are likely to experience very similar oncologic outcomes whether treated with adjuvant ET or RT only. It is still to be determined whether this subgroup of patients actually needs endocrine therapy in addition to radiotherapy. Several clinical trials are currently underway to answer this question. The phase 2–3 trial (NCT04134598) explore the role of exclusive partial breast irradiation vs exclusive endocrine therapy after breast conserving surgery for early breast cancer, women aged ≥ 70, with luminal A-like disease, to determine which of these options may be better in terms of quality of life.

Symposium: Radiosurgery for central nervous system disorders: Beyond glioblastoma and metastases

SP-0024 Radiotherapy for vestibular schwannoma and meningioma E. Hermann Switzerland

Abstract not available

SP-0025 SRS for Parkinson's disease and trigeminal neuralgia – In memoriam lecture for Professor Miszczyk L. Miszczyk 1 , G. Głowacki 1 , A. Roch-Zniszczoł 1 , D. Larysz 1 , M. Stąpór-Fudzińska 2 , B. Goc 1 , S. Blamek 1 , A. Rożek 1 1 MSC National Research Institute of Oncology, Radiotherapy, Gliwice, Poland; 2 MSC National Research Institute of Oncology, Radiotherapy Planning, Gliwice, Poland

Abstract Text Trigeminal neuralgia SRS

Objective: There is a wide selection of studies concerning this issue; I chose one meta-analysis, one study presenting other publications and two sets of individual results, showing only particular results to allow to compare them. - Metaanalysis - C. Tulesca et al. J Neurosurg. 2018 GammaKnife based SRS (GK) – 5687 pts – 60-97 Gy, freedom from pain (FFP) – med. 52%, hypoesthesia – med. 19% Linear accelerator based SRS (LINAC) – 511 pts – 50-90 Gy, FFP – med. 43%, hypoesthesia – 29% Cyber knife based SRS (CK) – 263 pts – 66-90 Gy, FFP – med. 58%, hypoesthesia – 19% - Comparison to other publications - S.C. Park et al. Yonsei Med J. 2020 GK – 4279 pts (18 studies), % patients with pain relief – 70-96%, complications rate – 2.7-42% GK (S.C. Park – own results) – 235 pts – 60-90 Gy, % patients with pain relief – 93.7%, complications rate - 17.6%, hypoesthesia – 13.4% Individual series - Peng Li et al. J Clin Neurosci. 2012 GK – 129 pts, - 80-90 Gy, % patients with pain relief – 86%, complications rate – 39% - P. Romanelli et al. Cureus 2019 CK – 387 pt. – 60 Gy, % patients with pain relief – 92%, hypoesthesia – 6.1% Our results Material: 93 patients irradiated (61 F, 32 M). 48 previously treated with other non-pharmacological methods. 48.8% used NSAIDs, 40% opioids, 15% steroids, 62% antiepileptic and19% anti-depressive drugs. 60% suffered from acute (classical), 29% from chronic and 11% from both types of trigeminalgia. V1 was involved in 39%, V2 in 66% and V3 in 50% of cases. NRS before SRS varied from 5 to 10 (mean 9.6, median 10). Method: All patients irradiated with CyberKnife using 25-246 beams. In 83 cases single dose of 60 Gy and in 1 – 50 Gy were delivered. In 7 cases 2x35 Gy and in 2 – 2x30 Gy were given. 22 cases were irradiated second time after previous ineffective linac-based SRS. Results: In 37% complete, in 45% partial pain relief was noted (82% of response). An improvement appeared in the period 1-12 months (54% < 1, 38% 2-3, 7% 4-6 and 1 in 12 th month). 18% of patient failed. NRS after SRS varied from 0 to 10 (mean 3.2, median 2). 48% of patients discontinued and 3% reduced drugs uptake. Adverse effects were reported in 11 cases (6 – paresthesia, 3 – hypoesthesia, 3 – pain increase). Parkinson’s disease (PD) related tremor SRS Objective: I found only 1 case report considering CK based SRS of PD. I chose 3 studies to present GK SRS results.