ESTRO 2023 - Abstract Book

S401

Sunday 14 May 2023

ESTRO 2023

PD-0493 Comfort Marker 2.0 vs Lancets skin markings - results from the COMFORTATTOO trial (NCT05371795) A.M. Pires 1 , L. Carvalho 1 , A. C. Santos 1 , A. M. Vilaça 1 , A. R. Coelho 1 , F. Fernandes 1 , L. Moreira 2 , J. Lima 3 , R. Vieira 1 , M. J. Ferraz 1 , M. Silva 1 , P. Silva 1 , R. Matias 1 , S. Zorro 1 , S. Costa 1 , S. Sarandão 1 , C. Costa 1 , A. F. Barros 1 1 IPO Porto, Serviço de Radioterapia Externa, Porto, Portugal; 2 IPO Porto, ., Porto, Portugal; 3 IPO PORTO, Serviço de Radioterapia Externa, Porto, Portugal Purpose or Objective Patient skin markings are routinely performed for set-up reproducibility. Permanent tattooing is the most popular method, and there are several methods. This study compares two of them: disposable lancets vs. Comfort Marker 2.0® (CM) - a device with a controlled depth tattoo pen. We present the results on comfort, satisfaction, effectiveness, and cosmesis (main trial). Additionally, a substudy was undertaken to assess for cosmesis, fading, and pts satisfaction at 6 months, which results are also presented. Materials and Methods COMFORTATTOO is a prospective, randomized, cohort study. Eligible pts had ≥ 18 years old, PS of 0-1, and RT schedule ≥ 13 daily fractions. Pts were randomized in a 1:1 ratio to lancets or CM. Primary endpoints of the main trial were pts comfort (11-point numeric pain scale) and effectiveness (bad, reasonable, good, and excellent); secondary endpoints included RTTs satisfaction with the ease of tattooing (easy, medium, and hard) and cosmesis at the end of RT (tattoo photographs scored by 20 observers on a bad to excellent score). On the substudy, the endpoints evaluated were tattoo fading (tattoo photographs scored by 3 observers on a 5-point scale from no fading to complete fading), cosmesis (same method of main study) and pts satisfaction (10-point scale from completely dissatisfied to completely satisfied), evaluated six months following the end of RT. Allocation was blinded to pts, RTTs in the LINACs, and photographic evaluators. Results Between 10/2021 and 01/2022, 100 pts were randomized and assessed for comfort and satisfaction; 98 for effectiveness and the cosmesis. 92 pts were analysed for the substudy between 05/2022 and 10/2022. Baseline characteristics were well balanced. CM was significantly less painful than the lancets, with 44% and 16%, respectively, considering the process painless (RR = 2.75). Pts receiving CM had a significantly higher proportion of markings graded as good and excellent compared to those receiving lancets (98.0% and 50.0%, respectively, had ≥ 75% of the tattoos assessed as good/excellent, RR = 1.96). On the RTT-reported satisfaction, CM was significantly easier to use compared to lancets (98.0% vs. 78.0% scored easy, respectively; RR = 1.26). On the cosmetic evaluation at the end of RT, pts receiving CM had significantly better cosmetic markings, with a median score of 4.4 (vs. 3.5 for lancets, p <0.001). For the substudy analysis, patients receiving CM had significantly better cosmetic markings at 6 months, with a median score of 4.4 (vs. 3.7 for lancets, p <0.001). The CM was associated with lower scores on the fading assessment compared to the lancets (median score of 1.3 and 3.3, respectively; p <0.001). No difference in pts satisfaction was observed (median score of 10 for both arms, p=0.952). Conclusion Tattooing with CM is significantly less painful, more effective, and easier, with better cosmetic outcomes compared to lancets, but with less fading at 6 months. These didn’t translate into pts satisfaction differences. PD-0494 Evaluation of patient positioning for accelerated partial breast irradiation on an MR-Linac L. Davies 1 , L. McDaid 1 , C. Anandadas 2 , L. Whiteside 1 , A. Clough 1 , R. Benson 1 , P. Fendall Amaro 1 , J. Parker 1 , H. Drury-Smith 3 , C. Eccles 1,4 1 The Christie NHS Foundation Trust, Radiotherapy, Manchester, United Kingdom; 2 The Christie NHS Foundation Trust, Clinical Oncology, Manchester, United Kingdom; 3 Sheffield Hallam University, Department of Allied Health Professions, Sheffield, United Kingdom; 4 University of Manchester, Division of Cancer Sciences, Manchester, United Kingdom Purpose or Objective The spatial confinement and longer treatment time to deliver online MR-guided adaptive radiotherapy on the MR-Linac (MRL), necessitates reliable and comfortable patient positioning. This work describes the steps taken to determine the optimal position and image sequence for accelerated partial breast irradiation (APBI), prior to clinical implementation, on a 1.5T Unity MRL (Elekta AB, Sweden). Materials and Methods A 2-phased approach was used. Phase 1 recruited 5 non-patient volunteers to an approved imaging study. Participants underwent 2 imaging sessions comparing 2 positioning approaches: supine, arms over head on an in-house manufactured thorax board, with and without an individualised (vac)uum-moulded-bag (Klarity Medical Products, USA). Participants completed a questionnaire using a 10-point numeric rating scale after each scan to assess comfort. Responses were analysed using descriptive statistics in Microsoft Excel. Qualitative responses adopted a simple thematic analysis. Image quality for