ESTRO 2020 Abstract book

S206 ESTRO 2020

effectively (51%), will eliminate jobs (20%), will not have an impact on jobs (6%), and not concerned at all with automation (9%). 27% of staff believe automation will reduce job satisfaction (Figure 2). 71% of respondents strongly agree/agree that automation will cause a loss of understanding of general principles of radiotherapy, while only 25% respondents strongly agree/agree that the current training and education tools provided by their department are sufficient to ensure staff do not lose their skillsets.

Biostatistics and Epidemiology, Villejuif, France ; 4 Gustave Roussy, Department of Radiation Oncology, Villejuif, France ; 5 Princess Margaret Cancer Centre, Cancer Clinical Research Unit, Toronto, Canada ; 6 Sun Yat-sen University Cancer Center, Department of Thoracic Surgery, Guangzhou, China ; 7 NRG Oncology, Statistics and Data Management Center, Philadelphia, USA ; 8 Fred Hutchinson Cancer Research Center, Clinical Research Division, Seattle, USA ; 9 Netherlands Cancer Institute, Department of Biometrics, Amsterdam, The Netherlands ; 10 Sun Yat-sen University Cancer Center, Department of Experimental Research, Guangzhou, China ; 11 University Hospital Zurich, Department of Radiation Oncology, Zurich, Switzerland ; 12 University of Groningen and University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, The Netherlands ; 13 Maastricht University Medical Cente MUMC, Department of Radiation Oncology Maastro, Maastricht, The Netherlands Purpose or Objective Our recent individual patient-based meta-analysis of phase III studies on prophylactic cranial irradiation (PCI) in stage III non-small cell lung cancer (NSCLC) showed a reduced incidence of brain metastases (BM) (hazard ratio [HR] 0.38), without a significant effect on overall survival (OS). In these RCTs, different fractionation schedules were used. We here performed subset analyses to explore the impact of different PCI fractionation schedules on brain metastases-free survival (BMFS) and neurocognitive toxicity. Material and Methods We compared two different PCI fractionation schedules (30 Gy in 10 fractions and 30 Gy in 15 fractions) to observation. All analyses were performed based on the intention-to- treat principle. Patients intended to be treated with other schedules (e.g. 30 Gy in 12 fractions or 36 Gy in 18 fractions) were excluded. The log-rank observed minus expected number of events and its variance as well as the HRs with 95% confidence intervals (95% CIs) were calculated. Interaction was tested using a chi-square test. The highest reported toxicity grade among all reported adverse events per patient in the PCI arm during follow-up was analysed and categorized into no toxicity (grade 0), mild toxicity (grade 1 or 2) and severe toxicity (≥ grade 3). A mixed-effects logistic regression model with a random intercept for study was used to compare any toxicity (≥ grade 1) to no toxicity (grade 0) between the two fractionation schedules. Furthermore, severe toxicity (≥ grade 3) was compared to mild/no toxicity (< grade 3) using the same approach. Results In total, 580 patients were included from three RCTs: RTOG 0214 using 30 Gy in 15 fractions; Guangzhou 2005 and NVALT-11 using 30 Gy in 10 fractions. For both PCI fractionation schedules, BMFS was statistically significantly higher than for observation (30 Gy in 10 fractions: HR 0.26, 95% CI [0.15 to 0.44], 30 Gy in 15 fractions: HR 0.52, 95% CI [0.31 to 0.86]). No statistically significant interaction was found between the two fractionation schedules (p = 0.07)(Figure 1). Among the 285 patients studied, those included in the 30 Gy in 15 fractions arm had a statistically significantly lower risk of neurocognitive toxicity compared to patients included in the 30 Gy in 10 fractions arm (Odds ratio [OR] 0.38, 95% CI [0.23 to 0.62]). A similar trend was observed when comparing high grade neurocognitive toxicity to mild/no toxicity, although not statistically significant (OR 0.21, 95% CI [0.02 to 2.45]).

Figure 1: Current level of automation in radiotherapy centres

Figure 2: Staff attitude toward automation in radiotherapy planning Conclusion Although the effect of automation is perceived positively with respect to work output and productivity, there are some concerns on loss of skillsets and the lack of training to maintain this. These results highlight the need for continued education to ensure that basic skills and knowledge of the principles of radiotherapy are not lost with automation of tasks in radiation oncology.

Poster Highlights: Poster highlights 11 CL : CNS

PH-0355 Impact of fractionation on brain metastases and neurocognitive toxicity of PCI in stage III NSCLC W. Witlox 1 , B. Ramaekers 2 , B. Lacas 3 , C. Le Pechoux 4 , J. Pignon 3 , A. Sun 5 , S. Wang 6 , C. Hu 7 , M. Redman 8 , V. Van der Noort 9 , N. Li 10 , M. Guckenberger 11 , H. Van Tinteren 9 , H. Groen 12 , M. Joore 1 , D. De Ruysscher 13 1 Maastricht University Medical Cente MUMC, Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht, The Netherlands ; 2 Maastricht University Medical Centre MUMC, Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht, The Netherlands ; 3 Gustave Roussy,