ESTRO 2023 - Abstract Book

S1280

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ESTRO 2023

The hotspot diameter was 1.5 cm with a center-to-center distance of 6 cm (4.5 cm edge to edge) in the orthogonal axes, and of 3 √ 2 cm along the diagonal axes. No peak closer than 1.5 cm from heath tissue was allowed. All oncological systemic therapies were suspended during LRT and daily conebeam was performed before every LRT session. Median patients’ age was 71 years (IQR1-3: 68.25 – 73.5 years) while median lesions volume amounted to 927 cc (IQR1-3: 363.25 -1943.63 cc). All patients had an ECOG PS 2 except 1 patients with an ECOG PS 1. Lesions response was evaluated at 3 and 6 months according to RECIST1.1 criteria, while the treatment toxicity was assessed with CTCAEv5 scale. Results At 3 and 6-month follow-up, 7 and 5 patients were alive, respectively. One patient died due to a bacterial pneumonia while 2 patients died because of sepsis. The 3 and 6-month objective response rate (ORR) was 71.43 % (95%CI 25.04 – 96.33%) and 60% (95%CI: 14.66 – 94.73%), respectively. No toxicity ≥ G3 was observed. Interestingly, the 3-month median lesions reduction was 26% (IQR1-3: 20% - 65%). All patients referred a quick symptoms relief after LRT and an improvement in their ECOG PS of at least 1 level was registered. Conclusion Although the limited number of patients and the short follow up, this work provides further data on LRT toxicity in the short term, highlighting how LRT could represent an innovative and promising strategy to safely manage large tumors. Moreover, our works contribute to show preliminary data on LRT response. 1 Charing Cross Hospital , Clinical Oncology, London, United Kingdom; 2 Charing Cross Hospital, Clinical Oncology, London, United Kingdom Purpose or Objective We explored the feasibility of developing and reporting potential quality metrics for patients undergoing palliative RT, by assessing the performance of those indicators in terms of co-linearity and discrimination between different patient groups. Materials and Methods We identified all patients who underwent their first course of palliative RT at our NHS centre between 2015 and 2020. We extracted their demographics, diagnosis, and treatment information. We considered the following five quality indicators: 30 DM, remaining life span spent receiving palliative RT, treatment completion/non-completion, travel distance from the hospital and time from referral to treatment. We calculated these metrics for every patient, and we compared them in groups: -Palliative RT to bone metastases versus palliative RT to brain metastases -Palliative RT to bone metastases in patients with breast and prostate cancer versus palliative RT to bone metastases in all the other tumour types Results The median age was 65 years. The commonest tumour sites were lung (26.3%), breast (13.6%), prostate (11.9%) and gynae (7.3%). Median OS was 7 months. 30 DM was 9.5%. The median proportion of remaining life span spent receiving RT was 2%. 98.7% of the study population completed their treatment. Median distance from the hospital was 6.11 km. Median referral time was 9 days. 1141 patients had palliative RT to bone metastases, 308 patients had palliative RT to brain metastases. 30 DM was 11.7% in patients with bone disease and 8.8% in patients with brain disease. Median proportion of remaining life span spent receiving RT was 3% in brain metastases patients and 1.2% in those with bone metastases. Non-completion rate was 1.3% in patients with brain disease and 0.8% in those with bone disease. Travel distance was 6.9 km in subgroup RT to bone and 5.8 km in subgroup RT to brain. Median referral time was 6 days in patients with bone disease and 11 days in those with brain metastases. There were 447 patients with breast and prostate cancer and 694 patients with other tumour types, receiving RT to bone metastases. 30 DM was 6.3% in patients with breast and prostate, and 15.3% in those with other tumours. The median percentage of remaining survival time spent receiving RT was 0.6% in breast and prostate, and 1.8% in the other tumours. One patient among breast and prostate and 8 patients among other tumours didn't complete RT. Median distance from the hospital was 6.8 km in subgroup breast and prostate, and 7.6 km in patients with other primary disease. Referral time was 7 days in patients with breast and prostate primary, and 6 days in patients with different tumour types. PO-1577 Developing Quality Indicators from routine data in patients receiving palliative RT C. Cavalli 1 , D.M. Williams 2 , K. Le Calvez 2