ESTRO 2022 - Abstract Book

S1224

Abstract book

ESTRO 2022

LDRT comprised of 6 fractions of 0.5-1 Gy on every-other day up to a total dose of 3-6 Gy. Clinical response was evaluated according to the visual analogic score (VAS) for pain level and to the von Pannewitz score (VPS) for joint functionality. Those patients not reaching subjective adequate pain relief after 12 weeks from treatment were offered a second identical LDRT course. Results With a median follow-up of 10 months (range 1-43) and starting with a median VAS before treatment of 8 (range 3-10), 80% of the patients referred improvement of the pain describing median VAS at 3, 6 and 12 months of 4 (range 0-9), 2 (range 0-9) and 2 (range 0-9), respectively, being this reduction statistically significant (p<0.001) (Image 1). Eighty-five patients

(67%) needed a second course of treatment at a median time interval of 13.6 weeks (range 7.4-21). 70% of patients reported functionality improvement after LDRT according to von Pannewitz score. In the univariant analysis we did not find any differences between variables. No acute or late complications were observed.

Conclusion LDRT appears to be safe and useful for hand and feet degenerative/inflammatory MSD associating good rates of pain relief and functionality improvement without treatment related toxicities. However, further studies are necessary to confirm these promising results.

PO-1443 Dosimetric evaluation of esophagus segmentation for esophagus-sparing palliative spine irradiation.

A. Mann Nielsen 1 , C. P. Behrens 1 , M. Riise Pedersen 1 , L. Möller Andersson 1 , M. Hiul Suppli 2 , I. Vogelius 2,3 , P. Sibolt 1 , G. Persson 1,3 1 Copenhagen University Hospital – Herlev and Gentofte, Dept. of Oncology, Copenhagen, Denmark; 2 Copenhagen University Hospital – Rigshospitalet, Dept. of Oncology, Copenhagen, Denmark; 3 Copenhagen University , Dept. of Clinical Medicine, Copenhagen, Denmark Purpose or Objective We have initiated the ESO-SPARE phase III trial where patients with metastatic spinal cord compression are randomized to either esophagus sparing- or standard IMRT with patient reported esophagus toxicity as primary endpoint. Another aim is to reduce time to treatment by using artificial intelligence (AI) software to automate the planning process. First step is to use AI automatic segmentation of the esophagus. Manual delineations are prone to interobserver variation and we hypothesize that the variation between automatic segmentation and manual delineation has the same magnitude as interobserver variation. Furthermore, we hypothesize that the dosimetric consequence of using the automatic segmented esophagus for plan optimization is minimal compared to a manual delineated esophagus.

Materials and Methods