ESTRO 2023 - Abstract Book

S524

Sunday 14 May 2023

ESTRO 2023

Fig. 1 – Individual 3D-printed applicator for treating the BCC located on the nose.

Results There were 15 women and 5 men treated in the mean age of 76,9 years. Among 25 tumors 19 were classified as T1 (76%), 3 as T2 (12%) and 3 as T3 (12%) according to UICC/AJCC TNM v.7. Lesions were located on the nose (76%), ear (12%) and peri-orbitally (12%). The HDR-BT were performed as the primary treatment for 14 lesions (56%) and as the salvage after previous surgery in remaining 11 (44%). All tumors were classified to be at the high risk of recurrence according to NCCN. The mean follow-up (counted from the end of HDR-BT) was 14 months (median 13 m.; 6,2 – 26,9). All tumors received planned dose of 42 – 45 Gy in 6 – 11 fractions within overall treatment time of 6 – 27 days. During the follow up both RR and LC were 100%. Acute skin toxicity presented as erythema (36%), patchy desquamation (4%), confluent desquamation (8%) and tumor disintegration with bleeding (40%). Late skin toxicity resulted in redness, depigmentation, or discoloration (44%) (fig. 2) and small telangiectasia (4%).

Fig. 2 – BCC T1 tumor located on the nose before the HDR-BT, and depigmentation visible 23 months after the treatment.

Conclusion This report shows very good preliminary results in terms of both high local tumor control and low toxicity for skin BCC obtained with superficial HDR-BT with 3D printed custom-made applicators. OC-0635 Assessing the clinical impact of brachytherapy source tracking uncertainties of a novel IVD system T. van Wagenberg 1 , R. Voncken 1 , C. Van Beveren 1 , F. Verhaegen 1 , G. Paiva Fonseca 1 1 Maastricht University Medical Centre+, Department of Radiation Oncology (Maastro), Maastricht, The Netherlands