S1282
Clinical - Urology
ESTRO 2026
p<0.003). Minor-changes(local-RT field/dose- modification) occurred in 26%vs41%, while-major- changes(M1-disease-treatment or systemic-therapy) occurred in 46.6%vs24.7%. No-change was-recorded in 27.4%vs24%, respectively.(table 4)
¹⁸ F-PSMA-1007 prompted-more pelvic-RT indications, while ¹⁸ F-DCFPyL-PSMA more-often guided-SBRT- based-treatments. In PSMA-negative-cases, expectant- management was more-frequent with ¹⁸ F-PSMA-1007. After PSMA-PET/CT, RT-fields were-adapted to include- positive-sites, with dose-escalation to 70–72Gy in the prostate-bed or 55Gy in involved-nodes. Oligometastatic-lesions were-treated with PSMA- guided-SBRT(24Gy/3Fx)±ADT± ARSI. Following.adaptation, mean-PSA decreased to 0.08ng/mL(p<0.001). Conclusion: PSMA PET/CT is a reliable-tool for early-detection of occult BCR after RP, showing high-DR even at low PSA- levels and a significant-impact on therapeutic decision- making in patients with positive-findings. Keywords: Prostate cancer, biochemical recurrence, 18F-PSMA Digital Poster 3964 Anatomical Analyses for the Prostate Region in Upright and Supine Postures Chung Tin Lo 1 , João M da Silva 2 , André M Pires 2 , Gordon Sands 1,3 , Jamie R McClelland 1 , Tracy Underwood 1,3 1 UCL Hawkes Institute, UCL, London, United Kingdom. 2 Department Radiotherapy and Imaging, Portuguese Institute of Oncology of Porto, Porto, Portugal. 3 Research Department, Leo Cancer Care Ltd, Crawley, United Kingdom Purpose/Objective: Interest in upright, gantry-less radiotherapy has increased, mainly due to its cost-saving potential: rotating an upright patient through a fixed treatment beam reduces the primary shielding required and the overall system complexity. However, limited availability of upright imaging systems means that anatomical changes between upright and supine postures remain underexplored. As prostate cancer is
Positive-PET results were observed in 75.3%(55/73) of ¹⁸ F-DCFPyL-PSMA and 64.7%(55/85) of ¹⁸ F-PSMA-1007 patients. Median pre-scan PSA 0.45ng/mL(95%CI 0.4– 0.8) and 0.34ng/mL(95%CI 0.2–0.6), respectively. Mean DT-PSA was 5months(95%CI 2.6–7.5) vs 6.5months(95%CI 3.5–8.3). A positive-correlation was- found between PSA/DT-PSA-values and DR(AUC=0.74, 0.75 respectively). The analysis of PSAng/mL cutoff- values to predict-positive-results in the ROC-curves showed a threshold of 0.46 in the ¹⁸ F-DCFPyL- PSMA(sensitivity-69%, specificity-72%) and 0.42 in the ¹⁸ F-PSMA-1007 group(sensitivity52%, specificity73%).Figure1Figure 1
DR by PSA/DT-PSA(table 2)
DR by location(table 3)
Nonspecific-uptake occurred in 9%vs26%, more frequently-affecting ribs in the ¹⁸ F-PSMA-1007- group.Therapeutic impact: changes in management were-observed in 78.1% of ¹⁸ F-DCFPyL-PSMA and 82.2% of ¹⁸ F-PSMA-1007 patients(p<0.001 and
Made with FlippingBook - Share PDF online