ESTRO 2024 - Abstract Book

S2576

Clinical - Urology

ESTRO 2024

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4. Skolarus TA, Dunn RL, Sanda MG, Chang P, Greenfield TK, Litwin MS, et al. Minimally important difference for the Expanded Prostate Cancer Index Composite Short Form. Urology. 2015;85(1):101-5.

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Poster Discussion

Patterns of PSMA PET/CT-detected Nodal Metastases in relation to the Dominant Intraprostatic Lesion

Hoda Abdel-Aty 1,2 , Nora Sundahl 3,1,2 , Nabil Hujairi 4,1 , Daniel Levine 4,1 , Sue Chua 4,1 , Alison Tree 2,1 , Christopher Parker 2,1 , Yae-eun Suh 2,1 , Nicholas van As 2,1 , Rosalind Eeles 1,2 , Vincent Khoo 2,1 , Robert Huddart 1,2 , Declan Cahill 1,5 , Nicholas James 1,2 , Julia Murray 2,1 1 The Institute of Cancer Research, Radiotherapy and Imaging, London, United Kingdom. 2 The Royal Marsden Hospital, Radiotherapy, London, United Kingdom. 3 AZ Groeninge, Radiotherapy, Kortrijk, Belgium. 4 The Royal Marsden Hospital, Radiology and Nuclear Medicine, London, United Kingdom. 5 The Royal Marsden Hospital, Urology, London, United Kingdom

Purpose/Objective:

PET/CT imaging with prostate specific membrane antigen ligands (PSMA) has better diagnostic accuracy compared with conventional imaging for staging high-risk prostate cancer and has been rapidly integrated in international clinical practice (1-3). Intuitively, it is assumed that the improved sensitivity will lead to optimised treatment strategies. We therefore undertook a descriptive study evaluating the patterns of PSMA PET/CT-detected nodal metastases in newly diagnosed node positive (N1 and M1a) prostate cancer patients and their relationship to the site of the MR-defined dominant lesion within the prostate gland.

Material/Methods:

Patients with PSMA PET/CT-detected newly diagnosed node positive (N1 and/or M1a) prostate cancer, diagnosed at the Royal Marsden Hospital between January 2016 and January 2022 were reviewed. All included patients had a baseline MRI prostate. Patient, tumour characteristics and imaging findings were collected, including age, presenting PSA, ISUP grade group, TNM 8th edition staging on PSMA PET/CT and MRI. The per-patient number and nodal regions involved on PSMA PET/CT was determined. The location of the dominant intra-prostatic lesion (DIL) on MRI was recorded utilising PIRADS v2.1 reporting system (4). Scan images and clinical reports were retrospectively reviewed. Descriptive analyses were utilised.

Results: