RT Journal Article SR Electronic T1 Intraprostatic Tumour Segmentation on PSMA-PET Images in Patients with Primary Prostate Cancer with a Convolutional Neural Network JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.120.254623 DO 10.2967/jnumed.120.254623 A1 Dejan Kostyszyn A1 Tobias Fechter A1 Nico Bartl A1 Anca L Grosu A1 Christian Gratzke A1 August Sigle A1 Michael Mix A1 Juri Ruf A1 Thomas F Fassbender A1 Selina Kiefer A1 Alisa S Bettermann A1 Nils H Nicolay A1 Simon Spohn A1 Maria U Kramer A1 Peter Bronsert A1 Hongqian Guo A1 xuefeng Qiu A1 Feng Wang A1 Christoph Henkenberens A1 Rudolf A Werner A1 Dimos Baltas A1 Philipp T Meyer A1 Thorsten Derlin A1 Mengxia Chen A1 Constantinos Zamboglou YR 2020 UL http://jnm.snmjournals.org/content/early/2020/11/06/jnumed.120.254623.abstract AB Accurate delineation of the intraprostatic gross tumour volume (GTV) is a prerequisite for treatment approaches in patients with primary prostate cancer (PCa). Prostate-specific membrane antigen positron emission tomography (PSMA-PET) may outperform MRI in GTV detection. However, visual GTV delineation underlies interobserver heterogeneity and is time consuming. The aim of this study was to develop a convolutional neural network (CNN) for automated segmentation of intraprostatic tumour (GTV-CNN) in PSMA-PET. Methods: The CNN (3D U-Net) was trained on 68Ga-PSMA-PET images of 152 patients from two different institutions and the training labels were generated manually using a validated technique. The CNN was tested on two independent internal (cohort 1: 68Ga-PSMA-PET, n = 18 and cohort 2: 18F-PSMA-PET, n = 19) and one external (cohort 3: 68Ga-PSMA-PET, n = 20) test-datasets. Accordance between manual contours and GTV-CNN was assessed with Dice-Sørensen coefficient (DSC). Sensitivity and specificity were calculated for the two internal test-datasets (cohort 1: n = 18, cohort 2: n = 11) by using whole-mount histology. Results: Median DSCs for cohorts 1-3 were 0.84 (range: 0.32-0.95), 0.81 (range: 0.28-0.93) and 0.83 (range: 0.32-0.93), respectively. Sensitivities and specificities for GTV-CNN were comparable with manual expert contours: 0.98 and 0.76 (cohort 1) and 1 and 0.57 (cohort 2), respectively. Computation time was around 6 seconds for a standard dataset. Conclusion: The application of a CNN for automated contouring of intraprostatic GTV in 68Ga-PSMA- and 18F-PSMA-PET images resulted in a high concordance with expert contours and in high sensitivities and specificities in comparison with histology reference. This robust, accurate and fast technique may be implemented for treatment concepts in primary PCa. The trained model and the study’s source code are available in an open source repository.