RT Journal Article
SR Electronic
T1 Comparison of Multiple Segmentation Methods for Volumetric Delineation of Primary Prostate Cancer with Prostate-Specific Membrane Antigen–Targeted <sup>18</sup>F-DCFPyL PET/CT
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 87
OP 93
DO 10.2967/jnumed.123.266005
VO 65
IS 1
A1 Wang, Felicia
A1 Liu, Chen
A1 Vidal, Igor
A1 Mana-Ay, Margarita
A1 Voter, Andrew F.
A1 Solnes, Lilja B.
A1 Ross, Ashley E.
A1 Gafita, Andrei
A1 Schaeffer, Edward M.
A1 Bivalacqua, Trinity J.
A1 Pienta, Kenneth J.
A1 Pomper, Martin G.
A1 Lodge, Martin A.
A1 Song, Daniel Y.
A1 Oldan, Jorge D.
A1 Allaf, Mohamad E.
A1 De Marzo, Angelo M.
A1 Sheikhbahaei, Sara
A1 Gorin, Michael A.
A1 Rowe, Steven P.
YR 2024
UL http://jnm.snmjournals.org/content/65/1/87.abstract
AB This study aimed to assess the accuracy of intraprostatic tumor volume measurements on prostate-specific membrane antigen–targeted 18F-DCFPyL PET/CT made with various segmentation methods. An accurate understanding of tumor volumes versus segmentation techniques is critical for therapy planning, such as radiation dose volume determination and response assessment. Methods: Twenty-five men with clinically localized, high-risk prostate cancer were imaged with 18F-DCFPyL PET/CT before radical prostatectomy. The tumor volumes and tumor-to-prostate ratios (TPRs) of dominant intraprostatic foci of uptake were determined using semiautomatic segmentation (applying SUVmax percentage [SUV%] thresholds of SUV30%–SUV70%), adaptive segmentation (using adaptive segmentation percentage [A%] thresholds of A30%–A70%), and manual contouring. The histopathologic tumor volume (TV-Histo) served as the reference standard. The significance of differences between TV-Histo and PET-based tumor volume were assessed using the paired-sample Wilcoxon signed-rank test. The Spearman correlation coefficient was used to establish the strength of the association between TV-Histo and PET-derived tumor volume. Results: Median TV-Histo was 2.03 cm3 (interquartile ratio [IQR], 1.16–3.36 cm3), and median TPR was 10.16%. The adaptive method with an A40% threshold most closely determined the tumor volume, with a median difference of +0.19 (IQR, −0.71 to +2.01) and a median relative difference of +7.6%. The paired-sample Wilcoxon test showed no significant difference in PET-derived tumor volume and TV-Histo using A40%, A50%, SUV40%, and SUV50% threshold segmentation algorithms (P &gt; 0.05). For both threshold-based segmentation methods, use of higher thresholds (e.g., SUV60% or SUV70% and A50%–A70%) resulted in underestimation of tumor volumes, and use of lower thresholds (e.g., SUV30% or SUV40% and A30%) resulted in overestimation of tumor volumes relative to TV-Histo and TPR. Manual segmentation overestimated the tumor volume, with a median difference of +2.49 (IQR, 0.42–4.11) and a median relative difference of +130%. Conclusion: Segmentation of intraprostatic tumor volume and TPR with an adaptive segmentation approach most closely approximates TV-Histo. This information might be used to guide the primary treatment of men with clinically localized, high-risk prostate cancer.