Value of 68Ga-PSMA PET/CT compared to mpMRI for primary tumor characterization based on radical prostatectomy histopathology = 근치적 전립선절제술 병리 소견을 기준으로 한 원발 병변 평가에서 ??Ga-PSMA PET/CT와 mpMRI의 비교 가치

다국어 초록 (Multilingual Abstract)

Purpose: Although 68Ga-prostate specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) represents a promising method for prostate cancer (PCa) diagnosis and staging, comparison of PSMA-based primary tumor characterization to multiparametric magnetic resonance imaging (mpMRI) is still limited. This study evaluated to compare the diagnostic accuracy of 68Ga-PSMA PET/CT to mpMRI against radical prostatectomy (RP) whole gland histopathology in patients with clinically localized PCa.
Materials and Methods: Between August 2022 and March 2023, consecutive 58 patients who underwent pre-operative mpMRI and 68Ga-PSMA PET/CT followed by RP were included in this study. Lesions based on RP histopathology were classified as either mpMRI negative (Prostate Imaging Reporting and Data System [PIRADS] ≤ 2) or positive (PIRADS ≥ 3) and 68Ga-PSMA PET/CT negative or positive by an experienced radiologist and a nuclear medicine specialist, respectively. International Society of Urological Pathology grade group ≥ 2 was defined as clinically significant PCa (csPCa). Clinical parameters and per-lesions analyses for image based detection according to RP histopathology were evaluated. Every imaging data were divided into 12 regions, and the concordance between pathology and imaging was evaluated.
Results: Fifty-eight patients underwent RP, resulting in 74 lesions on final histopathological examination (GG 5 in 3, GG4 in 13, GG 3 in 35, GG 2 in 16, and GG1 in 7). Among 74 lesions, mpMRI positive and 68Ga-PSMA PET/CT positive were 48 (64.9%) and 64 (86.5%) lesions, respectively. Among 26 lesions with mpMRI negative, 68Ga-PSMA PET/CT could detect 17 lesions (65.3%). In addition, for csPCa diagnostic accuracy was higher with PSMA PET/CT (85.1%) than with mpMRI (71.6%). In regard to “per region”, total 684 regions were evaluated. Compared to mpMRI, 68Ga-PSMA PET/CT showed better sensitivity (66% vs 92%) and positive predictive value (79% vs 91%).
Conclusions: 68Ga-PSMA PET/CT could better detect more lesions based on RP whole gland histopathology compared to mpMRI in patients with clinically localized PCa. These findings may influence surgical planning, targeted biopsy and focal therapy strategies and require further research.
Keywords: Prostate-specific membrane antigen; Positron emission tomography; Magnetic resonance imaging; Prostate cancer; Prostatectomy

목차 (Table of Contents)

• 1. Introduction 1
• 1.1 Epidemiology and Clinical Significance of Prostate Cancer 1
• 1.2 Role of mpMRI in Prostate Cancer Diagnosis and Localization 1
• 1.3 Limitations of Current Imaging Modalities & Study Rationale and Objectives 1
• 2. Materials and Methods 1
• 2.1 Study Design and Patient Population 1
• 2.2 Image Interpretation Criteria 1
• 2.3 Imaging and histopathologic Evaluation 2
• 3. Results 4
• 3.1 Patient Characteristics 4
• 3.2 Histopathologic Findings after Radical Prostatectomy and Lesion Detection Rates of mpMRI and PSMA PET/CT 4
• 3.3 Diagnostic Performance for Clinically Significant Prostate Cancer 4
• 3.4 ROC Curve Analysis 4
• 3.5 Region-Based Diagnostic Accuracy 5
• 4. Discussion 9
• 4.1 Principal Findings 9
• 4.2 Comparison with Previous Studies 10
• 4.3 Limitations of the Study 11
• 5. Conclusion 12
• References 13