PRIMARY Scoring in 68Ga-PSMA PET/CT: Correlation with Prostate Cancer Risk Groups and Its Potential Impact on Active Surveillance

doi:10.21203/rs.3.rs-4959890/v1

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PRIMARY Scoring in 68Ga-PSMA PET/CT: Correlation with Prostate Cancer Risk Groups and Its Potential Impact on Active Surveillance

https://doi.org/10.21203/rs.3.rs-4959890/v1

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Objective

The PRIMARY scoring system is a scale designed to identify clinically significant intraprostatic malignancies on 68Ga-PSMA PET/CT images. Active surveillance is a management method for patients with low-risk prostate cancer. In this study, we aimed to assess the efficacy of PRIMARY scoring in identifying appropriate candidates for active surveillance based on the distribution within prostate cancer risk groups.

Methods

The data of 134 patients diagnosed with PCa by biopsy who underwent 68Ga-PSMA PET/CT imaging for post-diagnostic staging purposes were retrospectively analyzed. Age, total PSA, ISUP grade, prostate lesion SUVmax values, PI-RADS scores, and PRIMARY scores were recorded. Patients were classified into low-risk and intermediate/high-risk groups.

Results

In the intermediate/high-risk group, the PRIMARY score was 1–2 in 17.6% and 3–5 in 82.4% of patients. In the low-risk group, the PRIMARY score was 1–2 in 34.7% and 3–5 in 65.3% of patients. None of the patients in the low-risk group had a PRIMARY score of 5. The most frequent PRIMARY score in both groups was 4, and there was a significant difference between the average SUVmax values of the intermediate/high and low-risk groups with a PRIMARY score of 4 (p = 0.018). The sensitivity of PRIMARY scoring in detecting patients in the intermediate/high-risk group was 82.3%, the specificity was 34.6%, and the positive predictive value (PPV) was 68.6%. When a cut-off SUVmax value 5.0 was used for the PRIMARY score of 4, the sensitivity was 67.0%, the specificity was 65.3% and the PPV was 77.0%. In the ROC analysis, the area under the curve was 0.727 for PRIMARY scoring, 0.662 for PI-RADS, and 0.744 for their combined mean.

Conclusion

The PRIMARY scoring system can complement PI-RADS scoring in mpMRI for selecting patients suitable for active surveillance. Revising the PRIMARY score 4 with an SUVmax cut-off value may increase the specificity.

PSMA

PET/CT

prostate cancer

active surveillance

multiparametric MRI

Prostate cancer (PCa) is the most commonly diagnosed cancer among men in more than half of global nations and represents the primary cause of cancer-related deaths in approximately a quarter of these countries [1]. Correct disease staging is essential in choosing the appropriate treatment or deciding on active surveillance and preventing unnecessary interventions.

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) is a non-invasive diagnostic technique to image PSMA-positive lesions in individuals with PCa [2]. PSMA plays a critical role in PCa imaging by serving as a target for molecular imaging techniques like PSMA-PET/CT. It allows for the accurate detection and localization of PCa lesions, providing valuable information for staging, biopsy, surgical resection, and assessing disease extent [3]. PSMA PET/CT is effective in detecting high-risk PCa before surgery or radiotherapy and can identify clinically significant lesions missed by other imaging modalities. Intraprostatic PSMA intensity on 68Ga-PSMA PET/CT can predict adverse pathological outcomes and progression-free survival in localized PCa [4]. The latest guidelines recommend it as the first-line imaging option for primary staging of PCa [2, 5].

Multiparametric magnetic resonance imaging (mpMRI) is a valuable tool for the detection and evaluation of PCa, with high diagnostic accuracy. It can reduce unnecessary biopsies and over-detection of clinically insignificant PCa [6]. The Prostate Imaging Reporting and Data System (PI-RADS), is a standardized method used to interpret and report findings from prostate mpMRI scans. It was developed to improve the consistency and reliability of prostate mpMRI interpretation, particularly for detecting and characterizing PCa [7]. It was proposed in 2012 and has evolved since then, with the latest available version being version 2.1, developed in 2019 [8].

The PRIMARY scoring system is a scale developed to distinguish clinically significant intraprostatic malignancies on 68Ga-PSMA PET/CT images. It consists of scores ranging from one to five, depending on the index intraprostatic lesion's localization, distribution patterns, and intensities [9, 10]. In this study, we aimed to assess the efficacy of PRIMARY scoring in identifying appropriate candidates for active surveillance, comparing it with PI-RADS scoring based on their distribution within PCa risk groups.

Patient selection and study design

In this retrospective and single-center study, the data of 134 patients diagnosed with PCa by biopsy between 2021 and 2023 who underwent 68Ga-PSMA PET/CT imaging in our center for post-diagnostic staging purposes were scanned. The patients' age, total PSA (tPSA), ISUP grade determined by biopsy, and SUVmax values of the index lesion in the prostate gland were recorded. Prostate biopsies contained at least 12 cores and the ISUP grade was determined by considering the most dominant pattern. According to the current National Comprehensive Cancer Network (NCCN) guidelines, patients were categorized into low, intermediate, and high-risk groups based on their ISUP grade, tPSA value, and clinical stage [5]. During statistical analysis, patients were classified into two groups: low-risk and intermediate/high-risk (non-low-risk). The cohort consisted of ninety patients for whom mpMRI imaging was available within three months before prostate biopsy. PI-RADS scores, reported by expert radiologists, were documented for these images. PRIMARY scores were determined through the evaluation of 68Ga-PSMA PET/CT images. The distribution of both PRIMARY scores and PI-RADS scores, categorized according to risk stratification, was examined. This study was approved by our institution’s ethical committee and conducted following the Declaration of Helsinki.

68Ga-PSMA PET/CT Imaging Protocol

The imaging protocol was carried out following the standard guidelines of EANM and SNMMI [2]. After injecting 111–259 MBq (3–7 mCi) of 68Ga-PSMA intravenously, there was a 50 to 70 minute uptake phase to allow for optimal distribution and accumulation of the radiotracer. In patients without medical contraindications, furosemide injection was performed 20 minutes after the radionuclide injection. PET images were obtained on a Philips Gemini TF 64 Slice PET/CT camera (Philips Medical Systems, Cleveland, OH, USA). Subsequent PET/CT imaging was done with the patient in a supine position, incorporating low-dose CT scans for attenuation correction and anatomical localization. All patients were scanned from the vertex to the upper thigh. PET acquisition was in 3D mode with approximately 3 minutes per bed position, followed by reconstruction using iterative list mode time-of-flight algorithm, to improve lesion detection and quantification. Per institutional guidelines, quality control measures were taken, including routine scanner checks and verification of dose administration and patient preparation.

PRIMARY Scoring

While determining PRIMARY scores, all 68Ga-PSMA PET/CT images underwent evaluation by two experienced nuclear medicine specialists. In cases where a common decision could not be reached, a decision was reached by taking the opinion of a third expert. The evaluators remained blinded to the patients' clinical information and pathologies.

The scoring system was as follows: A score of 1 was assigned if only low-level activity was observed in the prostate gland localization without any specific distinguishable pattern from the background. Score 2 was given for diffuse activity in the transition zone or activity in the central zone. Score 3 was defined as a significant focal activity in the transition zone that was at least twice the background. Score 4 was any level of focal activity in the peripheral zone. Regardless of location, a score of 5 was assigned if the SUVmax exceeded 12 in the lesion. A primary score of 1–2 was considered a low-risk pattern and 3–5 was considered a high-risk pattern [10].

Data and Statistical Analysis

Descriptive statistics were used to calculate the mean, median, standard deviation, minimum, and maximum values. Categorical variables were summarized as frequencies and percentages. Sensitivities, specificities, and PPV of PRIMARY and PI-RADS scoring systems were calculated. Receiver Operating Characteristic (ROC) curves were used to evaluate the diagnostic accuracy of the scoring systems. Differences between independent groups were assessed using the Mann-Whitney U test. Correlations between variables were examined using the Spearman test. Statistical significance was defined as a two-tailed p-value less than 0.05. The data was analyzed using the Statistical Package for the Social Sciences (SPSS), version 27.0 (IBM Corporation in Chicago, Illinois, USA).

The patient characteristics are listed in Table 1. The average tPSA value was 38.4 ± 102.9 ng/mL, and the average SUVmax value was 8.7 ± 10.0. The distribution of ISUP Grades among the patients was as follows: 70 (52.2%) ISUP Grade 1, 17 (12.7%) ISUP Grade 2, 8 (6.0%) ISUP Grade 3, 22 (16.4%) ISUP Grade 4, and 17 (12.7%) ISUP Grade 5. According to the NCCN, 49 (36.6%) patients were classified as low risk, 37 (27.6%) as intermediate risk, and 48 (35.8%) as high risk. The PI-RADS scoring distribution among the 90 patients with available mpMRI evaluation was as follows: score 2, 3.7% (n = 5); score 3, 9.7% (n = 13); score 4, 32.8% (n = 44); score 5, 20.9% (n = 28). The PRIMARY scoring distribution was as follows: score 1, 10.4% (n = 14); score 2, 13.4% (n = 18); score 3, 9.0% (n = 12); score 4, 49.3% (n = 66); score 5, 17.9% (n = 24).

Table 1

Patient Characteristics
Age (year)	66 (41–91)
tPSA (ng/mL)	38.4 (1.9–946)
SUVmax	8.7 (1.7–71.4)
ISUP Grade
1	70 (52.2%)
2	17 (12.7%)
3	8 (6.0%)
4	22 (16.4%)
5	17 (12.7%)
Risk Group
Low	49 (36.6%)
Intermediate	37 (27.6%)
High	48 (35.8%)
PI-RADS
2	5 (3.7%)
3	13 (9.7%)
4	44 (32.8%)
5	28 (20.9%)
PRIMARY
1	14 (10.4%)
2	18 (13.4%)
3	12 (9.0%)
4	66 (49.3%)
5	24 (17.9%)

In the risk group based PRIMARY score distribution analysis, the distribution of PRIMARY score 1–2 (low-risk pattern) and score 3–5 (high-risk pattern) in the low-risk and intermediate/high-risk groups was analyzed. In the intermediate/high-risk group, The PRIMARY score was 1–2 (low-risk pattern) in 15 (17.6%) patients, and 3–5 (high-risk pattern) in 70 (82.4%) patients. In the low-risk group, the PRIMARY score was 1–2 (low-risk pattern) in 17 (34.7%) patients and 3–5 (high-risk pattern) in 32 (65.3%) patients. None of the patients in the low-risk group had a PRIMARY score of 5 (Fig. 1).

The sensitivity of PRIMARY scoring in detecting patients in the intermediate/high-risk group was 82.3%, the specificity was 34.6%, and the PPV was 68.6%. The sensitivity of the PI-RADS score was 94.2%, the specificity was 5.2%, and the PPV was 57.6%. In the Receiver Operating Characteristic (ROC) curve (Fig. 2), the area under the curve (AUC) for PRIMARY scoring was 0.727 (95% CI: 0.623–0.830), while the AUC for PI-RADS was 0.662 (95% CI: 0.550–0.774), and for the 90 patients with both mpMRI and 68Ga-PSMA PET/CT, the AUC for the mean of PI-RADS and PRIMARY scores was 0.744 (95% CI: 0.643–0.846).

The most frequent PRIMARY score in both the intermediate/high-risk and the low-risk groups was 4 (48.2% and 51.0%, respectively). According to the Mann Whitney U test, a statistically significant difference was detected between the average SUVmax values of the intermediate/high and low-risk groups (6.7 ± 2.6 vs 5.0 ± 2.1, respectively) with a PRIMARY score of 4 (MWU(Z) = 333.0, p = 0.018) (Fig. 3). In an analysis, a cut-off SUVmax value of 5.0 was set for a PRIMARY score of 4, with values below this threshold categorized as score 2 (low-risk pattern). As a result, the sensitivity of the PRIMARY score decreased from 82.3–67.0%, while specificity increased from 34.6–65.3%, and the positive predictive value (PPV) increased from 68.6–77.0%.

In the analysis of the correlations using the Spearman correlation test, a statistically significant high correlation between the SUVmax value and the PRIMARY score (r = 0.76, p < 0.001), and a moderate correlation between the SUVmax value and the PI-RADS score (r = 0.30, p = 0.004) was observed. There was a moderate correlation between ISUP grade and PRIMARY score (r = 0.37, p < 0.001). Similarly, a moderate correlation was found between ISUP grade and PI-RADS score (r = 0.31, p = 0.003). There was a moderate correlation between tPSA value and PRIMARY score (r = 0.39, p < 0.001). Similarly, a moderate correlation was observed between the tPSA value and the PI-RADS score (r = 0.41, p < 0.001) (Table 2).

Table 2

Correlation coefficients and p values of PRIMAY and PI-RADS scores with tPSA, ISUP Grade and SUVmax values.
	tPSA		ISUP		SUV_max
	Correlation coefficient (r)	p value	Correlation coefficient (r)	p value	Correlation coefficient (r)	p value
PRIMARY	0.39	< 0.001	0.37	< 0.001	0.76	< 0.001
PI-RADS	0.41	< 0.001	0.31	0.003	0.30	0.004

68Ga-PSMA PET/CT is a valuable tool for detecting and assessing metastatic disease burden in PCa, as well as detecting and restaging PCa recurrence after curative treatment [11]. In addition to evaluating systemic metastases, 68Ga-PSMA PET/CT can identify the intraprostatic index lesion. It is known for its high sensitivity in detecting intraprostatic tumours, due to its ability to target PSMA expression on PCa cells [12]. The intensity of tumour-related tracer uptake on 68Ga-PSMA PET/CT correlates with PSA level and Gleason score in newly diagnosed PCa [13, 14].

The PRIMARY score, which incorporates intraprostatic patterns and intensity on 68Ga-PSMA PET/CT, is an accurate and reproducible method for reporting intraprostatic PSMA PET findings in men before prostate biopsy [9]. The recently updated PROMISE framework, which aims for standardization in 68Ga-PSMA PET/CT, includes the use of PRIMARY scoring in the definition of intraprostatic lesions [15]. Akcay et al. [16] showed that the PRIMARY scoring system had a sensitivity of 77% and specificity of 58% in identifying clinically significant PCa and is a potential tool for selecting patients for active surveillance. Active surveillance is a management method allowing to postpone definitive treatment and avoid the side effects of surgery and radiotherapy for patients with low-risk PCa. [17, 18, 19]. In our study, unlike the existing literature, we analyzed the distribution of PRIMARY scoring among PCa risk groups. Our results showed that while the PRIMARY scoring had good sensitivity, it was lower than the PI-RADS scoring (82.3% vs 94.2%), and PRIMARY scoring had higher specificity than PI-RADS (34.6% vs 5.2%) in identifying patients with intermediate/high-risk prostate cancer. Therefore, the use of PRIMARY scoring alone or in combination with PI-RADS scoring in the detection or follow-up of active surveillance patients can reduce unnecessary biopsies.

In the PROMIS trial investigating the diagnostic accuracy of mpMRI in PCa, the sensitivity of mpMRI for clinically significant cancer was 93% and the negative predictive value (NPV) was 89%. The specificity of mpMRI was 41% with a PPV of 51% [6]. The low specificity and PPV of mpMRI indicate that it may lead to unnecessary biopsy. mpMRI still misses a small number of clinically significant PCa, which leads to the need for new approaches to reduce false-negative rates [20]. The PRIMARY trial found that using PSMA PET/CT in combination with mpMRI increased sensitivity and NPV for clinically significant PCa compared to the use of mpMRI alone [21]. Scheltema et al. [22] showed that PSMA-PET demonstrated higher diagnostic accuracy, sensitivity, specificity, NPV, and PPV, especially for ISUP grades 2–3 compared to mpMRI, and the combination of PSMA-PET and mpMRI improved sensitivity, specificity, NPV, and PPV for detecting ISUP grades 2–3 PCa. Using 68Ga-PSMA PET/CT and mpMRI together has the potential to accurately predict clinically significant PCa prior to biopsy, offering a noninvasive method for clinicians to gauge clinically significant PCa risk and potentially reduce unnecessary biopsies [23]. As in our study, the higher sensitivity of the PI-RADS score suggests that it is effective in correctly identifying a larger proportion of patients with intermediate and high-risk PCa. However, the low specificity and positive predictive rates of PI-RADS may lead to unnecessary biopsies if used alone in decision-making during the follow-up of active surveillance patients. In contrast, PRIMARY scoring had a more balanced performance with lower sensitivity but relatively higher specificity compared to PI-RADS.

Active surveillance (AS) is a strategy that uses PSA testing, digital rectal examination, and prostate biopsies to monitor PCa in men rather than recommending preventive treatment for low-risk localized PCas [24]. Very low-risk and low-risk patients (biopsy Gleason score of ≤ 6, a PSA level less than 10 ng/mL, and a clinical stage of T1c or T2a) with a life expectancy greater than 10 years are candidates for AS. [25]. Although the overall risk of major complications from the prostate biopsy is low, it is still an invasive technique that can cause complications like bleeding, infection, pain, lower urinary tract symptoms, urinary retention, and erectile dysfunction [26]. On this basis, interest in the potential of imaging methods to replace biopsy in the diagnosis and AS of PCa has increased. mpMRI is used in some AS protocols to confirm eligibility, monitor for changes, and guide targeted biopsies, but current data do not support the use of negative mpMRI alone to avoid scheduled biopsies [18]. The ROC Curve analysis revealed a moderately higher AUC for PRIMARY scoring (0.727, 95% CI: 0.623–0.830) compared to PI-RADS scoring (0.662, 95% CI: 0.550–0.774). Moreover, the AUC of the means of PRIMARY and PI-RADS scores was even higher (0.744, 95% CI: 0.643–0.846). This suggests that PRIMARY scoring may offer an improved ability to select patients for active surveillance and has the potential to change the re-biopsy decision, preventing unnecessary biopsies during active surveillance when used together with PI-RADS.

SUVmax values can predict the grade groups of the primary tumor and may serve as a target for biopsy sampling in selected patients, in conjunction with mpMRI [14]. Jiao J et al. [27] recommended an SUVmax cutoff value of 5.30 to discriminate between clinically significant PCa and benign prostatic disease using 68Ga-PSMA PET/CT imaging. PRIMARY score 4 represents any focal activity in the peripheral zone without minimum intensity (10). In our results, the most frequent PRIMARY score in both the intermediate/high-risk group and the low-risk group was 4 (48.2% and 51.0%, respectively) and a statistically significant difference was detected between the average SUVmax values of the intermediate/high and low-risk groups with a PRIMARY score of 4 (6.7 and 5.0, respectively) (p = 0.018). Also in our analysis, when a cut-off SUVmax value of 5.0 was determined for the PRIMARY score of 4, despite the decrease in sensitivity (82.3–67.0%), the specificity (34.6–65.3%) and the PPV (68.6–77.0%) of the PRIMARY scoring had increased. This suggests that revising the PRIMARY score of 4 with a cut-off SUVmax value may improve the specificity and PPV of the scoring system.

Our study had limitations due to its single-center retrospective nature. The ISUP degree distributions of the patient group were not homogeneous. PI-RADS scores were recorded retrospectively based on reports, which gave rise to the possibility that the evaluation was made by a single expert. Although at least two expert opinions were taken when determining PRIMARY scores, the experts' experience in the use of this scoring was limited.

The PRIMARY scoring, which standardizes intraprostatic distribution in 68Ga-PSMA PET/CT, can complement PI-RADS scoring in mpMR for selecting patients suitable for active surveillance, reconsidering biopsy decisions during follow-up, and minimizing unnecessary biopsies. Revising PRIMARY score 4 with a SUVmax cut-off value may improve the specificity of the scoring system. Prospective studies are needed to determine the effectiveness of staging with the PRIMARY score and active surveillance decision on clinical outcomes.

Acknowledgments:

All of the authors declare that there is no conflict of interest and no funding has been received for this work.

Bergengren O, Pekala KR, Matsoukas K, Fainberg J, Mungovan SF, Bratt O, et al. 2022 Update on Prostate Cancer Epidemiology and Risk Factors-A Systematic Review. Eur Urol. 2023;84(2):191–206.
Fendler WP, Eiber M, Beheshti M, Bomanji J, Calais J, Ceci F, et al. PSMA PET/CT: joint EANM procedure guideline/SNMMI procedure standard for prostate cancer imaging 2.0. Eur J Nucl Med Mol Imaging. 2023;50(5):1466–86.
Tsechelidis I, Vrachimis A. PSMA PET in Imaging Prostate Cancer. Front Oncol. 2022;12:831429.
Roberts MJ, Morton A, Donato P, Kyle S, Pattison DA, Thomas P, et al. 68Ga-PSMA PET/CT tumour intensity pre-operatively predicts adverse pathological outcomes and progression-free survival in localised prostate cancer. Eur J Nucl Med Mol Imaging. 2021;48(2):477–82.
Schaeffer EM, Srinivas S, Adra N, An Y, Barocas D, Bitting R, et al. Prostate Cancer, Version 4.2023, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw. 2023;21(10):1067–96.
Ahmed HU, El-Shater Bosaily A, Brown LC, Gabe R, Kaplan R, Parmar MK, et al. PROMIS study group. Diagnostic accuracy of multi-parametric MRI and TRUS biopsy in prostate cancer (PROMIS): a paired validating confirmatory study. Lancet. 2017;389(10071):815–22.
Westphalen AC, Rosenkrantz AB. Prostate imaging reporting and data system (PI-RADS): reflections on early experience with a standardized interpretation scheme for multiparametric prostate MRI. AJR Am J Roentgenol. 2014;202(1):121–3.
Gupta RT, Mehta KA, Turkbey B, Verma S. PI-RADS: Past, present, and future. J Magn Reson Imaging. 2020;52(1):33–53.
Emmett L, Papa N, Counter W, Calais J, Barbato F, Burger I, et al. Reproducibility and Accuracy of the PRIMARY Score on PSMA PET and of PI-RADS on Multiparametric MRI for Prostate Cancer Diagnosis Within a Real-World Database. J Nucl Med. 2024;65(1):94–9.
Emmett L, Papa N, Buteau J, Ho B, Liu V, Roberts M, et al. The PRIMARY Score: Using Intraprostatic 68Ga-PSMA PET/CT Patterns to Optimize Prostate Cancer Diagnosis. J Nucl Med. 2022;63(11):1644–50.
Perera M, Papa N, Roberts M, Williams M, Udovicich C, Vela I, et al. Gallium-68 Prostate-specific Membrane Antigen Positron Emission Tomography in Advanced Prostate Cancer-Updated Diagnostic Utility, Sensitivity, Specificity, and Distribution of Prostate-specific Membrane Antigen-avid Lesions: A Systematic Review and Meta-analysis. Eur Urol. 2020;77(4):403–17.
Chow KM, So WZ, Lee HJ, Lee A, Yap DWT, Takwoingi Y, et al. Head-to-head Comparison of the Diagnostic Accuracy of Prostate-specific Membrane Antigen Positron Emission Tomography and Conventional Imaging Modalities for Initial Staging of Intermediate- to High-risk Prostate Cancer: A Systematic Review and Meta-analysis. Eur Urol. 2023;84(1):36–48.
Uprimny C, Kroiss AS, Decristoforo C, Fritz J, von Guggenberg E, Kendler D, et al. 68Ga-PSMA-11 PET/CT in primary staging of prostate cancer: PSA and Gleason score predict the intensity of tracer accumulation in the primary tumour. Eur J Nucl Med Mol Imaging. 2017;44(6):941–9.
Demirci E, Kabasakal L, Şahin OE, Akgün E, Gültekin MH, Doğanca T, et al. Can SUVmax values of Ga-68-PSMA PET/CT scan predict the clinically significant prostate cancer? Nucl Med Commun. 2019;40(1):86–91.
Seifert R, Emmett L, Rowe SP, Herrmann K, Hadaschik B, Calais J, et al. Second Version of the Prostate Cancer Molecular Imaging Standardized Evaluation Framework Including Response Evaluation for Clinical Trials (PROMISE V2). Eur Urol. 2023;83(5):405–12.
Akcay K, Kibar A, Sahin OE, Demirbilek M, Beydagi G, Asa S, et al. Prediction of clinically significant prostate cancer by [⁶⁸Ga] Ga-PSMA-11 PET/CT: a potential tool for selecting patients for active surveillance. Eur J Nucl Med Mol Imaging. 2024;51(5):1467–75.
Suardi N, Briganti A, Gallina A, Salonia A, Karakiewicz PI, Capitanio U, et al. Testing the most stringent criteria for selection of candidates for active surveillance in patients with low-risk prostate cancer. BJU Int. 2010;105(11):1548–52.
Shill DK, Roobol MJ, Ehdaie B, Vickers AJ, Carlsson SV. Active surveillance for prostate cancer. Transl Androl Urol. 2021;10(6):2809–19.
Ho MD, Ross AE, Eggener SE. Risk Stratification of Low-risk Prostate Cancer: Individualizing Care in the Era of Active Surveillance. J Urol. 2023;210(1):38–45.
Borofsky S, George AK, Gaur S, Bernardo M, Greer MD, Mertan FV, et al. What Are We Missing? False-Negative Cancers at Multiparametric MR Imaging of the Prostate. Radiology. 2018;286(1):186–95.
Emmett L, Buteau J, Papa N, Moon D, Thompson J, Roberts MJ, et al. The Additive Diagnostic Value of Prostate-specific Membrane Antigen Positron Emission Tomography Computed Tomography to Multiparametric Magnetic Resonance Imaging Triage in the Diagnosis of Prostate Cancer (PRIMARY): A Prospective Multicentre Study. Eur Urol. 2021;80(6):682–9.
Scheltema MJ, Chang JI, Stricker PD, van Leeuwen PJ, Nguyen QA, Ho B, et al. Diagnostic accuracy of 68 Ga-prostate-specific membrane antigen (PSMA) positron-emission tomography (PET) and multiparametric (mp)MRI to detect intermediate-grade intra-prostatic prostate cancer using whole-mount pathology: impact of the addition of 68 Ga-PSMA PET to mpMRI. BJU Int. 2019;124(Suppl 1):42–9.
Cheng C, Liu J, Yi X, Yin H, Qiu D, Zhang J, et al. Prediction of clinically significant prostate cancer using a novel 68Ga-PSMA PET-CT and multiparametric MRI-based model. Transl Androl Urol. 2023;12(7):1115–26.
Kinsella N, Helleman J, Bruinsma S, Carlsson S, Cahill D, Brown C, et al. Active surveillance for prostate cancer: a systematic review of contemporary worldwide practices. Transl Androl Urol. 2018;7(1):83–97.
Schaeffer EM, Srinivas S, Adra N, An Y, Bitting R, Chapin B, et al. NCCN Guidelines® Insights: Prostate Cancer, Version 3.2024. J Natl Compr Canc Netw. 2024;22(3):140–50.
Loeb S, Vellekoop A, Ahmed HU, Catto J, Emberton M, Nam R, et al. Systematic review of complications of prostate biopsy. Eur Urol. 2013;64(6):876–92.
Jiao J, Kang F, Zhang J, Quan Z, Wen W, Zhao X, et al. Establishment and prospective validation of an SUVmax cutoff value to discriminate clinically significant prostate cancer from benign prostate diseases in patients with suspected prostate cancer by 68Ga-PSMA PET/CT: a real-world study. Theranostics. 2021;11(17):8396–411.

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You are reading this latest preprint version

PRIMARY Scoring in 68Ga-PSMA PET/CT: Correlation with Prostate Cancer Risk Groups and Its Potential Impact on Active Surveillance

Status:

Version 1

Abstract

Objective

Methods

Results

Conclusion

Figures

Introduction

Materials and Methods

Patient selection and study design

68Ga-PSMA PET/CT Imaging Protocol

PRIMARY Scoring

Data and Statistical Analysis

Results

Discussion

Conclusion

Declarations

Acknowledgments:

References

Status:

Version 1