Defining Diagnostic Criteria for Prostatic Ductal Adenocarcinoma at Multiparametric MRI

68Ga-PSMA PET/CT and 18F-FDG PET/CT in the diagnosis of prostatic ductal cancer

PURPOSES

To explore the characteristics of PSMA PET/CT and FDG PET/CT images in prostatic ductal adenocarcinoma (DA) patients.

METHODS

We retrospectively enrolled prostatic DA patients with PET/CT scans at Tongji Hospital from 2018 to 2022. Patients with prostatic acinar adenocarcinoma (AA) and benign pathology (BP) were enrolled by 1:1 matching. Differences in the uptake of primary and metastatic foci on PET among the groups were analyzed.

RESULTS

A total of 42 patients were enrolled: 14 in each group. In primary foci, the mean PSMA uptake in the DA group was lower than that in the AA group (14.2 ± 9.6 vs. 27.1 ± 14.3, P = 0.009) and greater than that in the BP group (14.2 ± 9.6 vs. 4.7 ± 1.3, P = 0.003). The AUCs of the DA-AA ROC curve and DA-BP ROC curve were 0.781 and 0.872, respectively. The median PSMA uptake of metastatic lymph nodes in the DA group was lower than that in the AA group (5.6 vs. 14.2, P = 0.033), with no significant difference in metastatic bone lesions (9.5 vs 19.1, P = 0.485). No significant difference was found in the FDG uptake of primary and metastatic foci between the DA and AA groups (P > 0.05).

CONCLUSION

Prostatic DA has greater PSMA uptake than BP diseases, but lower uptake in both primary foci and metastatic lymph nodes than AA on PSMA PET/CT, aiding in the differential diagnosis of DA, AA and BP diseases. Clinicians should combine traditional imaging with PSMA PET/CT to avoid underestimating the clinical stage of DA patients.

Pitfalls in Prostate MR Imaging Interpretation

Multiparametric MR imaging of the prostate is an essential diagnostic study in the evaluation of prostate cancer. Several entities including normal anatomic structures, benign lesions, and posttreatment changes can mimic prostate cancer. An in depth understanding of the pitfalls is important for accurate interpretation of prostate MR imaging.

Nomogram Models for Distinguishing Intraductal Carcinoma of the Prostate From Prostatic Acinar Adenocarcinoma Based on Multiparametric Magnetic Resonance Imaging

OBJECTIVE

To compare multiparametric magnetic resonance imaging (MRI) features of intraductal carcinoma of the prostate (IDC-P) with those of prostatic acinar adenocarcinoma (PAC) and develop prediction models to distinguish IDC-P from PAC and IDC-P with a high proportion (IDC ≥ 10%, hpIDC-P) from IDC-P with a low proportion (IDC < 10%, lpIDC-P) and PAC.

MATERIALS AND METHODS

One hundred and six patients with hpIDC-P, 105 with lpIDC-P and 168 with PAC, who underwent pretreatment multiparametric MRI between January 2015 and December 2020 were included in this study. Imaging parameters, including invasiveness and metastasis, were evaluated and compared between the PAC and IDC-P groups as well as between the hpIDC-P and lpIDC-P subgroups. Nomograms for distinguishing IDC-P from PAC, and hpIDC-P from lpIDC-P and PAC, were made using multivariable logistic regression analysis. The discrimination performance of the models was assessed using the receiver operating characteristic area under the curve (ROC-AUC) in the sample, where the models were derived from without an independent validation sample.

RESULTS

The tumor diameter was larger and invasive and metastatic features were more common in the IDC-P than in the PAC group (P < 0.001). The distribution of extraprostatic extension (EPE) and pelvic lymphadenopathy was even greater, and the apparent diffusion coefficient (ADC) ratio was lower in the hpIDC-P than in the lpIDC-P group (P < 0.05). The ROC-AUCs of the stepwise models based solely on imaging features for distinguishing IDC-P from PAC and hpIDC-P from lpIDC-P and PAC were 0.797 (95% confidence interval, 0.750-0.843) and 0.777 (0.727-0.827), respectively.

CONCLUSION

IDC-P was more likely to be larger, more invasive, and more metastatic, with obviously restricted diffusion. EPE, pelvic lymphadenopathy, and a lower ADC ratio were more likely to occur in hpIDC-P, and were also the most useful variables in both nomograms for predicting IDC-P and hpIDC-P.

FDG PET/CT in a Case of Pure Ductal Adenocarcinoma of the Prostate With Osteolytic Metastases and Normal PSA Level

ABSTRACT

Prostatic ductal adenocarcinoma is an uncommon aggressive subtype of prostate carcinoma. It is more likely to present with advanced stage and lower prostate-specific antigen. We describe FDG PET/CT findings in a case of pure prostatic ductal adenocarcinoma with lymph node, bone and lung metastases, normal serum prostate-specific antigen level, and elevated serum carbohydrate antigen 19-9 and carbohydrate antigen 724 levels. The primary tumor, and lymph node and bone metastases were hypermetabolic. All the bone metastases were osteolytic. The multiple lung metastases showed no significant FDG uptake, which may be due to small size.

The rising incidence of ductal adenocarcinoma and intraductal carcinoma of the prostate: Diagnostic accuracy of biopsy, MRI-visibility, and outcomes

INTRODUCTION

Ductal adenocarcinoma (DA) and intraductal carcinoma (IDC) of the prostate are associated with higher stage disease at radical prostatectomy (RP). We evaluated diagnostic accuracy of biopsy, MRI-visibility, and outcomes for patients undergoing RP with DA/IDC histology compared to pure acinar adenocarcinoma (AA) of the prostate.

MATERIALS AND METHODS

A retrospective cohort study of men receiving RP between 2014 and 2021 revealing AA, DA, or IDC on final pathology was conducted. Multivariable logistic regression and Cox proportional hazards regression models were employed.

RESULTS

A total of 609 patients were included with 103 found to have DA/IDC. Patients with DA/IDC were older and had higher PSA, biopsy grade group (GG), RP GG, and other pathologic findings (extraprostatic extension, lymphovascular invasion, perineural invasion, pN stage) compared to AA patients (all P < 0.05). On multivariable analysis, higher age, RP GG, and pT3a were associated with DA/IDC on RP (all P < 0.05). Sensitivity and specificity of biopsy compared to RP for diagnosis of DA/IDC was 29.1% (16.7% DA, 27.8% IDC) and 96.6% (99.3% DA, 96.6% IDC), respectively. In a subset of 281 men receiving MRI, PI-RADS distribution was similar for patients with DA/IDC vs. AA (90.7% vs. 80.7% with PI-RADS 4-5 lesions, P = 0.23) with slightly higher biopsy sensitivity (41.9%). DA/IDC was associated with worse BCR (HR = 1.77, P = 0.02) but not biopsy DA/IDC (P = 0.90).

CONCLUSIONS

Sensitivity of prostate biopsy was low for detection of DA/IDC histology at RP. Patients with DA/IDC histology had unfavorable pathologic features at RP and worse BCR. Of patients with DA/IDC at RP, 90.7% were categorized as PI-RADS 4 to 5 on preoperative MRI.

68 Ga-PSMA-11 and 18 F-FDG PET/CT in a Case of Ductal Adenocarcinoma of the Prostate

ABSTRACT

Prostatic ductal adenocarcinoma is an uncommon variant of prostatic carcinoma with aggressive behavior and worse prognosis. We describe 68 Ga-PSMA-11 and FDG PET/CT findings in a case of prostatic ductal adenocarcinoma with pelvic lymph node metastases. The majority of the prostate tumor and all the metastatic lesions showed no significant PSMA uptake but intense FDG uptake. The role of PSMA and FDG PET in the management of prostatic ductal adenocarcinoma needs to be investigated in a large number of patients.