Aim: Our aim of this study was to evaluate the diagnostic accuracy of staging positron emission tomography/computed tomography (PET/CT) in early breast cancers (EBCs) and to assess its impact on disease management. Patients and Methods: We retrospectively reviewed preoperative PET/CT scans of patients from January 2015 to December 2018 with Stage I/II, clinically T1-T2 N0-N1 breast cancers. The diagnostic performance of PET/CT for nodal (N) and distant metastases (M), its correlation with patient/tumor-specific factors, and its impact on disease management were analyzed using histopathology/clinical follow-up as standards of reference. Results: Of 158 patients evaluated, 14% of patients were Stage I (T1N0), 60% were Stage IIA (T1N1, T2N0), and 26% were Stage IIB (T2N1). Sensitivity, specificity, and the diagnostic accuracy of PET/CT for axillary staging were 76%, 97%, and 84% and for distant metastasis evaluation were 100%, 98%, and 99%, respectively. The diagnostic accuracy of PET/CT for axillary staging was lower for low-grade, T1 tumors, postmenopausal group, and luminal A pathological subtype (77%, 84%, 81%, and 73%, respectively) compared to high-grade, T2 tumors, premenopausal group, and nonluminal A subtype (88%, 88%, 94%, and 87%, respectively). Distant metastases were detected on PET/CT in overall 16% (n = 25) of the patients (9% in Stage IIA and 27% in Stage IIB). PET/CT also incidentally identified clinically occult internal mammary nodes in 5% (n = 8) and organ-confined synchronous second malignancies in 5% (n = 8) of the patients. Conclusion: Preoperative PET/CT should be considered in all EBCs> 2 cm as it upstages the disease and alters management in about 24% of these patients. Given its high specificity for axillary staging PET/CT, patients with PET-positive axilla can be subjected to axillary dissection and those with PET-negative axilla to sentinel lymph node biopsy. The yield and diagnostic accuracy of PET/CT is less for low-grade tumors <2 cm and with luminal A subtype.

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Background: Gallium-68-prostate-specific membrane antigen ( 68 Ga-PSMA) positron emission tomography/computed tomography (PET/CT) has recently been shown to be very high accuracy in biopsy-naïve prostate cancer (PCa) detection and can potentially improve the low specificity noted with diffusion-weighted magnetic resonance imaging (DW-MRI), especially in instances of prostate inflammation. We aimed to compare the diagnostic accuracy of DW-MRI and PSMA PET/CT using apparent diffusion coefficient (ADC) and maximum standardized uptake (SUV max ) values in the diagnosis of PCa. Patients and Methods: A retrospective study comparing and analyzing the diagnostic accuracy of prebiopsy DW-MRI and 68 Ga-PSMA PET/CTs done in patients with suspected PCa (raised prostate specific antigen [PSA] and/or positive digital rectal examination) from January 2019 to December 2020. The standard of reference was transrectal ultrasound-guided biopsies. Results: Sixty-seven patients were included in the study, mean age: 70 years (range 49–84), mean PSA: 23.2 ng/ml (range 2.97–45.6). Biopsy was positive for PCa in 56% ( n = 38) and negative in 43% ( n = 29). Of the benign results, benign hyperplasia was noted in 75% ( n = 22) and prostatitis in 25% ( n = 7). Of the PCa, 55% ( n = 21) of were high International Society of Urological Pathology (ISUP) grade (4–5) and 45% ( n = 17) low/intermediate ISUP grade (1–3). Overall the sensitivity/specificity/Accuracy for prediction of PCa of MRI using prostate imaging and reporting data system version 2 criteria and PSMA PET/CT using PCa molecular imaging standardized evaluation criteria was 92.1%/65.5%/80.5% and 76.3%/96.5%/85.1% respectively. Mean apparent diffusion co-efficient (mean ADC) value of benign lesions and PCa was 1.135 × 10 -3 mm 2 /s and 0.723 × 10 -3 mm 2 /s, respectively ( P = 0.00001). Mean SUV max and ADC of benign and PCa lesions was 4.01 and 16.4 ( P = 0.000246). Mean SUV max /ADC ratio of benign and malignant lesions was 3.8 × 103 versus 25.21 × 103 ( P < 0.000026). Inverse correlation was noted between ADC and SUV max values ( R = −0.609), inverse correlation noted between ADC and Gleason's score ( R = −0.198), and positive correlation of SUV max and SUV max /ADC with Gleason's score ( R = 0.438 and R = 0.448). Receiver operating characteris...

Immunoglobulin G4-related disease (IgG4) is an immune-mediated fibro-inflammatory entity which affects multiple organs, most frequently the pancreas. Although extrapancreatic inflammations are commonly seen in 18F-fluorodeoxyglucose positron emission tomography/computed tomography of majority of these patients at follow-up, simultaneous involvement of the gastric/biliary tract at presentation is rare. Here, we present imaging findings of a patient who presented with obstructive jaundice and initially thought to be due to cholangiocarcinoma, but was subsequently diagnosed as an IgG4-related inflammation.

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