The active papillary muscle sign in 18F-FDG PET/CT cardiac sarcoidosis exams and its relationship with myocardial suppression.

OBJECTIVE: Papillary muscle (PM) activity may demonstrate true active cardiac sarcoidosis (CS) or mimic CS in 18FDG-PET/CT if adequate myocardial suppression (MS) is not achieved. We aim to examine whether PM uptake can be used as a marker of failed MS and measure the rate of PM activity presence in active CS with different dietary preparations. MATERIALS AND METHODS: We retrospectively reviewed PET/CTs obtained with three different dietary preparations. Diet-A: 24-h ketogenic diet with overnight fasting (n = 94); Diet-B: 18-h fasting (n = 44); and Diet-C: 72-h daytime ketogenic diet with 3-day overnight fasting (n = 98). Each case was evaluated regarding CS diagnosis (negative, positive, and indeterminant) and presence of PM activity. MaxSUV was measured from bloodpool, liver, and the most suppressed normal myocardium. Linear mixed-effects models were used to compare these factors between those with PM activity and those without. RESULTS: PM activity was markedly lower in the Diet-C group compared with others: Diet-C: 6 (6.1%), Diet-A: 36 (38.3%), and Diet-B: 26 (59.1%) (p < 0.001). MyocardiumMaxSUV was higher, and MyocardiummaxSUV/BloodpoolmaxSUV, MyocardiummaxSUV/LivermaxSUV ratios were significantly higher in the cases with PM activity (p < 0.001). Among cases that used Diet-C and had PM activity, 66.7% were positive and 16.7% were indeterminate. If Diet-A or Diet-B was used, those with PM activity had a higher proportion of indeterminate cases (Diet-A: 61.1%, Diet-B: 61.5%) than positive cases (Diet-A: 36.1%, Diet-B: 38.5%). CONCLUSION: Lack of PM activity can be a sign of appropriate MS. PM activity is less common with a specific dietary preparation (72-h daytime ketogenic diet with 3-day overnight fasting), and if it is present with this particular preparation, the likelihood that the case being true active CS might be higher than the other traditional dietary preparations.

Impact of piflufolastat F-18 PSMA PET imaging on clinical decision-making in prostate cancer across disease states: A retrospective review.

INTRODUCTION: Piflufolastat F-18 (18F-DCFPyL) prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging is approved by the US food and drug administration for initial staging of high-risk prostate cancer, biochemical recurrence (BCR), and restaging of metastatic prostate cancer. Here, we sought to assess how its integration into clinical care may have impacted the management of patients. METHODS: We identified 235 consecutive patients who underwent an 18F-DCFPyL PET scan from August 2021 to June 2022. The median prostate-specific antigen at the time of imaging was 1.8 ng/mL (Range: 0-3740 ng/mL). Descriptive statistics were used to analyze its impact on clinical care for a subset of 157 patients with available treatment information: 22 for initial staging, 109 with BCR, and 26 patients with known metastatic disease. RESULTS: PSMA-avid lesions were detected in 154/235 (65.5% of) patients. In patients undergoing initial staging, 18/39 (46.2% of) patients had extra-prostatic metastatic lesions; 15/39 (38.5% of) scans were negative and 6/39 (15.4%) had equivocal results. 12/22 (54.5% of) patients had a change in their treatment plan post-PSMA PET scan while 10/22 (45.5%) had no change in their treatment plan. In the BCR cohort, 93/150 (62.0%) had a local recurrence or metastatic lesions. Equivocal and negative scans accounted for 11/150 (7.3%) and 46/150 (30.7%) of scans, respectively. 37/109 (33.9% of) patients had a change in their treatment plan, while treatment was not altered in 72/109 (66.1% of) cases. In patients with metastatic disease, 43/46 (93.5%) had PSMA-avid lesions identified; equivocal and negative scans accounted for 2/46 (4.3%) and 1/46 (2.2%) of scan results, respectively. 6/26 (23.1%) had their tentative treatment plan adjusted after the PSMA PET scan. No change in the treatment plan was observed in 20/26 (76.9% of) cases. CONCLUSION: Integration of F-18 PSMA PET imaging impacted clinical decision-making and subsequent management across all stages of prostate cancer. It remains to be seen whether this translates into superior survival outcomes.

A bicentric retrospective analysis of clinical utility of 18F-fluciclovine PET in biochemically recurrent prostate cancer following primary radiation therapy: is it helpful in patients with a PSA rise less than the Phoenix criteria?

PURPOSE: 18F-Fluciclovine PET imaging has been increasingly used in the restaging of prostate cancer patients with biochemical recurrence (BCR); however, its clinical utility in patients with low prostate-specific antigen (PSA) levels following primary radiation therapy has not been well-studied. This study aims to determine the detection rate and diagnostic accuracy of 18F-fluciclovine PET and the patterns of prostate cancer recurrence in patients with rising PSA after initial radiation therapy, particularly in patients with PSA levels below the accepted Phoenix definition of BCR (PSA nadir +2 ng/mL). METHODS: This retrospective study included patients from two tertiary institutions who underwent 18F-fluciclovine PET scans for elevated PSA level following initial external beam radiation therapy, brachytherapy, and/or proton therapy. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to determine the diagnostic accuracy of 18F-fluciclovine PET and associations of PSA kinetic parameters with 18F-fluciclovine PET outcome. RESULTS: One hundred patients were included in this study. The overall detection rate on a patient-level was 79% (79/100). 18F-Fluciclovine PET was positive in 62% (23/37) of cases with PSA below the Phoenix criteria. The positive predictive value of 18F-fluciclovine PET was 89% (95% CI: 80-94%). In patients with PSA below the Phoenix criteria, the PSA velocity had the highest predictive value of 18F-fluciclovine PET outcome. PSA doubling time (PSADT) and PSA velocity were associated with the presence of extra-pelvic metastatic disease. CONCLUSION: 18F-Fluciclovine PET can identify recurrent disease at low PSA level and PSA rise below accepted Phoenix criteria in patients with suspected BCR after primary radiation therapy, particularly in patients with low PSADT or high PSA velocity. In patients with low PSADT or high PSA velocity, there is an increased probability of extra-pelvic metastases. Therefore, these patients are more likely to benefit from PET/CT or PET/MRI than pelvic MRI alone.

COMPARISON OF THE EFFECT OF THREE DIFFERENT DIETARY MODIFICATIONS ON MYOCARDIAL SUPPRESSION IN 18F-FDG PET/CT EVALUATION OF PATIENTS FOR SUSPECTED CARDIAC SARCOIDOSIS.

Rationale: A definitive dietary preparation recommendation is not possible based on literature in achievement of myocardial suppression for diagnosis of cardiac sarcoidosis (CS) with 18F-FDG PET/CT. Our goal is to compare three different dietary preparations in achievement of the best myocardial suppression and CS diagnosis. Methods: We retrospectively reviewed and compared three dietary preparations used at our institution. Three different diets were applied from 03/2014 to 12/2019. 24-h ketogenic diet with overnight fasting (n = 94); 18h-fasting (n = 44); 72-h daytime ketogenic diet with 3-day overnight fasting (n = 98). The interpretation of initial reports was recorded, and an independent radiologist (observer) retrospectively re-evaluated each case regarding CS diagnosis (Negative, Positive, Indeterminant) and myocardial suppression (Complete, Failed, Partial). Interobserver agreement was analyzed. We measured MaxSUV from bloodpool, liver, and the most suppressed normal myocardium. Results: We identified superior myocardial suppression with the 72-h preparation indicated by a higher bloodpool/myocardium and liver/myocardium ratios (P<0.001). Myocardial suppression rates for 72-h ketogenic diet, 24-h ketogenic diet and 18-h fasting preparations are as follows; Complete myocardial suppression: 96.9%/68.1%/52.3%, Failed myocardial suppression: 0%/23.4%/25%, Partial myocardial suppression: 3.1%/8.5%/22.7%) (P<0.001). The 72-hour preparation had significantly fewer "indeterminant" and "positive" exams. CS diagnosis rates for 72-h ketogenic diet, 24-h ketogenic diet and 18-h fasting preparations are as follows; Negative: 82.7%/52.1%/27.3%, Indeterminant: 2.0%/24.5%/40.9%, Positive: 15.3%/23.4%/31.8% (P<0.001). High agreement was present with the observer and the report (κ=0.88) Conclusion: A 72-h daytime ketogenic diet with 3-day overnight fasting, achieved substantially superior myocardial suppression versus 24-h ketogenic diet with overnight fasting and 18h-fasting using 18F-FDG PET/CT. This 72-h preparation results in significantly fewer "indeterminant" and potentially "false positive" CS results.

Solitary Penile Metastasis of Prostate Cancer on 18F-Fluciclovine PET/CT Imaging in a Patient With PSA of 1 ng/mL.

An 85-year-old asymptomatic man with suspected biochemical recurrence of prostate cancer underwent an F-fluciclovine PET/CT scan, which revealed a solitary suspicious tracer uptake in the dorsal right corporal body of the proximal pendulous penis. The patient underwent ultrasound-guided fine-needle aspiration of the penile lesion, which revealed metastatic prostate cancer. The patient had definitive external beam radiation therapy 3 years before the examination. At the time of scan, the prostatic-specific antigen (PSA) was only 1.0 ng/mL, although the PSA doubling time was 2.6 months. It is unusual to detect a solitary penile metastasis in a patient with a low level of PSA.

Positron Emission Tomography-Based Assessment of Metabolic Tumor Volume Predicts Survival after Autologous Hematopoietic Cell Transplantation for Hodgkin Lymphoma.

Autologous hematopoietic cell transplantation (AHCT) is curative for 60% of patients with relapsed or refractory Hodgkin lymphoma (R/R HL). A more precise assessment of the depth of remission before AHCT may help to identify patients likely to benefit from AHCT. We aimed to determine whether positron emission tomography (PET)-based quantitative parameters of total metabolic tumor volume (TMTV), total lesion glycolysis (TLG), and maximal standardized uptake volume (SUVmax) measured before AHCT predict progression-free survival (PFS) after transplant. Pretransplant PET/computed tomography images of 96 consecutive patients with R/R HL were analyzed. Median TMTV, TLG, and SUVmax were 7.97 cm3 (range, 1.3 to 102.1), 23.7 (range, 4.0 to 813.1), and 5.23 (range, 2.7 to 23.2). Two-year PFS in patients with high TMTV (TMTVhigh; more than median; n = 17) was only 12% (95% CI, 1% to 38%) compared with 53% (95% CI, 28% to 73%; P = .05) in patients with TMTVlow (lower or equal to median; n = 17) and 63% (95% CI, 50% to 74%) in 61 patients with no metabolically active tumor (TMTV0; P > .01). In concordance, high TLG (>19) and SUVmax (>4.9) predicted inferior 2-year PFS. In multivariate analysis patients with TMTVhigh had a 3.5-fold higher risk of treatment failure compared with TMTV0/TMTVlow (HR, 3.49; 95% CI, 1.75 to 6.93; P < .01). Deauville (D)-scores of 4 to 5 before AHCT predicted worse PFS compared with D-scores of 1 to 3 (HR, 3.7; 95% CI, 1.92 to 7.28; P < .01). Yet, TMTV and D-scores were disconcordant in 12 subjects; 9 patients in the D4 group with TMTVlow had 2-year PFS of 44% (95% CI, 14% to 72%), which was 2-fold higher than predicted by D4 score. In conclusion, in patients with R/R HL and PET-positive residual disease, TMTVhigh can identify very poor AHCT responders. Patients with TMTVlow, TLG, and SUVmax before AHCT have similar outcomes to those without metabolically active disease.

ACR guidance document on MR safe practices: 2013.

Because there are many potential risks in the MR environment and reports of adverse incidents involving patients, equipment and personnel, the need for a guidance document on MR safe practices emerged. Initially published in 2002, the ACR MR Safe Practices Guidelines established de facto industry standards for safe and responsible practices in clinical and research MR environments. As the MR industry changes the document is reviewed, modified and updated. The most recent version will reflect these changes.

Positron emission tomography scanning in the setting of post-transplant lymphoproliferative disorders.

BACKGROUND: Post-transplant lymphoproliferative disorder (PTLD) is a serious complication of transplantation. We examined the role of positron emission tomography (PET) scanning in PTLD. METHODS: All patients treated for PTLD from 2001-2006 who also underwent PET scans were reviewed. RESULTS: Nineteen PTLD patients were included. Seventeen patients had PET scans for staging at diagnosis. Of these, two patients with primary central nervous system lymphoma and one patient with only bone marrow involvement after complete surgical resection of a bowel lesion had no abnormalities on CT or PET scan. The remaining patients had measurable, extracranial disease by CT scan and PET scan. The median maximum standard uptake value was 8.2 (range 3-30). Thirteen patients had a PET scan following treatment. Eleven of 13 patients had a complete response (CR). Two of 13 patients had persistent disease following therapy; in one of these patients, relapsed disease was documented by PET scan alone. Of the 11 patients with CR, three patients relapsed shortly thereafter. In each case, at the time of relapse, the PET scan confirmed recurrent disease regardless of histopathologic subtype. CONCLUSIONS: PET scans may have a role in the staging and follow-up of patients with PTLD. Additional prospective studies are warranted.