Incidental Uptake of 68Ga-DOTATATE Gastrointestinal Stromal Tumor of Duodenum.

ABSTRACT: A 56-year-old man underwent 68Ga-DOTATATE PET/CT with suspicion of a pancreatic neuroendocrine tumor. However, in this imaging, a mass with 68Ga-DOTATATE uptake was observed not in pancreas but in the duodenojejunal junction. Abdominal tomography confirmed that the heterogeneously enhanced mass was originated from duodenum. The patient was operated, and the histopathology result was evaluated as low-risk gastrointestinal stromal tumor. Although there was low or no specific binding to gastrointestinal stromal tumor cells for all 68Ga-labeled DOTA peptides, uptake of 68Ga-DOTATATE was observed incidentally in this case.

Evaluation of metabolic changes in FDG PET/CT imaging after mRNA-based COVID-19 vaccination.

BACKGROUND: It isimportant to evaluate the vaccine-related metabolic changes on FDG PET/CT to avoid confusing results. We here aimed to assess the frequency and intensity of regional and systemic metabolic PET/CT changes of patients who received the mRNAbased COVID-19 vaccine (BNT162b2-Pfizer/BioNTech) and to analyze possible factors affecting these changes. METHODS: Among the patients who underwent FDG PET/CT for any indication in our department between July 2021 and December 2021, 129 volunteer patients with a history of COVID-19 vaccination were included in this prospective observational study. Bilateral axillary lymph nodes, ipsilateral deltoid muscle, bone marrow, spleen, thyroid, and liver FDG uptakes were evaluated visually and semiquantitatively for each examination. RESULTS: The frequencies of positive axillary lymph nodes after vaccination were 40%, 44.4%, 32.6%, and 44.7% in all, 1st dose, 2nd dose, and heterologous vaccination regimens groups, respectively. Maximum standardized uptake values of spleen, liver, and bone marrow were statistically high in patients with positive axillary lymph nodes than with negative ones (p < 0.05). Positive deltoid muscle uptake and diffusely increased thyroid uptake findings were observed in 10 and 8 patients, respectively. The median time interval between vaccination and imaging was 9.5 days for patients with positive axillary lymph nodes and 17 days for patients with negative nodes. In our study group, only 8 patients had a positive documented history of COVID-19 infection. DISCUSSION: Regional and systemic metabolic changes were occasionally found on FDG PET/CT imaging in patients who received the mRNA-based COVID-19 vaccine. To avoid these timely decreasing changes, we recommend managing the ideal timing of imaging or vaccination and taking a careful history.

The Role of Interim PET/CT on Survival in Diffuse Large B Cell Lymphoma.

BACKGROUND: Diffuse large B cell lymphoma is the most frequent aggressive non-Hodgkin lymphoma. Predicting response and estimating prognosis earlier makes management of this heterogeneous lymphoma more satisfying. Interim PET response is established in Hodgkin Lymphoma to tailor the therapy but results for non-Hodgkin Lymphoma is unconvincing. In the current study evaluation of interim PET and survival outcomes of 103 DLBCL patients is performed. PATIENTS AND METHODS: About 103 Patients with DLBCL followed up in a single center between 2009 and 2019 were enrolled the study. All patients received R-CHOP chemoimmunotherapy at first line. Interim PET was performed after at least one or more cycles. All PET scans were performed with 18F-FDG isotope as PET/CT. PET scoring results were evaluated according to the 5-Point Deauville Scoring system defined in the National Comprehensive Cancer Network clinical guidelines for iPET and eotPET. 5-P DS of scores of 1 to 3 were defined as negative scans, and scores of 4 to 5 were considered to be positive scans. RESULTS: Forty-six (44.7%) Female and 57 (55.3%) male aged between 25 and 83 (median 57) years newly diagnosed DLBCL patients were enrolled in the study. Median PFS was 21 (interquartile range 8.5-53.7) months and median OS was 33.5 (interquartile range 12.5-62.9) months for the total cohort. Positive predictive value of interim PET according to Deauville scoring system was 65.4% and negative predictive value was 77.9%. CONCLUSION: Our study showed that according to Deauville 5 point scale (D 5PS) scoring system, interim PET-positive patients have shorter both PFS and OS than iPET-negative patients.

Serum calprotectin (S100A8/A9) levels as a new potential biomarker of treatment response in Hodgkin lymphoma.

INTRODUCTION: Hodgkin lymphoma (HL) is unusual among malignancies, with inflammation playing such a prominent role in its pathogenesis. S100A8/A9 (calprotectin) is a heterodimeric protein, which has a role in the inflammatory response and oncogenesis. In this study in HL patients, the correlation between serum S100A8/A9 levels and treatment responses was investigated along with whether this marker is correlated with other inflammatory markers. MATERIALS AND METHODS: Thirty-three HL patients and 20 healthy volunteers were included. Demographic and clinical characteristics were recorded. Calprotectin levels were measured with Human S100A8/A9 Heterodimer Quantikine ELISA kit. Calprotectin levels were measured twice in patients, before and after treatment, and once in the control group. Treatment responses were evaluated with positron emission tomography-computed tomography (PET-CT). RESULTS: The mean age of patients was 44.3 ± 18.1 (66.3% male). The median (IQR) values of S100A8/A9 before and after treatment in the patient group were 4.98 (2.6-7.8) and 1.87 (1.1-4.8)µg/mL. Median (IQR) S100A8/A9 concentration in the control group was 1.41 (0.98-2.73)µg/mL. In patients, pretreatment values were significantly higher than in controls (P < .001). However, median values of patients after treatment and controls were similar. Patient median S100A8/A9 levels were significantly lower post-treatment compared with pretreatment values (P = .001). When inflammatory markers were examined within groups, no relationship was found between markers. In ROC analysis, a S100A8/A9 cutoff value of ≥3.31µg/mL accurately discriminated end-of-treatment PET positivity (AUC = 0.78; 95% CI 0.58-0.98; accuracy = 76.2%). CONCLUSION: S100A8/A9 may be a potential biomarker for treatment response in HL independent of inflammation. This is the first study to investigate and show this finding. However, further large-scale studies are still required.

Urinary Reflux Into the Prostate Gland and Seminal Vesicles: A Potential Pitfall in 18F-FDG and 68Ga-PSMA PET/CT.

A 64-year-old man with lung cancer underwent F-FDG PET/CT for restaging, which demonstrated intense F-FDG uptake in the right lobe of prostate gland and seminal vesicles, indicating a potential prostate cancer. In Ga-PSMA PET/CT, intense uptake in the right lobe of prostate gland and seminal vesicles was also observed but decreased in postmictional delayed images. Magnetic resonance imaging showed high signal intensity of urine in the same areas of uptakes. F-FDG and Ga-PSMA PET/CT findings in the prostate gland and seminal vesicles were considered to be a result of urinary reflux possibly because of the patient's previous transurethral resection.

More than Ophelia syndrome: Multiple paraneoplastic syndromes in pediatric Hodgkin lymphoma.

Demirsoy U, Alparslan B, Sen MC, Anik Y, Akansel G, Görür G, Gürel B, Aksu G, Çorapçioglu F. More than Ophelia syndrome: Multiple paraneoplastic syndromes in pediatric Hodgkin lymphoma. Turk J Pediatr 2019; 61: 139-141. Paraneoplastic syndromes in Hodgkin lymphoma (HL) can be seen with different symptoms and organ findings within a significant time before definite diagnosis of the primary disease. Achalasia, Holmes-Adie pupil, and limbic encephalitis are rarely reported paraneoplastic components in pediatric HL. In this report, we present an 11-year-old girl who had all these three paraneoplastic components synchronously before HL was identified.

Uptake of an Acrochordon Incidentally Detected on 68Ga Prostate-Specific Membrane Antigen PET/CT.

Ga prostate-specific membrane antigen (PSMA) PET/CT is a promising tool for imaging of prostate cancer. Ga-PSMA PET/CT uptake of prostate cancer and its metastases are reflective of significant overexpression of PSMA. However, PSMA expression of benign neoplasms and nonprostate epithelial malignancies is not very well defined. We report a moderate Ga-PSMA uptake of an acrochordon (skin tag), which was incidentally found in a patient referred for staging prostate cancer. Acrochordon is a frequent, small, soft, skin-colored or hyperpigmented, benign, and usually pedunculated neoplasm of the skin. Nuclear medicine physicians should be aware of it while reporting a Ga-PSMA PET/CT.

Pulmonary 18F-FDG microembolism detected on only delayed image in a PET/CT study.

Focal 18F-FDG pulmonary uptake on PET without corresponding abnormality on CT is an incidental and rare finding. This artifact is associated with iatrogenic FDG microembolus as a result of vascular endothelium damage during injection. We present a pulmonary FDG microembolus in a patient evaluated for suspicion of gallbladder cancer not in early (standard 1-hour imaging after FDG injection) but in delayed image. To our knowledge, this is the first case that describes the possibility of FDG microembolism on only delayed image in a PET/CT study.

Correlation of Cystatin-C and radionuclidic measurement method of glomerular filtration rate in patients with lung cancer receiving cisplatin treatment.

OBJECTIVE: Cisplatin is a chemotherapeutic agent which affects renal functions adversely. The best indicator of renal functions is glomerular filtration rate (GFR) measurement. Cystatin-C appears to be a good alternative to existing methods of measuring GFR. However, it is controversial whether Cystatin-C demonstrates GFR correctly for patients receiving chemotherapy. This study aimed to investigate the correlation between GFR values calculated by Cystatin-C based formulas, radionuclidic method (multiple blood sampling) and blood Cystatin-C values in patients with lung cancer, receiving cisplatin treatment in both pre-treatment and post-treatment periods. MATERIALS AND METHODS: Thirty-six patients with lung cancer who were going to receive cisplatin treatment were included in this study. However, the evaluation was performed with 20 patients since 16 of them could not complete the treatment. Blood Cystatin-C values, GFR values calculated via Cystatin-C based formulas, and radionuclidic method were investigated before and after the cisplatin treatment. RESULTS: After treatment significant decreases were detected in GFR values, obtained via radionuclidic measuring method. However, there was no significant difference in Cystatin-C values between pre-treatment and post-treatment periods. Also GFR values obtained by Cystatin-C based formulas were not significantly different in pre-treatment and post-treatment periods. There were meaningful correlations between radionuclidic method and Cystatin-C values and Cystatin-C based formulas before treatment. However, all correlations disappeared after the treatment. CONCLUSION: GFR values, calculated by Cystatin-C may not be reliable in following renal functions in patients receiving chemotherapy. When reliable monitoring of the renal functions is necessary radionuclidic method may be preferred in these patients.

Low radioiodine uptake in congestive heart failure.

OBJECTIVES: Our aim was to compare the radioiodine uptake (RAIU) of congestive heart failure (CHF) patients with that of a control group and investigate the prognostic value. We also assessed correlations of RAIU with other clinical parameters. METHODS: A total of 32 CHF patients and 14 controls were included in this study. RAIU was measured at the fourth and 24th hour using an uptake probe. The patients were followed up for a mean period of 32.09±8 months. RESULTS: The mean fourth-hour RAIU was 6.28±5.51 and the mean 24th-hour RAIU was 14.43±9.49 in the patient group. The mean fourth and 24th hour RAIUs of the control group were 9.93±1.92 and 22.90±5.89, respectively, which were statistically higher than that of the patient group (P=0.0001 and 0.001, respectively).Cardiac death occurred in nine patients during follow-up. The fourth and 24th hour uptake ratios were statistically significantly lower in the cardiac death group compared with the no-death group (3±2.01 vs. 7.57±5.93 and 7.39±7.34 vs. 17.18±8.9, respectively; P=0.003 and 0.007). On stepwise multivariate Cox regression analyses, only urea proved to be a significant independent predictor of cardiac death (hazard ratio 1.021; 95% confidence interval 1.005-1.037; P<0.008). Significant negative correlations were found between the fourth and 24th hour RAIUs and high-sensitivity C-reactive protein, urea, and creatinine levels, but no correlation was found between RAIUs and estimated glomerular filtration rate. CONCLUSION: CHF patients have lower RAIU values probably because of an expanded iodine pool and prolonged Wolff-Chaikoff effect. Also, patients who died during follow-up had lower RAIU values, but RAIU did not emerge as an independent predictor of death. However, studies with larger patient groups are definitely needed.

Excision of ectopic mediastinal parathyroid adenoma via parasternal videomediastinoscopy.

Mediastinum is one of the place in which ectopic parathyroid adenomas can be located.Here, an ectopic mediastinal parathyroid adenoma, which was excised via parasternal videomediastinoscopy was presented. The patient with chronic renal insufficiency had increased calcium levels persistence after the surgery for cervical parathyroid adenoma.Radiologic and scintigraphic examinations revealed a focal intense nodule in anterior mediastinum. Parasternal videomediastinoscopy was performed via parasternal incision through the second intercostal space. Ex-vivo specimen radioactivity measurements and frozen examination confirmed parathyroid adenoma. Calcium levels were decreased dramatically after the operation. Parasternal videomediastinoscopy could be an alternative surgical way in anterior mediastinal small masses such as ectopic parathyroid adenoma. It is the first case in which parasternal videomediastinoscopy was used for excision of mediastinal parathyroid adenoma.

Low serum triglyceride levels as predictors of cardiac death in heart failure patients.

Understanding the influence of sex differences on predictors of cardiac mortality rates in chronic heart failure might enable us to lengthen lifetimes and to improve lives. This study describes the influence of sex on cardiovascular mortality rates among chronic heart failure patients. From January 2003 through December 2009, we evaluated 637 consecutive patients (409 men and 228 women) with chronic heart failure, who ranged in age from 18 through 94 years (mean age, 64 ± 13 yr) and ranged in New York Heart Association (NYHA) functional class from II through IV. The mean follow-up period was 38 ± 15 months, the mean age was 64 ± 13 years, and the mean left ventricular ejection fraction was 0.27 ±0.11. By the end of the study, both sexes had similar cardiovascular mortality rates (36% men vs 37% women, P=0.559). In Cox regression analysis, NYHA functional class, triglyceride level, and history of coronary artery disease were independent predictors of cardiovascular death for women with chronic heart failure. For men with chronic heart failure, the patient's age, ejection fraction, and sodium level were independent predictors of cardiovascular death. In a modern tertiary referral heart failure clinic, decreased triglyceride levels were, upon univariate analysis, predictors of poor outcomes for both men and women. However, upon Cox regression analysis, reduced triglyceride levels were independent predictors of cardiac death only in women.

Radioiodine therapy in Graves' disease: is it possible to predict outcome before therapy?

OBJECTIVE: To assess the predictability of outcome and evaluate the factors that may lead to treatment failure in patients with Graves' disease who are treated with a single dose of radioiodine. MATERIALS AND METHODS: This is a retrospective study of 123 patients (M: 42; F: 81) with Graves' disease who received radioiodine therapy with a single fixed (10 mCi) dose for hyperthyroidism. Pretreatment age, sex, BMI, type of anti-thyroid drug used, propylthiouracil doses, iodine uptake, uptake ratio (4/24 h radioiodine uptake), and thyroid volume of the patients in whom radioiodine therapy succeeded or failed were compared. RESULTS: Post-therapy follow-up revealed that therapy failed in 22% of the patients. Iodine uptakes and uptake ratios and volumes were found to be significantly higher in patients in whom therapy failed. It was observed that uptake ratio was at least 1 in 25 patients (20%), and therapy failed in 20 (80%) of these patients. Of the 98 patients (80%) in whom uptake ratio was less than 1, therapy was unsuccessful in only seven (7%). CONCLUSION: Uptake ratio is a simple index that may be used to predict the patients in whom therapy may fail or succeed. In patients with Graves' disease who have an uptake ratio of less than 1, radioiodine appears to be an effective dose with high success rates. In contrast, because of the high rates of failure in patients with an uptake ratio of at least 1, use of radioiodine therapy at a dose of 10 mCi does not seem to be appropriate.

Reduced heart rate response to dipyridamole in patients undergoing myocardial perfusion SPECT.

OBJECTIVE: A mild decrease in blood pressure and increase in heart rate (HR) are considered normal hemodynamic responses to dipyridamole. In this study, we tried to investigate HR response to dipyridamole and its predictors in patients undergoing gated myocardial perfusion single photon emission computed tomography (SPECT). METHODS: 201 consecutive patients undergoing dipyridamole stress Tc99m-MIBI or Tl-201 gated myocardial perfusion SPECT were prospectively enrolled. Dipyridamole was infused over 4 min and radiopharmaceutical was injected 3 min after the end of infusion. A reduced heart rate response to dipyridamole considered if the HR ratio (peak HR/rest HR) was 1.20 or less. Stress (sLVEF), rest (rLVEF) left ventricular ejection fractions, stress and rest motion (SMS, RMS) and thickening scores (STS, RTS) were derived automatically by QGS. Summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for myocardial perfusion were calculated. Patients were grouped according to HR response and groups were compared. A logistic regression analysis was used to determine independent predictors of reduced HR response. RESULTS: Reduced HR response was found in 78 % of patients. Patients with abnormal HR response were more frequently had a history of diabetes mellitus, chronic renal failure, and had lower high-density lipoprotein (HDL) levels. Peak HR, SSS, SRS, sLVEF and rLVEF were lower; rest HR, RTS, and the number of patients with ≤ 45 % sLVEF and rLVEF were higher in reduced HR response group (all p < 0.05). There was no difference between groups by means of gender, rest and peak systolic or diastolic tension, SDS, SMS, STS, RMS, history of hypertension, peripheral arterial disease, metabolic syndrome, coronary interventions, digoxin, calcium channel blocker or beta blocker usage. Multivariable logistic regression analysis demonstrated that the independent predictors of reduced HR response were HDL, rest HR and SSS. When HDL was removed from the model, chronic renal failure also emerged as an independent predictor. CONCLUSION: Reduced HR response to dipyridamole is associated with ventricular dysfunction, cardiac autonomic neuropathy. Low HDL levels also seem to be related with reduced HR response.

Sentinel lymph node biopsy with a gamma probe in patients with high-risk cutaneous squamous cell carcinoma: follow-up results of sentinel lymph node-negative patients.

OBJECTIVE: Lymphoscintigraphy (LS) and sentinel lymph node biopsy have become the standard of care for melanoma and breast cancer. However, the data on patients with cutaneous squamous cell carcinoma (SCC) are limited. We aimed to evaluate and identify the role of LS and sentinel lymph node biopsy in patients with high-risk cutaneous SCC. METHODS: Nineteen patients (13 men, six women; 47-87 years of age, mean age 67.5 ± 12.3) with SCC were included in the study. LS was performed on all patients after intracutaneous injection of Tc-99m nanocolloid. Primary lesions and sentinel lymph nodes (SLNs) were excised with the help of a gamma probe. RESULTS: A total of 26 SLNs and 32 secondary lymph nodes were imaged on LS and were marked. During surgery, 29 SLNs, 21 secondary lymph nodes and three nonactive lymph nodes were excised. In total, 53 lymph nodes were removed surgically. A histopathological study revealed that all lymph nodes were negative for metastasis. Patients were followed up for an average of 41.1 ± 22.2 months (7-80 months). Until the time of data collection, 14 patients were alive and had no regional lymph node or distant metastasis. Local recurrence was seen in only one patient. He was reoperated upon 38 months ago. CONCLUSION: The feasibility of determining SLNs using LS and an intraoperative gamma probe in patients with cutaneous SCC was shown. Unnecessary elective lymph node dissection and possible complications could be avoided in 19 patients.

Comparison of exercise and pharmacological stress gated SPECT in detecting transient left ventricular dysfunction.

OBJECTIVE: Transient left ventricular contractile dysfunction (TLVD) is observed owing to post-exercise stunning in patients with coronary artery disease (CAD). Pharmacological stimulation differs from exercise stress because it does not cause demand ischemia. The aim of this study was to determine whether TLVD could also be seen after pharmacological stress (dipyridamole). METHODS: Of the patients in whom gated single-photon emission computed tomography (GSPECT) was performed in our institution from January 2004 to April 2007, 439 subjects with known or suspected CAD were included in the study. GSPECT was performed for all patients following exercise (group I, n = 220) or pharmacological stress (group II, n = 219) according to a 2-day (stress-rest) protocol after injection of Tc-99m methoxyisobutyl-isonitrile (MIBI). Stress, rest, and difference (stress-rest value) left ventricular ejection fractions (SLVEF, RLVEF, and DLVEF) and transient ischemic dilatation (TID) ratio were derived automatically. Summed stress score, summed rest score, and summed difference score (SDS) for myocardial perfusion were calculated using a 20-segment model and a five-point scoring system. An SDS > 3 was considered as ischemic. On the basis of the perfusion findings, patients were subdivided into a normal (group A, n = 216) and ischemia group (group B, n = 223). DLVEF and perfusion scores of all groups were compared. Relationships between DLVEF and perfusion, and between TID ratio and DLVEF were also evaluated. RESULTS: Stress-induced ischemia was observed in 223 of 439 patients (50.8%). In group A, the difference between stress and rest LVEF values was not significant (P = 0.670 and P = 0.200 for groups IA and IIA, respectively). However, LVEF was significantly decreased after stress compared with rest values for group B (P < 0.0001 for groups IB and IIB). TLVD (< or =-5% for DLVEF) was observed in 20 of 216 (9%) and 81 of 223 subjects (36%) in patients in groups A and B, respectively (P < 0.0001). In group I, we found TLVD in 46 of 119 (39%) and 12 of 101 (12%) subjects, in patients with and without ischemia, respectively (P < 0.0001). On the other hand, in group II, TLVD was detected in 35 of 104 (34%) and 8 of 115 (7%) patients with and without ischemia, respectively (P < 0.0001). And also, we found significant good correlations between TID ratios and DLVEF values in four subgroups (r = -0.55, r = -0.62, r = -0.59, and r = -0.41; for groups IA, IB, IIA, and IIB, respectively, P < 0.0001 for all). CONCLUSIONS: Dipyridamole is believed to be less likely than exercise to induce ischemia. However, in this study, TLVD after stress was observed following not only exercise but also pharmacological stress, consistent with ischemia.