The Effects of CoronaVac (Sinovac) and BNT162b2 (BioNTech/Pfizer) Vaccination on Oncologic 18F-FDG PET/CT Studies.

Objectives: BioNTech (Pfizer) and CoronaVac (Sinovac) vaccines are two of the most administered coronavirus disease-2019 (COVID-19) vaccines worldwide. Vaccination against severe acute respiratory syndrome-coronavirus-2 has caused a diagnostic challenge in oncological 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) studies. The aim of our study was to evaluate the 18F-FDG PET/CT findings of the two most commonly administered vaccines worldwide. Methods: Patients over 18 years old who underwent 18F-FDG PET/CT for oncological purposes in our institution between January 13, 2021 and January 31, 2022, who received a single or second dose of the BioNTech or CoronaVac vaccines in the last two months, were included in the study. Descriptive analyses were presented as mean, standard deviation, frequency and ratio. Additionally, chi-square test was used to analyze categorical variables. Results: Ipsilateral deltoid muscle hypermetabolism was observed in 6.9% (n=15) and 14.3% (n=22) patients who received CoronaVac and BioNTech vaccines, respectively. Ipsilateral axillary lymph node hypermetabolism was observed in 11% (n=24) and 41.6% (n=64) patients who received CoronaVac and BioNTech vaccines, respectively. Synchronous deltoid muscle and axillary lymph node hypermetabolism was observed in 4.14% (n=9) and 12.33% (n=19) patients who received CoronaVac and BioNTech vaccines, respectively. Significant differences were detected between CoronaVac and BioNTech vaccines in terms of ipsilateral deltoid muscle hypermetabolism, ipsilateral axillary lymph node hypermetabolism and synchronous deltoid muscle and axillary lymph node hypermetabolism (p<0.05). Conclusion: COVID-19 vaccination may result in ipsilateral axillary lymph node hypermetabolism, ipsilateral deltoid muscle hypermetabolism, or synchronous deltoid muscle and axillary lymph node hypermetabolism with different frequencies depending on the type of vaccination. Although synchronous deltoid muscle and axillary lymph node hypermetabolism can reduce misinterpretation of 18F-FDG PET/CT, to avoid misinterpretation, it is important to question the vaccination history during ongoing COVID-19 vaccination process.

Correlation of Morphological and Functional Cardiac Images: Fusion of Myocardial Perfusion SPECT and CT Angiography.

Objectives: The current study evaluates the value of cardiac hybrid imaging (CHI), performed by the fusion of functional and anatomic cardiac images, in the detection of hemodynamically significant coronary stenosis in cases with multiple coronary stenosis. Methods: A total of 36 patients (10 female, 26 male) in whom ischemia or infarction was detected on gated myocardial perfusion single photon emission computed tomography (gMPS) and multiple coronary stenosis were concomitantly detected on coronary computed tomography angiography (CCTA) and undergone invasive coronary angiography (ICA) was included in this study. Statistical analyses were performed using SPSS 22 Windows software. McNemar test was applied to show concordance between coronary CT angiography, ICA and CHI in the detection of anatomically or hemodynamically significant stenosis in three major coronary arteries. Comparison results of coronary arteries responsible for perfusion defects on CHI and gMPS are presented as percentages (%). Results: There was total accordance between coronary arteries leading to perfusion defects detected by gMPS and CHI in 50% of patients. It was observed a partial accordance in 36.1% of the patients. Additionally, it was also detected perfusion defects originated from side branches in 25% of the patients. Between results of CCTA and ICA, no statistically significant difference was noted in the detection of anatomically significant stenoses in the left main coronary artery, left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) (p=1.000, 0.070, 0.549, and 1.000, respectively). In addition, no statistically significant difference was found in the detection of anatomically and hemodynamically significant stenoses in LAD, LCx and RCA by CCTA and CHI (p=0.344, 0.629, and 0.219, respectively). No statistically significant difference was observed in the detection of anatomically and hemodynamically significant stenoses in LAD, LCx and RCA by ICA and CHI (p=0.804, 1.000, and 0.344, respectively). Conclusion: It is possible to detect hemodynamically significant coronary stenosis directly by CHI modality in patients with multiple coronary stenosis, wide perfusion defects.

Youtube videos for the most commonly applied radionuclide treatments: sufficient for patients as an information source?

OBJECTIVES: YouTube is one of the most popular online sources of information for patients. The purpose of the study is to analyze the quality of YouTube videos about the most commonly applied radionuclide treatments. METHOD: Related radionuclide therapy videos were searched on YouTube in October 2021. The quality of the videos was assessed by using the Journal of the American Medical Association (JAMA) benchmark criteria, the DISCERN Scale and the Global Quality Scale (GQS). RESULTS: A total of 473 videos were assessed and 270 were included in the study according to inclusion and exclusion criteria. According to the GQS score, videos were categorized as high-quality (n:63, 23.33%), intermediate quality (n:118, 43.70%) and low-quality (n:89, 32.96 %) groups. The findings of our study showed that the highest number of video views and comments were in the low-quality group. In addition; the number of video likes, views and comments were the lowest in the high-quality video group. The most viewed and commented as well as most liked videos and the videos of highest video power index scores were nonphysician sourced videos. The most quality videos were the physician-sourced videos in terms of JAMA, DISCERN and GQS scores. CONCLUSION: Although high-quality videos about radionuclide treatments on YouTube may enlighten and motivate patients positively; it should be kept in mind that improper information may also be uploaded to this platform. Under the guidance of the European Association of Nuclear Medicine, it is necessary to generate an official video in English with multilingual subtitles.

Use of YouTube as an Information Source for Radioactive Iodine Therapy: Do YouTube Videos Have High Quality?

OBJECTIVES: Radioactive iodine (RAI) therapy is a radionuclide treatment for hyperthyroidism and well-differentiated thyroid cancer. One of the most popular sources of information for patients on the internet is YouTube. This study aimed to examine the quality of videos about RAI treatment. METHODS: This cross-sectional study was performed by using videos in YouTube. The terms "radyoaktif iyot tedavisi" and "radioactive iodine treatment" were used to search related videos in June 2021. The quality of the videos was assessed by using the Journal of the American Medical Association (JAMA) benchmark criteria, the DISCERN scale, and the global quality scale (GQS). RESULTS: Of the total 88 videos evaluated, 56 videos (30 in English, 26 in Turkish) were analyzed according to the inclusion and exclusion criteria. Seven (12.5%) videos were assigned to the high-quality group, 16 (28.58%) to the intermediate quality group, and 33 (58.92%) to the low quality group. The findings of this study showed that the most popular videos with the highest video power index (VPI) scores and the highest number of video likes and comments belonged to the intermediate quality group. Contrarily, popularity level, number of video likes, and number of video views were the lowest in the high-quality group. The analysis of video sources revealed that viewers most preferred non-physician-sourced videos, with average total views of 59307.80 [standard deviation (SD): 122554.13]. The most liked videos were non-physician-made videos, with average total likes of 424.35 (SD: 639.41). The mean VPI scores were the highest in non-physician-made videos, with 25.18 (SD: 25.69). The average JAMA (1.92, SD: 0.50), DISCERN (34.31, SD: 14.33), and GQS scores (2.61, SD: 0.99) were the highest in physician-made videos. CONCLUSION: Although high-quality videos on YouTube may inform and encourage patients positively, unprofessional, incorrect, and incomplete information can be also uploaded on YouTube and may mislead patients.

Yttrium-90 (Y-90) resin microsphere therapy for patients with unresectable hepatocellular carcinoma. Identification of successful treatment response predictors and patient selection.

AIM: Selective intraarterial radionuclide therapy (SIRT) with Yttrium-90 (Y-90) resin microspheres has been applied for hepatocellular carcinoma (HCC) lately. The aim of this study is to present our clinical experience of radiomicrosphere therapy in the treatment of unresectable HCC and determine the proper cases who could benefit from this therapy according to response results yielded by initial staging and control imaging modalities. METHODS: We administered 43 Y-90 microsphere therapy to 34 patients with unresectable HCC (twice in 9 patients). Patients with histopathologically confirmed HCC having a life expectancy of ≥3 months; Child A-B, Okuda stage 1-2 and BCLC stage A-B-C classifications were included in the study. The patients were divided into two groups: Group A consisted of 29 patients who responded to Y-90 therapy (complete response, partial response and stable disease), Group B 5 of non-responders (progressive disease). Predefined parameters were evaluated for response to SIRT and compared between two groups. RESULTS: We found a significant decrease in platelet and lymphocyte counts one month after therapy (p=0.02, p=0.01, respectively). On control imaging tests performed 3 months later, we observed complete response in 19% (n=6), partial response in 44% (n=15), stable disease in 25% (n=8) and progressive diease in 12% (n=5) of the patients. Mean overall survival (OS) was 19 (median value: 14) months. CONCLUSIONS: Y-90 microsphere therapy is a safe and effective treatment option for the patients with unresectable HCC without any serious side effect. Mean tumor dose delivery and lack of bilobar disease seem the best predictors for treatment success. KEY WORDS: Selective intraarterial Radionuclide therapy, Yttrium-90, hepatocellular carcinoma.

Gammagrafía paratiroidea con 99mTc-MIBI: valor complementario de la paratohormona en el aspirado y análisis histopatológico de los tipos de células en los adenomas paratiroideos / Complementary role of parathormone washout test to 99mTc-MIBI parathyroid scintigraphy and histopathologic analysis of cell types in parathyroid adenomas

Objetivo: La gammagrafía paratiroidea (GP) puede ser negativa o equívoca (N/E) en un número considerable de casos con alta sospecha clínica y bioquímica de adenoma de paratiroides (AP). Los objetivos de este estudio fueron investigar el papel complementario de la determinación de paratohormona en punción con aguja fina (PTH en PAAF) con la GP en pacientes con hiperparatiroidismo primario (HPTP) y evaluar los aspectos histopatológicos de los AP en comparación con los resultados de GP. Material y métodos: Fueron incluidos en el estudio 38 pacientes con HPTP remitidos para realizar GP. Diecisiete pacientes tuvieron resultados gammagráficos y ecográficos concordantes con AP (grupo A). Veintiún pacientes con GP N/E pero sospecha de AP en la ecografía formaron el grupo B. Se realizó PTH en PAAF en todos los pacientes y todos fueron operados. Se extirpó un adenoma en cada uno de ellos y en todos los casos se establecieron las características histopatológicas. Resultados: El tamaño del tumor en la ecografía fue mayor en aquellos pacientes cuyos adenomas se vieron en la GP (p<0,001). Los porcentajes de células principales, oxífilas y claras en AP no fueron estadísticamente diferentes entre los grupos. El nivel de paratohormona sérica y PTH en PAAF no fueron estadísticamente significativos entre los grupos A y B (p=0,095 y p=0,04, respectivamente). Conclusión: Aunque no existe un valor umbral definitivo, la sensibilidad de la GP aumenta con el tamaño de la lesión. Mientras que el contenido de células principales y oxífilas tiende a reducirse en los AP con GP N/E EP, la tasa de células claras aumenta sustancialmente. La combinación de GP con la ecografía y la PTH en PAAF aumenta la sensibilidad de detección y localización de los AP

Objective: Parathyroid scintigraphy (PS) can be negative or equivocal (N/E) in a considerable number of cases with highly suspicious clinical findings and biochemical results for parathyroid adenoma (PA). The aims of this study were to investigate the complementary role of parathormone washout test (PWT) to PS in patients with primary hyperparathyroidism (PHPT) and evaluate histopathologic aspects of PAs in comparison with PS results. Material and methods: Thirty-eight patients with PHPT referred for PS were included in the study. Seventeen patients had both scintigraphic and ultrasonographic findings concordant with PA (Group A). Twenty-one patients having N/E PS, but suspected lesions for PA on ultrasonography (US) formed Group B. PWT was performed for all patients and they underwent the surgical intervention. An adenoma was removed in all patients and the histopathologic cell characteristics were established. Results: The tumor size on US was larger in those patients whose adenomas were seen on the PS (P<.001). The percentages of chief (or principal), oxyphilic and clear cells in PAs were not statistically different between the groups. Serum parathormone level and PWT were not statistically significant between Group A and Group B (P=.095 and P=.04, respectively). Conclusion: Although there is not a definitive threshold value, the sensitivity of PS increases with lesion size. While chief cell and oxyphilic cell content of PAs tend to deplete in N/E PS, clear cell rate increases substantially. Combining PS with both US and PWT increases the sensitivity of detection and localization of PAs

Complementary role of parathormone washout test to 99mTc-MIBI parathyroid scintigraphy and histopathologic analysis of cell types in parathyroid adenomas. / Gammagrafía paratiroidea con 99mTc-MIBI: valor complementario de la paratohormona en el aspirado y análisis histopatológico de los tipos de células en los adenomas paratiroideos.

OBJECTIVE: Parathyroid scintigraphy (PS) can be negative or equivocal (N/E) in a considerable number of cases with highly suspicious clinical findings and biochemical results for parathyroid adenoma (PA). The aims of this study were to investigate the complementary role of parathormone washout test (PWT) to PS in patients with primary hyperparathyroidism (PHPT) and evaluate histopathologic aspects of PAs in comparison with PS results. MATERIAL AND METHODS: Thirty-eight patients with PHPT referred for PS were included in the study. Seventeen patients had both scintigraphic and ultrasonographic findings concordant with PA (Group A). Twenty-one patients having N/E PS, but suspected lesions for PA on ultrasonography (US) formed Group B. PWT was performed for all patients and they underwent the surgical intervention. An adenoma was removed in all patients and the histopathologic cell characteristics were established. RESULTS: The tumor size on US was larger in those patients whose adenomas were seen on the PS (P<.001). The percentages of chief (or principal), oxyphilic and clear cells in PAs were not statistically different between the groups. Serum parathormone level and PWT were not statistically significant between Group A and Group B (P=.095 and P=.04, respectively). CONCLUSION: Although there is not a definitive threshold value, the sensitivity of PS increases with lesion size. While chief cell and oxyphilic cell content of PAs tend to deplete in N/E PS, clear cell rate increases substantially. Combining PS with both US and PWT increases the sensitivity of detection and localization of PAs.

Sphenoid Bone Fibrous Dysplasia Detected Incidentally on Bone Scintigraphy by the Contribution of SPECT/CT Hybrid Imaging.

Fibrous dysplasia (FD) is a benign fibroosseous bone disorder. It has poliostotic and monostotic patterns. Monostotic FD is frequently asymptomatic and is usually discovered incidentally by radiologic imaging performed for other reasons. Bone scintigraphy is valuable for identifying disease extent. Craniofacial FD (CFD) is a form of the disease where lesions are limited to contiguous bones of the craniofacial skeleton. We presented a case with monostotic CFD who was detected incidentally on bone scintigraphy single-photon emission computed tomography/computerized tomography while being investigated for inflammatory arthropaties.

Yttrium-90 (Y-90) Resin Microsphere Therapy for Patients with Unresectable Hepatocellular Carcinoma: a Single-Center Experience.

BACKGROUND/AIM: Selective intraarterial radionuclide therapy (SIRT) with yttrium-90 (Y-90) resin microspheres presently has successful results in primary or metastatic inoperable liver tumors. This procedure, which is also known as radioembolisation, delivers high doses of radiation selectively to hepatic tumors while minimum healthy liver exposure. The aim of this study was to present our clinical experience of radiomicrosphere therapy for the treatment of patients with unresectable hepatocellular carcinoma (HCC). METHODS: We performed 40 Y-90 microsphere therapies in 28 patients (5 females, 23 males; mean age ± SD 48 ± 8) with HCC during the period from April 2008 through December 2016. Pretreatment Tc-99m microaggregated albumin (MAA) scintigraphy was performed to all patients in order to detect eligibility for SIRT. All patients had pre- and post-biochemical tests (hemogram and serologic tests) and imaging methods (CT or MRI or PET/CT) at regular intervals to detect any possible complication and determine response rates. RESULTS: The mean shunting to the lungs on MAA scan was 6.5% and the mean ± SD administered dose of Y-90 was 1.55 ± 0.32 GBq in all patients. The estimated doses to the target tumors, normal liver parenchyma and lungs were 105.7 ± 55.3, 25.5 ± 8.2 and 5.8 ± 1.7 Gy, respectively. No significant complication was observed during or early after (first week) the treatment procedure and it was well tolerated by all the patients. Only one patient developed a treatment-related gastroduodenal ulcer 3 weeks after the treatment. In control imaging tests (MRI or FDG PET/CT) performed 2.5 months after the treatment, we observed complete response in 2 (7%) patients, partial response in 10 (36%) patients, stable disease in 5 (18%) patients and progressive disease in 11 (39%) patients. CONCLUSION: According to our clinical experience, we can conclude that Y-90 microsphere therapy is a safe and effective treatment option for the patients with unresectable HCC without any serious side effects.

Clinical Significance of Fluorine-18-fluorodeoxyglucose Positron Emission Tomography/computed Tomography in the Follow-up of Colorectal Cancer: Searching off Approaches Increasing Specificity for Detection of Recurrence.

BACKGROUND: Nearly 40% of colorectal cancer (CRC) recurs within 2 years after resection of primary tumor. Imaging with fluorine-18-fluorodeoxyglucose (l8F-FDG) positron emission tomography/computed tomography (PET/CT) is the most recent modality and often applied for the evaluation of metastatic spread during the follow-up period. Our goal was to study the diagnostic importance of 18F-FDG-PET/CT data of maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG) and the difference of SUVmax on dual-time imaging in CRC. PATIENTS AND METHODS: We examined the SUVmax value of lesions on control or restaging 18F-FDG-PET/CT of 53 CRC patients. All lesions with increased SUVmax values were confirmed by colonoscopy or histopathology. We compared PET/CT results with conventional imaging modalities (CT, MRI) and tumor markers (carbohydrate antigen 19-9 [Ca 19-9], carcinoembryonic antigen [CEA]). RESULTS: Mean SUVmax was 6.9 ± 5.6 in benign group, 12.7 ± 6.1 in malignant group. Mean TLG values of malignant group and benign group were 401 and 148, respectively. 18F-FDG-PET/CT was truely positive in 48% of patients with normal Ca 19-9 or CEA levels and truely negative in 10% of cases with elevated Ca 19-9 or CEA. CT or MRI detected suspicious malignancy in 32% of the patients and 18F-FDG-PET/CT was truely negative in 35% of these cases. We found the most important and striking statistical difference of TLG value between the groups with benign and recurrent disease. CONCLUSIONS: Although SUVmax is a strong metabolic parameter (p = 0.008), TLG seems to be the best predictor in recurrence of CRC (p = 0.001); both are increasing the specificity of 18F-FDG-PET/CT.

Risk factors and stratification for recurrence of patients with differentiated thyroid cancer, elevated thyroglobulin and negative I-131 whole-body scan, by restaging 18F-FDG PET/CT.

OBJECTIVE: In nearly 20%-30% of patients with differentiated thyroid carcinoma (DTC) relapse and 7% of them die during the next 10 years after initial diagnosis. In 10%-30% of patients with DTC after ablation therapy during the follow-up show a negative iodine-131 (131I) whole-body screening test (131I WBS) and increased serum thyroglobulin (Tg) level. Loss of ability of DTC metastatic lesions to trap 131I is associated with pure survival and often aggressive disease. Several studies have shown that in DTC cases non trapping 131I, fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET) can detect recurrence or metastases with high sensitivity (80%-90%). The purpose of this study was to investigate the clinicopathologic features and other related risk factors of patients with DTC having elevated Tg levels and negative 131I WBS in which recurrence was detected by 18F-FDG PET/CT. We tried to study and stratify patients in this grey zone who could benefit from 18F-FDG PET/CT for the detection of metastases/recurrence according to predefined risk factors not investigated by other researchers. SUBJECTS AND METHODS: We studied retrospectively 165 DTC patients with elevated Tg levels and a negative 131I WBS during their follow-up between 2004-2015. Metastases/recurrence was found in 49% of the patients on restaging with 18F-FDG PET/CT and were compared with nonmetastatic group according to predefined risk factors. These factors were also evaluated in true positive and false negative cases. RESULTS: The sensitivity and specificity of 18F-FDG PET/CT for detecting recurrent/metastatic disease were 90% and 98.5%, respectively. No apparent predefined risk factor impacting a false negative 18F-FDG PET/CT was found. Findings in follicular carcinoma, Hürtle cell carcinoma and papillary carcinoma were not different from positive PET findings. The variants of papillary carcinoma also had no statistically difference with regard to 18F-FDG results. CONCLUSION: The most important factors affecting a true positive 18F-FDG PET/CT study were: ETE, high total 131I dose and the SUVmax values over 4.5.