Prognostic risk factors for rare oncocytic variantin 101 cases of papillary thyroid carcinoma.

OBJECTIVE: Oncocytic variant (OV) is an unusual subtype of papillary thyroid cancer whose histopathologic diagnostic criteria, clinicopathologic features and biological behavior are different and have not been comprehensively studied, characterized in literature. Previous studies present conflicting results upon its prognosis. We investigated demographic and clinicopathologic risk factors affecting its prognosis while presenting our clinical experience. SUBJECTS AND METHODS: This is a retrospective cohort study reviewing 101 patients of OV from an archive of 4500 well-differentiated thyroid cancer patients treated with iodine-131 (131I) between 1991 and 2017. Predefined parameters of age, gender, tumor size (TS), total 131I dose, time to recurrent disease, overall survival, extrathyroidal extension, multifocality, vascular invasion, accompanying other variants, capsular status of thyroid gland, initial cervical lymph node (LN) metastases, preablation stimulated thyroglobulin level, background thyroiditis and stage were evaluated by statistical comparison between metastatic and nonmetastatic groups. RESULTS: Seventeen cases (17%) developed metastases/recurrence, 70% of the recurrences occured before 24 months. Four patients (4%) died during the follow-up. Metastatic sites were usually cervical LN, local recurrence in thyroid bed and lungs. Multivariate analysis revealed stage (IV) and TS were the main parameters impacting recurrence/metastases. In the follow-up, isolated cervical LN metastases were found in 41% of metastatic cases, while 12% had sole recurrence in thyroid bed. Eighty eight percent of the metastatic disease included locoregional (cervical) and/or remote LN. The recurrences were associated with initial thyroid masses greater than 3.5cm in diameter. CONCLUSION: We found that the prognosis of OV is not poor in our series. Stage (IV) and tumor size are the main risk factors in metastatic development.

Evaluation of predictor variables of diagnostic [18F] FDG-PET/CT in fever of unknown origin.

BACKGROUND: Fever of unknown origin (FUO) is defined as an illness having fever which lasts at least 3 weeks of duration and is higher than 38.3 ºC on several measurements. The causes are infections, malignancies, noninfectious inflammatory diseases and miscellaneous. If [18F]FDG-PET/CT helps the final diagnosis, it is called contributory. The aim of the study is to evaluate the predictor variables effecting a contributory PET/CT for the diagnosis. METHODS: This is a retrospective cohort study conducted between June 2006 and May 2015 including 76 patients. The evaluated predictor variables are age, sex, ESR, CRP, fibrinogen, ferritin, albumin, haemoglobin level, platelet count, total leukocyte count, neutrophil percentage, lymphocyte percentage, ALP, LDH, ALAT, ASAT, GGT, total bilirubin, CK, RF, ANA, urinanalysis, chest radiography, abdominal US, lymphadenopathy, duration of fever, comorbid diseases and previous therapies. RESULTS: ESR (P=0.001), CRP (P=0.001), fibrinogen (P=0.009), lymphopenia (P<0.001), neutrophilia (P<0.001), ferritin (P<0.001), leukocytosis (P=0.003), duration of fever before PET/CT (<3 months) were found to be statistically significant for positive contribution of PET/CT results to the diagnosis. CONCLUSIONS: [18F]FDG-PET/CT is helpful and contributory for the diagnosis of FUO in patients having higher levels of CRP, ESR, ferritin, fibrinogen, leukocytosis, neutrophilia and shorter durations of fever (<3 months).

Impact of tall cell variant histology on predicting relapse and changing the management of papillary thyroid carcinoma patients.

OBJECTIVE: There has been much discussion recently about the risk category of tall cell variant (TVC) histology and its effects on the management of papillary thyroid carcinoma (PTC). We, therefore, undertook a retrospective study to compare stage-matched risk factors and recurrence rates between classical PTC (cPTC) patients and patients with TCV histology. SUBJECTS AND METHODS: A total of 3128 well-differentiated thyroid carcinoma patients who were treated and followed-up for more than 5 years in our clinic from 1995 to 2016 were included in this study. There were 2783 PTC (89%) patients, 1113 (40%) of them were cPTC and 56 (2%) of them were TCV patients. RESULTS: In all stages, the stage-matched incidence of extrathyroidal extension (ETE), lymphovascular invasion and initial lymph node metastases were significantly higher in TCV patients than in cPTC patients (P<0.001). Recurrence was in 10 of 27 patients (37%) with TCV and in 91 of 890 (10%) patients with cPTC diagnosed in stage I (odds ratio (OR)=5.16); in 4 of 6 patients with TCV and 18 of 84 (21%) patients with cPTC in stage II (OR=7.33); in 5 of 6 patients with TCV and 11 of 46 (23%) patients with cPTC in stage III (OR=15.90); and in 13 of 17 patients with TCV and 31 of 93 (33%) patients with cPTC in stage IV (OR=6.50). Stage-matched recurrence rates were found significantly higher in all stages of TCV patients than in cPTC patients (OR=8.49, P<0.001). Recurrence with distant metastases was seen more frequently in TCV patients than in cPTC patients (P<0.001) and treatment of metastatic disease was more difficult in TCV patients. CONCLUSION: Tall cell variant was an independent poor prognostic factor in papillary thyroid carcinoma patients even if they were diagnosed at early stages of the disease. Patients with tall cell variant histology required more aggressive therapeutic approach and closer follow-up than classical patients.

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.

Prognosis estimation under the light of metabolic tumor parameters on initial FDG-PET/CT in patients with primary extranodal lymphoma.

BACKGROUND: Non-Hodgkin's lymphomas arising from the tissues other than primary lymphatic organs are named primary extranodal lymphoma. Most of the studies evaluated metabolic tumor parameters in different organs and histopathologic variants of this disease generally for treatment response. We aimed to evaluate the prognostic value of metabolic tumor parameters derived from initial FDG-PET/CT in patients with a medley of primary extranodal lymphoma in this study. PATIENTS AND METHODS: There were 67 patients with primary extranodal lymphoma for whom FDG-PET/CT was requested for primary staging. Quantitative PET/CT parameters: maximum standardized uptake value (SUVmax), average standardized uptake value (SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were used to estimate disease-free survival and overall survival. RESULTS: SUVmean, MTV and TLG were found statistically significant after multivariate analysis. SUVmean remained significant after ROC curve analysis. Sensitivity and specificity were calculated as 88% and 64%, respectively, when the cut-off value of SUVmean was chosen as 5.15. After the investigation of primary presentation sites and histo-pathological variants according to recurrence, there is no difference amongst the variants. Primary site of extranodal lymphomas however, is statistically important (p = 0.014). Testis and central nervous system lymphomas have higher recurrence rate (62.5%, 73%, respectively). CONCLUSIONS: High SUVmean, MTV and TLG values obtained from primary staging FDG-PET/CT are potential risk factors for both disease-free survival and overall survival in primary extranodal lymphoma. SUVmean is the most significant one amongst them for estimating recurrence/metastasis.

18F-FDG PET/CT findings in a case of a semantic variant of primary progressive aphasia.

UNLABELLED: Progressive speech and language disorders are commonly referred to as primary progressive aphasia (PPA), which is a clinical syndrome eroding both speech and language. Functional imaging may reveal the cause of this disorder even if structural imaging is absent. Fluorine-18- fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) allows the assessment of neuronal activity by semi-quantitatively measuring glucose metabolism in the brain. In medical literature, (18)F-FDG PET/CT studies show hypometabolic areas in different regions of the brain which are special clues for differentiating the subgroups of PPA. CONCLUSION: This case was reported to demonstrate the characteristic (18)F-FDG PET CT findings for a semantic variant of PPA.

Evaluation of radiographic and metabolic changes in bone metastases in response to systemic therapy with (18)FDG-PET/CT.

BACKGROUND: The aim of the study was to retrospectively evaluate radiographic and metabolic changes in bone metastases in response to systemic therapy with (18)FDG-PET/CT and determine their roles on the evaluation of therapy response. PATIENTS AND METHODS: We retrospectively evaluated radiographic and metabolic characteristics of bone metastases in 30 patients who were referred for the evaluation of response to systemic therapy with (18)FDG-PET/CT. All patients underwent integrated (18)FDG-PET/CT before and after treatment. RESULTS: The baseline radiographic patterns of the target lesions in responders group were lytic, sclerotic, mixed and CT negative; after treatment the radiographic patterns of all target lesions changed to a sclerotic pattern and attenuation increased (p = 0.012) and metabolic activity decreased (p = 0.012). A correlation was found between decreasing metabolic activity and increasing attenuation of the target lesions (r = -0.55) (p = 0.026). However, in nonresponders group, the baseline radiologic patterns of the target lesions were lytic, blastic, mixed and CT negative; after treatment all lytic target lesions remained the same and one CT negative lesion turned to lytic pattern and the attenuation of the target lesions decreased (p ± 0.12) and metabolic activity increased (p = 0.012). A correlation was found between increasing metabolic activity and decreasing attenuation (r = -0.65) (p = 0.032). An exception of this rule was seen in baseline blastic metastases which progressed with increasing in size, metabolic activity and attenuation. CONCLUSIONS: This study shows that the metabolic activity of lesions is a more reliable parameter than the radiographic patterns for the evaluation of therapy response.

Reliability and readability analysis of ChatGPT-4 and Google Bard as a patient information source for the most commonly applied radionuclide treatments in cancer patients.

PURPOSE: Searching for online health information is a popular approach employed by patients to enhance their knowledge for their diseases. Recently developed AI chatbots are probably the easiest way in this regard. The purpose of the study is to analyze the reliability and readability of AI chatbot responses in terms of the most commonly applied radionuclide treatments in cancer patients. METHODS: Basic patient questions, thirty about RAI, PRRT and TARE treatments and twenty-nine about PSMA-TRT, were asked one by one to GPT-4 and Bard on January 2024. The reliability and readability of the responses were assessed by using DISCERN scale, Flesch Reading Ease(FRE) and Flesch-Kincaid Reading Grade Level(FKRGL). RESULTS: The mean (SD) FKRGL scores for the responses of GPT-4 and Google Bard about RAI, PSMA-TRT, PRRT and TARE treatmens were 14.57 (1.19), 14.65 (1.38), 14.25 (1.10), 14.38 (1.2) and 11.49 (1.59), 12.42 (1.71), 11.35 (1.80), 13.01 (1.97), respectively. In terms of readability the FRKGL scores of the responses of GPT-4 and Google Bard about RAI, PSMA-TRT, PRRT and TARE treatments were above the general public reading grade level. The mean (SD) DISCERN scores assesses by nuclear medicine phsician for the responses of GPT-4 and Bard about RAI, PSMA-TRT, PRRT and TARE treatments were 47.86 (5.09), 48.48 (4.22), 46.76 (4.09), 48.33 (5.15) and 51.50 (5.64), 53.44 (5.42), 53 (6.36), 49.43 (5.32), respectively. Based on mean DISCERN scores, the reliability of the responses of GPT-4 and Google Bard about RAI, PSMA-TRT, PRRT, and TARE treatments ranged from fair to good. The inter-rater reliability correlation coefficient of DISCERN scores assessed by GPT-4, Bard and nuclear medicine physician for the responses of GPT-4 about RAI, PSMA-TRT, PRRT and TARE treatments were 0.512(95% CI 0.296: 0.704), 0.695(95% CI 0.518: 0.829), 0.687(95% CI 0.511: 0.823) and 0.649 (95% CI 0.462: 0.798), respectively (p < 0.01). The inter-rater reliability correlation coefficient of DISCERN scores assessed by GPT-4, Bard and nuclear medicine physician for the responses of Bard about RAI, PSMA-TRT, PRRT and TARE treatments were 0.753(95% CI 0.602: 0.863), 0.812(95% CI 0.686: 0.899), 0.804(95% CI 0.677: 0.894) and 0.671 (95% CI 0.489: 0.812), respectively (p < 0.01). The inter-rater reliability for the responses of Bard and GPT-4 about RAI, PSMA-TRT, PRRT and TARE treatments were moderate to good. Further, consulting to the nuclear medicine physician was rarely emphasized both in GPT-4 and Google Bard and references were included in some responses of Google Bard, but there were no references in GPT-4. CONCLUSION: Although the information provided by AI chatbots may be acceptable in medical terms, it can not be easy to read for the general public, which may prevent it from being understandable. Effective prompts using 'prompt engineering' may refine the responses in a more comprehensible manner. Since radionuclide treatments are specific to nuclear medicine expertise, nuclear medicine physician need to be stated as a consultant in responses in order to guide patients and caregivers to obtain accurate medical advice. Referencing is significant in terms of confidence and satisfaction of patients and caregivers seeking information.

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.

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.

Utility of FDG PET/CT in the Management of Primary Testicular Lymphoma.

OBJECTIVE: Primary testicular lymphoma (PTL) is a form of extra-nodal lymphoma originating from the testicles. Currently, positron emission tomography (PET) with glucose analogue 18F-fluorodeoxyglucose (18F-FDG) is the most popular and widely used modality for evaluating tumor metabolism, and PTL usually displays increased 18F-FDG uptake. Despite the rapid increase in clinical applications of FDG PET/ computed tomography (CT), its role in PTL has neither been clearly defined nor reviewed systematically. This study reviews the usefulness and limitation of FDG PET/CT in the diagnosis and treatment of PTL. METHODS: This study included 12 patients with PTL between 2004 and 2015. We retrospectively examined PET/CT results along with patient outcome. The maximum standardized uptake value (SUVmax) was calculated. RESULTS: The mean overall survival (OS) and disease-free survival (DFS) was 44.5 months and 35.5 months, respectively. The mean SUVmax was identified as 18.5 in recurrent/metastatic group. The 1-year and 3-year OS was 94% and 69%, while the 1-year and 2-year DFS was 93.5% and 56%, respectively. CONCLUSION: FDG PET/CT is very helpful in both staging and evaluating treatment response. Although it is not a perfect tool in the initial diagnosis, it might aid in the differential diagnosis of challenging testicular tumors. Pre-treatment and post-treatment FDG uptake values may also have a prognostic value in patients with PTL.

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.

Thyroid medullary carcinoma in a teenager with Cowden syndrome.

Cowden syndrome is a multisystemic cancer predisposition disorder, in which the mucocutaneous lesions are the most constant features. We present a case of Cowden syndrome in a teenage boy with hyperkeratotic papules of the facial skin, especially on the eyelids, with episcleritis, proptosis, and papillomatous lesions on the tip of the tongue and lip mucosa. In addition, two nodules in the thyroid gland were detected. On laboratory examination, the carcinoembryonic antigen (CEA) was 34 ng/mL (normal limits: 0-3 ng/mL). Total thyroidectomy was performed. Histopathologic examination of the specimen revealed thyroid medullary carcinoma. After operation, levels of CEA decreased to normal limits.

Assessment of risk factors in metastatic/recurrent tall cell variant of papillary thyroid carcinoma.

INTRODUCTION: Papillary thyroid carcinoma (PTC) is the most common malignant thyroid tumor. A great majority of the cases live a disease-free life with quite favorable prognosis. There are lots of variants of PTC and a few of them exhibit aggressive behaviour. Typical example is the tall cell variant (TCV). Patients experience a greater incidence of recurrence, nodal and extranodal metastases, tumor associated mortality than other variants of PTC. Studies related to TCV almost always compared it with its patient population of PTC according to risk factors and clinicopathologic features. The aim of this study is to evaluate the risk factors in metastatic/recurrent TCV. MATERIALS AND METHODS: This is a retrospective cohort study of 1813 patients with differentiated thyroid carcinoma treated with radioiodine between 1992 and 2011. 56 of these patients are TCV. 34 of them developed metastasis/recurrence and 22 lived a disease-free life during the 23-year follow-up. We evaluated the risk factors in these metastatic and nonmetastatic subgroups. RESULTS: We found tumor size, preablation thyroglobulin level, vascular invasion, preablation central and lateral cervical lymph node metastasis, preablation lung metastasis and stage independent risk factors. However age, preablation thyroglobulin level and stage appeared together as striking factors impacting metastasis in multivariate analysis. CONCLUSION: Higher ablation doses up to 250-300 mCi should be administered to TCV patients having advanced stage (III,IV), pretty high preablation thyroglobulin level (over 400 ng/ml) and older age (over 52 years) especially with large tumor size (over 3.5 cm) and initial cervical lymph node metastasis.

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.

Uptake Patterns of Untreated Primary Gastrointestinal Extranodal Lymphomas on Initial Staging 18F-FDG PET/CT and Metabolic Tumor Parameters.

OBJECTIVE: Non-Hodgkin's lymphomas arising from tissues other than primary lymphatic sites are classified as primary extranodal lymphomas (PEL). PELs of the gastrointestinal system (PGISL) originate from the lymphatic tissues within the gastrointestinal tract. The prognostic value of 18F-FDG PET/CT in lymphomas is high in terms of both overall survival (OS) and disease-free survival (DFS). Our aim was to investigate the uptake patterns and properties of low-grade and high-grade PGISL on primary staging 18F-FDG PET/CT, as well as the prognostic significance of metabolic tumor parameters in high grade PGISL. METHODS: Thirty-nine patients with PGISL were enrolled in this retrospective cohort study between 2004-2015. Primary staging 18F-FDG PET/CT have been performed and quantitative parameters of SUVmax, SUVmean, metabolic tumor volume (MTV), total lesion glycolysis (TLG) have been calculated for all patients prior to treatment. Low-grade and high-grade PGISL were compared in terms of metabolic tumor parameters. Cox regression models were performed to determine factors that correlate with DFS in high-grade PGISL. RESULTS: There were statistically significant differences between high-grade and low-grade PGISL in terms of SUVmax, SUVmean, MTV, TLG, recurrence, mortality, DFS and OS. None of the potential risk factors (sex, age, site, SUVmax, SUVmean, MTV, TLG) for recurrence and metastasis in high grade PGISL was identified as a risk factor on univariate and multivariate Cox regression analysis. CONCLUSION: Metabolic tumor parameters are not predictive markers in high-grade PGISL, especially in diffuse large B cell variant and primary gastric lymphoma. The first implications suggest they will not play a role in patient management.

The Correlation Between Pre-treatment Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters and Clinical Prognostic Factors in Pediatric Hodgkin Lymphoma.

OBJECTIVE: To compare standardized uptake values (SUV) derived from pre-treatment 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging and clinical prognostic factors in pediatric patients with Hodgkin lymphoma (HL). METHODS: Pre-treatment FDG PET/CT findings of 28 children with HL were evaluated in this retrospective study. Metabolic tumor volume (MTV), SUVmax normalized by weight (SUVweight), lean body mass (SUVlbm), body surface area (SUVbsa) and plasma glucose levels of tumors (SUVglucose) were calculated using pre-treatment FDG PET/CT scan images. These metabolic parameters were correlated with clinical factors [age, sex, number of lymph node groups, presence of splenic involvement, bulky mediastinal disease, Ann Arbor stage, serum white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), serum albumin and hemoglobin levels]. RESULTS: SUVbsa, SUVlbm, SUVweight, SUVglucose and MTV were higher in patients with stage III-IV disease, bulky tumor and ≥3 lymph node groups (p<0.05). SUVbsa and SUVglucose were higher in patients with splenic involvement (p<0.05). There was no significant correlation between these metabolic parameters and sex, ESR, levels of albumin and WBC (p>0.05). SUVbsa and SUVlbm were higher in patients with anemia (p<0.05). Additionally, significant increases were detected in SUVweight, MTV, and SUVglucose with increasing age (p=0.005, p=0.027, and p=0.009, respectively). SUVbsa and SUVlbm had no significant correlation with age (p>0.05). CONCLUSION: Metabolic parameters derived from pre-treatment FDG PET/CT may have an important role in predicting high-risk disease in patients with HL. Also, SUVbsa and SUVlbm may be better markers than SUVweight in the quantitative evaluation of FDG PET/CT scans in pediatric patients.

An Extremely Rare Intersection: Neurolymphomatosis in a Patient with Burkitt Lymphoma Detected by 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Neurolymphomatosis (NL) is a rarely seen neurologic involvement of the systematic lymphoma. Its diagnosis is challenging, and requires biopsy. In cases where biopsy is not appropriate, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) may aid in diagnosis. Here, we present a 54-year old male patient diagnosed with Burkitt lymphoma who underwent FDG-PET/CT in order to evaluate the treatment response after chemotherapy and radiotherapy. On viewing PET/CT images of the patient who complained of pain and weakness in his upper extremities after therapy, linear FDG uptake was observed in bilateral cervical 5 (C5), left cervical 6 (C6), bilateral cervical 7 (C7), and right lumbar 4 (L4) nerve roots. Magnetic resonance imaging (MRI) revealed dilation and thickening of nerve roots consisted with FDG uptake observed on PET/CT images. Since biopsy was not performed, histopathological diagnosis could not be established. However, overlapping of clinical, PET/CT, and MRI findings strongly suggested the presence of NL. As is the case of this patient, in cases with non-Hodgkin lymphoma, a combined evaluation of FDG-PET/CT and MRI modalities aid in the establishment of the diagnosis of NL.