Synchronous occurrence of medullary and papillary thyroid cancer and survival rates

PURPOSE

Concurrence of medullary and papillary thyroid carcinoma (MTC and PTC) represents less than 1% of all thyroid malignancies. We aimed to reveal the demographic and clinical characteristics of this rare pathology and to evaluate the effect of the same or contralateral lobular localization of these two malignancies in clinical and laboratory features. Evaluation of progression-free survival (PFS) in current pathology is one of the important features of our study.

METHODS

All patients diagnosed with simultaneous MTC and PTC after thyroidectomy were evaluated retrospectively. Data on the following variables were recorded: age, gender, tumor localization (ipsilateral lobe located MTC and PTC-Group I, contralateral lobe located MTC and PTC-Group II), tumor size, cervical lymph node metastasis, distant metastasis, tumor stage, postoperative basal calcitonin, carcinoembryonic antigen, thyroglobulin (Tg), and anti-Tg values. In all our cases, since MTC progressed before PTC, progression was accepted as serum calcitonin values exceeded 150 pg/mL.

RESULTS

Groups were formed as follows: Group I, four cases where MTC and PTC were localized in different foci in the same lobe; Group II, nine cases where they were localized in different lobes. There was only one case in which two tumors were located in the same focus. The case with dual differentiation was included in Group I (35. 7%). When the PFS of the two groups were compared, no statistically significant difference was found ( P = 0.87).

CONCLUSIONS

As a result of this analysis, the location of the simultaneously detected PTC in the same or different lobes with the MTC does not make a significant difference in clinical and laboratory features.

Hybrid Ga-68 prostate-specific membrane antigen PET/MRI in the detection of skeletal metastasis in patients with newly diagnosed prostate cancer: Contribution of each part to the diagnostic performance

PURPOSE

Bone metastasis is essential in patients with prostate cancer (PCa) as it determines prognosis and survival. Hybrid PET/MRI allows simultaneous acquisition of PET and MRI data, thus combining the strength of both technologies allows the detection of bone marrow metastases that are missed by PET/CT. In this retrospective study, we aimed to evaluate the diagnostic efficiency of hybrid PET/MRI with Ga-68 prostate-specific membrane antigen (PSMA) in detecting skeletal metastases in newly diagnosed PCa patients and compared the effectiveness of stand-alone PSMA PET reviewing versus stand-alone whole-body (WB) MRI evaluation. We also investigated the effect of the interpretation of all PET/MR data together on clinical management.

METHODS

We studied 74 newly diagnosed PCa patients who underwent PSMA PET/MRI for staging purposes. At first, PET and MRI were evaluated separately for bone lesions on a patient-and-lesion basis and then a further joint PSMA PET/MRI interpretation was made.

RESULTS

Patient-based sensitivity, specificity, positive predictive value, negative predictive value and accuracy analysis for bone metastasis was, respectively, 1.0, 0.83, 0.54, 1.0, 0.86 for PET; 0.75, 0.96, 0.81, 0.95, 0.93 for WB MRI and 0.91, 0.95, 0.78, 0,98, 0.94 for PET/MRI. The combined PET/MRI evaluation changed the clinical impact in 13.5% of patients (eight correct and two wrong decisions) compared to PET stand-alone interpretation.

CONCLUSION

PSMA PET imaging showed superior sensitivity to WB MRI in detecting bone metastases in newly diagnosed PCa patients, whereas WB MRI has superior specificity and PPV. Furthermore, the specificity and PPV of joint PET/MRI evaluation are better than PSMA PET alone. Despite the longer acquisition period, adding WB MRI sequences to PSMA PET imaging appears beneficial for PCa patient management.

Diagnostic Performance of 99mTc-Methoxy-Isobuty-Isonitrile (MIBI) for Risk Stratification of Hypofunctioning Thyroid Nodules: A European Multicenter Study

^99mTc-MIBI (MIBI) imaging is able to exclude malignancy of hypofunctioning thyroid nodules (TNs) with high probability but false positive results are frequent due to low specificity. Therefore, pre-test selection of appropriate TNs is crucial. For image evaluation visual and semiquantitative methods (Washout index, WOInd) are used. Aim of this study was to evaluate the diagnostic performance of MIBI imaging in hypofunctioning TNs with indeterminate fine-needle aspiration cytology results in a multicentric European setting. Patients with hypofunctioning TNs, EU-TIRADS 4 or 5, Bethesda III/IV and MIBI imaging were included. For visual evaluation the intensity of MIBI uptake in the TN was compared to normal thyroid tissue. 358 patients with 365 TNs (n = 68 malignant) were included. Planar imaging (SPECT) showed a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 96% (94%), 21% (22%), 22% (15%), 96% (96%), and 35% (32%). The WOInd (38.9% of all cases, optimal cutoff: −19%) showed a sens 100% (spec 89%, PPV 82%, NPV 100%, ACC 93%). For hypofunctioning TNs at intermediate or high risk with indeterminate cytology, a MIBI negative result on visual evaluation is an effective tool to rule-out thyroid malignancy. The semi-quantitative method could considerably improve overall diagnostic performance of MIBI imaging.

A multicenter survey of current practices of 99mTc-methoxy-isobutyl-isonitrile (MIBI) imaging for the diagnosis of thyroid nodules: more standardization is essential

Purpose

Molecular imaging with 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI, MIBI) has been used in the assessment of thyroid nodules (TNs) for more than two decades. Many studies showed that MIBI imaging is a suitable tool to rule-out malignancy when negative. However, relatively low specificity and accuracy have been described, thus, limiting its acceptance in clinical practice. Additionally, different technologies, protocols, and interpretation criteria are adopted accounting for heterogeneous data reported in the literature. Therefore, the present study was undertaken to assess the clinical use and methodology of MIBI imaging in patients with nodular thyroid disease in Europe.

Methods

A questionnaire was sent to 12 European centers of Nuclear Medicine. The questionnaire encompassed ultrasound (US) and fine-needle aspiration cytology (FNAC) procedures and their evaluation as well scintigraphy imaging indications, technical procedures, and interpretation criteria of MIBI imaging.

Results

The survey showed a good agreement of different centers in approaching TNs by TSH measurement, US evaluation and 99mTc-pertechnetate thyroid scintigraphy. MIBI imaging is mainly used to assess TNs with inconclusive/indeterminate cytological findings and selection of target nodule(s) for FNAC in patients with multi-nodular goiter. Technical procedures adopted in different centers are globally comparable and the recorded differences are unlikely to impact clinical results. However, as the main result of the present study, substantial differences were found in interpretation criteria adopted in different centers.

Conclusions

Our survey supports the urgent need of standardized interpretation criteria of thyroid MIBI imaging in order to improve its diagnostic performance and make results comparable in clinical practice.

Evaluation of F-18 DOPA PET/CT in the detection of recurrent or metastatic medullary thyroid carcinoma: comparison with GA-68 DOTA-TATE PET/CT

OBJECTIVE

PET imaging with F-18 DOPA (FDOPA) and Ga-68 DOTATATE (TATE) shows the most promising results to detect medullary thyroid cancer (MTC) recurrence. We performed this comparative study to detect the site of recurrent or metastatic disease in MTC patients with elevated serum calcitonin (Ctn) and/or carcinoembryonic antigen (CEA) levels.

METHODS

We studied 46 MTC patients (25 women, 21 men) with elevated Ctn and/or CEA levels during follow-up who had both FDOPA and TATE PET/CT scans for re-staging purposes.

RESULTS

FDOPA PET imaging yielded an overall sensitivity of 86.8%, specificity of 100%, PPV of 100%, NPV of 61.5%, and accuracy of 89.1%, while TATE PET scan had the same values as 84.2%, 87.5%, 96.9%, 53.8%, and 84.6%, respectively, and there was no statistically significant difference between the two modalities with the exception of the specificity value that was higher for FDOPA imaging. In a subgroup of patients with overt Ctn or CEA elevation, sensitivity of FDOPA increased significantly, whereas TATE sensitivity did not change. FDOPA PET imaging was significantly superior in detecting liver and regional lymph node (LN) metastases, while TATE PET scan was significantly better in the skeletal metastases. Early FDOPA demonstrated 11 invisible lesions on late FDOPA.

CONCLUSION

Both FDOPA and TATE PET/CT imaging are useful to localize recurrences in MTC patients. While TATE imaging is superior to reveal skeletal disease, FDOPA seems better in liver and regional LN metastases; therefore, the two modalities appear complementary in monitoring MTC patients with elevated serum Ctn and/or CEA levels.

Comparison of brain F-18 FDG PET/MRI with PET/CT imaging in pediatric patients

BACKGROUND

Standardized uptake values (SUVs) are important indexes for evaluating the accuracy of disease diagnoses achieved via fluoro-18 deoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance imaging (PET/MRI). The purpose of this study is to describe normal cerebral FDG uptake in the pediatric population and compare SUVmax/mean results for brain images obtained from PET/CT and PET/MRI in neurologically healthy pediatric examinees.

METHODS

This study included 20 patients who were < 18 years of age and were without intracranial malignancy and/or brain disorders. Patients underwent either PET/CT imaging (n = 10) or PET/MRI imaging (n = 10) after 70-80 min of F-18 FDG injection. The SUVmax and SUVmean for various brain regions were calculated and compared between sides and imaging modalities using with appropriate statistical tests.

RESULTS

The median SUVmax/SUVmean values of the right-sided frontal, parietal, temporal, and occipital lobes were 8.63/ 6.18, 8.85 / 6.97, 6.88 / 4.99, and 11.06 / 7.02 in PET/CT, respectively, and 11.45 / 8.59, 10.16 / 8.47, 8.82 / 6.6, and 11.71 / 8.25 in PET/MRI, respectively. The median SUVmax/SUVmean values of the left-sided frontal, parietal, temporal, and occipital lobes were 9.05 / 6.86, 8.03 / 6.62, 6.49 / 4.77, and 10.6 / 7.73 in PET/CT, respectively, and 10.7 / 8.16, 11.06 / 7.88, 8.13 / 6.09, and 10.96 / 9.22 in PET/MRI, respectively.

CONCLUSIONS

These results showed that there was no statistically significant difference in SUVs values between the two brain imaging modalities except from SUVmax value of left-sided parietal lobe and no asymmetric radiopharmaceutical uptake between the left and right brain regions or cerebellums in each modality, suggested that in brain imaging, PET/MRI can be used reliably instead of PET/CT.

Performance of F-18 Fluorocholine PET/CT for Detection of Hyperfunctioning Parathyroid Tissue in Patients with Elevated Parathyroid Hormone Levels and Negative or Discrepant Results in conventional Imaging

Objective

Our aim was to assess the diagnostic performance of F-18 fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) in detecting hyperfunctioning parathyroid tissue (HPT) in patients with elevated parathyroid hormone levels with negative or inconclusive conventional imaging results and to compare the findings with those obtained using technetium-99m sestamibi (MIBI) scintigraphy and neck ultrasonography (US).

Materials and Methods

Images of 105 patients with hyperparathyroidism who underwent FCH PET/CT, dual-phase MIBI parathyroid scintigraphy (median interval: 42 days), and neck US were retrospectively analyzed. The gold standard was histopathological findings for 81 patients who underwent parathyroidectomy and clinical follow-up findings in the remaining 24 patients. Sensitivities, positive predictive values (PPVs), and accuracies were calculated for all imaging modalities.

Results

Among the 81 patients who underwent parathyroidectomy, either parathyroid adenoma (n = 64), hyperplasia (n = 9), neoplasia (n = 4), or both parathyroid adenoma and hyperplasia (n = 1) were detected, except 3 patients who did not show HPT. Of the 24 (23%) patients who were followed-up without operation, 22 (92%) showed persistent hyperparathyroidism. FCH PET/CT showed significantly higher sensitivity than MIBI scintigraphy and US in detection of HPT (p < 0.01). Sensitivity, PPV, and accuracy of FCH PET/CT were 94.1% (95/101), 97.9% (95/97), and 92.4% (97/105), respectively. The corresponding values for MIBI scintigraphy and US were 45.1% (46/102), 97.9% (46/47), and 45.7% (48/105) and 44.1% (45/102), 93.8% (45/48), and 42.9% (45/105), respectively. Among the 35 patients showing negative MIBI scintigraphy and neck US findings, 30 (86%) showed positive results on FCH PET/CT. FCH PET/CT could demonstrate ectopic locations of HPT in 11 patients whereas MIBI and US showed positive findings in only 6 and 3 patients, respectively.

Conclusion

FCH PET/CT is an effective imaging modality for detection of HPT with the highest sensitivity among the available imaging techniques. Therefore, FCH PET/CT can be recommended especially for patients who show negative or inconclusive results on conventional imaging.

Thyroid uptake test with portable device (COTI) after 131I tracer administration: proof of concept

COTI (collar therapy indicator) has been recently introduced for the detection of gamma rays with emphasis on thyroid investigations. The aim of this study was to test the feasibility of a prototype version of COTI including activity detectors with low sensitivity in performing thyroid uptake measurements for a large group of patients. Consequently, thyroid uptake tests were carried out for a total of 89 patients (22 males and 67 females; age: 44 ± 13 years) with thyroid cancer (n = 74), hyperthyroidism (n = 16) at 2 and 24 h after administration of 0.44-2 MBq of ¹³¹I. Eight individuals among the thyroid cancer patients were monitored up to 96 h after administration. The COTI device was equipped with two CsI (Tl) detectors, known as LoHi type, sensitive to activity ranges from 0.02 to 30 MBq of ¹³¹I. The uptake values from COTI were compared with those measured with a standard probe. It was found that the mean uptake of thyroid activity in thyroid cancer patients was 2.1 ± 1.3% at 2 h when measured with the standard probe, while it was 2.2 ± 1.2% when measured with COTI. In addition, the average uptake at 24 h after administration was 2.5 ± 3.2% and 3.2 ± 3.8% measured with COTI and the standard probe, respectively. A strong correlation was found at 24 h between the results obtained with COTI and the standard probe, while a weaker correlation was seen at 2 h. Overall, there was no significant difference between the results obtained with the standard probe and those obtained with COTI at both 2 and 24 h (P_value ≥ 0.05). Besides, 85% of the uptake values measured with COTI were less than those measured with the standard probe at the 24 h after administration. The average uptake value was 0.9 ± 0.8% after 96 h by COTI, and 1.4 ± 1.3% by the standard probe. Pertaining to the hyperthyroidism patients, COTI showed mean uptake values of 20 ± 16% and 23 ± 18% at 2 and 24 h, respectively. In contrast, the standard probe suggested higher mean uptake values of 26 ± 18% and 30 ± 22%, respectively. It is concluded that the prototype of COTI used in the present study has been proved to be a feasible and promising tool in thyroid investigations. It is noted, however, that the next COTI generation should include detectors equipped with collimator and energy discrimination.

The contribution of SPECT/CT in patients with radionuclide shuntography through shunt dysfunction

OBJECTIVE

Radionuclide CSF study is a simple, effective, and low-radiation-dose procedure for the assessment of shunt patency. With the help of CT image of single-photon emission computed tomography/computed tomography (SPECT/CT), the interpretation becomes more accurate and easier.The aim of this study was to compare the classical methods and 2D planar scintigraphic images with radionuclide shuntography fused SPECT/CT.

METHODS

Between 2015-2019 all hydrocephalic patients who underwent radionuclide shuntography and classical methods (cranial CT, USG and/or direct X-rays), for suspected VP shunt malfunction at our hospital were retrospectively enrolled in the study. Fusion with SPECT/CT is provided in all radionuclide shuntographies. Approximately 0.5-1 mCi diethylene-triaminepentaaceticacid (DTPA) was intrathecally injected. Images were collected as 5-second frames for the first minute, and 1-min frames for the second to the 30th min. Static whole body images were obtained as early (30 min) and delayed (120 min) images. SPECT/CT was performed in 120 min.

RESULTS

When the classical methods were evaluated in the operated patients, according to the direct radiographic findings, in only 17 patients had shunt dysfunction due to disconnection-kinking or laceration, was obtained.On the other hand,while67 shuntography were evaluated,65 of these patients (97%) whose intraoperative and shuntography findings were found to be compatible with each other.

CONCLUSION

The 3D SPECT images combined with the two-dimensional planar images added to the CT provide more accurate information and also provide detailed anatomical information. The patient's operation was performed successfully in one session in cooperation with the other surgical branches when needed.

Complete response after ceritinib treatment in non-small cell lung cancer in an elderly patient

INTRODUCTION

Ceritinib is a selective second-generation ALK inhibitor that is highly sensitive to echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) molecule.

CASE REPORT

In this paper, we report a 68-year-old female that was diagnosed with stage 4 ALK-positive non-small cell lung cancer (NSCLC).Management and outcome: She was treated with crizotinib first-line, cisplatin and gemcitabine as second-line. And for third-line, ceritinib was started. She had complete response over 3.5 years under ceritinib treatment. And she is still receiving ceritinib with no adverse event.

DISCUSSION

Cases achieving complete response with ceritinib treatment are rare. In this paper, we aimed to emphasize the complete response in stage 4 NSCLC in an elderly patient.

Diagnostic Capabilities of MRI Versus 18F FDG PET-CT in Postoperative Patients with Thyroglobulin Positive, 131I-negative Local Recurrent or Metastatic Thyroid Cancer

BACKGROUND

The detection of recurrence or metastasis might be challenging in patients, who underwent total thyroidectomy and radioactive iodine therapy for Differentiated Thyroid Carcinoma (DTC), with increased serum Thyroglobulin (Tg) levels and negative 131I whole body scan (131I-WBS) results.

AIMS

The purpose of this study was to compare the ability of Magnetic Resonance Imaging (MRI) and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F FDG PET-CT) to detect recurrence or cervical and upper mediastinal metastases in postoperative DTC patients who had negative 131I-WBS despite elevated serum Tg levels.

STUDY DESIGN

This study has a retrospective study design.

METHODS

We evaluated cervical and upper mediastinal MRI and 18F FDG PET-CT of 32 postoperative patients with DTC (26 patients with papillary thyroid carcinoma and 6 patients with follicular thyroid carcinoma).

RESULTS

We evaluated 44 lesions in 32 patients. For all lesions, the Positive Predictive Value, (PPV) Negative Predictive Value (NPV), sensitivity, specificity, and accuracy of MRI were 81.4%, 76.4%, 84.6%, 72.2%, and 79.5% respectively. The PPV, NPV, sensitivity, specificity, and accuracy of 18F FDG PET-CT were 100.0%, 85.7%, 88.4%, 100.0%, and 93.1%, respectively.

CONCLUSION

Although we could not replace 18F FDG PET-CT, MRI might be used as an adjunct to 18F FDG PET-CT for the evaluation of recurrent or cervical and upper mediastinal metastatic thyroid cancers; however, MRI is inadequate for the detection of metastases in small lymph nodes.

Prognostic value of ADC measurements in predicting overall survival in patients undergoing 90Y radioembolization for colorectal cancer liver metastases

AIM

To assess the ability of diffusion-weighted imaging (DWI) in predicting the overall survival in patients who underwent Yttrium 90 radioembolization (⁹⁰Y-RE) for colorectal liver metastases (CLM) with other well-established clinical and imaging parameters by comparing the pre- and post-treatment apparent diffusion coefficient (ADC) values of the lesions.

METHODS

A total of 81 metastatic lesions of 27 consecutive patients who underwent DWI before and after the ⁹⁰Y-RE session were enrolled in the study. ADC values were calculated from the entire (ADC_e) and peripheral (ADC_p) tumor on pre- and post-treatment DWI, and any relative increase in ADC >0% accepted as a functional imaging response. The impact of functional imaging response in addition to other well-known parameters including Response Evaluation Criteria in Solid Tumors (RECIST), hepatic tumor burden, Eastern Cooperative Oncology Group performance status (ECOG-PS) and the presence of extrahepatic metastases in predicting overall survival (OS) was assessed using Kaplan-Meier curves and Cox-regression analyses.

RESULTS

The median OS of the patients was 10 months (range, 6-20 months) while the median OS of the responders being significantly longer than the non-responders for ADC_e and ADC_p (median 11 vs 7 months, P = 0.003; median 12 vs. 7 months, P < 0.0001, respectively). The RECIST score was also significantly affected the OS (progressive or stable disease median 8 months vs. partial response 15 indent months, P = 0.019). The other parameters including hepatic tumor burden, gender, ECOG score, the involvement of the liver lobes, and the presence of extrahepatic metastases were not associated with the OS. In multivariate analysis, only ADC_p remained as an independent predictor of OS (P = 0.003, HR = 19.878).

CONCLUSION

Any increase in relative ADC_p or ADC_e values after Y90-RE treatment was associated with longer OS in CLM patients, and DWI seems to be valuable imaging biomarker in predicting OS in CLM patients during the early post-interventional period after ⁹⁰Y-RE.

Comparison of day 3 and day 5 thyroglobulin results after thyrogen injection in differentiated thyroid cancer patients

BACKGROUND

It is necessary to stimulate serum thyroid-stimulating hormone (TSH) levels either endogenously by thyroid hormone withdrawal (THW) or exogenously by administration of recombinant human TSH (rhTSH) for radioactive iodine (RAI) therapy. Thyrotropin alfa (Thyrogen) has many advantages over THW. Radiation dose to laboratory staff while drawing blood for tests on the day 5 is one of the disadvantages of preferring Thyrogen. Our aim was to compare day 3 and day 5 blood test results after Thyrogen injections.

MATERIAL AND METHOD

In our study, Thyrogen was preferred in 32 differentiated thyroid cancer patients with a mean age of 50.5 ± 12.3 years. Thyrogen was injected on day 1 and day 2 intramuscularly in all patients before I-131 was given on day 3. A total of 22 patients received 5 mCi RAI for ablation control scintigraphy and 10 patients received 100-250 mCi RAI for ablation or therapy (high-dose group). Blood tests were performed on day 3 and day 5 after Thyrogen injections.

RESULTS

Mean TSH level was 98.1 mg/dl for day 3 and 29.5 mg/dl for day 5. In the diagnostic group, thyroglobulin (Tg) and anti-Tg levels were nearly the same on day 3 and day 5. In the therapy group, day 5 Tg levels were higher than day 3.

CONCLUSION

After Thyrogen injection of two consecutive days, blood sampling might be enough on day 3. Day 5 blood sampling may not be necessary routinely for radiation protection of laboratory staff. For the diagnostic group, if Tg and anti-Tg is normal then 5 mCi imaging may not be necessary.

What is the role of florine-18 fluorodeoxyglucose/positron emission tomography/computed tomography imaging in well-differentiated thyroid cancers with negative iodine-131 scan high thyroglobulin and normal anti-thyroglobulin levels

PURPOSE

This retrospective study aims to assess the cut-off value of thyroglobulin (Tg) levels in nux or metastatic well-differentiated thyroid cancers (DTCs) with normal anti-Tg levels using with fluorodeoxyglucose/positron emission tomography/computed tomography (FDG PET/CT).

MATERIALS AND METHODS

We reviewed FDG PET/CT images of 104 patients with well DTC (28 men, 76 women) whose: Iodine-131 (131 I) whole-body scanning was negative but had elevated Tg with normal anti-Tg levels.

RESULTS

The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of florine-18-FDG PET/CT findings were found to be 95.92%, 87.27%, 87.04%, 96.00%, and 91.35%, respectively. The best Tg cut-off value was found to be 10.4 ng/ml. In the Tg level <10.4 ng/ml group, the sensitivity, specificity, PPV, NPV, and accuracy of FDG PET/CT were found to be 94.1%, 91.30%, 88.8%, 95.4%, and 92.5%, respectively. In the other group, which Tg level ≥10.4 ng/ml, sensitivity, specificity, PPV, NPV, and accuracy of FDG PET/CT exams were found to be 96.8%, 84.3%, 86.1%, 96.4%, and 90.6%, respectively.

CONCLUSION

FDG PET/CT imaging is a valuable imaging method in the evaluation of patients with elevated serum Tg levels and normal anti-Tg levels. Furthermore, it has potential utility in the dedifferentiation of active foci that are present, and in assessing optimal decision making during follow-up.

Standardized Uptake Values of Normal Organs on 18F-Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography Imaging

Standardized uptake values (SUVs) of normal organs were evaluated by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography and computed tomography (PET-CT) scanning. Seventy patients (38 men and 32 women) with no non-physiological 18F-FDG uptake participated in the study. All patients fasted for at least 4 h before PET-CT imaging and their fasting blood glucose levels were within the normal range. Image acquisition was performed after intravenous administration of 18F-FDG and images were obtained from the vertex to the upper thigh region. The SUVs of various organs were determined from the transverse views. The uptake of 18F-FDG was highest in the cerebrum, cerebellum, myocardium, tonsils, liver and spleen in both sexes. Having knowledge of the physiological uptake of 18F-FDG and normal organ SUVs is required for the correct interpretation of whole-body 18F-FDG-PET-CT studies.

Detection of Metastases in Patients with Cutaneous Melanoma Using FDG-PET/CT

This study aimed to detect metastases in patients with stage III or IV cutaneous melanoma by 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT). Thirty-nine patients with clinically evident stage III or IV melanoma underwent whole-body FDG-PET/CT scans for metastatic disease and these results were compared with those of biopsy. Scans for 38 of the patients were evaluated; one patient's scan could not be evaluated. There were 11 true-positive, two false-positive, 24 true-negative and one false-negative scans for the detection of melanoma metastases, with sensitivity 91%, specificity 92%, accuracy 92%, and positive and negative predictive values 84% and 96%, respectively. False-positive FDG-PET/CT scans were due to sarcoidosis in the lung and infected cyst in the liver. It is concluded that FDG-PET/CT scanning has high sensitivity and specificity for detecting stage III or IV metastatic melanoma.

Diagnostic value of F-18 FDG PET/CT in patients with spondylodiscitis: Is dual time point imaging time worthy?

PURPOSE

In this retrospective study, we aimed to investigate the value of FDG-PET/CT in the diagnosis of spondylodiscitis (SD), the significance of dual time point imaging (DTPI) for SD diagnosis and the worth of SUVmax data for distinguishing tuberculous vs. non-tuberculous SD.

MATERIALS AND METHODS

32 patients with suspected SD were scanned with FDG-PET/CT. For quantitative analysis maximum standardized uptake value (SUVmax) of the lesion area was measured. Nineteen patients had DTPI of FDG-PET/CT. The final diagnoses were achieved by histopathological, microbiological, and clinical results.

RESULTS

Specific pathogens were isolated in 21 patients; other patients were accepted as nonspecific bacterial SD. In all patients, FDG-PET/CT results were compatible with SD diagnosis. The SUVmax data for tuberculous and non-tuberculous SD and DTPI results were statistically insignificant.

CONCLUSION

FDG-PET/CT is a successful modality for SD diagnosis; additionally, DTPI protocol for FDG-PET/CT in SD diagnosis and SUVmax data for differentiation between non-tbc SD and tbc SD are useless.

Incidental Detection of Follicular Thyroid Carcinoma in 68Ga-PSMA PET/CT Imaging

Prostate-specific membrane antigen (PSMA) is a type II transmembrane protein. It has been shown to be expressed in various solid malignant neoplasms. We report a case of a prostate cancer patient who underwent (68)Ga-PSMA PET/CT imaging. There is a large thyroid nodule in the right thyroid gland, which had intense PSMA accumulation. Follicular thyroid lesions can be seen on (68)Ga-PSMA PET/CT imaging.

Assessment of yttrium-90 citrate radiosynovectomy treatment with bone scintigraphy in lipoma arborescens

A 37-year-old male patient presented with right knee pain and swelling. The patient had a 6-year history of rheumatoid arthritis. Physical examination was notable for swelling and tenderness of the right knee. The diagnosis of lipoma arborescens (LA) was confirmed from the magnetic resonance imaging of the right knee. Herein, we report the use of bone scintigraphy in a case of LA treated with yttrium-90 radiosynovectomy.

Comparison of FDG and FDG-labeled leukocytes PET/CT in diagnosis of infection

The aim of this study is to compare FDG and FDG-labeled leukocyte (WBC) PET/CT in the diagnosis of infection using different SUV and visual thresholds for interpretation. Patients, material, method: 49 consecutive patients (27 men, 22 women, mean age: 55.7 years, range: 16-89 years) with suspected musculoskeletal infection (n = 34), vascular graft infection (n = 5), aortitis (n =1 ), endocarditis (n = 1), mass lesion which is suspicious for infection or malignity (n = 6), and fever of unknown origin (n = 2) underwent both FDG and WBC-PET/CT. Images were evaluated by both visual analysis (grade 1-3) according to uptake intensity and quantitative grading (grade 1-3) based on lesion to background SUVmax values. Final diagnosis was made by histopathological, microbiological analysis or clinical-radiological work-up.

RESULTS

The diagnosis of infection was made in total 24 patients, of whom 14 were diagnosed by histopathological and the rest by clinical-radiological work-up. WBC-PET/CT imaging with the visual threshold of 1b as infection positivity (for truncal lesions uptake equivalent to liver or lumbar vertebrae uptake; for extremity lesions uptake significantly higher than neighbouring soft tissue uptake or higher than neighbouring bone marrow uptake) was found to have the highest diagnostic accuracy (AUC: 0.874, CI: 0.771-0.997, p < 0.001). The optimal SUV threshold was found to be 8.8 (p = 0.006; sensitivity: 72.7%, specificity: 82.8) and 5.3 (p < 0.001; sensitivity: 81.8%, specificity: 79.3%) for FDG and WBC-PET/CT, respectively by ROC curve analysis.

CONCLUSION

WBC-PET/CT is more valuable than FDG PET/CT in the imaging of infection. Visual threshold of >1b seems to be more suitable for detection of infection.

Comparison of F-18 FDG-PET/CT and Tc-99m MIBI in the preoperative evaluation of cold thyroid nodules in the same patient group

Recent studies have reported that standardized uptake values of FDG-PET imaging might predict malignant thyroid nodules and can be used in the preoperative evaluation of thyroid lesions. The aim of our study was to evaluate FDG-PET imaging in patients with cold thyroid nodules and to compare the imaging findings with Tc-99m MIBI scans and with post-op histopathology results. Twenty-three patients (18F, 5M) with 24 nodules that were suspicious in ultrasound and cold in Tc-99m pertechnetate scan, were included in the study. Each nodule underwent sonographically guided fine-needle aspiration biopsy. FDG-PET and MIBI scans were performed with an interval of 3-5 days. All patients underwent thyroidectomy and their FDG-PET, and MIBI thyroid scan results were compared with post-thyroidectomy pathology results. Post-op histopathology results found 7 malignant and 17 benign nodules. Six of the seven malignant nodules had increased uptake, which were positive for malignancy in both PET and MIBI scans. Each imaging method used different radiopharmaceuticals but showed one false-negative result in two different patients. FDG-PET produced false positives in eight nodules and MIBI scans found false positives in four nodules. FDG-PET imaging and MIBI scan showed the same sensitivity in malignant nodule evaluation, but their specificity differed. As a result, we suggest that FDG-PET imaging is not superior to MIBI scanning in differentiating malignant from benign thyroid nodules. MIBI imaging should be the first choice in the preoperative evaluation of patients with cold thyroid nodules as an adjunct procedure to FNAB because of its low cost and availability. This imaging technique can be used routinely in patients who are reluctant to undergo FNAB.

Regional ventilation/perfusion mismatch pattern in patient with Swyer James (MacLeod's) syndrome

Swyer James (McLeod's) syndrome (SJMS) is an uncommon disease, which occurs as a result of childhood bronchiolitis obliterans. Patients may not be diagnosed until later in their life. A 46-year-old man underwent ventilation/perfusion scintigraphy for acute onset of dyspnea. The scan showed markedly diminished ventilation and perfusion unilaterally on the right middle and inferior lobes. However, mismatched ventilation-perfusion pattern was shown on the upper right lobe, which was consistent with pulmonary embolism. Unilaterally matched ventilation/perfusion defect can see in SJMS in lung scintigraphy; however, when pulmoner embolism may accompany, scintigraphy should be carefully examined.

Comparison of Tc-99m pertechnetate images with dual-phase Tc 99m MIBI and SPECT images in primary hyperparathyroidism

BACKGROUND

The purpose of this study was to evaluate the value of Tc-99m pertechnetate planar, dual-phase MIBI and MIBI-SPECT images in the determination and localization of parathyroid lesions.

MATERIALS AND METHODS

In this study, 38 patients who underwent operation for primary hyperparathyroidism were included. Tc-99m pertechnetate planar-pinhole imaging of the neck and then MIBI planar and SPECT images in supine position was performed. Late SPECT images were acquired 120 minutes after the injection. Early and late MIBI images were quantitatively evaluated.

RESULTS

Of the 38 patients, 30 of them had adenoma, 2 patients had hyperplasia and 6 of them were normal on planar images. Thirty-four of 38 patients were positive on SPECT images. SPECT images of the patients with positive results were matched with pathology results.

CONCLUSION

As a result, Tc-99m pertechnetate planar-pinhole, Tc-99m MIBI planar and SPECT images are useful for localization of parathyroid lesions especially in multinodular thyroid gland. However, US or CT images are necessary for more accurate localization and Tc-99m pertechnetate images are useful for interpreting and comparing with the early and late MIBI images.

Multiple cardiac masses and distant metastatic foci in a patient with high grade pleomorphic sarcoma of the heart revealed by follow-up FDG PET/CT

Undifferentiated high grade pleomorphic sarcoma of the heart is a rare clinical entity and efficiency of FDG PET/CT in this tumour was not well studied.

Disseminated metastatic penile squamous cell carcinoma detected by fluorodeoxyglucose PET/computerized tomography

Penile cancer is an uncommon malignancy which of the management depends on the clinical stage and location of the lesion. Positron emission tomography/computerized tomography (PET/CT) is a promising method for detection of distant metastatic lesions and therapeutic strategy planning. Here, we report a case of penile squamous cell carcinoma of 57-year-old male patient, was referred to PET/CT department for investigation of metastases. There were significantly increased fluoro-18 fluorodeoxyglucose activities in supradiaphragmatic and infradiaphragmatic lymphatic stations.

A Case of Complete Response to Letrozol Treatment in a Postmenopausal Woman With Breast Cancer Who has Progressed After Multiple Lines of Chemotherapy

Approximately 60% of all breast cancers are endocrine dependent. Postmenopausal patients who have positive hormone receptor status are eligible for aromatase inhibitor treatment. Letrozole is a potent, selective, non-steroidal, third-generation aromatase inhibitor which reduces oestrogen biosynthesis approximately 99% at the dose of 2.5 mg/day. We report a 54-years-old female patient diagnosed with grade 2 invasive ductal carcinoma of the breast. She received adjuvant chemotherapy, followed by 5 years of tamoxifen. After 8 years, recurrence appeared in lung, supraclavicular lymph nodes and brain. She had many cycles of cytotoxic chemotherapeutic agents, trastuzumab and lapatinib previously. After the progression (lung and brain), palliative therapy was thought due to very poor performance status of the patient. (ECOG: 3) Letrozole was added in the treatment and we obtained near-complete remission from her lung and brain metastasis with 2.5 mg/day dose of letrozole. This study might support successfully use of aromatase inhibitors in patients who has been previously treated with multiple lines of chemotherapy and had still progressive disease.

Positron emission tomography/computed tomography imaging of brown tumors mimicking multiple skeletal metastases in patient with primary hyperparathyroidism

Brown tumors of bone are highly vascular, lytic bone lesions representing a reparative cellular process rather than a neoplastic process usually seen in patients with hyperparathyroidism. These tumors can behave aggressively and be destructive. We report a 49-year-old male patient who was admitted to our hospital with a long-term history of right shoulder and right hip pain. Multiple lytic and destructive bone lesions were found in X-ray graphy and CT images. These bone lesions mimicked multiple skeletal metastatic lesions and seemed to be those of the terminal stage of malignancy. PET scan was requested for the evaluation of FDG uptake of these lesions and to search the unknown primary tumor site. Positron emission tomography/computed tomography (PET/CT) images showed multiple hypermetabolic malignant or metastatic FDG avid bone lesions in skeletal system. However the biopsy results revealed no signs of malignancy and laboratory data showed elevated serum calcium, alkaline phosphatase, parathyroid hormone, low serum phosphate and parathyroid scintigraphy was performed. Adenoma in the left parathyroid gland was seen with Tc-99m MIBI parathyroid scintigraphy. Pathological results confirmed the diagnosis of parathyroid adenoma. Brown tumor is the potential cause of false-positive result in evaluation of a patient for unknown primary tumor or skeletal metastases with PET/CT imaging.

Gastrointestinal stromal tumor of the rectum with scapular metastasis: a case report

Introduction

Gastrointestinal stromal tumors are rare tumors. They commonly metastasize within the abdominal cavity, particularly to the liver. Less commonly, metastases can be found in the bone.

Case presentation

We here present a case of metastasis to the scapula in a 54-year-old Caucasian male patient with an advanced gastrointestinal stromal tumor, which was subsequently successfully treated with resection and sunitinib.

Conclusion

The present study is, to the best of our knowledge, the second to describe scapular metastasis of a gastrointestinal stromal tumor. Our patient was treated by scapulectomy. The overwhelming majority of scapular tumors are metastases that arise from soft tissue, hepatocellular and thyroid tumors. Gastrointestinal stromal tumor metastasis occurs rarely. Scapular surgery can successfully provide local control of the disease. After the surgery, patients should continue with medical treatment.

Initial evaluation of inflammatory breast cancer with fluorodeoxyglucose positron emission tomography

Inflammatory breast cancer (IBC) is the most aggressive form of locally advanced breast cancer. We present here ¹⁸F FDG PET/CT findings of two patients with IBC. These patients were referred to the Nuclear Medicine department for staging of IBC. FDG PET/CT images showed diffuse infiltration of breasts with multiple lymph nodes and multiple metastases in whole-body PET/CT images. FDG PET provides additional information regarding lymph nodes or distant metastases in the initial evaluation of IBC.

Unilateral thalamic hypometabolism on FDG brain PET in patient with temporal lobe epilepsy

Interictal Brain F-18 fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) imaging has been widely used for localizing the focus of a seizure. Hypometabolism in the extratemporal cortex on FDG-PET study is an important finding to localize seizure focus, which might be seen as ipsilateral, contralateral or bilateral thalamus hypometabolism in epileptic patients. In this case report, it is aimed to show ipsilateral thalamus hypomethabolism on FDG PET brain study of a 24-year-old male patient with temporal lobe epilepsy.