FDG PET and alternative imaging in the management of thyroid carcinoma

Differentiated carcinoma of the thyroid are one of rare malignancies that is associated with excellent prognosis. Follow-up with regular thyroglobulin assay and 131I whole-body scan is capable of detecting residual or recurrent disease with great sensitivity and specificity. However, there is overwhelming evidence to suggest that this approach is not fail-safe due to increasing reports of false negative and false positive results, which may result in missed or unwarranted therapy with 131I. This article will review the current management of differentiated carcinoma of the thyroid and the possible causes of the reported inadequacy of thyroglobulin and 131I whole-body scan to detect residual or recurrent disease, and the increasing role of alternative imaging, particularly 18F-FDG PET in the management of this curable malignancy

Improving UAV Communication in Cell Free MIMO Using a Reconfigurable Intelligent Surface

Communication with unmanned aerial vehicles (UAVs) in current terrestrial networks suffers from poor signal strength due to the down-tilt of the access points (APs) that are optimized to serve ground users ends (GUEs). To solve this, one could tilt the AP antenna upwards or allocate more power to serve the UAV. However, this negatively affects GUE downlink (DL) rates. In this paper, we propose to solve this challenge using a reconfigurable intelligent surface (RIS) to enhance the UAV communication while preserving the 3GPP- prescribed downwards antenna tilt and potentially improving the DL performance of the GUE. We show that under conjugate beamforming (CB) precoding and proper power split between GUEs and the UAV at the APs, an RIS with phase-shifts configured to reflect radio signals towards the UAV can significantly improve the UAV DL throughput while simultaneously benefiting the GUEs. The presented numerical results show that the RIS- aided system can serve a UAV with a required data rate while improving the GUEs DL performance relative to that in a CF- MIMO system without a UAV and an RIS. We support this conclusion through simulations under a varying numbers of RIS reflecting elements, UAV heights, and power split factor

Deepfake Image Generation for Improved Brain Tumor Segmentation

As the world progresses in technology and health, awareness of disease by revealing asymptomatic signs improves. It is important to detect and treat tumors in early stage as it can be life-threatening. Computer-aided technologies are used to overcome lingering limitations facing disease diagnosis, while brain tumor segmentation remains a difficult process, especially when multi-modality data is involved. This is mainly attributed to ineffective training due to lack of data and corresponding labelling. This work investigates the feasibility of employing deep-fake image generation for effective brain tumor segmentation. To this end, a Generative Adversarial Network was used for image-to-image translation for increasing dataset size, followed by image segmentation using a U-Net-based convolutional neural network trained with deepfake images. Performance of the proposed approach is compared with ground truth of four publicly available datasets. Results show improved performance in terms of image segmentation quality metrics, and could potentially assist when training with limited data.Comment: 6 pages, 8 figures, 2 tables, conference pape

Skin eruptions following treatment with Iodine-131 for hyperthyroidism. A rare and un-reported early/intermediate side effect

BACKGROUND: Iodine-131 (131I) is a well-established method for the treatment of hyperthyroidism. Following such therapy, patients may experience symptoms relating to early or delayed side effects that can be prevented or minimized if necessary measures are taken. We have noticed an unusual side effect of 131I therapy in the form of a skin eruption (iododerma) and aimed at assessing the frequency and severity of this side effect. MATERIAL AND METHODS: Retrospective review of 141 patients treated with 131I between January 1994 to December 2000 (86 F, 55 M; mean age 41.35 ± 11.02 years) was performed. The dose of 131I ranged from 250-500 MBq. Post therapy clinical and biochemical evaluation of thyroid function was done at 6 weeks, 3, 6, and 9 months then annually. RESULTS: Of the 141 treated patients, 3 patients (2.1%) presented with iododerma 4-6 weeks after 131I therapy administration. Lesions were observed at both ankles & lower legs in all 3 cases. All lesions disappeared within 6 months with no residual effect. No other skin lesions were seen thereafter during the follow-up period. CONCLUSION: Iododerma is a rare complication of 131I therapy that has not been reported before. It appears within 4-6 weeks after therapy and is a self-limiting condition

Distant metastases of differentiated thyroid cancer: diagnosis, treatment and outcome

The remarkably good prognosis and long-term survival in differentiated thyroid cancer (DTC) are significantly reduced in patients with distant metastasis (DM). Multi-site metastases are associated with a high mortality rate reaching 92% at 5 years necessitating early diagnosis and treatment. The most common site of metastases are the lungs, followed by the bone, with the former having better prognosis than the latter due to late detection. A number of factors contribute to the development of DM including large and multifocal primary tumour, extrathyroidal extension, aggressive histology and advanced age. In patients with good 131I uptake, 131I therapy appears highly effective and should be offered up to a cumulative activity of 22 GBq. Other measures such as surgery, radiotherapy, arterial embolisation and cementoplasty may be required. If there is low or no 131I uptake, FDG-PET should be obtained due to its prognostic impact. It may help in selecting patients for other modalities such as cytotoxic chemotherapy and redifferentiation therapy by 13-cis retinoic acid. The development of tyrosine kinase inhibitors has raised hopes in providing alternative therapy for bone metastasis, especially in older age groups with poorly differentiated tumours with no 131I uptake but good uptake of FDG

Modified Mamdani-fuzzy inference system for predicting the cost overrun of construction projects

Cost overruns are a common worldwide problem in the construction industry; improved proactive risk management and cost control are much needed. Several models have been proposed, but all have weaknesses, particularly in data demands and the severity of critical risks or uncertainties associated with expert judgment. In response, this study develops a new 3-part model based on the Mamdani-type fuzzy inference system (FIS) to predict the cost overrun of construction projects. The first part assesses the weight of each expert, evaluating the severity of cost overrun factors. The second part contains a list of 40 in-built cost overrun factors and their degree of severity, while the third part establishes the relationships of every factor's occurrence probability and severity to predict the cost overrun of a specific project. The severity of each factor is assessed based on a survey of 31 randomly selected experts in the Saudi Arabian construction industry. The model is demonstrated on two completed projects in Saudi Arabia. For each project, this involves a group of project-based experts rating the probability of occurrence of each factor on that project and applying this to the factor severity list to obtain a predicted cost overrun (PCO) for the whole project. The model is validated for robustness by sensitivity analysis comparing the predicted and actual whole project cost overrun and shown to be of practical value in assessing critical risks and predicting the likely amount of cost overrun. The model is equally applicable in the early project stages.</p

The prognostic value of 18F-FDG PET-CT in the management of Hodgkin&#8217;s lymphoma: preliminary results of a prospective study

BACKGROUND: To date, Hodgkin&#8217;s lymphoma (HL) patients have achieved long-term survival of more than 80%. Unfortunately, longer follow-up has shown serious adverse effects of the treatments used. For this reason, therapeutic strategies are becoming more tailored to the individual patient´s prognosis. Pre-treatment risk factors for early-stage and advanced-stage HL are well known indicators of prognosis. Recently, early interim 18F-FDG PET has been shown as a strong and independent predictor of progression-free survival in HL. Our aim was to assess response to therapy by repeating 18F-FDG-PET/CT after four and six chemotherapy cycles. MATERIAL AND METHODS: We evaluated 21 consecutive patients affected by (HL) and presenting for assessment over a period of three years. All patients underwent initial staging with 18F-FDG-PET/CT along with standard staging procedures. We tailored an individual treatment plan dependent on pre-treatment risk factors and initial 18F-FDG-PET/CT. With the aim of the best definition of response to treatment, we repeated 18F-FDG-PET/CT after two (FDG-PET 2), four (FDG-PET 4) and six (FDG-PET 6) chemotherapy cycles. Chemotherapy was typically given for four cycles in early disease stages and was prolonged to six to eight cycles in advanced disease stages, depending on PET findings. RESULTS: Our results showed a strong negative predictive value in detecting responders in early stage HL and a positive predictive value in advanced-stage patients. Clinical stage, extra-nodal sites and the positivity of the 18F-FDG-PET/CT performed during chemotherapy were also noted as strong determinants of response to treatment. Moreover, in our series the 18F-FDG-PET/CT data obtained after only two chemotherapy cycles (FDG-PET 2) were the same of those obtained after FDGPET 4 and FDG-PET 6 controls. CONCLUSION: The preliminary data of the present study confirm those of previous published studies about the negative predictive value of 18F-FDG-PET/CT performed after four and six chemotherapy cycles, which contributed to the decision to stop treatment and to avoid radiotherapy in HL patients. Nonetheless, our preliminary data seems to suggest that only the 18F-FDG-PET/CT performed after two cycles of chemotherapy (FDG-PET 2) is able to provide the same prognostic information of the FDG-PET 4 and FDG-PET 6 earlier

Clinical significance of metabolic superscan in patients with hyperthyroidism

BACKGROUND: Hyperthyroid patients commonly complain of generalized bony aches, which are frequently overlooked due to the more prominent symptoms of cardiovascular and nervous disturbances. Hyperthyroid patients are expected to have abnormal bone metabolism as part of the generalized hypermetabolic status. The aim of this study is to verify the presence of metabolic bone superscan in association with the hypermetabolic stats in various groups of hyperthyroidism. Secondly, to correlate these superscan features with the various laboratory results in hyperthyroid patients. MATERIAL AND METHODS: Forty-five hyperthyroid patients confirmed by clinical and laboratory results were enrolled in this work. In all patients, a 99mTc-pertechnetate thyroid uptake scan was acquired. On a different day, total body bone scan was acquired three hours post IV injection of 555-925 MBq of 99mTc-MDP. Serum FT3, FT4, TSH, Ca++, alkaline phosphatase (AP) and parathyroid hormone (PTH) were monitored in all patients as markers of thyroid and bone metabolism. Ten cases with no thyroid diseases were included as a control group. Patients with thyroiditis or long history of antithyroid drugs for more than one year were excluded from the study. RESULTS: The patients were subdivided into three groups: Graves´ disease (GD) (n = 30), toxic nodular goiter (TNG) (n = 10) and autonomous toxic adenoma (AT) (n = 5). The TSH for the whole group was significantly suppressed compared to the control group with higher suppression in the Graves´ disease group than in the TNG or AT groups. 99mTc-pertechnetate uptake values in the Graves´ disease group were significantly higher than the TNG and AT groups (p < 0.05). Metabolic superscan (MSS) was noted in 90% of the Graves´ cases, 20% in TNG and in none of the AT group. There were no significant differences regarding Ca+, AP and PTH between the Graves´ and non-Graves´ groups (p > 0.05). CONCLUSIONS: Disturbances in bone metabolism are more prevalent in Graves´ disease than in other types of hyperthyroidism. The addition of the bone scan to the diagnostic work up of patients with Graves´ disease is a sensitive indicator for metabolic bone changes and could help in the future management and follow up for this group of patients

The value of simultaneous co-registration of 99mTc- MDP and 131Iodine in metastatic differentiated thyroid carcinoma

BACKGROUND: The lack of anatomical details in standard 131Iodine whole body scanning (131I WBS) interferes with the proper localization of metastatic differentiated thyroid carcinoma (DTC) lesions. In addition, nearby or overlapping variable physiological distribution of 131I may affect the specificity of 131I uptake, giving indeterminate results. The aim of this study was to demonstrate the clinical usefulness of simultaneous co-registration of 99mTc MDP bone scanning as an anatomical landmark with 131I scanning in the evaluation of metastatic DTC. MATERIAL AND METHODS: Twenty-five patients (16 females and 9 males, mean age &#177; SD = 52 &#177; 13 years) with metastatic DTC (17 papillary, 8 follicular), were included. Whole body scanning using a 256 x 1024 matrix and an 8 cm/min scan rate were obtained 48 hours after oral administration of 185-370 MBq 131I and 2 hours after IV administration of 185-370 MBq 99mTc MDP using a dual head gamma camera equipped with high energy parallel hole collimators. Occasionally, additional simultaneous co-registration of localised detailed images was also performed using a 256 x 256 matrix size. The two planar images were fused with optional fusion of SPECT images. The data from standard 131I scanning and fused 131I/ 99mTc-MDP scanning were separately assessed by two nuclear medicine physicians. Fusion images were considered to improve image interpretation in comparison with standard 131I scanning when they provided better localization of lesions. RESULTS: All lesions in the present study were validated by radiological images and clinical follow up for at least 12 months. Forty-eight metastatic lesions were confirmed as follows: 2 in the skull, 10 in the neck, 20 in the thorax, 12 in the pelvic-abdominal region and 4 in the extremities. Standard 131I WBS showed 54 extra-thyroidal foci with 8 false positive lesions of which 2 were located in the scalp and 6 in the pelvic-abdominal region extra-skeleton (i.e. sensitivity 100%, specificity 86%). Out of the 48 validated lesions, 16 were indeterminately localized: 10 in the thorax (3 mediastinal nodal lesions, 5 vertebral lesions and 2 ribs) and 6 in the pelvic-abdominal region (2 upper sacral, 2 sacroiliac region and 2 ischial bone). Fusion images confirmed the precise localization of the pathological uptake in the validated 48 lesions (sensitivity 100%, specificity 100%). There were 2 (4%) indeterminate lesions in fused planar imaging that were clearly localized via fused SPECT images. CONCLUSIONS: Fusion images using simultaneous co-registration of 131I and 99mTc MDP scanning is a simple and feasible technique that improves the anatomically limited interpretation of scintigraphy using 131I alone in patients with metastatic differentiated thyroid carcinoma. The diagnostic advantage of this technique seems to be more apparent in the thoracic and pelvic- abdominal regions in contrast to the neck and extremities