Unveiling the Metabolic Maze: FDG PET/CT Findings in Peritoneal Carcinomatosis - A Case Series.

Peritoneal carcinomatosis (PC), the spread of cancer cells in the peritoneum, is a significant concern in advanced gastrointestinal and gynecological cancers. This case series includes findings on the appearance and pattern of PC on 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT). The primary sources of peritoneal dissemination are direct invasion from abdominal or pelvic tumors and metastatic spread from distant tumors. The accurate preoperative diagnosis and quantification of PC play a vital role in determining the appropriate treatment approach, with a particular emphasis on surgical planning. Several imaging modalities have been employed in preoperative evaluation, such as computed tomography (CT), magnetic resonance imaging (MRI), and 18F-FDG PET/CT. Among these modalities, 18F-FDG PET/CT has demonstrated improved anatomical localization and accurate information about the nature of pathological findings. The case series showcases four cases that illustrate the imaging characteristics of PC on FDG PET/CT. FDG PET/CT plays a vital role in diagnosing and assessing PC, aiding in its detection, staging, and treatment planning. It surpasses conventional imaging techniques in identifying and characterizing lesions and detecting the primary tumor site in cases where its location is unknown. Furthermore, FDG PET/CT additionally assists in evaluating treatment response and monitoring disease progression, providing insights into treatment effectiveness and guiding patient management decisions.

Circumferential Laryngotracheal Resection in Thyroid Cancer: Experience and Outcome in a Single Center.

There is limited experience of laryngotracheal resection in patients with differentiated thyroid carcinoma (DTC). The aim of this study was to report our experience of circumferential laryngotracheal resection in DTC and its long-term outcome. In this retrospective study, 10 patients of locally invasive DTC who underwent circumferential laryngotracheal resection between January 2000 and December 2015 were included. Clinicopathologic profile and follow up was noted. Mean age of the cohort was 50.1 ± 7.8 years (M:F = 1: 2.3). Papillary carcinoma was the commonest pathology (60%) followed by follicular carcinoma (20%), 10% each had Hurthle cell and poorly differentiated thyroid carcinoma. Sixty percent patients presented with recurrent or persistent disease and 20% with distant metastases. Vocal cord palsy was observed in 30%. Fifty percent patients underwent tracheal resection with end to end anastomosis and remaining laryngotracheal resection. Carotid artery resection and anastomosis was performed in one patient. Shin stage IV invasion was observed in 80% and stage III in remaining. There was no perioperative mortality. All patients received adjuvant radioiodine therapy and 40% external beam radiotherapy. Median follow up was 48 months. One patient who earlier had tracheal resection underwent total laryngectomy due to recurrent disease after 24 months. Forty percent patients developed distant metastases during follow-up. Mean survival was 77.8 months (CI = 63.0-92.5). Five-year overall survival was 60% and was significantly high in those without distant metastases (p = 0.006). The outcome of circumferential larygotracheal resections for DTC is excellent in terms of local disease control and long term survival.

Outcome of 18f-Fluorodeoxyglucose Positron Emission Tomography (PET)-Directed Resections in Differentiated Thyroid Carcinoma (DTC): Experience in a Developing Country.

The aim of this study was to assess the accuracy of 18F-fluorodeoxyglucose positron emission tomography (18-FDG-PET scan) in localizing the disease in differentiated thyroid carcinoma patients undergoing re-operations. This is a retrospective analysis of a prospectively maintained data (December 2007 to December 2016). The patients included had elevated serum thyroglobulin (Tg) levels and negative iodine uptake (TENIS) and planned for re-operation with one or more accessible site of metastasis detected on FDG-PET scan. Clinical details, FDG-PET/CT findings, operative findings, histology, pre-, and post-operative Tg levels were recorded. Thirty-two patients were included. The mean age of the patients was 46.8 ± 15.8 years (M:F = 1:1.6) and mean pre-operative Tg value was 247.6 ± 92.3 ng/ml. FDG-PET disclosed a total of 77 hot spots in these 32 patients, 56 of which were surgically explored and resections performed. Patient- and lesion-based positive predictive value (PPV) of FDG-PET in detecting recurrent/metastatic DTC lesions was 87.5 and 71%, respectively. Remaining cases had granulomatous or nonspecific inflammatory lesions. A total of 12.5% of recurrent DTC patients explored could achieve biochemical cure. All these had disease confined to neck. Remaining patients continued to have high serum Tg level, though it fell substantially in majority of patients. False positive scans are frequent in regions with high prevalence of inflammatory diseases. Hence, FDG-PET directed re-operations should be taken up judiciously.

Factors predicting the risk of biochemical incomplete response in well-differentiated thyroid cancer after total thyroidectomy.

BACKGROUND: Differentiated thyroid cancer (DTC) is the most common endocrine carcinoma with an overall good prognosis. However, persistent or recurrent disease (P/R disease) and incomplete biochemical response (BIR) are causes of morbidity. Histopathology and TNM stage may not predict P/R disease and BIR in all patients. Various clinical parameters, histopathological features and preablative-stimulated thyroglobulin (presTg) have been proposed to predicts P/R disease. However, there is uncertainty for presTg cutoff and diagnostic accuracy. The study's objective was to predict the BIR before radioiodine ablation from available clinical, histopathological and biochemical parameters. METHODS: A retrospective, single-center study, including DTC patients, was done. Demography and factors predicting BIR evaluated. RESULT: In comparison to the patients in remission, patients with BIR were older (P = 0.042), had higher presTg (P < 0.001), and lymph nodes (LN) metastases [central or lateral compartment (P < 0.001)]. Visualization of LN on whole-body scan (P = 0.014), higher TNM stage (P = 0.001) and distance metastasis (P < 0.001) were also associated with BIR. On multivariate analysis, high presTg (P < 0.001) and LN metastases (LNscan and histopathologically proven LN involvement, P < 0.001) were associated with BIR. A presTg level ≥12.30 ng/ml has high sensitivity (90.6%) and specificity (80.6%) to predict the BIR (odds ratio 39.90). CONCLUSIONS: The presTg and LN involvement are robust markers that predict BIR. A raised presTg level with LN metastases and nonvisualization of the LN on the whole-body scan is a worrying feature for the future BIR. We propose the inclusion of high presTg as a high-risk factor in DTC.

Clinical outcome of patients with differentiated thyroid cancer and raised antithyroglobulin antibody levels: a retrospective study.

BACKGROUND: Thyroglobulin (Tg) is a specific tumor marker for differentiated thyroid cancer (DTC). However, in the presence of an antithyroglobulin antibody (TgAb), it becomes unreliable. The purpose of the study was to assess the long-term outcome of DTC patients with raised TgAb. METHOD: In a retrospective study, we included patients with DTC who had raised TgAb following total thyroidectomy. We excluded patients with persistently raised Tg (≥ 1 ng/ml) or radioiodine avid disease. Serial TgAb levels, excellent response (ER), incomplete response (IR), and anatomical recurrence were evaluated. RESULTS: A total of seventy-six patients were included in the study. Patients with IR had higher baseline TgAb (1071.27 ± 1216.17 vs. 99.61 ± 91.29 IU/ml, p < 0.001) and central compartment lymph node metastases (70.8% vs. 46.4%, p = 0.035) in comparison to those in the ER group. In the first follow-up, 64 (84.2%) patients had a stable or fall in the TgAb (0 to - 98.3%). Sixty-eight patients received high-dose radioiodine therapy (RIT). Out of these, 59 (86.5%) had transient, and 51 (75%) had a long-term fall in TgAb. After a follow-up period of 58.74 ± 26.26 months, 63.2% (48 out of 76) patients had IR. Nine (11.8%) patients had a rising TgAb level (3.7-170.9%) from baseline. Eleven patients underwent 18F-FDG PET/CT, and five of them demonstrated metabolically active recurrent disease. Three patients underwent cervical lymph nodes dissection. None of the patients died during the follow-up period. CONCLUSION: High post-operative TgAb levels and central compartment lymph nodal metastases are risk factors for IR. RIT leads to a significant fall in the TgAb in these patients. The low level of raised TgAb is associated with an excellent outcome. Patients with recurrences had very high baseline TgAb > 1000 IU/ml. Raised TgAb was associated with good clinical outcomes and not associated with increased mortality.

The Utility of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Differentiated Thyroid Cancer Patients with Biochemical Recurrence and Negative Whole-Body Radioiodine Scintigraphy and Evaluation of the Possible Role of a Limited Regional Scan.

PURPOSE OF THE STUDY: 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is used in the management of recurrent differentiated thyroid cancer (DTC) patients presented with rising thyroglobulin (Tg) or anti-Tg antibody (Atg) levels and negative whole-body I-131 scan (WBS). We aimed to evaluate the utility of regional or limited PET/CT in a large population preset with variable Tg/(ATg) levels. MATERIALS AND METHODS: In a retrospective study, we analyzed 137 PET/CT done on DTC patients presented with raised Tg/Atg and negative WBS. Retrospective evaluation of other available clinical information was done. RESULTS: One hundred and thirty-seven patients aged 8-72 years (41 ± 17.7 years) were included in the study. Eighty-nine (64.9%) patients had positive findings on 18F-FDG PET-CT. It included thyroid bed recurrence, cervical, mediastinal lymphadenopathy, lung, and bone lesions. In addition, 36 patients had metabolically inactive lung nodules detected on CT. Serum Tg and female sex were the only predictors for a positive PET scan. In most (97.1%) of the patients, the disease was limited to the neck and thoracic region. CONCLUSIONS: PET/CT is an excellent imaging modality for evaluating DTC patients presented with biochemical recurrence. It not only finds the disease in more than 80% of the patients but also detects distant metastatic disease, which precludes regional therapies. Lesions were noted mostly in the neck and thoracic region with very few distant skeletal metastases (4/137 patients). In most of the patients, routine vertex to mid-thigh imaging could be avoided.

Idiopathic Hepatic and Splenic Uptake of 99mTc-Methylene Diphosphonate.

Tc-99m-methylene diphosphonate (MDP) bone scintigraphy is mainly directed toward identifying sites of altered skeletal metabolism and abnormal foci of calcium phosphate deposition due to various etiologies. One of the requirements of an ideal bone scintigraphy is little or no extraosseous uptake. Nonosseous uptake of MDP in the bone scintigraphy is an unusual finding. We report a case of carcinoma prostate referred for bone scan, where diffuse hepatic and splenic uptake has been seen on the bone scan. However, on a further repeat bone scan, there was no nonosseous uptake.

Lymphoscintigraphy In a Case of Recurrent Chylopericardium.

Chylopericardium is an uncommon and benign condition in which triglyceride-containing chylous fluid collects in the pericardial cavity at high concentrations. Usually, chylopericardium occurs due to congenital malformation of lymphatic vessels or secondary to any trauma, surgeries, neoplasms, etc. However, if exact aetiology cannot be identified, the condition is referred to as Idiopathic chylopericardium which is a very rare presentation in day-to-day clinical practice. General physical examination, routine blood investigations and various anatomical imaging modalities may give a clue in the diagnosis, however, diagnosis can be challenging as they have a variable presentation. Also, optimal treatment poses greater difficulty as it remains controversial in most cases. We report a 47-year-old gentleman who presented with recurrent chylous pericardial effusion with no history of trauma, thoracic surgeries, cardiac disease and neoplasm in the past. Lymphoscintigraphy confirmed the communication between the lymphatic trunk and the pericardial space. The patient was managed conservatively with pericardial drainage and the patient recovered is doing well at present.

Semi-quantitative assessment of diffuse hepatic uptake seen in I-131 scans - an indicator of functioning thyroid tissue and disease burden in differentiated thyroid cancer.

BACKGROUND: To semi-quantitatively analyze liver uptake of I-131 in diagnostic and post-therapy scans by calculating hepatic to thigh ratios (HTR) and evaluate its clinical significance in management of differentiated thyroid cancer. METHOD: Two hundred forty-nine patients were included in the study. Hepatic to thigh ratio (HTR) of counts were calculated for 249 diagnostic and 104 post-therapy scans. Patients were divided into six study groups based on their disease status:1-Serum thyroglobulin (serum Tg) negative (serum Tg ≤ 4 ng/dl) and scan negative; 2-Thyroid remnant only; 3-Thyroid remnant and lymph node metastasis; 4- Tg positive (serum Tg > 4 ng/dl) and scan negative; 5-Bone or/and lung metastasis, and 6-Only lymph node metastasis. Comparison of HTR between these groups was done using one-way ANOVA test. Correlation of HTR with serum Tg, serum thyroid stimulating hormone (TSH), anti-thyroglobulin antibody (ATg) titer and therapeutic dose of I-131 was also assessed. RESULTS: Comparison of HTR between different study groups (1 to 6) showed significant difference in HTR (p = .001). Study group 5 (bone or/and lung metastasis) showed significantly higher mean HTR compared to other groups (p = 0.001). There was only a weak correlation between serum Tg and HTR (r = 0.395). Dose of I-131 administered also had a weak correlation with HTR (r = 0.207). CONCLUSION: HTR has good correlation with functional status of tumor cells, while it has weak correlation to therapeutic dose of I-131 administered and serum Tg. Increased HTR predicts significant disease burden in the form of distant bone and lung metastasis and may potentially be used as a second prognostic factor apart from serum Tg.

Standardization of administered activities in pediatric nuclear medicine: a report of the first nuclear medicine global initiative project, part 1-statement of the issue and a review of available resources.

The Nuclear Medicine Global Initiative (NMGI) was formed in 2012 and consists of 13 international organizations with direct involvement in nuclear medicine. The underlying objectives of the NMGI were to promote human health by advancing the field of nuclear medicine and molecular imaging, encourage global collaboration in education, and harmonize procedure guidelines and other policies that ultimately lead to improvements in quality and safety in the field throughout the world. For its first project, the NMGI decided to consider the issues involved in the standardization of administered activities in pediatric nuclear medicine. This article presents part 1 of the final report of this initial project of the NMGI. It provides a review of the value of pediatric nuclear medicine, the current understanding of the carcinogenic risk of radiation as it pertains to the administration of radiopharmaceuticals in children, and the application of dosimetric models in children. A listing of pertinent educational and reference resources available in print and online is also provided. The forthcoming part 2 report will discuss current standards for administered activities in children and adolescents that have been developed by various organizations and an evaluation of the current practice of pediatric nuclear medicine specifically with regard to administered activities as determined by an international survey of nuclear medicine clinics and centers. Lastly, the part 2 report will recommend a path forward toward global standardization of the administration of radiopharmaceuticals in children.

Preoperative contrast-enhanced computerized tomography should not delay radioiodine ablation in differentiated thyroid carcinoma patients.

BACKGROUND: There is concern about potential interference of iodinated contrast used in contrast-enhanced computerized tomography (CECT) with radioiodine therapy in differentiated thyroid carcinoma (DTC). The aim of this study was to determine the effect of iodinated contrast on urinary iodine concentration (UIC) in patients having thyroidectomy compared with control groups without CECT and without thyroidectomy. METHODS: This prospective control study consisted of 4 groups each comprising 32 patients. Group 1- DTC patients undergoing preoperative CECT, group 2- DTC patients not undergoing CECT, group 3- benign goiter patients undergoing preoperative CECT, and group 4- patients with non-thyroidal diseases undergoing preoperative CECT. Spot UIC before CECT, after surgery (5-7 d), and at follow-up (4-6 wk) were compared among the groups. RESULTS: The median basal UIC levels were not significantly different between the four groups (232.2 versus 263.9 versus 268.2 versus 178.2 µg/L, respectively, P = 0.443). In contrast, groups having preoperative CECT had significantly higher UIC levels at discharge (924 versus 329 versus 776 versus 661 µg/L, respectively, P = 0.001). These differences became insignificant at follow-up (225 versus 252 versus 310 versus 275 µg/L, respectively, P = 0.505). Patients having follow-up UIC values above the conventional cut-off of clinically relevant iodine excess (>200 µg/L) also had significantly higher basal values than those having lower follow-up values (283.0 versus 181.7 µg/L; P = 0.037). CONCLUSIONS: Irrespective of the fact whether a patient is thyroidectomized or not preoperative CECT using non-lipophilic contrast does not result in long-term iodine retention.

Central post stroke pain: clinical, MRI, and SPECT correlation.

OBJECTIVE: The objective of this study was to report clinical spectrum of central post stroke pain (CPSP) and correlate these with magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) findings. DESIGN: The study was designed as a prospective study. SETTING: The study was set in a tertiary care teaching hospital. SUBJECT AND METHOD: Twenty-three consecutive CPSP patients were included and their severity of pain, sensory threshold, allodynia, hyperalgesia, and temporal summation were assessed by quantitative sensory testing (QST). Cranial MRI and (99)Tc ethylene cystine dimmer SPECT findings correlated with QST. RESULTS: The duration of CPSP was 5 months (0.25-108). Allodynia was present in 12 patients, punctuate hyperalgesia in 11, and temporal summation in 12. SPECT was abnormal on visual analysis in 17 patients; hypoperfusion in corresponding thalamus in nine, and parietal cortex in 11 patients. Semiquantitative analysis revealed hyperperfusion of thalamus in four and parietal cortex in five patients. MRI revealed infarction in 14 and hematoma in nine patients. The QST findings were similar in thalamic and extrathalamic CPSP. The MRI and SPECT findings were also not different in CPSP patients with and without allodynia. CONCLUSION: The QST findings in patients with CPSP were similar in patients with thalami and extrathalamic lesions. SPECT and MRI findings were also not different in CPSP patients with and without allodynia.

Long-term outcome of differentiated thyroid carcinoma: experience in a developing country.

BACKGROUND: The presentation and outcome of differentiated thyroid carcinoma (DTC) in developing countries are different from the developed nations. We report the clinicopathologic profile and long-term outcome of DTC in an iodine-deficient area (IDA) in a developing country. METHODS: This retrospective study included 302 patients with DTC operated between 1989 and 2002. These patients had been followed up for a minimum period of 5 years after surgery. Clinicopathological profile, intervention, and follow-up details were noted. RESULTS: Mean age of the patients was 42 +/- 14 years. Mean follow-up period was 80 +/- 34 (24-196) months. Papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), and poorly differentiated thyroid carcinoma (PDTC) was present in 62, 30, and 8% patients, respectively. Mean tumor size was 3.5 cm. Tumor multicentricity was noted in 40% of PTC, 22.2% of FTC, and 25% of PDTC patients. Lymphadenopathy was observed in 45, 10, and 67% patients with PTC, FTC, and PDTC, respectively. Extrathyroidal invasion and distant metastasis were observed in 36.8% (PTC 33%; FTC 36%; PDTC 71%) and 27% (PTC 17%; FTC 44%; PDTC 42%) of cases, respectively. Twenty percent of patients had synchronous metastases. Risk stratification ratio was 1:1.8 (high-risk vs. low-risk). Initial operative procedure was total thyroidectomy in 86.5% cases, and therapeutic lymph node dissection was performed in 37% cases. A total of 77.2% patients received adjuvant radioiodine therapy. Disease recurred in 26.6% of patients (thyroid bed recurrence 1.7%), and 21.2% patients died during follow-up. Overall survival (OS) rate at 10 years in both low-risk and high-risk groups of FTC (80 and 54%) was inferior to PTC (94 and 62%). Five-year OS for PDTC was 50%. Tumor multicentricity was a significant risk factor for OS in the low-risk group, whereas the presence of skeletal metastases and extrathyroidal invasion were significant factors for OS in the high-risk group. CONCLUSIONS: Advance stage at presentation and proportionately high rates of FTC and PDTC contribute to poor outcome of DTC in developing countries. Despite dismal outcome, total thyroidectomy seems to prevent thyroid bed recurrence in surviving patients.

Comparative evaluation of Tc-99m cystine and Tc-99m MAG3 in normals and patients with renal functional impairment.

Tc-99m cystine has been proved to be a good renal agent in animals for morphologic as well as the functional status of the kidney. In this study, we compared Tc-99m cystine with Tc-99m mercaptoacetyltriglycine, which is used for evaluation of renal function in normal patients, and those with various degrees of renal functional impairment. The clearance values and static images are compared with Tc-99m mercaptoacetyltriglycine. The results show that Tc-99m cystine has good radiopharmaceutical characteristics suitable for evaluation of both renal function as well as morphology.

Functional expression of sodium iodide symporter (NIS) in human breast cancer tissue.

Sodium iodide symporter (NIS) is a molecule involved in active accumulation of iodine in thyroid gland for the biosynthesis of thyroid hormone. Its expression has also been demonstrated in extra-thyroidal tissues including lactating mice mammary gland and also in human breast cancers. Iodide transport in thyroid cells through NIS is the basis for using radioiodine for diagnosis and treatment of differentiated thyroid carcinoma. The similar approach may prove beneficial for the diagnosis and treatment of breast cancer if iodine uptake, its retention and NIS expression can be shown unequivocally in malignant tumors. The aim of the present study was to investigate NIS expression, in vivo iodine transport ability and fate of iodine in human breast tumors. Women (age 33-58 years) with infiltrating duct carcinoma confirmed by FNAC and subsequent histopathology were the subject of this study. Expression of NIS RNA and protein was confirmed by RNAase protection assay, western blot and immunohistochemistry respectively in surgically excised breast tumor tissue. Iodine transport ability and its nature was assessed both in vivo and in vitro. We report high NIS expression at both transcriptional and translational level and its ability to transport iodine in human breast tumors. The in vivo iodine transport ability was confirmed by scintigraphy. Unlike thyroid, perchlorate and thiocyanate do not inhibit iodine transport in breast tumors. The presence of iodinated proteins suggests the longer retention time. The unequivocal demonstration of NIS expression, its functionality and retention of iodine by organification further provides supportive evidence for use of radioiodine as an additional treatment modality of human breast carcinoma.

Co-existent massive renal replacement lipomatosis and xanthogranulomatous pyelonephritis--a case report.

Renal replacement lipomatosis is a benign condition that may assume major clinical significance by producing pyelocalyceal deformities that may be mistaken for true renal masses. While the number of reported cases of renal replacement lipomatosis has been relatively small, this entity's prevalence is probably underestimated. We report a case of co-existent massive renal replacement lipomatosis and xanthogranulomatous pyelonephritis.