Comparing Estimated and Measured Glomerular Filtration Rate in Children with Posterior Urethral Valve.

Background: Posterior urethral valve (PUV) is obstructive uropathy that may lead to chronic kidney disease (CKD) and end-stage renal disease (ESRD) in children. Glomerular filtration rate (GFR) measurement remains the gold standard for renal function measurement. However, due to its less availability and cumbersome, it is not commonly used, and GFR is estimated utilizing various endogenous filtration markers. Objective: This study includes pediatric patients with PUV. We aimed to compare the measured GFR (mGFR) with various creatinine-based estimated GFR methods (eGFR). Materials and Methods: A single-center retrospective study included 62 treated cases of PUV, postvalve fulguration. The mGFR measured by 99mTc-diethylenetriaminepentaacetate in vitro method and compared with eight eGFR (Schwartz, Cockcroft-Gault [CG], Counahan-Barratt [CB], CKD Epidemiology Collaboration [CKD-EPI], full-age spectrum [FAS] age, FAS height (FAS Ht), Schwartz-Lyon [SL], and Ht independent). Patients were subdivided into different CKD grades and compared with various eGFR. Discussion: PUV is a common cause of CKD in children and needs special consideration as there is growth retardation associated with it. It decreases creatinine production and thus fallacies in eGFR measurement. There is a requisite to identify and closely monitor the subset of patients with baseline decreased renal function and therefore at risk of developing ESRD. Results: A total of 62 patients were included. Mean age and serum creatinine levels were 8.02 ± 5.53 years and 1.15 ± 0.95 mg/dl (range: 0.4-4.5), respectively. The mean mGFR was 61.6 ± 31.80 mL/min/1.73 m2 and a positive variable correlation was 0.46-0.77 between mGFR and eGFR. Based on mGFR, there were 14 (22.6%), 21 (33.8%), 13 (20.9%), 9 (14.5%), and 5 (8.1%) patients in Grades I-V, respectively. The correct classification of the CKD grades was noted in 25 (40.3%), 16 (25.8%), 32 (51.6%), 16 (25.8%), 25 (40.3%), 27 (43.5%), 26 (41.9%), and 28 (45.2%) patients by Schwartz, CG, CB, CKD-EPI, FAS age, FAS Ht, SL, and Ht-independent equation. The eGFR overestimates GFR at the lower level and underestimates at higher levels. Conclusion: Our results confirm the considerable limitations of various creatinine-based clearance methods for estimating actual GFR. The creatinine clearance-based eGFR should not replace the measurement of the GFR. An initial measure of the mGFR followed by serial follow-up with the eGFR equation may be done. The most accurate eGFR equations are CB for Grade II, SL or Ht independent for Grade III, FAS age for Grade IV, and SL for Grade V CKD.

Metabolic flare phenomenon mimicking disease progression on 18Flouride- Fluorodeoxyglucose PET/CT scan in breast cancer treated with paclitaxel-based chemotherapy.

18F-fluorodeoxyglucose Positron emission tomography (18F-FDG PET/CT ) is now being used as a single modality for metastatic workup and response evaluation in breast cancer. An increase in metabolic activity indicates disease progression; however, metabolic flare should be kept in mind. Metabolic flare is a well-documented phenomenon reported in metastatic breast and prostate cancer. Despite a favorable response to therapy, there is a paradoxical increase in radiopharmaceutical uptake. The flare phenomenon with various chemotherapeutic and hormonal agents is well acknowledged in bone scintigraphy. However, very few cases have been documented on PET/CT. Increased uptake may be noted after treatment is instituted. The increased osteoblastic activity is associated with the healing response of bone tumors. We report a case of treated breast cancer. She presented with metastatic recurrence after four years of initial management. The patient was started on paclitaxel chemotherapy. Serial 18F- FDG PET/CT demonstrated metabolic flare and complete metabolic response.

Fibroblast Activation Protein Inhibitor-Based Radionuclide Therapies: Current Status and Future Directions.

Metastatic malignancies have limited management strategies and variable treatment responses. Cancer cells develop beside and depend on the complex tumor microenvironment. Cancer-associated fibroblasts, with their complex interaction with tumor and immune cells, are involved in various steps of tumorigenesis, such as growth, invasion, metastasis, and treatment resistance. Prooncogenic cancer-associated fibroblasts emerged as attractive therapeutic targets. However, clinical trials have achieved suboptimal success. Fibroblast activation protein (FAP) inhibitor-based molecular imaging has shown encouraging results in cancer diagnosis, making them innovative targets for FAP inhibitor-based radionuclide therapies. This review summarizes the results of preclinical and clinical FAP-based radionuclide therapies. We will describe advances and FAP molecule modification in this novel therapy, as well as its dosimetry, safety profile, and efficacy. This summary may guide future research directions and optimize clinical decision-making in this emerging field.

18 F-FDG PET/CT in Extensive Follicular Dendritic Cell Sarcoma With Response Assessment to Chemotherapy.

ABSTRACT: Follicular dendritic cell sarcoma (FDCS) is a low-grade sarcoma of mesenchymal dendritic cell origin, and it constitutes <0.4% of soft tissue sarcomas. We report a rare case of FDCS in a 32-year-old man. 18 F-FDG PET/CT demonstrated the involvement of cervical, axillary, mediastinal, abdominal, and pelvic groups of lymph nodes and spleen. A cervical lymph node biopsy suggested FDCS. 18 F-FDG PET/CT scan done after 3 cycles of chemotherapy (CHOP regime) revealed a complete metabolic response. This case presents the rarity of extensive presentation and complete response to the CHOP regime.

Extensive Extramedullary Involvement at Presentation in B-Cell Acute Lymphoblastic Leukemia.

ABSTRACT: Extensive extramedullary involvement as presentation is uncommon in pediatric B-cell acute lymphoblastic leukemia. A 7-year-old boy was diagnosed with painless parotid gland enlargement. He had pancytopenia and significantly raised serum lactate dehydrogenase. Fine-needle aspiration cytology from the parotid was suggestive of lymphoid malignancy. Flow cytometry and bone marrow biopsy suggested B-cell acute lymphoblastic leukemia. 18 F-FDG PET/CT revealed extensive bone marrow disease and the involvement of the spleen, pancreas, kidneys, and the parotid, submandibular, and lacrimal glands. He had negligible physiological brain uptake.

Ureteral Stone Mimicking Metastasis - Planar Bone Scan When Single-photon Emission Computed Tomography/Computed Tomography Is a Necessity.

In this case, we demonstrated a ureteric stone that resembled bone metastasis. Because bone-seeking radiopharmaceuticals are excreted into the urine by the kidneys, normal kidneys and bladder are well visualized on skeletal scintigraphs leading to incidental detection of urinary tract abnormalities. Bone tracer uptake related to ureteral stones has been reported [Figure 1] several times before. We present a right ureteral stone mimicking abnormal focal sacral uptake on planar scan in a patient with rectal cancer. This case emphasizes the importance of using single-photon emission computed tomography/computed tomography to determine the cause of abnormal uptake on a planar scan.

Robotic computed tomography-guided celiac plexus neurolysis: our experience of technique and outcomes.

Aim: We report the use of robot assistance for computed tomography-guided celiac plexus neurolysis for the first time. Materials & methods: Four patients of upper abdominal cancer with intractable pain despite opioids were positioned prone on the PET-computed tomography scanner, which measured the accurate coordinates for the entry, depth and angle of the target point. The robot positioned its arm over the patient in accordance with the set needle path. The physician manually inserted needle through it and injected 20 ml of 0.75% alcohol after dye confirmation. Results: Significant reduction in pain scores and oral morphine consumption were observed in patients during 3 months follow-up. Conclusion: The robot precisely orients and helps in accurate placement of the needle through the robotic arm.

Relapsed Carcinoma Cervix Presented with Multiple Rare Visceral Metastases: Role of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Carcinoma cervix spread to locoregional lymph nodes. Distance metastases are uncommon and occur through hematogenous routes in advanced stages. The common sites include bone and lungs. Another organ involvement is uncommon. Computed tomography (CT) and magnetic resonance imaging have a crucial role in diagnosing local and distant metastasis. 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) is a sensitive molecular imaging modality for various cancers, including gynecological ones. We present a case of recurrent cervical carcinoma presented with cervical mass and several rare visceral metastases. 18F-FDG PET/CT is a whole-body modality that accurately localized all lesions in a single study.

Utility of F-18 Fluorodeoxyglucose Positron Emission Tomography - Computed Tomography in Primary Thyroid Lymphoma.

Primary thyroid lymphoma (PTL) is an uncommon malignancy. The majority of PTLs are non-Hodgkin's lymphoma. Fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) is the state-of-the-art imaging in lymphoma and plays a pivotal role in staging, follow-up, and treatment decisions. There is good evidence that it performs well in a wide variety of nodal and extranodal lymphomas (ENL). However, the data are scarce on its usefulness in rare ENL. Herein, we describe four cases of PTLs and a brief review of the literature. FDG PET/CT was performed at baseline to assess the disease status and response to treatment. This case series highlights the varied appearance of PTL and response to treatment. It establishes the importance of FDG PET/CT in the personalized management of PTL.

Incidental Diagnosis of Multiple Paragangliomas by Ga-68 DOTANOC Positron Emission Tomography-Computed Tomography.

A 65-year-old man presented with intermittent abdominal pain for three months. Abdominal ultrasonography revealed a mass in the body of the pancreas. Moreover, abdominal contrast-enhancing computed tomography revealed a homogenously enhancing mass in the body of the pancreas. Scan findings were in favor of the neuroendocrine tumor, and the serum chromogranin level was slightly raised (111.9 ng/ml, normal <98). He had no history of vomiting, jaundice, melena, hematemesis, constipation, diarrhea, weight gain, weight loss, loss of appetite, and fever. He also had no symptoms related to the excessive production of catecholamines, such as hypertension. The patient was referred for Ga-68 DOTANOC positron emission tomography-computed tomography (Ga-68 DOTANOC PET-CT) for further evaluation. The scan was done to rule out metastatic disease or other synchronous lesions to plan surgical excision. The Ga-68 DOTANOC PET-CT revealed a pancreatic lesion with no other abdominal lesions. We noted multiple tracer avid soft tissue lesions on both sides of the neck that were not diagnosed previously. This case report demonstrates a rare case with multiple paragangliomas diagnosed by the Ga-68 DOTANOC PET-CT. This finding could lead to changes in patient management.

Calvarial Lesions: A Tertiary Centre's Experience Over Fifteen Years.

BACKGROUND: The human calvaria harbors a variety of pathology and majority of them are incidentally noticed as painless swelling. The aim of the present study is to describe the histopathological subtypes of calvarial lesions, their management and factors affecting their surgical outcome at a tertiary care referral center. MATERIAL AND METHODS: All patients who underwent excision of the calvarial lesions over the last 15 years (from January 2005 to July 2019) were included in this study. Patients having calvarial pathology of infective origin and recurrent lesions were excluded. Any patient with multiple calvarial lesions who have been operated more than one time for same histopathological diagnosis was counted as one patient. We studied Karnofsky Performance Status (KPS) scores and radiological changes at 3-month follow up. RESULTS: Total 65 patients were recruited in this retrospective observational study. The median age of patients in the study was 29 years (range: 8 years to 68 years). Fibrous dysplasia 20 (30.7%) was the commonest lesion while metastatic thyroid carcinoma 3 (4.6%) was the most common malignant pathology. Complete excision was performed in 51 (78.5%) of patients while in 14 (21.5%) cases, subtotal or near total decompression were achieved. After three months of surgery, there was significant improvement in the KPS score (P < 0.00001). Duration of follow up ranges from 6 months to 5 years with 4 mortality in the study. CONCLUSIONS: Most of the calvarial tumors were benign and surgically addressable. The malignant lesions were scattered with diverse underlying pathology and required individualized holistic approach.

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.

Renal Cell Carcinoma with Unusual Visceral and Cutaneous Metastasis.

Renal cell carcinoma is a common urogenital malignancy. It often metastasizes to the lungs, liver, bone, adrenal glands, and brain in the advanced stage. However, the involvement of the skin and subcutaneous region of the head and neck is rare. We report a case of a middle-aged man presented with extensive metastases to post radical nephrectomy. The nose and lower lip metastasis with submental lymph nodal mass is not previously reported. He also had metachronous prostatic adenocarcinoma. The case highlights the excellent capability of molecular imaging using fluorodeoxyglucose-positron-emission tomography/computed tomography to pick up all metastatic lesions and find metachronous prostate malignancy.

Malakoplakia Presenting as a Mass in the Transplanted Kidney: A Malignancy Mimicker on PET/CT.

Malakoplakia is a rare inflammatory condition that can affect many organ systems, including the genitourinary tract. It is associated with impaired immune function. Isolated renal parenchymal involvement has been reported in very few cases. Urinary tract and digestive malakoplakia have been reported in transplant recipients, but the involvement of transplant itself is rare. Variable clinical manifestations and nonspecific radiological appearance make the diagnosis difficult. The differential diagnosis includes infective etiologies and malignancy. We report a case of renal allograft malakoplakia, mimicking as a malignancy on F-FDG PET/CT.

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.

Gastric Emptying Scintigraphy: Beyond Numbers - An Observational Study to Differentiate between Various Etiologies and a Step toward Personalized Management.

AIM: Gastric emptying (GE) scintigraphy is commonly used as a standard diagnostic procedure for the assessment of functional dyspepsia (FD). Results of the study are often reported as either normal or delayed GE times. The aim of this study was to recognize various patterns of scintigraphy among both normal and abnormal emptying times. MATERIALS AND METHODS: Fifty patients with suspected FD were included in the study. GE study was performed with a standardized vegetarian solid meal. RESULTS: Out of 50 patients, 33 patients had deranged GE. Thirty patients had delayed GE. Three patients demonstrated gastric hurrying. Five different patterns were demonstrated in patients having similar emptying and retention times such as reduced fundus compliance, decreased fundic accommodation, antral dysmotility, gastric hurrying, and gastroesophageal reflux. CONCLUSION: According to our findings, it may be suggested that visual assessment of GE and identification of various pattern is a very important aspect of the GE study. It not only subcategorized patients but also decreases the number of "normal" studies. This finding may have an impact on patient management in the era of personalized medicine.