SUV max as Predictor of Metastatic Disease on 18 F-FDG PET-CT in Hepatocellular Carcinoma.

OBJECTIVE: To ascertain the utility of maximum standardised uptake value (SUVmax) in 18F-FDG PET-CT in predicting metastatic disease burden in hepatocellular carcinoma (HCC) patients. STUDY DESIGN: Descriptive study. Place and Duration of the Study: Department of Nuclear Medicine and PET-CT Imaging, Institute of Nuclear Medicine and Oncology (INMOL), Lahore, Pakistan, from April to October 2022. METHODOLOGY: 18F-FDG PET-CT data of 87 patients were analysed prospectively. Patients were considered regardless of resection status. The SUVmax measurements were performed, and their association with metastases was determined. Molecular docking studies were conducted to determine a mechanism behind the higher SUVmax at the metastatic sites. RESULTS: A higher number of patients (49) was found to have metastasis (1 to 5 in numbers) and demonstrated higher SUVmax, especially in cases of pre-surgery and post-transplant state. A positive correlation existed between SUVmax of pre-surgery (r = 0.419, p = 0.001) and post-transplant patients (r = 0.779, p = 0.001). Molecular docking studies revealed a strong binding affinity (-5.18± 0.25 kcal/mol) between the hexokinase (HK-II) and 18F-FDG. CONCLUSION: SUVmax positively correlated with metastatic tumour burden. The strong binding affinity between the HK-II and 18F-FDG may be the reason. 18F-FDG PET-CT appeared beneficial in providing prognostic information for HCC in a selected group. KEY WORDS: Hepatocellular carcinoma, 18F-FDG, Positron emission tomography, Maximum standardised uptake value, SUVmax, HK-II binding, PET-CT, Metastases.

Gallbladder Emulating Hepatic Haemangioma On Gastrointestinal Bleed Scan.

Tc-99m labelled erythrocyte scan is a sensitive method for detection of gastrointestinal (GI) bleed and liver haemangioma but false positive results can occur, as in this case gallbladder is visualized which is not a common finding. Single­photon emission computed tomography/computed tomography (SPECT-CT) is helpful to avoid such false­positive results.

68Ga-PSMA PET-CT and PSMA score affecting therapeutic decision-making in high-risk prostatic carcinoma.

Purpose: This research study was conducted to evaluate the impact of (68Ga)-tagged prostatic-specific membrane antigen (68Ga-PSMA) positron emission tomography and computed tomography (PET-CT), compare its role with conventional radiology in early staging of high-risk prostate cancer, and calculate the PSMA score evaluating its usefulness in 68Ga-PSMA PET-CT reporting in our patient population. Material and methods: 68Ga-PSMA PET-CT of 65 high-risk cases of prostate cancer was performed for staging purpo-ses. Any change in disease stage was noted after 68Ga-PSMA PET-CT findings and PSMA score leading to a change in the management plan. Results: Change in disease stage post-PSMA imaging was seen in 39% cases, high PSMA score (03) was noted in > 80% of upstaged cases, while low score (0) and (1) was seen in 65% and 35% down-staged individuals, respectively. Change in therapeutic decision-making was observed in 32% (21) of patients. Conclusions: 68Ga-PSMA PET-CT scans have a significant influence on the planned clinical management of high-risk prostate cancer patients; hence, they can be utilized as a replacement for radiological imaging tools, particularly in the detection of pelvic nodal and distant metastatic disease. PSMA score can be considered as an effective tool in standardized reporting of 68Ga-PSMA imaging.

Renal tumoural calcinosis: Extensive and multifocal form.

Renal tumoural calcinosis is rare, but the incidence is rising with increasing life expectancy due to dialysis. Whole body skeletal scintigraphy with 99mTc- MDP is a sensitive method to detect sites of osseous involvement. We share an interesting image of the bone scan, in a patient with extensive renal tumoural calcinosis.

Detection of Primary Hepatocellular Carcinoma on 18F-Fluorodeoxyglucose Positron Emission Tomography-computed Tomography.

Aims and background: Hepatocellular carcinoma (HCC), ranks as the third most prevalent malignancy contributing to cancer-related death on a global scale. Hepatocellular carcinoma is known to be the fifth most frequently diagnosed malignancy of the males while among females, it is ranked as the seventh most common malignancy. The study was conducted to detect the sensitivity of primary HCC using 18F-flourodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) scan. Materials and methods: This prospective study was conducted to identify the primary HCC in a sample size of 51 patients, in whom FDG PET-CT scan was performed between May 2022 and December 2022. Results: Among the cohort of 51 patients, primary HCC was detected on FDG PET-CT in 43 individuals representing true-positive cases. Conversely, FDG PET-CT was unable to detect HCC in 8 cases, representing false-negative. Out of 51 patients, 74.5% of HCC cases exhibited multifocal pattern. The maximum standardized uptake value (SUV max) of the primary malignant site ranged from 1.9 to 16.1, with a mean of 3.7 ± 2.8. The FDG PET-CT revealed abnormal sites of the uptake outside liver in 23 individuals. The research confirmed the tumor recurrence in four previously treated patients. In the conducted investigation, FDG PET-CT showed 84.3% sensitivity for the diagnosis of HCC. Conclusion: The study demonstrates that FDG PET-CT is a viable option for the detection of HCC. The sensitivity of FDG PET-CT in our population is comparable and in agreement with international data for diagnosis of HCC thereby favoring its reproducibility among geographical and ethnic groups. However, owing to the reduced ability of FDG PET-CT scan to identify well-differentiated/low-grade HCC, the routine use of FDG PET-CT scan may not be considered in cases requiring evaluation of primary disease only. How to cite this article: Arshad K, Hanan SD, Younis MN, et al. Detection of Primary Hepatocellular Carcinoma on 18F-Fluorodeoxyglucose Positron Emission Tomography-computed Tomography. Euroasian J Hepato-Gastroenterol 2023;13(2):66-72.

Tc-99m PSMA and Lu-177 PSMA Theranostic Pair in a Patient of Metastatic Castration Resistant Prostate Cancer.

Prostate specific membrane antigen (PSMA) targeted PET-CT imaging labeled with Gallium-68 (68Ga) is a standard diagnostic investigation in patients of carcinoma of prostate, for detection of primary tumour, initial staging of high risk disease for metastases as well as detection of recurrence. 99mTechnetium labeled PSMA SPECT-CT is a more cost-effective and logistically simple alternative for it. We present pre-therapy images of 99mTc-PSMA and post-therapy scan with 177Lu- PSMA in the same patient.

Comparing High and Low-Dose Radio-Iodine Therapy in Thyroid Remnant Ablation Among Intermediate and Low-Risk Papillary Thyroid Carcinoma Patients-Single Centre Experience.

The role of Iodine-131 therapy is well established as an adjuvant therapy and for thyroid remnant ablation in differentiated thyroid cancer (DTC); however controversy still exists regarding its appropriate dose. Purpose of this study was to compare the effectiveness of low-dose and high-dose Iodine-131 ablation therapies in low- and intermediate-risk PTC patients. Eighty-four patients were divided equally into Group I: Ablated with high dose of Iodine-131 and Group II: Ablated with low dose of Iodine-131. Iodine-131 WBS, serum TG levels and USG neck of all patients were performed at first presentation, 6 months, 1 year, and 2 years follow up. Results are as follows: Group I: 64%, 72%, and 76% intermediate-risk patients were disease free at the follow up intervals of 6 months, 1 year, and 2 years, respectively. Similarly 70%, 82%, and 82% low-risk patients were disease free at above mentioned intervals. Group II: 56%, 60%, and 64% were disease free among intermediate-risk patients while percentage of disease free low-risk patients was 70%, 76%, and 76% at follow up intervals. Low dose of radioactive Iodine-131 was found as effective as high dose in thyroid remnant ablation of PTC patients.

Detection of Recurrence in Retromolar Trigone using "Puffed Cheek" F-18 FDG PET-CT Scan.

Fluorine-18 Fluorodeoxyglucose positron emission tomography computed tomography (18FDG PET-CT) is routinely used for post treatment monitoring of oral cavity cancers. In addition to physiological uptake of 18FDG, apposition of anatomical structures poses a big challenge in accurate localization of pathology in oral cavity that is further complicated by surgery and/or radiotherapy related distortion. Case of recurrent Squamous Cell Carcinoma (SCC) of tongue is being presentedin a patient who underwent 18FDG PET-CT for post treatment monitoring. Simple 'Puffed Cheek' maneuver helped in accurately localizing tumour recurrence site within the retro-molar trigone.