Imaging urothelial bladder cancer: A VPAC PET targeted approach.

INTRODUCTION Accurate staging of urothelial bladder cancer (UBC) with imaging, which guides effective bladder cancer treatment, remains challenging. This investigation is to validate a hypothesis that targeting Vasoactive intestinal and pituitary adenylate cyclase activating peptide (VPAC) receptors using 64Cu-TP3805 can PET image UBC efficiently. MATERIALS AND METHODS: Nineteen patients (44-84 years of age) scheduled for radical cystectomy, underwent VPAC positron emission tomography (PET) imaging prior to surgery. Sixteen had completed neoadjuvant chemotherapy prior to imaging. All 19 received 64Cu-TP3805 (148 % ± 10% MBq) intravenously, and were imaged 60 to 90 minutes later. Standard uptake value (SUV)max for malignant lesions and SUVmean for normal tissues were determined and mean +/-SEM recorded. Following radical cystoprostatectomy, pelvic lymphadenectomy and urinary diversion imaging, results were compared with final surgical pathology. RESULTS: 64Cu-TP3805 had no adverse events, negligible urinary excretion and rapid blood clearance. UBC PET images for residual disease were true positive in 11 patients and true negative in four. Of remaining 4, one had false positive and 3 had false negative scans, equating to 79% sensitivity (95%, CI 49%-95%), 80% specificity (95%, CI 28%-100%), 92% positive predictive value (95%, CI 62%-100%) and 57% negative predictive value (95%, CI 18%-90%). CONCLUSIONS: These first in man results, in a group, heavily pretreated with neoadjuvant chemotherapy, indicate that VPAC PET imaging can identify UBC effeiciently and suggest, that VPAC PET can diagnose UBC in a treatment naïve cohort for accurate staging, guide biopsy and treatment in patients with suspected metastasis and determine response to therapy. Further investigation of this molecular imaging approach is warranted.

The role of [18F]FDG PET/CT for gastric cancer management.

Gastric cancer (GC) is a common cause of cancer-related deaths in the world. In addition to the patient's clinical history and clinical examination, nuclear medicine tools are required for diagnosis. [¹8F]FDG PET/CT has been commonly used for cancer patients for staging, restaging, evaluation of treatment response. This study aimed to review the current literature on the role of [¹8F]FDG PET/CT for GC management.

The levels of oxidative and nitrosative stress in patients who had 99mTc-MIBI myocardial perfusion scintigraphy and 99mTc-DMSA, 99mTc-MAG-3 renal scintigraphy.

BACKGROUND: Ionizing radiation is a strong stimulator of reactive oxygen specises (ROS) and reactive nitrogen species (RNS). These reactive species may cause oxidative and nitrosative stress. In this study, we aimed to evaluate possible effects of 99mTechnetium (99mTc)-methoxyisobuthylisonitrite (MIBI), 99mTc-dimercaptosuccinic acid (DMSA), 99mTc-mercaptoacetyltriglycine (MAG-3) on oxidative and nitrosative stress biomarkers in patients who were performed myocardial perfusion scintigraphy (MPS) and renal scintigraphy. MATERIAL AND METHODS: Patients (n = 29) who were referred to nuclear medicine department were chosen as the patient group. They were divided into three subgroups according to the type of disease and 99mTc labelled agent. The first patient group had MPS (n = 9). The second patient group had 99mTc-DMSA renal scintigraphy (n = 12). The third patient group had 99mTc-MAG-3 renal scintigraphy (n = 8). The blood samples were taken from first, second and third patient groups 1 h, 3 h, 45 min after injection of the agent, respectively. The samples were taken from healthy volunteers (n = 25) as a control group. Alterations in catalase (CAT),superoxide dismutase (SOD), malondialdehyde (MDA) levels as oxidative stress biomarkers and nitric oxide (NO) and 3-Nitrotyrosine (3-NTx) levels as nitrosative stress biomarkers in all blood samples were evaluated. RESULTS: Results of MPS and renal scintigraphy performed patients were compared with control group separately. CAT, SOD, MDA and 3-NTx levels were higher in the first group than the control group (p < 0.05). Although NO levels were higher in the first group than the control group, it was not statistically significant (p > 0.05). CAT and SOD levels were lower in second and third groups than the control group (p < 0.0 5). However, MDA, NO, 3-NTx levels were higher in second and third groups than the control group (p < 0.05). CONCLUSIONS: These results show that oxidative and nitrosative balance is impaired due to ionization radiation. These reactive species might stimulate an adaptive and protective cellular defense mechanism in irradiated cells soon after exposure to radiation. Thereby, this mechanism protect organism from the effects of low dose ionizing radiation.

Currently Available Radiopharmaceuticals for Imaging Infection and the Holy Grail.

Infection is ubiquitous. However, its management is challenging for both the patients and the health-care providers. Scintigraphic imaging of infection dates back nearly half a century. The advances in our understanding of the pathophysiology of disease at cellular and molecular levels have paved the way to the development of a large number of radiopharmaceuticals for scintigraphic imaging of infection. These include radiolabeling of blood elements such as serum proteins, white blood cells (WBCs), and cytokines, to name a few. Infectious foci have also been imaged using a radiolabeled sugar molecule by taking advantage of increased metabolic activity in the infectious lesions. Literature over the years has well documented that none of the radiopharmaceuticals and associated procedures that facilitate imaging infection are flawless and acceptable without a compromise. As a result, only a few compounds such as 99mTc-hexamethylpropyleneamineoxime, 18F-FDG, the oldest but still considered as a gold standard 111In-oxine, and, yes, even 67Ga-citrate in some countries, have remained in routine clinical practice. Nonetheless, the interest of scientists and physicians to improve the approaches to imaging and to the management of infection is noteworthy. These approaches have paved the way for the development of numerous, innovative radiopharmaceuticals to label autologous WBCs ex vivo or even those that could be injected directly to image infection or inflammation without direct involvement of WBCs. In this review, we briefly describe these agents with their pros and cons and place them together for future reference.

A glance at imaging bladder cancer.

PURPOSE: Early and accurate diagnosis of Bladder cancer (BCa) will contribute extensively to the management of the disease. The purpose of this review was to briefly describe the conventional imaging methods and other novel imaging modalities used for early detection of BCa and outline their pros and cons. METHODS: Literature search was performed on Pubmed, PMC, and Google scholar for the period of January 2014 to February 2018 and using such words as "bladder cancer, bladder tumor, bladder cancer detection, diagnosis and imaging". RESULTS: A total of 81 published papers were retrieved and are included in the review. For patients with hematuria and suspected of BCa, cystoscopy and CT are most commonly recommended. Ultrasonography, MRI, PET/CT using 18F-FDG or 11C-choline and recently PET/MRI using 18F-FDG also play a prominent role in detection of BCa. CONCLUSION: For initial diagnosis of BCa, cystoscopy is generally performed. However, cystoscopy can not accurately detect carcinoma insitu (CIS) and can not distinguish benign masses from malignant lesions. CT is used in two modes, CT and computed tomographic urography (CTU), both for dignosis and staging of BCa. However, they cannot differentiate T1 and T2 BCa. MRI is performed to diagnose invasive BCa and can differentiate muscle invasive bladder carcinoma (MIBC) from non-muscle invasive bladder carcinoma (NMIBC). However, CT and MRI have low sensitivity for nodal staging. For nodal staging PET/CT is preferred. PET/MRI provides better differentiation of normal and pathologic structures as compared with PET/CT. Nonetheless none of the approaches can address all issues related for the management of BCa. Novel imaging methods that target specific biomarkers, image BCa early and accurately, and stage the disease are warranted.