Molecular Imaging in Pediatric Brain Tumors

Abstract

In the last decade, several radiopharmaceuticals have been developed and investigated for imaging in vivo of pediatric brain tumors with the aim of exploring peculiar metabolic processes as glucose consumption, amino-acid metabolism, and protein synthesis with nuclear medicine techniques. Although the clinical shreds of evidence are limited, preliminary results are encouraging. In this review, we performed web-based and desktop research summarizing the most relevant findings of the literature published to date on this topic. Particular attention was given to the wide spectrum of nuclear medicine advances and trends in pediatric neurooncology and neurosurgery. Furthermore, the role of somatostatin receptor imaging through single-photon emission computed tomography (SPECT) and positron emission tomography (PET) probes, with reference to their potential therapeutic implications, was examined in the peculiar context. Preliminary results show that functional imaging in pediatric brain tumors might lead to significant improvements in terms of diagnostic accuracy and it could be of help in the management of the disease.

Medical Imaging in the Diagnosis of Schistosomiasis: A Review

“…The main disadvantages of PET/CT are represented by the high cost of the procedure and the exposure to high radiation doses [ 84 ]. Moreover, it is important to underline that 18 F-FDG PET/CT may present several limitations in the detection of cerebral schistosomiasis lesions due to the high physiological uptake of the radiopharmaceutical in the brain, thus hampering the visualization of possible focal hypermetabolic areas [ 85 ].…”

Peptide Receptor Radionuclide Therapy and Primary Brain Tumors: An Overview

“…It is well known that SSTRs, especially subtype 2 (SSTR2), are overexpressed in different cancer types, especially in tumors of neuroendocrine origin (NET) [51,52]. In these cases, SSTRs are targeted with high affinity using somatostatin analogs, also allowing a theragnostic approach centered on radiolabeled somatostatin analogs using radioisotopes such as 177 Lu, 111 In, 68 Ga and 90 Y [53,54].…”

“…This approach utilizes an octreotide derivative as a targeting portion that is linked to a radioisotope using chelators such as tetraazacyclododecane-tetraacetic acid (DOTA) and diethylenetriamine pentaacetic acid (DTPA). In clinical practice, the two most used radiopeptides for therapeutic purposes are 90 Y-DOTATOC ([[DOTA]^0-D-PHE1, [Tyr]^3] octreotide) and 177 Lu-DOTATATE ([[DOTA]^0-[Tyr]^3] octreotate) [ 53 , 55 , 56 ]. On the other hand, gamma-emitting isotopes such as 68 Ga or 111 In may be used in somatostatin receptor imaging (SRI) in PET and SPECT, respectively, thus predicting the behavior of therapeutic radiopharmaceuticals and allowing biodistribution assessments as well.…”

The Role of PET in Supratentorial and Infratentorial Pediatric Brain Tumors

“…Accordingly, the use of amino acidic PET radiotracers, characterized by high tumor/nontumor contrast, is increasing in neuro-oncology; however, the available literature involving pediatric patients is still limited, so far. In this scenario, 18F-fluorodeoxyglucose (18F-FDG) plays a fundamental role in pediatrics patients, due to its widespread in the clinical setting despite the limitations of high uptake in normal grey matter and inflammatory lesions (Tables 1 and 2) [9,15,16]. LGR: lesion to gray matter ratio; NR: not reported; N/A: not applicable.…”

“…These information may be useful for noninvasive grading, differential diagnosis, delineation of tumor extent, surgical and radiotherapy treatment planning, and prognostic stratification [ 14 ]. Molecular imaging may also provide an early indication of response to therapy, with unique information on timely biological changes that occur before anatomical changes [ 15 ]. Another setting for which molecular imaging may be beneficial is post-treatment surveillance such as pseudoprogression is particularly challenging for MRI [ 9 ].…”