No abstract

¹²³I-metaiodobenzylguanidine (¹²³I-MIBG) scintigraphy is widely used for the detection and staging of neuroblastoma. Risk-adapted treatment in patients with neuroblastic tumors is based on many clinical and genetic factors including histopathology. Purpose: non-invasive prediction of an unfavorable histological variant in patients with neuroblastic tumors using quantitative assessment of ¹²³I-MIBG uptake. This study was approved by the Independent Ethical Committee and the Academic Council of Dmitriy Rogachev National Medical Research Center of Pediatric Hematology, Oncology, Immunology Ministry of Healthcare of Russian Federation. 96 patients were included in this retrospective study. ¹²³I-MIBG-scintigraphy including whole body planner images and SPECT/CT were performed for all patients before any type of treatment. Semiquantitative and quantitative assessment of ¹²³I-MIBG uptake were calculated and analyzed. Out of 96 patients: 54 with neuroblastoma (NB), 28 with ganglioneuroblastoma (GNB) and 14 with ganglioneuroma (GN). The average values of TLCRR and SUVmax for NB were 5.67 and 7.5, for GNB – 2.58 and 3.1 and for GN – 1.48 and 1.85, respectively. A centile analysis was carried out for all groups. SPECT/CT in combination with modern software allows semiquantitative and quantitative assessment of ¹²³I-MIBG uptake in neuroblastic tumor. The TLCRR and SUVmax can be used separately as well as in combination with NSE for prediction of histological variant.

The risk of posthepatectomy liver failure (PHLF) remains an important concern following major liver resection. Assessment of future remnant liver function (FRLF) by hepatobiliary scintigraphy has shown its significance to prevent PHLF after major liver resection in adults with a threshold value of FRLF greater than 2.7%/min per m 2 . However, such data for pediatric patients were not published. Methods: A total of 77 pediatric patients with liver tumors who underwent 1-stage liver resection were included in this study. Assessment of FRLF, future remnant liver volume (FRLV), and the ratio of remnant liver volume to body weight (RLV-BWR) was performed before the surgery. Results: All patients had RLV-BWR values of more than 0.5%/kg. Future remnant liver volume values ranged from 19% to 89%, and FRLF values ranged from 1.8% to 31.8%/min per m 2 . Only 7 of 77 patients had FRLV values less than 25%, but their FRLF values exceeded 2.7%/min per m 2 . Two patients developed grade A and grade B PHLF. Conclusion: Future remnant liver volume and the RLV-BWR can be used in most pediatric patients for the assessment of liver before hepatectomy. According to our data, implementation of FRLF assessment using hepatobiliary scintigraphy can be most beneficial for children with FRLV of less than 25%. The cutoff value of FRLV greater than 25% can be slightly decreased with minimal risk of developing PHLF. However, to establish a new cutoff value for FRLV in children, further prospective studies including larger numbers of patients with FRLV of less than 25% are needed.

Primary neuroblastoma is the most common extracranial solid tumor in children and may occur anywhere along the sympathetic chain, but most commonly occur in abdominal/retroperitoneal region including the adrenal glands, followed by the thorax. In children, the most primary neuroblastomas in the thorax are in the posterior mediastinum. We present herein an extremely rare case of primary neuroblastoma of thymus in pediatric patient.

The value of single-photon emission computed tomography combined with computed tomography imaging in ¹²³I-Metaiodobenzylguanidine scintigraphy in children with neuroblastomaWhole body scintigraphy with ¹²³I-Metaiodobenzylguanidine (¹²³I-MIBG) is an important imaging modality for evaluation of patients with neuroblastoma (NB). As the intrinsic nuclear scintigraphic characteristics, the assessment of conventional planar ¹²³I-MIBG images presents some difficulties. The limited resolution of planar images can induce false-negative results for small lesions, whereas the presence of physiologic MIBG uptake is not always easily differentiable from pathologic uptake and can induce false-positive results. Single-photon emission computed tomography combined with computed tomography (SPECT/ CT) hybrid imaging technique, allowing the direct fusion of morphologic and functional information, has been suggested to be more accurate. However, SPECT/CT imaging renders slightly more radiation to patients from CT portion of the study and is time consuming. The aim of our study was to investigate how much SPECT/CT can have additional diagnostic value over planar imaging in NB patients at initial staging. The study was approved by the Independent Ethics Committee and the Scientific Council of the D. Rogachev NMRCPHOI. A total of 251 SPECT/CT scans following by planar ¹²³I-MIBG imaging scans performed in 251 patients with NB were retrospectively analyzed. In 72.1% of the studies, the whole-body planar images and SPECT/CT images showed the same result. In 27.9% of studies, however, SPECT/CT images provided additional very important information. In our study, the diagnosis reached by planar imaging was revised or specified by SPECT/CT in 70 of the 251 patients and was clinically significant.