MRI Characteristics of Pediatric Renal Tumors: A SIOP‐RTSG Radiology Panel Delphi Study

Abstract

Background:The SIOP-Renal Tumor Study Group (RTSG) does not advocate invasive procedures to determine histology before the start of therapy. This may induce misdiagnosis-based treatment initiation, but only for a relatively small percentage of approximately 10% of non-Wilms tumors (non-WTs). MRI could be useful for reducing misdiagnosis, but there is no global consensus on differentiating characteristics. Purpose: To identify MRI characteristics that may be used for discrimination of newly diagnosed pediatric renal tumors. Study Type: Consensus process using a Delphi method. Population: Not applicable.

How we approach paediatric renal tumour core needle biopsy in the setting of preoperative chemotherapy: A Review from the SIOP Renal Tumour Study Group

“…Hence, upfront surgery is still recommended before the age of 3 months, but between 3 and 6 months, the clinical and radiological characteristics need to be discussed carefully within tumour board meetings (TBM) to make an optimal risk/benefit judgement regarding primary nephrectomy in the context of the most likely diagnosis. Classical MN usually demonstrates suggestive features, 13,14 whereas the cellular variant of MN and WT share similar radiological features.…”

“…Imaging appearances are often contributory to deciding whether biopsy is indicated. The MRI features that can differentiate between different tumours have been described by a Delphi study of the RTSG radiology panel 14 …”

Similarities and controversies in imaging of pediatric renal tumors: A SIOP‐RTSG and COG collaboration

“…Furthermore, US is important to evaluate the renal vein and inferior vena cava for vascular extension of the renal tumor 12 . Cross‐sectional abdominal imaging with computed tomography (CT) and magnetic resonance imaging (MRI) has become an essential addition in the diagnostic assessment of both COG and SIOP‐RTSG, and is key for locoregional staging of pediatric renal tumors 11,13–15 …”

“…Besides clinical presentation, mainly based on age or unusual metastatic patterns, imaging findings that are uncommon for WTs (as defined in the SIOP‐RTSG 2016 UMBRELLA protocol, which is further referred to as the UMBRELLA protocol) include numerous calcifications, voluminous lymphadenopathy, nonvisible renal parenchyma, and/or the identification of a near‐complete extra‐renal process 7,14 . Apart from these characteristics, the discrimination of pediatric renal tumors based on solely CT or MRI characteristics remains challenging 11,33 …”

Editorial for “MRI‐Characteristics of Pediatric Renal Tumors: A SIOP‐RTSG Radiology Panel Delphi Study”: Standardized Assessment of Pediatric Renal Tumors with MRI: A Laudable Objective That Requires Further Investigation

“…In this issue of JMRI , van der Beek et al used the Delphi method to establish appropriate magnetic resonance imaging (MRI) protocols and the typical ultrasound/MRI findings of WT and non‐WT pediatric renal masses based on expert radiologist opinion from the Renal Tumor Study Group of the International Society of Pediatric Oncology (SIOP‐RTSG) 5 . The MRI technique, imaging findings, and patient characteristics that can be used to differentiate among the various pediatric renal tumors were clarified.…”