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

Abstract

The International Society of Paediatric Oncology Renal Tumour Study Group (SIOP-RTSG) advocate treating children with Wilms tumour (WT) with preoperative chemotherapy, whereas the Renal Tumor Committee of the Children's Oncology Group (COG) advocates primary nephrectomy (without biopsy) when feasible. Successive SIOP-RTSG trial protocols recommended pretreatment biopsy of children with unilateral tumours only where there were features to suggest an increased probability of a non-WT requiring a change in management. The UK experience in the SIOP WT 2001 trial showed that an alternate approach of performing biopsies on all

Prognostic impact of pre‐referral tumor resection in unilateral Wilms tumor: A single‐institute experience from a lower middle‐income country

“…During the study period, a needle biopsy was recommended to rule out other pathologies. However, the UMBRELLA guidelines recommend considering clinical, radiological, and biochemical parameters to decide if the tumor should be biopsied or not 29 …”

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

“…Preoperative identification of the tumor type within the SIOP‐RTSG is therefore primarily based on imaging, or a percutaneous biopsy in infrequent cases. Nevertheless, invasive procedures to determine histology before start of therapy are not advocated, except when a non‐WT is suspected based on specific clinical, biochemical, or radiological features 7,9,25,31,32 . 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 .…”

“…While age currently seems the most important discriminating factor to favor RCC over other renal tumors, hypointensity on T2‐weighted imaging is often reported as a distinguishing characteristic 44–46 . Finally, tumor size might play a differentiating role, with WTs and CCSKs presenting with large volumes compared to the smaller size of RCCs and RTKs, especially 9,31,47,48 …”

“…Nevertheless, invasive procedures to determine histology before start of therapy are not advocated, except when a non-WT is suspected based on specific clinical, biochemical, or radiological features. 7,9,25,31,32 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.…”

Size Matters, at Least Sometimes…

“…The SIOP Renal Tumor Study Group recently published guidelines on selecting patients who would likely benefit from core needle biopsies. 2 To minimize the administration of inappropriate neoadjuvant chemotherapy, they provide a thoughtful approach for patients without a predisposition syndrome. Their recommendations are sound and interestingly include the use of tumor volume (which correlates with single axis maximum dimension of the neoplasm) as a factor to be considered in the 7- to 10-year-old group.…”