In Neuroblastic Tumors

Image-Defined Risk Factors (IDRFs)

International Neuroblastoma Risk Group Staging System

A risk-group staging system now coming into use is known as the International Neuroblastoma Risk Group Staging System (INRGSS). It is similar to the INSS, but it does not use the results of surgery to help define the stage. This lets determine a stage before surgery, based on the results of imaging tests (usually a CT or MRI scan, and an MIBG scan), as well as exams and biopsies. The stage can then be used to help predict how resectable the tumor is – that is, how much of it can be removed with surgery.

The INRGSS uses image-defined risk factors (IDRFs), which are factors seen on imaging tests that might mean the tumor will be harder to remove (Table 9.4). This includes things like the tumor growing into a nearby vital organ or growing around important blood vessels.

The INGRSS divides neuroblastomas into 4 stages:

L1: Localized tumor not involving vital structures as defined by the list of image-defined risk factorsa and confined to one body compartment.

L2: Locoregional tumor with presence of one or more IDRFs.

M: Distant metastatic disease (except MS).

MS: Metastatic disease in children younger than 18 months with metastases confined to skin, liver, and/or bone marrow.

Table 9.4

Ipsilateral tumor extension within two body compartments · Neck-chest, chest-abdomen, abdomen-pelvis

Neck · Tumor encasing carotid and/or vertebral artery and/or internal jugular vein · Tumor extending to base of skull · Tumor compressing the trachea

Cervico-thoracic junction · Tumor encasing brachial plexus roots · Tumor encasing subclavian vessels and/or vertebral and/or carotid artery · Tumor compressing the trachea

Thorax · Tumor encasing the aorta and/or major branches · Tumor compressing the trachea and/or principal bronchi · Lower mediastinal tumor, infiltrating the costo-vertebral junction between T9 and T12

Thoraco-abdominal · Tumor encasing the aorta and/or vena cava

Abdomen/pelvis · Tumor infiltrating the porta hepatis and/or the hepatoduodenal ligament · Tumor encasing branches of the superior mesenteric artery at the mesenteric root · Tumor encasing the origin of the coeliac axis, and/or of the superior mesenteric artery · Tumor invading one or both renal pedicles · Tumor encasing the aorta and/or vena cava · Tumor encasing the iliac vessels · Pelvic tumor crossing the sciatic notch

Intraspinal tumor extension whatever the location provided that: · More than one third of the spinal canal in the axial plane is invaded and/or the perimedullary leptomeningeal spaces are not visible and/or the spinal cord signal is abnormal

Infiltration of adjacent organs/structures · Pericardium, diaphragm, kidney, liver, duodeno-pancreatic block, and mesentery

Conditions to be recorded, but not considered IDRFs · Multifocal primary tumors · Pleural effusion, with or without malignant cells · Ascites, with or without malignant cells

Дата добавления: 2014-10-15