Childhood Rhabdomyosarcoma Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Stage Information
Before a biopsy of a suspected tumor mass is performed, imaging studies of the mass and baseline laboratory studies should be obtained. After the diagnosis of rhabdomyosarcoma has been made, an extensive evaluation to determine the extent of the disease should be performed before instituting therapy. This evaluation should include a chest x-ray, computed tomography (CT) scan of the chest, bilateral bone marrow aspirates and biopsies, bone scan, magnetic resonance imaging (MRI) of the base of the skull and brain (for parameningeal primary tumors only), and CT scan of the abdomen and pelvis (for lower extremity or genitourinary primary tumors).
A CT or MRI scan of regional lymph nodes should be considered. Abnormal-appearing lymph nodes should be biopsied when possible. One study has demonstrated that sentinel lymph node biopsies can be safely performed in children with rhabdomyosarcoma, and tumor-positive biopsies may alter the treatment plan. Positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (FDG) scans can identify areas of possible metastatic disease not seen by other imaging modalities.[2,3,4] However, the efficacy of these two procedures for identifying involved lymph nodes or other sites is currently under investigation, and these procedures are not required by current treatment protocols.
A retrospective study of 1,687 children with rhabdomyosarcoma enrolled in Intergroup studies from 1991 to 2004 suggests that about one-third of patients (those with localized noninvasive embryonal tumors) can have limited staging procedures that eliminate bone marrow and bone scan examinations at diagnosis.
Terms used in this summary section are defined below in Table 1.
Table 1. Definition of Terms
|Favorable site||Orbit; nonparameningeal head and neck; genitourinary tract other than kidney, bladder, and prostate; biliary tract.|
|Unfavorable site||Any site other than favorable.|
|T1||Tumor confined to anatomic site of origin (noninvasive).|
|T2||Tumor extension and/or fixation to surrounding tissue (invasive).|
|a||Tumor ≤5 cm in maximum diameter.|
|b||Tumor >5 cm in maximum diameter.|
|N0||No clinical regional lymph node involvement.|
|N1||Clinical regional lymph node involvement.|
|NX||Regional lymph nodes not examined; no information.|
|M0||No metastatic disease.|