Use of sentinel node biopsy for staging parameningeal rhabdomyosarcoma

Therapy and prognostic significance of regional lymph node involvement in embryonal rhabdomyosarcoma: a report from the European paediatric Soft tissue sarcoma Study Group

PURPOSE

Regional lymph node disease (N1) is a component of the risk-based treatment stratification in rhabdomyosarcoma (RMS). The purpose of this study was to determine the contribution of nodal disease to the prognosis of patients with non-metastatic embryonal RMS (ERMS) and analyse their outcome by treatment received.

PATIENTS AND METHODS

Between 2005 and 2016, 1294 children with ERMS were enrolled in the European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS 2005 protocol, 143 patients with N1. Treatment comprised 9 cycles of ifosfamide, vincristine and dactinomycin. Some patients also received doxorubicin and/or maintenance if enrolled in the randomised studies. Local treatment was planned after 4 cycles of chemotherapy and included surgery to remove macroscopic residual tumour and/or radiotherapy (primary tumour and involved nodes).

RESULTS

N1 patients were older and presented with tumours of unfavourable size, invasiveness, site and resectability. Unlike alveolar RMS, nodal involvement was more frequent in the head and neck area and rare in extremity sites. The 5-year event-free and overall survival were 75.5% and 86.3% for patients with N0, and 65.2% and 70.7% for patients with N1, respectively. The nodal involvement and the result of surgery at diagnosis (Intergroup Rhabdomyosarcoma Study group) were independent prognostic factors on multivariate analysis. Considering only patients with N1 ERMS, we were not able to identify any treatment variables which correlated with the outcome.

CONCLUSION

In the case of nodal involvement, patients with ERMS present different characteristics and a better outcome than alveolar RMS. Regional nodal involvement is an independent prognostic factor in ERMS, therefore it is appropriate to include this population in the high-risk category.

Sentinel lymph node biopsy in head and neck rhabdomyosarcoma

Head and neck rhabdomyosarcoma lymph node staging is challenging due to varied patterns of lymphatic drainage and the suboptimal predictive value of available imaging modalities. Furthermore, regional relapse rates are unacceptably high, and the toxicity of empiric radiation is undesirable in the pediatric and young adult population. In an attempt to improve locoregional control without excess morbidity, we have adopted routine sentinel lymph node biopsy in head and neck rhabdomyosarcoma, which is safe and feasible in pediatric patients. Of six procedures reported here, pathologic findings led to intensification of regional and/or systemic therapy in two patients.

Detection of lymph node metastases in pediatric and adolescent/young adult sarcoma: Sentinel lymph node biopsy versus fludeoxyglucose positron emission tomography imaging-A prospective trial

BACKGROUND

Lymph node metastases are an important cause of treatment failure for pediatric and adolescent/young adult (AYA) sarcoma patients. Nodal sampling is recommended for certain sarcoma subtypes that have a predilection for lymphatic spread. Sentinel lymph node biopsy (SLNB) may improve the diagnostic yield of nodal sampling, particularly when single-photon emission computed tomography/computed tomography (SPECT-CT) is used to facilitate anatomic localization. Functional imaging with positron emission tomography/computed tomography (PET-CT) is increasingly used for sarcoma staging and is a less invasive alternative to SLNB. To assess the utility of these 2 staging methods, this study prospectively compared SLNB plus SPECT-CT with PET-CT for the identification of nodal metastases in pediatric and AYA patients.

METHODS

Twenty-eight pediatric and AYA sarcoma patients underwent SLNB with SPECT-CT. The histological findings of the excised lymph nodes were then correlated with preoperative PET-CT imaging.

RESULTS

A median of 2.4 sentinel nodes were sampled per patient. No wound infections or chronic lymphedema occurred. SLNB identified tumors in 7 of the 28 patients (25%), including 3 patients who had normal PET-CT imaging of the nodal basin. In contrast, PET-CT demonstrated hypermetabolic regional nodes in 14 patients, and this resulted in a positive predictive value of only 29%. The sensitivity and specificity of PET-CT for detecting histologically confirmed nodal metastases were only 57% and 52%, respectively.

CONCLUSIONS

SLNB can safely guide the rational selection of nodes for biopsy in pediatric and AYA sarcoma patients and can identify therapy-changing nodal disease not appreciated with PET-CT. Cancer 2017;155-160. © 2016 American Cancer Society.