Sentinel node biopsy in pediatric soft tissue sarcomas of extremities

Radical Resection of Pediatric Fibrosarcoma Is Not Associated With Survival Benefit: A Nationwide Database Analysis

INTRODUCTION

Fibrosarcoma is one of the most common nonrhabdomyosarcoma soft tissue sarcomas in the pediatric population. Surgical resection is the cornerstone of treatment; however, optimal factors regarding the extent of fibrosarcoma resection in localized versus regional disease is poorly understood.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for patients who are 19 y old or younger with a diagnosis of fibrosarcoma from 1975 to 2016. Kaplan-Meier analyses were performed for disease-specific survival on clinical and pathologic variables. Multivariate analysis was performed based on significant predictors of disease-specific survival.

RESULTS

There were 1290 patients (median age 13 [7-17] y) identified with fibrosarcoma. The overall survival rate at 20 y was 93%. Radical resection was performed on 22%, 40%, and 52% of patients with localized, regional, and distant Surveillance, Epidemiology, and End Results disease stage, respectively. Chemotherapy (P < 0.001), radiation (P < 0.001), histology (P < 0.001), and stage (P = 0.004) were significant predictors of increased mortality using univariate Kaplan-Meier analysis. Most patients (86%) with localized or regional stage who underwent radiation had fibrosarcomas of nondermatofibrosarcoma histology (P < 0.001). Dermatofibrosarcoma subtype comprised most radical resections (41%). Excluding distant stage, nondermatofibroma histology (hazard ratio 16.94, 95% confidence interval 3.77-76.01) and regional stage (hazard ratio 8.15, 95% confidence interval 2.93-22.69) were independent prognostic factors of mortality (both P < 0.001). Radical resection was not a significant independent prognostic indicator of survival.

CONCLUSIONS

Nondermatofibrosarcoma subtype is independently associated with increased mortality. Although surgery remains the mainstay of treatment, the extent of resection is not a predictor of survival for patients with the localized and regional stage of disease.

Sentinel lymph node biopsy in pediatric Wilms tumor

INTRODUCTION

Although the sentinel lymph node Biopsy (SLNB) is well stablished in solid tumors among adults but the experience on SLNB in pediatrics is still limited. In this article we report our experience of sentinel lymph node detection that is applied on pediatric solid renal tumors.

MATERIAL AND METHODS

Twenty 1-16 year old children with non-metastatic primary Wilms tumor regarding the radiological studies were enrolled. Radio tracer injection was carried out after renal vein, artery and ureter ligation, at the time of radical nephrectomy. Sentinel node detection and sampling was performed in every location with radiotracer count of 3 times more than background. Finally lymph node sampling was completed following the standard current discipline in Wilms tumor surgery.

RESULTS

A single SLN was detected in 16 patients. 4 patients had more than one SLN. The most common site of SLN was inter aortocaval space. Histopathologic studies revealed tumor involvement in 3 sentinel nodes (15%). All other lymph node samples were also studied histologically and LN involvement was not detected in any of the cases with tumor free sentinel lymph node (no false negative case). Multiple LN involvement was reported in two patients with positive SLN in which, other involved lymph nodes were removed with the tumor during radical nephrectomy.

CONCLUSION

Intraoperative SLNB is a safe and feasible tool to improve the accuracy of staging in pediatric Wilms' tumor. We suggest to ligate renal artery and vein prior to radiotracer injection to diminish the background confounding effect.

LEVEL OF EVIDENCE

Level II (development of diagnostic criteria in a consecutive series of patients and a universally applied "gold standard") TYPE OF STUDY: Study of Diagnostic Test.

A Machine Learning-Based Predictive Model for Predicting Lymph Node Metastasis in Patients With Ewing's Sarcoma

Objective

In order to provide reference for clinicians and bring convenience to clinical work, we seeked to develop and validate a risk prediction model for lymph node metastasis (LNM) of Ewing’s sarcoma (ES) based on machine learning (ML) algorithms.

Methods

Clinicopathological data of 923 ES patients from the Surveillance, Epidemiology, and End Results (SEER) database and 51 ES patients from multi-center external validation set were retrospectively collected. We applied ML algorithms to establish a risk prediction model. Model performance was checked using 10-fold cross-validation in the training set and receiver operating characteristic (ROC) curve analysis in external validation set. After determining the best model, a web-based calculator was made to promote the clinical application.

Results

LNM was confirmed or unable to evaluate in 13.86% (135 out of 974) ES patients. In multivariate logistic regression, race, T stage, M stage and lung metastases were independent predictors for LNM in ES. Six prediction models were established using random forest (RF), naive Bayes classifier (NBC), decision tree (DT), xgboost (XGB), gradient boosting machine (GBM), logistic regression (LR). In 10-fold cross-validation, the average area under curve (AUC) ranked from 0.705 to 0.764. In ROC curve analysis, AUC ranged from 0.612 to 0.727. The performance of the RF model ranked best. Accordingly, a web-based calculator was developed (https://share.streamlit.io/liuwencai2/es_lnm/main/es_lnm.py).

Conclusion

With the help of clinicopathological data, clinicians can better identify LNM in ES patients. Risk prediction models established in this study performed well, especially the RF model.

Value of the Sentinel Node Procedure in Pediatric Extremity Rhabdomyosarcoma: A Systematic Review and Retrospective Cohort Study

Background

Our aim is to show whether the sentinel node procedure (SNP) is recommendable for pediatric patients with extremity rhabdomyosarcoma (RMS). Lymph node metastases are an important prognostic factor in pediatric patients with extremity RMS. Accurate nodal staging is necessary to treat the patient accordingly. An alternative to the current recommended lymph node sampling is the sentinel node procedure (SNP).

Methods

A systematic review was performed summarizing all published cases of SNP in addition to 13 cases from our hospital and 8 cases from two other hospitals that have not been published before.

Results

For all patients (n = 55), at least one SLN was identified, but the SNP technique used was not uniform. The SNP changed the nodal classification of eight patients (17.0%) and had a false-negative rate of 10.5%.

Conclusions

The SNP is recommendable for pediatric patients with extremity RMS. It can change lymph node status and can be used to sample patients in a more targeted way than nodal sampling alone. Therefore, we recommend use of the SNP in addition to clinical and radiological nodal assessment for pediatric patients with extremity RMS.

Alternative approaches to retroperitoneal lymph node dissection for paratesticular rhabdomyosarcoma

PURPOSE

The aim of this study was to evaluate outcomes based on surgical approach for retroperitoneal lymph node dissection (RPLND) in patients with paratesticular rhabdomyosarcoma (PT-RMS).

METHODS

Patients undergoing RPLND for PT-RMS over 10 years at a single institution were retrospectively reviewed. Length of stay (LOS), complications, oral morphine equivalents per kilogram (OME/Kg), lymph node yield, and time to chemotherapy were assessed. The surgical approaches compared were: open transabdominal, open extraperitoneal, laparoscopic, and retroperitoneoscopic. For cases with lymphatic mapping, indocyanine green (ICG) was injected into the spermatic cord.

RESULTS

Twenty patients were included: five open transabdominal, six open extraperitoneal, three laparoscopic, and six retroperitoneoscopic operations. LOS was shorter in the retroperitoneoscopic group than laparoscopic (p = 0.029) and both open groups (p < 0.001). Mean OME/kg used was lowest in the retroperitoneoscopic (0.13 ± 0.15) group compared to laparoscopic (0.68 ± 0.53, p = 0.043), open transabdominal (14.90 ± 8.87, p = 0.003), and extraperitoneal (10.11 ± 2.44, p < 0.001). Time to chemotherapy was shorter for retroperitoneoscopic patients (0.13 days ± 0.15) compared to open transabdominal (15.6 days±6.5, p = 0.005). There was no difference in lymph node yield between groups. Spermatic cord ICG demonstrated iliac lymph node avidity on near-infrared spectroscopy.

CONCLUSIONS

Minimally invasive RPLND appears to offer a faster recovery without compromising lymph node yield for patients with PT-RMS.

LEVEL OF EVIDENCE

III.

The clinical and radiologic features of paediatric rhabdomyosarcoma

Rhabdomyosarcoma is the most common soft-tissue sarcoma in children. The most common sites are head and neck, genitourinary tract and extremities. In this review we outline the clinical and radiologic features of paediatric rhabdomyosarcoma, as well as imaging considerations and imaging of relapse.

Nonparameningeal head and neck rhabdomyosarcoma in children and adolescents: Lessons from the consecutive International Society of Pediatric Oncology Malignant Mesenchymal Tumor studies

BACKGROUND

This article reports risk factors and long-term outcome in localized nonparameningeal head and neck rhabdomyosarcomas in children and adolescents from a combined dataset from 3 consecutive international trials.

METHODS

Data from 140 children (9.3% of total) prospectively enrolled in the International Society of Pediatric Oncology Malignant Mesenchymal Tumor (SIOP-MMT)-84/89/95 studies were analyzed.

RESULTS

Primary site was: superficial face in 46%; oral cavity (21%); neck (19%); and salivary glands (14%). Local control was achieved in 96%, but 49% relapsed (locoregionally 91%). At median follow-up of 10 years, 5-year overall survival (OS) was 74.7% (67.4% to 81.9%) and event-free survival 48.9% (40.6% to 57.2%), although this improved with successive studies. Radiotherapy (RT) as first-line treatment was independently prognostic for event-free survival (relative risk [RR] = 0.4 [range, 0.2-0.7]; p < .01) even if it did not impact OS (RR = 1 [range, 0.5-2]).

CONCLUSION

High rates of locoregional relapse were seen in head and neck rhabdomyosarcoma that should be prevented by more frequent use of RT in this primary. © 2016 Wiley Periodicals, Inc. Head Neck 39: 24-31, 2017.

Application of nuclear medicine to achieve less invasive surgery for malignant solid tumors in children

BACKGROUND

The use of nuclear medicine for the management of malignant tumor, such as radioguided surgery and sentinel lymph node biopsy (SLNB), has been widely accepted in the adult practice. However, there are very few studies to apply those techniques for pediatric diseases. The aim of this study was to investigate the feasibility of application of nuclear medicine in surgery for neuroblastoma (NB) or rhabdomyosarcoma (RMS) in children.

METHODS

Radioguided surgery using (123) I-metaiodobenzylguanidine was performed on six children with NB. SLNB using technetium-labeled tin or sulfur colloid was performed on two children with perineal RMS. Histological evaluation of resected specimens was performed to determine the accuracy of intraoperative detection and SLNB. All patients were evaluated for overall survival and complications.

RESULTS

Intraoperative tumor localization using hand-held gamma probe was helpful in 85.7% of NB patients. Sensitivity and specificity of this technique were 81.8% and 93.3%, respectively. There were no postoperative complications, and four out of five patients with high-risk NB experienced disease-free survival (median follow up, 57 months). Sentinel lymph nodes were easily detected in patients with perineal RMS, and histological assessment revealed complete consistency with regional lymph node status.

CONCLUSIONS

Nuclear medicine may have a potential application in the use of less invasive surgery for advanced NB or perineal RMS, the two most challenging pediatric malignancies.

Diagnosis and treatment of lymph node metastases in pediatric rhabdomyosarcoma in the Netherlands: a retrospective analysis

BACKGROUND

In pediatric rhabdomyosarcoma (RMS), evaluation of lymph node involvement (N1) is an important staging aspect, but difficult to assess. The aim of our study was to evaluate the assessment of lymph node infiltration and impact on outcome in N1 RMS patients.

METHODS

We identified 277 non-metastatic RMS patients diagnosed and treated between 1990 and 2008. Patients with recorded N1 disease were evaluated for their diagnostic procedures and outcome.

RESULTS

In 13.7% N1 status was reported. In 19 of 34 N1 patients, lymph node biopsies were performed for histologically confirmation. Different treatment modalities were used to treat lymph node metastases. In total 23 of 31 patients received local treatment of the node (11/23 RT, 4/23 surgery, and 8/23 both). All patients received chemotherapy. Lymph node relapse occurred in 7 of 31 patients who were treated with one or two modalities. Only 1 (14%) of 8 patients treated with three modalities relapsed. In N0 patients 10 (4.2%) of 239 had a regional lymph node relapse, and 9 of 10 died.

CONCLUSION

Lymph node metastases are an essential part of staging. Node positivity contributes to relapse of disease. Nodal relapse is also associated with a high mortality rate. These data imply that nodal assessment needs to be optimal and standardized for improved staging.

Sentinel lymph node biopsy in pediatric soft tissue sarcoma patients: utility and concordance with imaging

BACKGROUND

The purpose of this study was to report our experience with sentinel lymph node biopsy (SLNB) for pediatric soft tissue sarcomas to add to the limited literature about its feasibility, utility, and concordance with pre-operative imaging, including CT and (18)F-FDG PET (PET) scanning.

METHODS

Medical records of patients with a sarcoma who underwent SLNB as part of their treatment for a soft tissue sarcoma at our institution from 2000 to 2011 were identified and reviewed.

RESULTS

Eight patients underwent SLNB for soft tissue sarcoma during the study period. Two patients had positive SLNBs; both of these patients had rhabdomyosarcoma. Three patients with pathologically enlarged lymph nodes on CT scan underwent PET functional imaging prior to SLNB. The PET suggested the presence of nodal disease in all three patients; however, only one of these patients had a positive SLNB.

CONCLUSIONS

Our series confirms that SLNB is feasible in pediatric sarcoma patients. Small numbers preclude definitive conclusions regarding the utility of SLNB compared with PET, however our data suggest functional imaging alone may not be sufficient to definitively determine lymph node status in these patients. Surgical lymph node sampling may still need to be performed to accurately identify nodal status in pediatric patients with soft tissue sarcoma.

What is new in rhabdomyosarcoma management in children?

Optimal management of rhabdomyosarcoma requires establishing the correct pathologic diagnosis, histologic sub-type, primary site, extent of disease (Stage), and extent of resection (Group). Based on these features, cooperative groups in North America and Europe have defined risk-adapted treatments that include surgery, chemotherapy, and usually radiotherapy. This article focuses on recent findings that can impact or have already impacted rhabdomyosarcoma treatment guidelines and highlights controversies that should be addressed in order to improve outcome for children with rhabdomyosarcoma. Rhabdomyosarcoma is currently sub-classified in children based on histology into the favorable embryonal/botryoid/spindle cell types and the unfavorable alveolar form. Risk group assignment depends in part on histologic sub-type. Alveolar rhabdomyosarcoma is sometimes associated with chromosomal translocations, which impact clinical behavior. An important ongoing debate is whether molecular diagnostic tools to identify chromosomal translocations and/or define gene expression profiles should be used to sub-classify rhabdomyosarcoma rather than histology. Clinical trials continue to evaluate retrospective as well as prospective cohorts in order to carefully determine the impact of histology versus biologic features on outcome in the context of specific therapeutic regimens. Most rhabdomyosarcoma recurrences involve the primary site or adjacent region. Cooperative groups continue to investigate new approaches to local control in order to reduce local recurrences and sequelae associated with local therapy. Delaying primary resection until after chemotherapy has started appears to increase the number of tumors that can be completely resected with acceptable morbidity in some primary sites. Radiation dose reductions following delayed primary resection have been investigated. Although outcomes appear similar to the conventional approach of full-dose radiotherapy without delayed primary resection, long-term effects of the two approaches have not been rigorously compared. Early evidence suggests that newer methods of delivering radiotherapy, including intensity-modulated radiotherapy (IMRT), proton beam radiotherapy, and brachytherapy maintain efficacy but may reduce long-term sequelae compared with 3-dimensional conformal radiotherapy. Chemotherapy regimens defined by the cooperative groups vary by risk group. The most commonly used regimens include vincristine and dactinomycin in combination with an alkylating agent, either cyclophosphamide or ifosfamide. In order to improve outcomes, recent clinical trials have introduced new chemotherapeutic agents (e.g. topotecan, carboplatin, or epirubicin) into the treatment regimens. However, outcomes have not been significantly impacted. Novel chemotherapy administration schedules have been tested in patients with metastatic rhabdomyosarcoma, including interval compressed dosing or maintenance therapy, and may be promising. Molecularly targeted agents are currently under investigation in combination with chemotherapy for patients with recurrent or metastatic rhabdomyosarcoma. It is hoped that these novel agents will benefit all patients with rhabdomyosarcoma in the future.

Role of lymphoscintigraphy and sentinel lymph node biopsy in the management of pediatric melanoma and sarcoma

PURPOSE

The purpose of this study was to describe the use of lymphoscintigraphy and sentinel lymph-node biopsy (SLNB) for the management of children with melanoma and sarcomas. We report the experience of two children's hospitals that utilize this technique to identify sentinel lymph nodes for lymph-node biopsy and dissection.

METHODS

We identified 56 patients (median age 10.8 years) who underwent 58 lymphoscintigraphy procedures. There were 33 patients with melanoma and melanocytic lesions, and 23 with sarcomas.

RESULTS

Of 58 lymphoscintigraphy procedures, sentinel lymph nodes were identified in 52 (90% success rate). Using the combination of intraoperative blue dye injection and lymphoscintigraphy, the success rate was 95% (55/58). Metastatic disease was found in 14 sentinel lymph nodes (13 patients with melanoma and melanocytic lesions, and 1 patient with rhabdomyosarcoma).

CONCLUSION

We have found that lymphoscintigraphy with SLNB is an effective method to identify patients who may benefit from more extensive lymph-node dissection and to identify those patients who are unlikely to benefit from further lymph-node exploration.

Update on rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a malignant childhood tumor of mesenchymal origin that currently has a greater than 70% overall 5-year survival. Multimodality treatment is determined by risk stratification according to pretreatment stage, postoperative group, histology, and site of the primary tumor. Pretreatment staging is dependent on primary tumor site, size, regional lymph node status, and presence of metastases. Unique to RMS is the concept of postoperative clinical grouping that assesses the completeness of disease resection and takes into account lymph node evaluation. At all tumor sites, the clinical grouping, and therefore completeness of resection, is an independent predictor of outcome. Overall, the prognosis for RMS is dependent on primary tumor site, patient age, completeness of resection, extent of disease, including the presence and number of metastatic sites and histology and biology of the tumor cells. Therefore, the surgeon plays a vital role in RMS by contributing to risk stratification for treatment, local control of the primary tumor, and outcome. The current state-of-the-art treatment is determined by treatment protocols developed by the Soft Tissue Sarcoma Committee of the children's Oncology Group.

Use of sentinel node biopsy for staging parameningeal rhabdomyosarcoma

Identification of nodal involvement is important for treatment planning in patients with rhabdomyosarcoma, and is facilitated by sentinel node biopsy. Although it is employed primarily for extremity tumors, we report using sentinel node biopsy in a patient with parameningeal rhabdomyosarcoma arising in the ethmoid sinus. Lymphoscintigraphy with single photon emission computed tomography following injection of tracer at the tumor site helped identify contralateral cervical node involvement not previously recognized by physical exam, cross sectional imaging, or other functional imaging. This case demonstrates how information from sentinel node identification and biopsy can change therapy recommendations in patients with parameningeal rhabdomyosarcoma.

Low-grade myxofibrosarcoma presenting at the site of prior high-grade disease

Myxofibrosarcoma is one of the most common soft tissue sarcomas occurring in older adults. It can arise de novo or can be radiation induced, and the term myxofibrosarcoma was originally devised to encompass a spectrum of myxoid tumors with characteristics similar to malignant fibrous histiocytoma (MFH). Confusion exists, however, regarding the distinction between microscopic grade and characteristics of myxofibrosarcoma and MFH. Correct classification is vital to prognosis, as the degree of myxoid change is inversely related to the incidence of metastasis. We present a case of a 76-year-old man with a history of high-grade MFH of the left lower extremity, status post excision and radiation therapy, who presented 2 years later with a regional metastatic recurrence of high-grade MFH to the left groin as well as new nodules adjacent to and within his prior excision and radiation site. These new nodules were determined to represent low-grade myxofibrosarcoma. These new low-grade lesions either represent a low-grade recurrence of high-grade sarcoma or a new, radiation-induced soft tissue sarcoma occurring at the same site. Radiotherapy, however, is an unlikely cause; specific postradiation sarcoma criteria have not been fulfilled. This article discusses both the nosology and histopathological spectrum of these important soft tissue sarcomas, their aggressive and recurrent nature and their association with radiation therapy.

Rhabdomyosarcoma of the extremities: a focus on tumors arising in the hand and foot

BACKGROUND

Extremities are peculiar sites of origin for rhabdomyosarcomas (RMS) and are usually associated with an unfavorable outcome.

METHODS

The authors reviewed the clinical data on 60 patients <21 years old with limb RMS treated at the Pediatric Oncology Unit of the Istituto Nazionale Tumori of Milan, in Italy, over a 30-year period. Twelve patients had tumors arising in the hand and foot.

RESULTS

Complete tumor resection was achieved in 21 patients (but in only 1 case of hand/foot RMS); all patients received chemotherapy and 43 also had radiotherapy. The alveolar subtype was identified in 62% of cases. Half of the hand/foot cases had metastatic disease at onset. Overall survival at 5 years was 33% among the hand/foot cases and 56% for the others. Most of the relapsing cases had distant metastases.

CONCLUSIONS

A particularly poor survival was observed for RMS of the hand/foot due its marked tendency to spread. Surgical resection is particularly difficult in such cases and a multimodality treatment approach seems crucial to improving their outcome.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.