Local control, survival, and operative morbidity and mortality after re-resection, and intraoperative radiation therapy for recurrent or persistent primary high-risk neuroblastoma

Intraoperative radiation therapy for pediatric sarcomas and other solid tumors

PURPOSE

To evaluate local failure (LF) and toxicity after intraoperative radiation therapy (IORT) in pediatric solid tumors (ST).

METHODS

A single-institution retrospective study of 96 pediatric patients (108 applications) with ST treated from 1995 to 2022 with IORT. LF was calculated via cumulative incidence function and overall survival (OS) by Kaplan-Meier method, both from the day of surgery.

RESULTS

Median age at time of IORT was 8 years (range: 0.8-20.9 years). Median follow-up for all patients and surviving patients was 16 months and 3 years, respectively. The most common histologies included rhabdomyosarcoma (n = 42), Ewing sarcoma (n = 10), and Wilms tumor (n = 9). Most (95%) received chemotherapy, 37% had prior external beam radiation therapy to the site of IORT, and 46% had a prior surgery for tumor resection. About half (54%) were treated with upfront IORT to the primary tumor due to difficult circumstances such as very young age or challenging anatomy. The median IORT dose was 12 Gy (range: 4-18 Gy), and median area treated was 24 cm2 (range: 2-198 cm2). The cumulative incidence of LF was 17% at 2 years and 23% at 5 years. Toxicity from IORT was reasonable, with postoperative complications likely related to IORT seen in 15 (16%) patients.

CONCLUSION

Our study represents the largest and most recent analysis of efficacy and safety of IORT in pediatric patients with ST. Less than one quarter of all patients failed locally with acceptable toxicities. Overall, IORT is an effective and safe technique to achieve local control in patients with challenging circumstances.

Intraoperative Radiation Therapy for Relapsed or Refractory High-Risk Neuroblastoma: A 27-Year Experience

PURPOSE

To evaluate outcomes after intraoperative radiation therapy (IORT) in high-risk neuroblastoma (NB), including local control, overall survival, and toxicity.

METHODS AND MATERIALS

This was a single institution retrospective study of 92 pediatric patients with NB treated with IORT from 1995 to 2022. Each IORT application was considered a separate event for a total of 110 sites treated. Local failure was calculated using the cumulative incidence function and survival by Kaplan-Meier method from the day of surgery.

RESULTS

All patients had high-risk relapsed or treatment refractory disease. Median age was 6 years (range, 2-34 years). Median follow-up for all patients and surviving patients was 16 months and 4 years, respectively. All patients previously received chemotherapy, 93% had prior external beam radiation therapy to the site of IORT (median dose, 21.6 Gy; range, 10-36 Gy), and 94% had a prior surgery for tumor resection. The median IORT dose was 12 Gy (range, 8-18 Gy) and median area treated was 18 cm2 (range, 2.5-60 cm2). The cumulative incidence of local failure was 23% at 2 years and 29% at 5 years. The overall survival (OS) was 44% at 2 years and 29% at 5 years. Local failure after IORT was associated with worse OS (hazard ratio, 1.74; 95% CI, 1.07-2.84; P = .0267). Toxicity from IORT was rare, with postoperative complications likely related to IORT seen in 7 (8%) patients.

CONCLUSIONS

Our study represents the largest, most recent analysis of the efficacy and safety of IORT in patients with relapsed or refractory NB. Less than one-third of patients failed locally at 5 years, and achieving local control affected overall survival. Minimal toxicities directly related to IORT were observed. Overall, IORT is an effective and safe technique to achieve local control in high-risk relapsed or refractory neuroblastoma.

Efficacy and Feasibility of Proton Beam Therapy in Relapsed High-Risk Neuroblastoma-Experiences from the Prospective KiProReg Registry

BACKGROUND

Despite an intensive multimodal treatment approach, approximately 50% of high-risk (HR) neuroblastoma (NB) patients experience progression. Despite the advances in targeted therapy, high-dose chemotherapy, and other systemic treatment options, radiation therapy (RT) to sites of relapsed disease can be an option to reduce tumor burden and improve chance for disease control.

METHODS

Patients who received salvage irradiation with proton beam therapy (PBT) for local or metastatic relapse of HR NB within the prospective registry trials KiProReg and ProReg were eligible for this retrospective analysis. Data on patient characteristics, multimodality therapy, adverse events, and oncologic endpoints were evaluated. Adverse events were assessed before, during, and after PBT according to common terminology criteria for adverse events (CTCAE) V4.0.

RESULTS

Between September 2013 and September 2020, twenty (11 male; 9 female) consecutive patients experiencing local (N = 9) or distant recurrence (N = 25) were identified for this analysis. Distant recurrences included osteomedullary (N = 11) or CNS lesions (N = 14). Salvage therapy consisted of re-induction chemo- or chemo-immuno-therapy (N = 19), surgery (N = 6), high-dose chemotherapy and stem cell transplantation (N = 13), radiation (N = 20), and concurrent systemic therapy. Systemic therapy concurrent to RT was given to six patients and included temozolomide (N = 4), carboplatine (N = 1), or anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKI) (N = 1). A median dose of 36 Gy was applied to the 34 recurrent sites. Local RT was applied to 15 patients, while five patients, received craniospinal irradiation for CNS relapse. After a median follow-up (FU) of 20 months (4-66), the estimated rate for local control, distant metastatic free survival, and overall survival at 3 years was 68.0%, 37.9%, and 61.6%, respectively. During RT, ten patients (50%) presented with a higher-grade acute hematologic adverse event. Late higher-grade sequelae included transient myelitis with transverse section (N = 2) and secondary malignancy outside of the RT field (N = 1).

CONCLUSION

Our study demonstrates the efficacy and safety of RT/PBT for recurrent HR NB in a multimodality second-line approach. To better define the role of RT for these patients, prospective studies would be desirable.

Pediatric Patients with Adrenal Neuroblastoma: A SEER Analysis, 2004–2013

Adrenal neuroblastoma (NB) is a relatively common malignancy in children. The Surveillance, Epidemiology, and End Results database was used to present demographic data and a survival analysis with the aim of making tumor management better. The Surveillance, Epidemiology, and End Results database was used to search pediatric patients (age £16 years) with NB from 2004 to 2013. The Kaplan-Meier method was used to calculate the overall survival. And, we used Cox regression analysis to determine hazard ratios for prognostic variables. Independent prognostic factors were selected into the nomogram to predict individual's three-, five-, and seven-year overall survival. The study included a total of 1870 pediatric patients with NB in our cohort. Overall, three-, five-, and seven-year survival rates for adrenal NB were 0.777, 0.701, and 0.665, respectively, whereas the rates for nonadrenal NB were 0.891, 0.859, and 0.832, respectively. The multivariate analysis identified age >1 year, no complete resection (CR)/CR, radiation, and regional/distant metastasis as independent predictors of mortality for adrenal NB. Concordance index of the nomogram was 0.665 (95% confidence interval, 0.627–0.703). Pediatric patients with adrenal NB have significantly worse survival than those with nonadrenal NB. Adrenal NB with age <1 year, treated with surgery, no radiation, and localized tumor leads to a better survival. There was no survival difference for patients to receive CR and no CR.

The American Brachytherapy Society consensus statement on intraoperative radiation therapy

PURPOSE

Although radiation therapy has traditionally been delivered with external beam or brachytherapy, intraoperative radiation therapy (IORT) represents an alternative that may shorten the course of therapy, reduce toxicities, and improve patient satisfaction while potentially lowering the cost of care. At this time, there are limited evidence-based guidelines to assist clinicians with patient selection for IORT. As such, the American Brachytherapy Society presents a consensus statement on the use of IORT.

METHODS

Physicians and physicists with expertise in intraoperative radiation created a site-directed guideline for appropriate patient selection and utilization of IORT.

RESULTS

Several IORT techniques exist including radionuclide-based high-dose-rate, low-dose-rate, electron, and low-energy electronic. In breast cancer, IORT as monotherapy should only be used on prospective studies. IORT can be considered in the treatment of sarcomas with close/positive margins or recurrent sarcomas. IORT can be considered in conjunction with external beam radiotherapy for retroperitoneal sarcomas. IORT can be considered for colorectal malignancies with concern for positive margins and in the setting of recurrent gynecologic cancers. For thoracic, head and neck, and central nervous system malignancies, utilization of IORT should be evaluated on a case-by-case basis.

CONCLUSIONS

The present guidelines provide clinicians with a summary of current data regarding IORT by treatment site and guidelines for the appropriate patient selection and safe utilization of the technique. High-dose-rate, low-dose-rate brachytherapy methods are appropriate when IORT is to be delivered as are electron and low-energy based on the clinical scenario.

Novel intraoperative radiotherapy utilizing prefabricated custom three-dimensionally printed high-dose-rate applicators

BACKGROUND

Intraoperative radiotherapy (IORT) is an effective strategy for the delivery of high doses of radiotherapy to a residual tumor or resection cavity with relative sparing of nearby healthy tissues. This strategy is an important component of the multimodality management of pediatric soft tissue sarcomas, particularly in cases where patients have received prior courses of external beam radiotherapy.

PURPOSE

Tumor beds with significant topographic irregularity remain a therapeutic challenge because existing IORT technologies are typically most reliable with flat surfaces. To address this limitation, we have developed a novel strategy to create custom, prefabricated high-dose-rate (HDR)-IORT applicators designed to match the shape of an anticipated surgical cavity.

METHODS AND MATERIALS

Silastic applicators are constructed using three-dimensional (3D) printing and are derived from volumetric segmentation of preoperative imaging.

RESULTS

HDR preplanning with the applicators improves dosimetric accuracy and minimizes incremental operative time. In this report, we describe the fabrication process for the 3D-printed applicators and detail our experience utilizing this strategy in two pediatric patients who underwent HDR-IORT as part of complex base of skull sarcoma resections.

CONCLUSIONS

Early experience suggests that usage of the custom applicators is feasible, versatile for a variety of clinical situations, and enables the uniform delivery of high superficial doses of radiotherapy to irregularly shaped surgical cavities.

Managing local-regional failure in children with high-risk neuroblastoma: A single institution experience

BACKGROUND

Intensification of systemic therapy for high-risk neuroblastoma (HRNB) has resulted in improved local control and overall survival (OS) leaving potential for de-escalation of primary site radiotherapy. The utility of primary site de-escalation should be evaluated in the context of potential for successful local-regional salvage. We evaluated salvage strategies and outcomes in patients with HRNB with local-regional recurrence as a component of first failure.

METHODS

Twenty of 89 patients with HRNB experienced local-regional recurrence as a component of first relapse after chemotherapy, radiotherapy, surgery, and stem cell transplant from 1997 to 2013. We reviewed salvage therapy strategies and disease control, and report on the impact of local therapy as salvage for local-regional relapse.

RESULTS

Six of 20 patients with local-regional failure (LRF) were alive after a median follow-up of 13 years (range, 0.9-25.2 years). Median OS was 4.6 years (95% CI, 0.6 to not reached) versus 0.6 years (95% CI, 0.05-2.6) after LRF with and without distant failure, respectively (P = 0.03). OS in patients receiving salvage radiotherapy was comparable to those receiving initial adjuvant but no salvage radiotherapy. Time to first failure and death was significantly impacted by the intensity of frontline systemic therapy (P = 0.03). Salvage radiotherapy reduced the hazard for subsequent LRF (hazard ratio 0.3, 95% CI 0.1-0.9, P = 0.04) but not OS (P = 0.07).

CONCLUSIONS

Our study highlights the potential of local control strategies at first failure in patients with LRF when primary site radiotherapy was initially omitted, and delineates potential selection factors which may further improve the therapeutic ratio.

Analysis of the risk factor for the poor prognosis of localized neuroblastoma after the surgical

Neuroblastoma is a unique malignancy in infants often presenting with either localized or metastatic disease. The study was carried out to explore the risk stratification of the poor prognosis for patients underwent surgical treatment.60 patients diagnosed with neuroblastoma were primarily enrolled in the study from April 2008 to April 2016. All the patients underwent surgical treatment and received 5-year follow-up. Clinical variables, including age, International Neuroblastoma Staging System (INSS) stage, tumor size and site, histology, and MYCN status were retrospectively analyzed, and EFS was chosen as the endpoint.The median age of patients was 8.2 months and average follow-up period was 40.2 ± 8.6 months. Among 60 patients, complete remission was achieved in 35 patients and partial remission in 14 subjects. Poor prognosis including patient death and tumor progression were overserved in 11 patients. Cox multifactor regression analysis revealed that age, histology and MYCN status had significant prognostic effect on event-free survival (EFS) rate for neuroblastoma patients underwent surgical treatment.In our study, we identified a series of prognostic factors including age, histology, and MYCN status predicting the prognosis of neuroblastoma patients after surgical treatment.

Neuroblastoma

Neuroblastoma is one of the most common solid tumors in children and has a diverse clinical behavior that largely depends on the tumor biology. Neuroblastoma exhibits unique features, such as early age of onset, high frequency of metastatic disease at diagnosis in patients over 1 year of age and the tendency for spontaneous regression of tumors in infants. The high-risk tumors frequently have amplification of the MYCN oncogene as well as segmental chromosome alterations with poor survival. Recent advanced genomic sequencing technology has revealed that mutation of ALK, which is present in ~10% of primary tumors, often causes familial neuroblastoma with germline mutation. However, the frequency of gene mutations is relatively small and other aberrations, such as epigenetic abnormalities, have also been proposed. The risk-stratified therapy was introduced by the Japan Neuroblastoma Study Group (JNBSG), which is now moving to the Neuroblastoma Committee of Japan Children's Cancer Group (JCCG). Several clinical studies have facilitated the reduction of therapy for children with low-risk neuroblastoma disease and the significant improvement of cure rates for patients with intermediate-risk as well as high-risk disease. Therapy for patients with high-risk disease includes intensive induction chemotherapy and myeloablative chemotherapy, followed by the treatment of minimal residual disease using differentiation therapy and immunotherapy. The JCCG aims for better cures and long-term quality of life for children with cancer by facilitating new approaches targeting novel driver proteins, genetic pathways and the tumor microenvironment.

Design of a compact collimator and 3D imaging system for a scanning beam low-energy intraoperative radiation therapy system for pancreatic cancer

Intraoperative radiation therapy (IORT) involves delivering high doses of radiation directly to tumors while sparing healthy tissues in a surgical setting. Current IORT systems are limited in their lack of image guidance and variable needs for shielded operating rooms. They also lack the capability to deliver non-uniform therapeutic radiation to irregular shaped clinical targets. We developed a scanning beam IORT system (SBIORT) to overcome these limitations. SBIORT consists of a low energy x-ray source, a custom compact dynamic x-ray collimator system, a robotic arm, and a 3D surface imaging module. Here we describe the design and validation of the compact dynamic x-ray collimator system and the 3D surface imaging module for use in SBIORT. The proposed collimator can achieve a leaf position accuracy of ± 0.25 mm (95% confidence interval). Phantom studies indicated the 3D surface-imaging module has an accuracy of 1.0 ± 0.6 mm with ability to obtain high resolution surface image within 5 seconds. SBIORT is a novel approach to deliver conformal intensity-modulated intraoperative radiation therapy.

Intraoperative phosphorus-32 brachytherapy plaque for multiply recurrent high-risk epidural neuroblastoma

Achieving local control is a crucial component in the management of neuroblastoma, but this may be complicated in the setting of prior radiation treatment, especially when the therapeutic target is in proximity to critical structures such as the spinal cord. The authors describe a pediatric patient with multiply recurrent neuroblastoma and prior high-dose radiation therapy to the spine who presented with progressive epidural disease. The patient was managed with resection and intraoperative high-dose-rate brachytherapy using a phosphorus-32 ((32)P) plaque previously developed for the treatment of brain and spine lesions.

Clinical results of proton beam therapy for advanced neuroblastoma

PURPOSE

To evaluate the efficacy of proton beam therapy (PBT) for pediatric patients with advanced neuroblastoma.

METHODS

PBT was conducted at 21 sites in 14 patients with neuroblastoma from 1984 to 2010. Most patients were difficult to treat with photon radiotherapy. Two and 6 patients were classified into stages 3 and 4, respectively, and 6 patients had recurrent disease. Seven of the 8 patients who received PBT as the initial treatment were classified as the high risk group. Twelve patients had gross residual disease before PBT and 2 had undergone intraoperative radiotherapy before PBT. Five patients received PBT for multiple sites, including remote metastases. Photon radiotherapy was used in combination with PBT for 3 patients. The PBT doses ranged from 19.8 to 45.5 GyE (median: 30.6 GyE).

RESULTS

Seven patients are alive with no evidence of disease, 1 is alive with disease progression, and 6 died due to the tumor. Recurrence in the treatment field was not observed and the 3-year locoregional control rate was 82%. Severe acute radiotoxicity was not observed, but 1 patient had narrowing of the aorta and asymptomatic vertebral compression fracture at 28 years after PBT, and hair loss was prolonged in one patient.

CONCLUSION

PBT may be a better alternative to photon radiotherapy for children with advanced neuroblastoma, and may be conducted safely for patients with neuroblastoma that is difficult to manage using photon beams.

Surgical treatment of neuroblastoma: twenty-three years of experience at a single institution

PURPOSE

Neuroblastoma (NB) is treated with surgery, chemotherapy and radiotherapy. We assessed the effects of surgical resection on the outcome over a 23-year period at our institution.

METHODS

85 children were included with a median age at diagnosis of 2.0 (range 0.1-15) years. We assessed the correlation of the complete surgical resection (CR) rate, metastases, NMYC amplification (NMYCA) and chemotherapeutic response with the 5-year overall survival (OS).

RESULTS

The INSS stage of NB was 1 in 11 (13 %) patients, 2 in 10 (11 %), 3 in 13 (17 %), 4 in 46 (53 %) and 4S in five patients (6 %). Fifty-two (61 %) patients had high-risk NB and 22 (26 %) had NMYCA. The resection was complete in 72 (85 %) patients, incomplete (ICR) in seven (8 %) and six (7 %) patients did not undergo surgery. Fifty-five patients were administered neoadjuvant and 61 were administered adjuvant chemotherapy (high-dose, n = 50). The OS (5 year) was 68 %: stage 1 (100 %), 2 (90 %), 3 (77 %), 4 (52 %), 4S (80 %) and high-risk NB (52 %). The OS in high-risk NB patients was correlated with a good chemotherapeutic response of the primary tumour, with a RR for mortality = 0.3 (95 % CI 0.1-0.7; p = 0.01), but not with the CR, which had an RR = 0.9 (95 % CI 0.3-2.4; p = 0.84).

CONCLUSIONS

The OS in high-risk NB patients was related to a good histological chemotherapeutic response, but not with complete excision of the primary tumour.

Historical trends in the use of radiation therapy for pediatric cancers: 1973-2008

PURPOSE

This study was undertaken to assess historical trends in the use of radiation therapy (RT) for pediatric cancers over the past 4 decades.

METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results database of the 9 original tumor registries (SEER-9) was queried to identify patients aged 0 to 19 years with acute lymphoblastic leukemia, acute myeloid leukemia, bone and joint cancer, cancer of the brain and nervous system, Hodgkin lymphoma, neuroblastoma, non-Hodgkin lymphoma, soft tissue cancer, Wilms tumor, or retinoblastoma from 1973 to 2008. Patients were grouped into 4-year time epochs. The number and percentage of patients who received RT as part of their initial treatment were calculated per epoch by each diagnosis group from 1973 to 2008.

RESULTS

RT use for acute lymphoblastic leukemia, non-Hodgkin lymphoma, and retinoblastoma declined sharply from 57%, 57%, and 30% in 1973 to 1976 to 11%, 15%, and 2%, respectively, in 2005 to 2008. Similarly, smaller declines in RT use were also seen in brain cancer (70%-39%), bone cancer (41%-21%), Wilms tumor (75%-53%), and neuroblastoma (60%-25%). RT use curves for Wilms tumor and neuroblastoma were nonlinear with nadirs in 1993 to 1996 at 39% and 19%, respectively. There were minimal changes in RT use for Hodgkin lymphoma, soft tissue cancer, or acute myeloid leukemia, roughly stable at 72%, 40%, and 11%, respectively. Almost all patients treated with RT were given external beam RT exclusively. However, from 1985 to 2008, treatments involving brachytherapy, radioisotopes, or combination therapy increased in frequency, comprising 1.8%, 4.6%, and 11.9% of RT treatments in brain cancer, soft tissue cancer, and retinoblastoma, respectively.

CONCLUSIONS

The use of RT is declining over time in 7 of 10 pediatric cancer categories. A limitation of this study is a potential under-ascertainment of RT use in the SEER-9 database including the delayed use of RT.