Long-term side effects of radiotherapy for pediatric localized neuroblastoma : results from clinical trials NB90 and NB94

Clinical characteristics and prognoses in pediatric neuroblastoma with bone or liver metastasis: data from the SEER 2010-2019

BACKGROUND

To investigate clinical characteristics, prognoses, and impacts of treatments on prognoses of neuroblastoma patients with bone or liver metastasis.

METHODS

This retrospective cohort study extracted data from the Surveillance, Epidemiology, and End Results (SEER) database 2010-2019. The outcomes were 3-year cancer-specific survival (CSS) and 5-year CSS. Multivariable COX risk proportional models were established to assess the association between metastasis types and CSS. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated.

RESULTS

Totally 425 patients with metastatic neuroblastoma were eligible for 3-year CSS analysis and 320 for 5-year CSS analysis. For 3-year follow-up, 62 (14.59%) patients had liver metastasis alone, 289 (0.68%) had bone metastasis alone, and 74 (17.41%) had both liver and bone metastasis. For 5-year follow-up, 44 (13.75%) patients had liver metastasis alone, 223 (69.69%) had bone metastasis alone, and 53 (16.56%) had both liver and bone metastasis. Significant differences were observed in age, tumor size, surgery for the primary site, chemotherapy, radiation, brain metastasis, lung metastasis, and vital status between patients with liver metastasis alone, bone metastasis alone, and both liver and bone metastasis (all P < 0.05). Compared with patients with liver metastasis alone, patients with bone metastasis alone (HR = 2.30, 95%CI: 1.10-4.82, P = 0.028) or both (HR = 2.35, 95%CI: 1.06-5.20, P = 0.035) had significantly poorer 3-year CSS; patients with bone metastasis alone (HR = 2.32, 95%CI: 1.14-4.70, P = 0.020) or both liver and bone metastasis (HR = 2.33, 95%CI: 1.07-5.07, P = 0.032) exhibited significantly worse 5-year CSS than those with liver metastasis alone. In patients with bone metastasis, those with chemotherapy had significantly better 3-year CSS than those without (HR = 0.24, 95%CI: 0.07-0.75, P = 0.014). Among patients with liver metastasis, receiving radiation was associated with significantly worse 3-year CSS (HR = 2.00, 95%CI: 1.05-3.81, P = 0.035).

CONCLUSION

Compared with patients with liver metastasis alone, those with bone metastasis alone or both had poorer 3- and 5-year CSS. For patients with bone metastasis, undergoing chemotherapy was associated with better 3-year CSS. For patients with liver metastasis, receiving radiation was associated with worse 3-year CSS.

Potential Treatment Options for Neuroblastoma with Polyphenols through Anti-Proliferative and Apoptotic Mechanisms

Neuroblastoma (NB) is an extracranial tumor of the peripheral nervous system arising from neural crest cells. It is the most common malignancy in infants and the most common extracranial solid tumor in children. The current treatment for high-risk NB involves chemotherapy and surgical resection followed by high-dose chemotherapy with autologous stem-cell rescue and radiation treatment. However, those with high-risk NB are susceptible to relapse and the long-term side effects of standard chemotherapy. Polyphenols, including the sub-class of flavonoids, contain more than one aromatic ring with hydroxyl groups. The literature demonstrates their utility in inducing the apoptosis of neuroblastoma cells, mostly in vitro and some in vivo. This review explores the use of various polyphenols outlined in primary studies, underlines the pathways involved in apoptotic activity, and discusses the dosage and delivery of these polyphenols. Primary studies were obtained from multiple databases with search the terms "neuroblastoma", "flavonoid", and "apoptosis". The in vitro studies showed that polyphenols exert an apoptotic effect on several NB cell lines. These polyphenols include apigenin, genistein, didymin, rutin, quercetin, curcumin, resveratrol, butein, bisphenols, and various plant extracts. The mechanisms of the therapeutic effects include calpain-dependent pathways, receptor-mediated apoptosis, and, notably, and most frequently, mitochondrial apoptosis pathways, including the mitochondrial proteins Bax and Bcl-2. Overall, polyphenols demonstrate potency in decreasing NB proliferation and inducing apoptosis, indicating significant potential for further in vivo research.

Haematological and renal toxicity of radiation therapy in neuroblastoma paediatric patients

PURPOSE

The objective of this study was to evaluate the renal and hematologic toxicity in paediatric patients with adrenal high-risk neuroblastoma who have received radiation therapy (RT) as part of radical treatment.

MATERIAL AND METHODS

Pediatric patients diagnosed with high-risk adrenal neuroblastoma who received RT as part of the definitive treatment between January 2004 and May 2020 in a single institution were selected. Complete blood counts (CBC) and creatinine clearance (CrCl) pre-RT and post-RT were compared through the Wilcoxon signed-rank test and correlated with survival analysis by Cox regression.

RESULTS

Forty-two children with a median age of 3 years at diagnosis and 2.8 years of follow-up were selected. A significant and acute decrease in lymphocytes was found (p = 0.002) 1 month from RT. Patients with a drop higher than 50% of the previous value experimented a significant reduction in overall survival (55 vs 10%; p = 0.031). At the end of the follow-up, a significant increase in all blood counts was observed. With respect to renal function, an acute and significant decrease in CrCl was observed tin patients younger than 4 years who received RT (p = 0.013). However, it was not clinically relevant.

CONCLUSION

Our data suggest that acute lymphopenia occurs after RT and could be associated with a poorer prognosis. Other blood counts are reduced after RT and all of them are in physiological range at the end of follow-up. Our cohort presented excellent renal outcomes without any case of chronic renal dysfunction.

MYCN Impact on High-Risk Neuroblastoma: From Diagnosis and Prognosis to Targeted Treatment

Among childhood cancers, neuroblastoma is the most diffuse solid tumor and the deadliest in children. While to date, the pathology has become progressively manageable with a significant increase in 5-year survival for its less aggressive form, high-risk neuroblastoma (HR-NB) remains a major issue with poor outcome and little survivability of patients. The staging system has also been improved to better fit patient needs and to administer therapies in a more focused manner in consideration of pathology features. New and improved therapies have been developed; nevertheless, low efficacy and high toxicity remain a staple feature of current high-risk neuroblastoma treatment. For this reason, more specific procedures are required, and new therapeutic targets are also needed for a precise medicine approach. In this scenario, MYCN is certainly one of the most interesting targets. Indeed, MYCN is one of the most relevant hallmarks of HR-NB, and many studies has been carried out in recent years to discover potent and specific inhibitors to block its activities and any related oncogenic function. N-Myc protein has been considered an undruggable target for a long time. Thus, many new indirect and direct approaches have been discovered and preclinically evaluated for the interaction with MYCN and its pathways; a few of the most promising approaches are nearing clinical application for the investigation in HR-NB.

The application and value of radiotherapy at the primary site in patients with high-risk neuroblastoma

OBJECTIVE

To retrospectively analyze radiotherapy (RT) regimens for patients with high-risk neuroblastoma (HRNB) at the primary site after surgery, and to further analyze the characteristics of patients who would benefit more from RT.

METHODS

98 pediatric patients with HRNB were analyzed for local control (LC), RT dose, extent of excision and prognostic factors. Among them, 69 children received RT.

RESULTS

The 3 year LC rates were 96.9 and 62.1% (p < 0.001) in the RT and non-RT groups, respectively. In the non-RT group, LC was better in patients with complete macroscopic resection (CME) than in those with incomplete macroscopic resection (IME) (p = 0.026), while in the RT group, no significant difference in LC was found (p = 0.985). Among patients with IME, the LC was 100% in patients with RT doses >= 36 Gy and 66.7% in patients with doses <36 Gy.

CONCLUSION

RT is valuable, provides patients with excellent LC, and is safe in the short term. RT had a complementary therapeutic effect on incompletely resected tumors, thus bringing their LC to the level of patients with CME. For patients with IME, RT at a dose of not less than 36 Gy may improve LC.

ADVANCES IN KNOWLEDGE

This study analysed the role of radiotherapy in HRNB, investigated the dose of RT depending on the degree of resection, and explored the characteristics of patients who would benefit more from RT.

Recent strategies for nano-based PTT combined with immunotherapy: from a biomaterial point of view

Cancer has been a great threat to humans for decades. Due to the limitations of monotherapy, combinational therapies such as photothermal therapy (PTT) and immunotherapy have gained increasing attention with expectation to overcome the shortfalls of each other and obtain satisfactory therapeutic outcomes. PTT can inhibit primary tumors by thermal ablation but usually fails to achieve complete eradication and cannot prevent metastasis and recurrence. Meanwhile, the efficacy of immunotherapy is usually attenuated by the weak immunogenicity of tumor and the immunosuppressive tumor microenvironment (ITM). Therefore, many recent studies have attempted to synergize PTT with immunotherapy in order to enhance the therapeutic efficacy. In this review, we aim to summarize the cutting-edge strategies in combining nano-based PTT with immunotherapy for cancer treatment. Herein, the combination strategies were mainly classified into four categories, including 1) nano-based PTT combined with antigens to induce host immune responses; 2) nano-based PTT in combination with immune adjuvants acting as in situ vaccines; 3) nano-based PTT synergized with immune checkpoint blockade or other regulators to relieve the ITM; 4) nano-based PTT combined with CAR-T therapy or cytokine therapy for tumor treatment. The characteristics of various photothermal agents and nanoplatforms as well as the immunological mechanisms for the synergism were also introduced in detail. Finally, we discussed the existing challenges and future prospects in combined PTT and immunotherapy.

Proton Beam Therapy for Children With Neuroblastoma: Experiences From the Prospective KiProReg Registry

Objective

Radiotherapy (RT) is an integral part of the interdisciplinary treatment of patients with high-risk neuroblastoma (NB). With the continuous improvements of outcome, the interest in local treatment strategies that reduce treatment-related side effects while achieving optimal oncological results is growing. Proton beam therapy (PBT) represents a promising alternative to conventional photon irradiation with regard to the reduction of treatment burden.

Method

Retrospective analysis of children with high or intermediate risk NB receiving PBT of the primary tumor site during first-line therapy between 2015 and 2020 was performed. Data from the prospective in-house registry Standard Protonentherapie WPE - Kinder- (KiProReg) with respect to tumor control and treatment toxicity were analyzed. Adverse events were classified according to CTCAE Version 4 (V4.0) before, during, and after PBT.

Results

In total, 44 patients (24 male, 20 female) with high (n = 39) or intermediate risk NB (n = 5) were included in the analysis. Median age was 3.4 years (range, 1.4-9.9 years). PBT doses ranged from 21.0 to 39.6 Gray (Gy) (median 36.0 Gy). Five patients received PBT to the MIBG-avid residual at the primary tumor site at time of PBT according to the NB-2004 protocol. In 39 patients radiation was given to the pre-operative tumor bed with or without an additional boost in case of residual tumor. After a median follow-up (FU) of 27.6 months, eight patients developed progression, either local recurrence (n = 1) or distant metastases (n = 7). Four patients died due to tumor progression. At three years, the estimated local control, distant metastatic free survival, progression free survival, and overall survival was 97.7, 84.1, 81.8, and 90.9%, respectively. During radiation, seven patients experienced higher-grade (CTCAE ≥ °3) hematologic toxicity. No other higher grade acute toxicity occurred. After PBT, one patient developed transient myelitis while receiving immunotherapy. No higher grade long-term toxicity was observed up to date.

Conclusion

PBT was a well tolerated and effective local treatment in children with high and intermediate risk NB. The role of RT in an intensive multidisciplinary treatment regimen remains to be studied in the future in order to better define timing, doses, target volumes, and general need for RT in a particularly sensitive cohort of patients.

Role and toxicity of radiation therapy in neuroblastoma patients: A literature review

Neuroblastoma is the most common extracranial solid tumor, arising from primitive sympathetic ganglion cells, in pediatric patients. The unique features of neuroblastoma include variable clinical behaviors, such as rapid progression to death and maturation to benign ganglioneuroma, followed by regression. Radiation therapy (RT) is usually administered to both the primary tumor bed and persistent metastatic sites after induction chemotherapy for high-risk neuroblastoma. RT to the tumor bed after surgical resection contributes significantly to local disease control and prevention of local relapse, confirming the role of RT. Palliative radiotherapy for metastatic neuroblastoma is also effective and safe and mainly provides symptomatic relief. The late side effects of RT in neuroblastoma patients include growth and developmental failure, hypothyroidism, gastrointestinal dysfunction, neurocognitive defects, pulmonary and cardiac abnormalities, infertility, and secondary cancers. In this article, we reviewed the role and toxicity of RT in neuroblastoma patients.

Role of the extent of prophylactic regional lymph node radiotherapy on survival in high-risk neuroblastoma: A report from the COG A3973 study

PURPOSE

Neuroblastoma is the most common extracranial solid pediatric malignancy, with poor outcomes in high-risk disease. Standard treatment approaches employ an increasing array of aggressive multimodal therapies, of which local control with surgery and radiotherapy remains a backbone; however, the benefit of broad regional nodal irradiation remains controversial. We analyzed centrally reviewed radiation therapy data from patients enrolled on COG A3973 to evaluate the impact of primary site irradiation and the extent of regional nodal coverage stratified by extent of surgical resection.

METHODS

Three hundred thirty high-risk neuroblastoma patients with centrally reviewed radiotherapy plans were analyzed. Outcome was evaluated by the extent of nodal irradiation. For the 171 patients who also underwent surgery (centrally reviewed), outcome was likewise analyzed according to the extent of resection. Overall survival (OS), event-free survival (EFS), and cumulative incidence of local progression (CILP) were examined by Kaplan-Meier, log-rank test (EFS, OS), and Grey test (CILP).

RESULTS

The five-year CILP, EFS, and OS for all 330 patients receiving radiotherapy on A3973 were 8.5% ± 1.5%, 47.2% ± 3.0%, and 59.7% ± 3.0%, respectively. There were no significant differences in outcomes based on the extent of lymph node irradiation regardless of the degree of surgical resection (< 90% or ≥90%).

CONCLUSION

Although local control remains a significant component of treatment of high-risk neuroblastoma, our results suggest there is no benefit of extensive lymph node irradiation, irrespective of the extent of surgical resection preceding stem cell transplant.

Reduced-Dose Radiation Therapy to the Primary Site is Effective for High-Risk Neuroblastoma: Results From a Prospective Trial

PURPOSE

For patients with high-risk neuroblastoma (HR-NB), a dose of 21 Gy to the primary tumor site after gross total resection (GTR) provides excellent local control. However, no clinical trial has specifically evaluated the optimal dose of radiation therapy (RT), and RT-related long-term toxicities are of increasing concern. We sought to assess local control, survival outcomes, and toxicity after a reduction in dose to the primary site from 21 Gy to 18 Gy.

METHODS AND MATERIALS

After induction chemotherapy and GTR, patients with HR-NB were enrolled and treated on an RT dose-reduction prospective trial with 18 Gy hyperfractionated RT given in twice-daily fractions of 1.5 Gy each.

RESULTS

The 25 study subjects were 1.6 to 9.5 (median, 4.3) years old at enrollment and included 23 (92%) with stage IV and II (8%) with MYCN-amplified stage III disease. Eleven (44%) were in complete remission (CR), and 14 (56%) had persistence of osteomedullary disease postinduction. Three patients (12%) received proton therapy, and the rest received intensity modulated photon therapy. After a follow-up of 1.8 to 4.2 (median, 3.5) years from initiation of RT, no failures occurred within the RT field; 3 patients had marginal recurrences. The respective 3-year progression-free and overall survival rates were 54.5% and 90.9% for patients in first CR and 42.9% and 76.2% for patients not in metastatic CR. Acute toxicity was negligible.

CONCLUSIONS

Reduced-dose RT with 18 Gy did not compromise local control or survival outcomes in our cohort of patients with HR-NB after GTR. These findings support assessing further RT dose reduction and validation on a larger, multi-institutional trial.

Outcomes After Proton Therapy for Treatment of Pediatric High-Risk Neuroblastoma

PURPOSE

Patients with high-risk neuroblastoma (HR-NBL) require radiation to the primary tumor site and sites of persistent metastatic disease. Proton radiation therapy (PRT) may promote organ sparing, but long-term outcomes have not been studied.

METHODS AND MATERIALS

Sequential patients with HR-NBL received PRT: 2160 cGy (relative biological effectiveness) to primary tumor bed and persistent metastatic sites, with 3600 cGy (relative biological effectiveness) to gross residual disease.

RESULTS

From September 2010 through September 2015, 45 patients with HR-NBL received PRT after systemic therapy, primary tumor resection, and high-dose chemotherapy with stem cell rescue. Median age was 46 months at the time of PRT (range, 10 months to 12 years); 23 patients (51%) were male. Primary tumors were adrenal in 40 (89%); 11 (24%) received boost. Ten metastatic sites in 8 patients were radiated. Double scattered proton beams were used for 19 (42%) patients, in combination with x-rays for 2 (5%). The remaining 26 (58%) received pencil beam scanning, available since January 2013. We observed 97% freedom from primary site recurrence at 3, 4, and 5 years. Overall survival rates were 89%, 80%, and 80% and disease-free survival rates were 77%, 70%, and 70%, at 3, 4, and 5 years, respectively. With median follow-up of 48.7 months from diagnosis (range, 11-90 months) for all patients (57.4 months for those alive), 37 (82%) patients are alive, and 32 (71%) are without evidence of disease. One patient experienced locoregional recurrence; the remaining 12 (27%) experienced relapse at distant, nonradiated sites. Acute toxicities during treatment were mainly grade 1. No patient has experienced World Health Organization grade 3 or 4 long-term renal or hepatic toxicity. Pencil beam scanning plans required less planning time and resources than double scattered plans.

CONCLUSIONS

We observe excellent outcomes in patients treated with PRT for HR-NBL from 2010 through 2015, with 82% of patients alive and 97% free of primary site recurrence. No patient has experienced long-term renal or liver toxicity. This treatment maximizes normal tissue preservation and is appropriate for this patient population.

The dietary flavonoid isoliquiritigenin is a potent cytotoxin for human neuroblastoma cells

Neuroblastoma (NB) is the most common extracranial solid tumor of early childhood; it accounts for approximately 8–10% of all childhood cancers and is the most common cancer in children in the first year of life. Patients in the high-risk group have a poor prognosis, with relapses being common and often refractory to drug treatment in those that survive. Moreover, the drug treatment itself can lead to a range of long-term sequelae. Therefore, there is a critical need to identify new therapeutics for NB. Isoliquiritigenin (ISLQ) is a naturally-occurring, dietary chalcone-type flavonoid with a range of biological effects that depend on the cell type and context. ISLQ has potential as an anticancer agent. Here we show that ISLQ has potent cytotoxic effects on SK-N-BE(2) and IMR-32 human NB cells, which carry amplification of the MYCN gene, the main prognostic marker of poor survival in NB. ISLQ was found to increase cellular reactive oxygen species (ROS). The cytotoxic effect of ISLQ was blocked by small molecule inhibitors of oxidative stress-induced cell death, and by the antioxidant N-acetyl-l-cysteine (NAC). Combined treatment of either SK-N-B-E(2) or IMR-32 cells with ISLQ and the anticancer agent cisplatin resulted in loss of cell viability that was greater than that induced by cisplatin alone. This study provides proof-of-principle that ISLQ is a potent cytotoxin for MYCN-amplified human NB cells. This is an important first step in rationalizing the further study of ISLQ as a potential adjunct therapy for high-risk NB.

Somatic late effects in 5-year survivors of neuroblastoma: a population-based cohort study within the Adult Life after Childhood Cancer in Scandinavia study

Because of the rarity of neuroblastoma and poor survival until the 1990s, information on late effects in neuroblastoma survivors is sparse. We comprehensively reviewed the long-term risk for somatic disease in neuroblastoma survivors. We identified 721 5-year survivors of neuroblastoma in Nordic population-based cancer registries and identified late effects in national hospital registries covering the period 1977-2012. Detailed treatment information was available for 46% of the survivors. The disease-specific rates of hospitalization of survivors and of 152,231 randomly selected population comparisons were used to calculate standardized hospitalization rate ratios (SHRRs) and absolute excess risks (AERs). During 5,500 person-years of follow-up, 501 5-year survivors had a first hospital contact yielding a SHRR of 2.3 (95% CI 2.1-2.6) and a corresponding AER of 52 (95% CI 44-60) per 1,000 person-years. The highest relative risks were for diseases of blood and blood-forming organs (SHRR 3.8; 95% CI 2.7-5.4), endocrine diseases (3.6 [3.1-4.2]), circulatory system diseases (3.1 [2.5-3.8]), and diseases of the nervous system (3.0 [2.6-3.3]). Approximately 60% of the excess new hospitalizations of survivors were for diseases of the nervous system, urinary system, endocrine system, and bone and soft tissue. The relative risks and AERs were highest for the survivors most intensively treated. Survivors of neuroblastoma have a highly increased long-term risk for somatic late effects in all the main disease groups as compared to background levels. Our results are useful for counseling survivors and should contribute to improving health care planning in post-therapy clinics.

Musculoskeletal outcomes and the effect of radiation to the vertebral bodies on growth trajectories for long-term survivors of high-risk neuroblastoma

OBJECTIVE

Here, we report musculoskeletal outcomes and the impact of radiotherapy dose on vertebral body growth for an institutional series of long-term survivors of high-risk neuroblastoma.

METHODS

We conducted a retrospective study of 23 patients who were disease-free and at least 36 months from the end of treatment. The patients were initially treated from July 2003 to May 2012. Patient records were reviewed for growth percentiles (obtained at approximately 6-month intervals from onset of treatment to the last follow-up) and musculoskeletal comorbidities. RT plans and most recent surveillance CT scans were reviewed for locations of in-field vertebral bodies and corresponding vertebral growth patterns.

RESULTS

The median follow-up was 7.93 years. The median prescribed radiation dose was 21.6 Gy. Musculoskeletal abnormalities included scoliosis (5 patients), muscular hypoplasia (3), and hypodontia (1). The median growth percentile at treatment onset was 35.5 (range, 4.7-100) versus 10 (0-94.1) at the last follow-up. The median numbers of vertebral bodies encompassed (by at least half of their volume) by the 5-, 10-, 15-, and 20-Gy isodose lines were 7 (mean, 6.78), 7 (6.56), 6 (6.17), and 6 (5.52), respectively. Sixteen patients (70.0%) had in-field abnormalities in vertebral body growth, manifesting as stretches of successive vertebral bodies at the same height, while normally there is a gradual vertebral body height increase progressing caudally down the spinal column.

CONCLUSIONS

Musculoskeletal abnormalities, below average height, and stunted in-field vertebral body growth are routine in long-term survivors of high-risk neuroblastoma. Sparing vertebral bodies when feasible may lead to improvement in patient growth trajectories.

A single center clinical analysis of children with high-risk neuroblastoma

The current multidisciplinary treatment for patients with high-risk neuroblastoma (NB) is the common census. However, protocols and opinions are different in different regions and institutions. We aimed to assess the protocol formulated by Chinese Children's Cancer Group study in 2009, and the impact of surgery extent was highlightly evaluated.

METHODS

This study enrolled patients with high-risk neuroblastoma between 2009 and 2014 in Department of Pediatric Oncology of Tianjin Medical University Cancer Institute and Hospital. The clinical characteristics of patients were illustrated and surgery extent was evaluated by the impact on survival rate.

RESULTS

The 3-year overall survival (OS) and progression-free survival (PFS) were 56.2% and 50.5%, respectively. LDH (P<0.001), bone marrow metastasis at time of diagnosis (P=0.001), bone marrow negative after neoadjuvant chemotherapy (P<0.001), radiotherapy (P<0.001) were significant predictors of OS and PFS. And surgery extent had no impact on the enhancement of high-risk neuroblastoma patients in short time.

CONCLUSIONS

This study showed no substantial survival benefit in patients with high-risk NB undergoing gross total tumor resection. Multidisciplinary intensive treatment was essential, especially for patients received subtotal tumor resection. Longer term follow-up is needed to survey complications in surviving patients who received intensive chemotherapy and radiotherapy.

Use of expanders for bowel protection in pediatric pelvic tumor radiation therapy: 15 years of tolerance results

PURPOSE

Bowel is often the dose-limiting organ in curative pelvic irradiation because of radiation enteritis when dose exceeds 40 to 45 Gy. To limit radiation enteritis, a silicone tissue-expander prothesis (STEP) connected to a subcutaneous self-sealing valve was prospectively used in children undergoing pelvic or abdominal radiation therapy. This study reports the 15-year long-term outcomes of this prospective series.

METHODS AND MATERIALS

Between 1987 and 2008, 29 children from 3 Paris institutions received pelvic radiation therapy after surgical placement of a STEP in the pelvis. The median prescribed dose was 50.4 Gy (44.1-55 Gy) using 5 daily fractions of 1.8 Gy per week, except for 1 patient receiving 4 fractions of 2.5 Gy per week. The median treatment duration was 40 days (29-49 days). After 2000, computed tomography (CT) conformal 3-dimensional radiation therapy was used, and 12 patients had CT simulation. Four had CT before and after insertion of the STEP, enabling us to compare pre- and postprosthesis insertion bowel dose-volume histograms. Acute and late toxicities were captured using the Radiation Therapy Oncology Group or the National Cancer Institute Common Terminology Criteria for Adverse Events 4.0 scale.

RESULTS

No patient experienced significant perioperative complications. Pre- and post-STEP insertion small bowel dose-volume histograms show significant reductions in small bowel: 51%, 45%, and 64%, respectively, in V₁₀, V₁₅, and V₄₀ (V_x = irradiated volume by x Gy). Twenty-five patients (86%) completed their radiation therapy with no or minimal small bowel toxicity. One patient also treated with neutrons developed delayed grade 4 toxicities. The 15-year complication-free survival for those surviving was 70.3%.

CONCLUSIONS

We report the long-term follow-up of STEP prosthesis insertion in children to reduce the small bowel volume in the radiation field. The acute and long-term tolerances were excellent. The STEP reduced the bowel dose over 40 Gy by 64%.

Long-term follow-up after proton beam therapy for pediatric tumors: a Japanese national survey

Proton beam therapy (PBT) is a potential new alternative to treatment with photon radiotherapy that may reduce the risk of late toxicity and secondary cancer, especially for pediatric tumors. The goal of this study was to evaluate the long‐term benefits of PBT in cancer survivors. A retrospective observational study of pediatric patients who received PBT was performed at four institutions in Japan. Of 343 patients, 62 were followed up for 5 or more years. These patients included 40 males and 22 females, and had a median age of 10 years (range: 0–19 years) at the time of treatment. The irradiation dose ranged from 10.8 to 81.2 GyE (median: 50.4 GyE). The median follow‐up period was 8.1 years (5.0–31.2 years). The 5‐, 10‐ and 20‐year rates for grade 2 or higher late toxicities were 18%, 35% and 45%, respectively, and those for grade 3 or higher late toxicities were 6%, 17% and 17% respectively. Univariate analysis showed that the irradiated site (head and neck, brain) was significantly associated with late toxicities. No malignant secondary tumors occurred within the irradiated field. The 10‐ and 20‐year cumulative rates for all secondary tumors, malignant secondary tumors, and malignant nonhematologic secondary tumors were 8% and 16%, 5% and 13%, and 3% and 11%, respectively. Our data indicate that PBT has the potential to reduce the risk of late mortality and secondary malignancy. Longer follow‐up is needed to confirm the benefits of PBT for pediatric tumors.

Favorable Local Control From Consolidative Radiation Therapy in High-Risk Neuroblastoma Despite Gross Residual Disease, Positive Margins, or Nodal Involvement

PURPOSE

To report the influence of radiation therapy (RT) dose and surgical pathology variables on disease control and overall survival (OS) in patients treated for high-risk neuroblastoma at a single institution.

METHODS AND MATERIALS

We conducted a retrospective study of 67 high-risk neuroblastoma patients who received RT as part of definitive management from January 2003 until May 2014.

RESULTS

At a median follow-up of 4.5 years, 26 patients (38.8%) failed distantly; 4 of these patients also failed locally. One patient progressed locally without distant failure. Local control was 92.5%, and total disease control was 59.5%. No benefit was demonstrated for RT doses over 21.6 Gy with respect to local relapse-free survival (P=.55), disease-free survival (P=.22), or OS (P=.72). With respect to local relapse-free survival, disease-free survival, and OS, no disadvantage was seen for positive lymph nodes on surgical pathology, positive surgical margins, or gross residual disease. Of the patients with gross residual disease, 75% (6 of 8) went on to have no evidence of disease at time of last follow-up, and the 2 patients who failed did so distantly.

CONCLUSIONS

Patients with high-risk neuroblastoma in this series maintained excellent local control, with no benefit demonstrated for radiation doses over 21.6 Gy, and no disadvantage demonstrated for gross residual disease after surgery, positive surgical margins, or pathologic lymph node positivity. Though the limitations of a retrospective review for an uncommon disease must be kept in mind, with small numbers in some of the subgroups, it seems that dose escalation should be considered only in exceptional circumstances.

Impact of Extent of Resection on Local Control and Survival in Patients From the COG A3973 Study With High-Risk Neuroblastoma

Purpose This analysis of patients in the Children's Oncology Group A3973 study evaluated the impact of extent of primary tumor resection on local progression and survival and assessed concordance between clinical and central imaging review-based assessments of resection extent. Patients and Methods The analytic cohort (n = 220) included patients who had both central surgery review and resection of the primary tumor site. For this analysis, resection categories of < 90% and ≥ 90% were used, with data on resection extent derived from operating surgeons' assessments (all patients), as well as blinded central imaging review of computed tomography scans for a subset of 84 patients; assessment results were compared for concordance. Treatment outcomes included event-free survival (EFS), overall survival (OS), and cumulative incidence of local progression (CILP). Results Surgeon-assessed extent of resection was ≥ 90% in 154 (70%) patients and < 90% in 66 (30%). Five-year EFS, OS, and CILP (± SE) were 43.5% ± 3.7%, 54.9% ± 3.7%, and 11.9% ± 2.2%, respectively. EFS was higher with ≥ 90% resection (45.9% ± 4.3%) than with < 90% resection (37.9% ± 7.2%; P = .04). Lower CILP ( P = .01) was associated with ≥ 90% resection (8.5% ± 2.3%) compared with < 90% resection (19.8% ± 5.0%). On multivariable analysis, ≥ 90% resection was associated with longer EFS after adjustment for MYCN amplification or diploidy but had no significant effect on OS. Concordance between surgeons' assessments of resection extent and central image-guided review was low, with agreement of 63% (< 90% v ≥ 90%; simple κ = -0.0301). Conclusion Despite discordance between clinical assessment of resection extent and assessment via central imaging review, a surgeon-assessed resection extent ≥ 90% was associated with significantly better EFS and lower CILP. Improving OS, however, remains a challenge in this disease. These findings support continued attempts at ≥ 90% resection of the primary tumor in high-risk neuroblastoma.

Local Control With 21-Gy Radiation Therapy for High-Risk Neuroblastoma

PURPOSE

To evaluate local control after 21-Gy radiation therapy (RT) to the primary site in patients with high-risk neuroblastoma.

METHODS AND MATERIALS

After receiving dose-intensive chemotherapy and gross total resection (GTR), 246 patients (aged 1.2-17.9 years, median 4.0 years) with high-risk neuroblastoma underwent RT to the primary site at Memorial Sloan Kettering from 2000 to 2014. Radiation therapy consisted of 21 Gy in twice-daily fractions of 1.5 Gy each. Local failure (LF) was correlated with biologic prognostic factors and clinical findings at the time of diagnosis and start of RT.

RESULTS

Median follow-up of surviving patients was 6.4 years. Cumulative incidence of LF was 7.1% at 2 years after RT and 9.8% at 5 years after RT. The isolated LF rate was 3.0%. Eighty-six percent of all local failures were within the RT field. Local control was worse in patients who required more than 1 surgical resection to achieve GTR (22.4% vs 8.3%, P=.01). There was also a trend toward inferior local control with MYCN-amplified tumors or serum lactate dehydrogenase ≥1500 U/L (P=.09 and P=.06, respectively).

CONCLUSION

After intensive chemotherapy and maximal surgical debulking, hyperfractionated RT with 21 Gy in high-risk neuroblastoma results in excellent local control. Given the young patient age, concern for late effects, and local control >90%, dose reduction may be appropriate for patients without MYCN amplification who achieve GTR.

[Neonatal neuroblastoma complicated with a threatening tumoral hepatomegaly treated by irradiation: No sequel 20 years later]

In this article, we report the case of a newborn who presented a life-threatening hepatomegaly with respiratory distress at 12 days of life, complicating a metastatic neuroblastoma. Low-dose liver radiotherapy was performed in emergency in order to decompress. Chemotherapy has also been delivered due to a tumoral relapse 1 month after radiotherapy. After a follow-up of 20 years, this young woman is still in complete remission, with no long-term sequelae.