Proton therapy for pediatric and adolescent esthesioneuroblastoma

Retinopathy, Optic Neuropathy, and Cataract in Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

Few reports describe the risks of late ocular toxicities after radiation therapy (RT) for childhood cancers despite their effect on quality of life. The Pediatric Normal Tissue Effects in the Clinic (PENTEC) ocular task force aims to quantify the radiation dose dependence of select late ocular adverse effects. Here, we report results concerning retinopathy, optic neuropathy, and cataract in childhood cancer survivors who received cranial RT.

METHODS AND MATERIALS

A systematic literature search was performed using the PubMed, MEDLINE, and Cochrane Library databases for peer-reviewed studies published from 1980 to 2021 related to childhood cancer, RT, and ocular endpoints including dry eye, keratitis/corneal injury, conjunctival injury, cataract, retinopathy, and optic neuropathy. This initial search yielded abstracts for 2947 references, 269 of which were selected as potentially having useful outcomes and RT data. Data permitting, treatment and outcome data were used to generate normal tissue complication probability models.

RESULTS

We identified sufficient RT data to generate normal tissue complication probability models for 3 endpoints: retinopathy, optic neuropathy, and cataract formation. Based on limited data, the model for development of retinopathy suggests 5% and 50% risk of toxicity at 42 and 62 Gy, respectively. The model for development of optic neuropathy suggests 5% and 50% risk of toxicity at 57 and 64 Gy, respectively. More extensive data were available to evaluate the risk of cataract, separated into self-reported versus ophthalmologist-diagnosed cataract. The models suggest 5% and 50% risk of self-reported cataract at 12 and >40 Gy, respectively, and 50% risk of ophthalmologist-diagnosed cataract at 9 Gy (>5% long-term risk at 0 Gy in patients treated with chemotherapy only).

CONCLUSIONS

Radiation dose effects in the eye are inadequately studied in the pediatric population. Based on limited published data, this PENTEC comprehensive review establishes relationships between RT dose and subsequent risks of retinopathy, optic neuropathy, and cataract formation.

Physics Considerations for Evaluation of Dose for Dose-Response Models of Pediatric Late Effects From Radiation Therapy: A PENTEC Introductory Review

PURPOSE

We describe the methods used to estimate the accuracy of dosimetric data found in literature sources used to construct the Pediatric Normal Tissue Effects in the Clinic (PENTEC) dose-response models, summarize these findings of each organ-specific task force, describe some of the dosimetric challenges and the extent to which these efforts affected the final modeling results, and provide guidance on the interpretation of the dose-response results given the various dosimetric uncertainties.

METHODS AND MATERIALS

Each of the PENTEC task force medical physicists reviewed all the journal articles used for dose-response modeling to identify, categorize, and quantify dosimetric uncertainties. These uncertainties fell into 6 broad categories. A uniform nomenclature was developed for describing the "dosimetric quality" of the articles used in the PENTEC reviews. Among the multidisciplinary experts in the PENTEC effort, the medical physicists were charged with the dosimetric evaluation, as they are most expert in this subject.

RESULTS

The percentage dosimetric uncertainty was estimated for each late effect endpoint for all PENTEC organ reports. Twelve specific sources of dose uncertainty were identified related to the 6 broad categories. The most common reason for organ dose uncertainty was that prescribed dose rather than organ dose was reported. Percentage dose uncertainties ranged from 5% to 200%. Systematic uncertainties were used to correct the dose component of the models. Random uncertainties were also described in each report and in some cases used to modify dose axis error bars. In addition, the potential effects of dose binning were described.

CONCLUSIONS

PENTEC reports are designed to provide guidance to radiation oncologists and treatment planners for organ dose constraints. It is critical that these dose constraint recommendations are as accurate as possible, acknowledging the large error bars for many. Achieving this accuracy is important as it enables clinicians to better balance target dose coverage with risk of late effects. Evidence-based dose constraints for pediatric patients have been lacking and, in this regard, PENTEC fills an important unmet need. One must be aware of the limitations of our recommendations, and that for some organ systems, large uncertainties exist in the dose-response model because of clinical endpoint uncertainty, dosimetric uncertainty, or both.

The impact of multidisciplinary approaches on the outcomes of olfactory neuroblastoma treated with postoperative radiotherapy

BACKGROUND

We investigated the outcomes of postoperative radiation therapy for olfactory neuroblastoma (ONB) and our cross-departmental collaboration to enhance the effectiveness of cancer treatment.

METHODS

We retrospectively evaluated 22 patients with ONB who underwent postoperative radiotherapy after tumor resection. En bloc resection was performed; pathology specimens were prepared in coronal sections; and irradiation fields were determined after discussion with radiation oncologists, head and neck surgeons, and pathologists.

RESULTS

The overall survival and local control rates were 95.5% and 100%, respectively, at a median 37-month follow-up. The 3- and 5-year disease-free survival (DFS) rates were 64.4% and 56.3%, respectively. Of the 22 patients, 9 (8 Kadish C and 1 Kadish B) had disease recurrence. Of the nine patients, five had positive margins and two had closed margins; cervical lymph node recurrence occurred in six, and distant metastasis with or without cervical lymph node recurrence occurred in three. DFS analysis of risk factors showed no statistically significant differences, but positive margins were a significant recurrence factor in multivariate analysis.

CONCLUSIONS

The local control rate of ONB treated with postoperative radiation therapy was 100%. This may be attributed to cross-departmental cooperation between head and neck surgeons, pathologists, and radiation oncologists, which resulted in accurate matching of CT images for treatment planning with the location of the tumor and positive margins. Longer follow-up periods are required to evaluate the effectiveness of our strategy.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Outcomes following proton therapy for pediatric esthesioneuroblastoma

BACKGROUND

Pediatric esthesioneuroblastoma (EN) can infiltrate skull base anatomy, presenting challenges due to high radiation doses and pediatric tissue sensitivity. This study reports outcomes of pediatric EN treated with proton radiotherapy (PT).

PROCEDURE

Using an IRB-approved prospective outcomes registry, we evaluated patient, tumor, and treatment-related variables impacting disease control and toxicity in pediatric nonmetastatic EN treated with modern multimodality therapy, including PT.

RESULTS

Fifteen consecutive patients (median age 16) comprising Kadish stage B (n = 2), C (n = 9), and D (n = 4) tumors were assessed, including six with intracranial involvement, four with cranial nerve deficits, and four with cervical lymphadenopathy. Before radiation, two had subtotal and 13 had gross total resections (endoscopic or craniofacial). Two underwent neck dissection. Eleven received chemotherapy before radiation (n = 5), concurrent with radiation (n = 4), or both (n = 2). Median total radiation dose (primary site) was 66 Gy/CGE for gross disease and 54 Gy/CGE (cobalt Gray equivalent) for microscopic disease. Median follow-up was 4.8 years. No patients were lost to follow-up. Five-year disease-free and overall survival rates were 86% (no local or regional recurrences). Two patients developed vertebral metastases and died. Two required a temporary feeding tube for oral mucositis/dysphagia. Late toxicities included symptomatic retinopathy, major reconstructive surgery, cataracts, chronic otitis media, chronic keratoconjunctivitis, hypothyroidism, and in-field basal cell skin cancer.

CONCLUSIONS

A multimodality approach for pediatric EN results in excellent local control. Despite the moderate-dose PT, serious radiation toxicity was observed; further dose and target volume reductions may benefit select patients. Longer follow-up and comparative data from modern photon series are necessary to fully characterize any relative PT advantage.

Upright proton therapy for esthesioneuroblastoma: a single-institution experience

Aim

This study presents an analysis (efficacy and toxicity) of outcomes in patients with esthesioneuroblastoma after pencil beam proton therapy with a fixed beamline in the upright position.

Background

Esthesioneuroblastoma (ENB) is an extremely rare tumor of sinonasal area located in critical proximity to vital structures. Proton therapy (PT) is often considered the optimal radiation treatment for head-and-neck tumors, although of limited availability. Upright PT delivered using fixed pencil beamline and rotating chair is a fairly promising option.

Methods

This is a single-center experience describing the outcomes of PT in 14 patients with ENB treated between January 2016 and October 2022; half of the cases had a history of previous irradiation. The therapy was applied using a fixed pencil beamline with 6D-chair for positioning. The median dose was 63 GyRBE (total range 48-70 GyRBE; based on 1.1 RBE multiplier for protons) with 2.0 GyRBE per fraction. The mean gross tumor volume was 109.5 cm3 (17.1-257.7 cm3). Patient demography, pathology, treatment parameters and toxicity data were analyzed. Radiation-induced reactions were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v 4.0.

Results

The median follow-up time was 28 months. The 1- and 2-year locoregional control rates constituted 100% and 88.9%, respectively; the median duration of local control was 52 months. The 1- and 2-year progression-free survival (PFS) rates constituted 92.9% and 75.0%, respectively; the median PFS duration was 52 months. The 1- and 2-year overall survival (OS) rates constituted 92.9% and 84.4%, respectively. Two patients died of non-cancer-related causes (coronavirus-induced pneumonia) and 1 patient died of tumor progression. All patients tolerated PT well without any treatment gaps. Serious late toxicity reactions included glaucoma in 1 patient and cataract in 2 patients, in over half a year since irradiation.

Conclusion

PT with upright design of the unit affords promising outcomes in terms of disease control and toxicity rates in ENB, a sinonasal tumor of complicated localization.

Persistent pain and numbness in the extremities of an adult due to paraneoplastic peripheral neuropathy caused by olfactory neuroblastoma: A case report

Background

Paraneoplastic peripheral neuropathy (PPN) caused by olfactory neuroblastoma (ONB) has not yet been reported.

Case report

We present a rare case of an adult who hospitalized repeatedly over the past 9 months for persistent pain and numbness in the limbs. This patient was initially diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) and treated accordingly, but neurological symptoms did not improve significantly. After this admission, FDG-PET/CT showed focal hypermetabolism of a soft-tissue mass in the nasal cavity, and further lesion biopsy suggested ONB. Combined with positive serum anti-Hu antibody, the diagnosis of PPN associated with ONB was eventually made. Furthermore, the patient's neurological symptoms were relieved after removal of the primary tumor, confirming the accuracy of the diagnosis.

Conclusion

Our case not only expanded the clinical characteristics of ONB but also highlighted the importance of early and comprehensive tumor screening for the diagnosis of PPN.

Proton therapy for pediatric diencephalic tumors

Diencephalic tumors tend to be low grade tumors located near several critical structures, including the optic nerves, optic chiasm, pituitary, hypothalamus, Circle of Willis, and hippocampi. In children, damage to these structures can impact physical and cognitive development over time. Thus, the goal of radiotherapy is to maximize long term survival while minimizing late effects, including endocrine disruption leading to precocious puberty, height loss, hypogonadotropic hypogonadism, and primary amenorrhea; visual disruption including blindness; and vascular damage resulting in cerebral vasculopathy. Compared to photon therapy, proton therapy offers the potential to decrease unnecessary dose to these critical structures while maintaining adequate dose to the tumor. In this article, we review the acute and chronic toxicities associated with radiation for pediatric diencephalic tumors, focusing on the use of proton therapy to minimize treatment-related morbidity. Emerging strategies to further reduce radiation dose to critical structures will also be considered.

Radiation-induced optic neuropathy: a review

Radiation is a commonly used treatment modality for head and neck as well as CNS tumours, both benign and malignant. As newer oncology treatments such as immunotherapies allow for longer survival, complications from radiation therapy are becoming more common. Radiation-induced optic neuropathy is a feared complication due to rapid onset and potential for severe and bilateral vision loss. Careful monitoring of high-risk patients and early recognition are crucial for initiating treatment to prevent severe vision loss due to a narrow therapeutic window. This review discusses presentation, aetiology, recent advances in diagnosis using innovative MRI techniques and best practice treatment options based on the most recent evidence-based medicine.

Proton Radiotherapy to Reduce Late Complications in Childhood Head and Neck Cancers

In most childhood head and neck cancers, radiotherapy is an essential component of treatment; however, it can be associated with problematic long-term complications. Proton beam therapy is accepted as a preferred radiation modality in pediatric cancers to minimize the late radiation side effects. Given that childhood cancers are a rare and heterogeneous disease, the support for proton therapy comes from risk modeling and a limited number of cohort series. Here, we discuss the role of proton radiotherapy in pediatric head and neck cancers with a focus on reducing radiation toxicities. First, we compare the efficacy and expected toxicities in proton and photon radiotherapy for childhood cancers. Second, we review the benefit of proton radiotherapy in reducing acute and late radiation toxicities, including risks for secondary cancers, craniofacial development, vision, and cognition. Finally, we review the cost effectiveness for proton radiotherapy in pediatric head and neck cancers. This review highlights the benefits of particle radiotherapy for pediatric head and neck cancers to improve the quality of life in cancer survivors, to reduce radiation morbidities, and to maximize efficient health care use.

Carbon ion radiation therapy for sinonasal malignancies: Promising results from 2282 cases from the real world

The aim of this study is to compare the effectiveness of carbon ion radiation therapy (CIRT), proton radiation therapy (PRT), and photon‐based intensity‐modulated radiation therapy (IMRT) in the treatment of sinonasal malignancies. We identified studies through systematic review and divided them into three cohorts (CIRT group/PRT group/IMRT group). Primary outcomes of interest were overall survival (OS) and local control (LC). We pooled the outcomes with meta‐analysis and compared the survival difference among groups using Chi² (χ²) test. A representative sample of 2282 patients with sinonasal malignancies (911 in the CIRT group, 599 in the PRT group, and 772 in the IMRT group) from 44 observation studies (7 CIRT, 16 PRT, and 21 IMRT) was included. The pooled 3‐year OS, LC, distant metastasis–free survival, and progression‐free survival rates were 67.0%, 72.8%, 69.4%, and 52.8%, respectively. Through cross‐group analysis, the OS was significantly higher after CIRT (75.1%, 95% CI: 67.1%‐83.2%) than PRT (66.2%, 95% CI: 57.7%‐74.6%; χ² = 13.374, P < .0001) or IMRT (63.8%, 95% CI: 55.3%‐72.3%; χ² = 23.814, P < .0001). LC was significantly higher after CIRT (80.2%, 95% CI: 73.9%‐86.5%) than PRT (72.9%, 95% CI: 63.7%‐82.0%; χ² = 8.955, P = .003) or IMRT (67.8%, 95% CI: 59.4%‐76.2%; χ² = 30.955, P < .0001). However, no significant difference between PRT and IMRT for OS and LC was observed. CIRT appeared to provide better OS and LC for patients with malignancies of nasal cavity and paranasal sinuses. A prospective randomized clinical trial is needed to confirm the superiority of CIRT in the treatment of sinonasal tumors.

Esthesioneuroblastoma in children, adolescents and young adults

The esthesioneuroblastoma (ENB) is characterized as a rare malignant sinonasal tumor of neuroectodermal origin. Its starting point is the olfactory epithelium located in the upper part of the nasal cavities. Different nomenclatures have been proposed, but the most common are "esthesioneuroblastoma" and "olfactory neuroblastoma". ENBs have a bimodal distribution and mainly occur in teenagers, young adults and people aged 50-60. It is a very rare tumor in pediatrics since only around 100 cases have been reported so far. Within ENBs, we can distinguish tumors with different biological behavior ranging from localized forms with slow evolution to aggressive and metastatic forms at onset. In addition, precisely diagnosing undifferentiated tumors and distinguishing them from other etiologies of sinonasal tumors are sometime difficult. Added to its very low incidence, these characteristics make the study of ENB complicated. The standard treatment currently includes broad surgery followed by radiation therapy in localized resectable tumors. Neoadjuvant chemotherapy is indicated in large unresectable tumors and in metastatic forms. However, in certain indications, such as high-grade operable tumors, the role of perioperative chemotherapy remains to be defined. The objective of this analysis is to detail current knowledge regarding ENBs' epidemiological, biological, clinical and radiological characteristics as well as how to manage ENB in young patients.

Treatment Strategies and Outcomes of Pediatric Esthesioneuroblastoma: A Systematic Review

Introduction: Esthesioneuroblastoma, also known as olfactory neuroblastoma, is a small round blue cell tumor of nasal neuroepithelium first described in 1924. Though this tumor is especially rare in the pediatric population with an incidence of <0.1 per 100,000, it is the most common pediatric nasal cavity neoplasm. The purpose of this systematic review is to examine the treatment modalities utilized for pediatric esthesioneuroblastoma and overall survival.

Methods: A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Pubmed, EMBASE, and Ovid MEDLINE databases were queried for studies pertinent to treatment modalities for pediatric esthesioneuroblatoma and survival outcomes.

Results: Two hundred and seventy-sixth articles were identified, with seven meeting inclusion criteria. Ninety-four patients with an age range of 0.9–21 years old with esthesioneuroblastoma were included. Nearly 90% of patients were of stage Kadish B or C at time of presentation, while 20% presented with cervical lymphadenopathy. Only about 10% of patients underwent single modality therapy. Overall, 5-year survival ranged from 44 to 91% with a median follow-up of 3–13 years.

Conclusion: Children with esthesioneuroblastoma usually present at an advanced stage and undergo multi-modality therapy at a higher rate than adult patients. There is a wide range of documented overall survival though this lack of precision could be due to a paucity of patients.

Pattern of loco-regional relapses and treatment in pediatric esthesioneuroblastoma: The French very rare tumors group (Fracture) contribution

BACKGROUND

Esthesioneuroblastoma (ENB) is a rare neuroectodermal tumor that seldom occurs during childhood. Multimodal treatments are currently proposed, but the place of each therapy is still in debate. Our objective is to describe clinical evolution, especially the pattern of relapses and determine contributors to tumor progression.

PROCEDURE

Medical charts of all children (≤18 years) affected by ENB treated in France from January 1990 to December 2015 were retrospectively analyzed.

RESULTS

Eighteen patients were selected (10 males). Median age at diagnosis was 12.2 years (0.9-18). Tumor extension was Kadish stage A (n = 1), B (n = 3), C (n = 10), and D (n = 4). Hyams histological grades were I (n = 1), II (n = 3), III (n = 6), and IV (n = 6) (in two cases not defined). Initial cervical nodal spread was assessed by magnetic resonance imaging (n = 15), computed tomography scan (n = 16), fluorodeoxyglucose-positron emission tomography-computed tomography (n = 7), and cytological/histological analysis (n = 2). N1 stage was confirmed by imaging in two of 18 cases and one of two cases had cervical node dissection with neck irradiation (58 Gy). After a median follow-up of survivors of 7.6 years (3.8-17.9), 10 patients developed neuromeningeal progression, whereas no cervical nodal relapse occurred and only eight survived. Both 5-year overall and event-free survival rates were 44.4% (±11.7%).

CONCLUSIONS

The poor prognosis is mainly related to neuromeningeal dissemination that should be considered during treatment strategy. However, cervical lymph node relapse is rare.

Delaying Postoperative Radiotherapy in Low-Grade Esthesioneuroblastoma: Is It Worth the Wait?

Background  Consensus in timing of radiotherapy is yet to be established in esthesioneuroblastoma (ENB). Objective  This study was aimed to investigate if planned adjuvant radiotherapy improves tumor control after complete margin negative resection of low Hyams' grade (1 or 2) ENB. Methods  A retrospective review of patients with pathologically confirmed negative margin resection of Kadish's stage B or C and Hyams' grade 1 and 2 ENBs was conducted. Seventeen patients meeting the criteria were divided into the following two groups for cohort study: (1) those who underwent planned immediate postoperative adjuvant radiotherapy (IR group) and (2) those who did not (delayed radiotherapy [DR] group). Results  The IR group included nine patients (Kadish's stage B in one and stage C in eight; Hyams' grade 1 in two and grade 2 in seven). Mean follow-up was 140.8 months. Seven patients (78%) had disease progression (DP) at a median of 88 months (four with cervical lymph node metastasis [CLNM], one with distant metastasis, and two with both local recurrence and CLNM). One patient experienced frontal lobe abscess. The DR group included eight patients (Kadish's stage B in six and stage C in two; all Hyams' grade 2). Mean follow-up was 123.3 months. Four (50%) patients who developed DP (all local recurrence) were salvaged with surgery and adjuvant radiotherapy at a median of 37.5 months. There was no statistically significant difference in DP rate ( p  = 0.23), time to DP ( p  = 0.26), or the local tumor control rate ( p  = 0.23). Conclusion  In our limited cohort, immediate postoperative radiotherapy did not demonstrate superiority in tumor control, although risk of radiotherapy toxicity appears low.

Isolated leptomeningeal progression from sinonasal carcinomas: Implications for staging workup and treatment

PURPOSE

To evaluate the rate and risk factors of isolated leptomeningeal progression in sinonasal carcinomas.

METHODS

We retrospectively reviewed imaging and clinical records to determine progression patterns, and estimated rates using the Kaplan-Meier method. We evaluated risk factors using proportional hazard regression.

RESULTS

We analyzed 120 patients who received adjuvant or primary radiotherapy for sinonasal carcinomas. Most patients had T4 disease (68%) and underwent surgery (84%) and chemotherapy (72%). Twenty-seven (23%) patients developed distant metastases (DM), including 20 (17%) with isolated DMs. Leptomeningeal progression was the most common site of isolated DMs (n = 9; 45%) with an average disease-free interval of 1.2 years (0.1-4.3 years). High-grade histology (P = 0.0003), intracranial invasion (P < 0.0001), and neuroendocrine histology (P = 0.06) were associated with increased risk.

CONCLUSIONS

Isolated leptomeningeal progression is a common pattern of DM in advanced sinonasal carcinomas. We recommend adding cerebrospinal fluid cytology and contrast-enhanced spine MRI to routine staging evaluations for high-risk patients.

Proton Therapy for Juvenile Pilocytic Astrocytoma: Quantifying Treatment Responses by Magnetic Resonance Diffusion Tensor Imaging

Purpose

Proton therapy is increasingly used to treat pediatric brain tumors. However, the response of both tumors and healthy tissues to proton therapy is currently under investigation. One way of assessing this response is magnetic resonance (MR) diffusion tensor imaging (DTI), which can measure molecular mobility at the cellular level, quantified by the apparent diffusion coefficient (ADC). In addition, DTI may reveal axonal fiber directional information in white matter, quantified by fractional anisotropy (FA). Here we report use of DTI to assess tumor and unexposed healthy brain tissue responses in a child who received proton therapy for juvenile pilocytic astrocytoma.

Materials and Methods

A 10-year-old boy with recurrent juvenile pilocytic astrocytoma of the left thalamus received proton therapy to a dose of 50.4Gy (RBE) in 28 fractions. Functional magnetic resonance imaging was used to select beam angles for treatment planning. Over the course of the 7-year follow-up period, magnetic resonance imaging including DTI was done to assess response. The MR images were registered to the treatment-planning computed tomography scan, and the gross tumor volume (GTV) was mapped onto the MR images at each follow-up. The GTV contour was then mirrored to the right side of brain through the midline to represent unexposed healthy brain tissue.

Results

Proton therapy delivered the full prescribed dose to the target while completely sparing the contralateral brain. The MR ADC images obtained before and after proton therapy showed that enhancement corresponding to the GTV had nearly disappeared by 25 months. The ADC and FA measurements confirmed that contralateral healthy brain tissue was not affected, and the GTV reverted to clinically normal ADC and FA values.

Conclusion

Use of DTI allowed quantitative evaluation of tumor and healthy brain tissue responses to proton therapy.

Multimodality Treatment of Pediatric Esthesioneuroblastoma

BACKGROUND

Esthesioneuroblastoma (ENB) is a rare cancer of the nasal cavity in children. Radical surgery followed by postoperative radiation is considered the standard of care in adults. A similar approach in children can lead to significant long-term morbidity.

PROCEDURE

A retrospective multi-institutional review of patients less than 21 years of age diagnosed with ENB between 1990 and 2014 was performed. Clinical features, treatment, and outcome were obtained from the medical records.

RESULTS

Twenty-four patients were identified with a median age of 14 years (range 0.6-20 years) at diagnosis. The majority (75%) were females. Headache was the most common presenting symptom, followed by nasal obstruction and epistaxis. Eight patients had Kadish stage B tumors and 16 had Kadish stage C tumors. Nine patients had metastatic disease. Gross total resection was achieved at diagnosis in eight patients and after neoadjuvant chemotherapy in four patients. Twenty-one patients received radiation therapy (45-68.4 Gy). Thirteen patients received neoadjuvant chemotherapy with 84% objective response rate. Seven patients experienced disease progression or relapse-five in central nervous system, one local, and one in cervical lymph node. Fifteen patients were alive at the last follow-up. The 5-year disease-free survival and overall survival were 74% and 73%, respectively. Late effects were observed in 78% of long-term survivors. Four patients developed subsequent malignant neoplasms.

CONCLUSIONS

Pediatric ENB is a chemosensitive disease. Preoperative chemotherapy-based multimodal approach should be used in patients with advanced stage disease. Radiation therapy is effective for local control, but lower doses should be considered in children.