Patterns of failure in pediatric medulloblastoma and implications for hippocampal sparing

BACKGROUND

Hippocampal avoidance (HA) has been shown to preserve cognitive function in adult patients with cancer treated with whole-brain radiation therapy for brain metastases. However, the feasibility of HA in pediatric patients with brain tumors has not been explored because of concerns of increased risk of relapse in the peri-hippocampal region. Our aim was to determine patterns of recurrence and incidence of peri-hippocampal relapse in pediatric patients with medulloblastoma (MB).

METHODS AND MATERIALS

We identified pediatric patients with MB treated with protons between 2002 and 2016 and who had recurrent disease. To estimate the risk of peri-hippocampal recurrence, three hippocampal zones (HZs) were delineated corresponding to ≤5 mm (HZ-1), 6 to 10 mm (HZ-2), and >10 mm (HZ-3) distance of the recurrence from the contoured hippocampi. To determine the feasibility of HA, three standard-risk patients with MB were planned using either volumetric-modulated arc therapy (VMAT) or intensity-modulated proton therapy (IMPT) plans.

RESULTS

Thirty-eight patients developed a recurrence at a median of 1.6 years. Of the 25 patients who had magnetic resonance imaging of the recurrence, no patients failed within the hippocampus and only two patients failed within HZ-1. The crude incidence of peri-hippocampal failure was 8%. Both HA-VMAT and HA-IMPT plans were associated with significantly reduced mean dose to the hippocampi (p < .05). HA-VMAT and HA-IMPT plans were associated with decreased percentage of the third and lateral ventricles receiving the prescription craniospinal dose of 23.4 Gy.

CONCLUSIONS

Peri-hippocampal failures are uncommon in pediatric patients with MB. Hippocampal avoidance should be evaluated in a prospective cohort of pediatric patients with MB.

PLAIN LANGUAGE SUMMARY

In this study, the patterns of disease recurrence in patients with a pediatric brain tumor known as medulloblastoma treated with proton radiotherapy were examined. The majority of failures occur outside of an important structure related to memory formation called the hippocampus. Hippocampal sparing radiation plans using proton radiotherapy were generated and showed that dose to the hippocampus was able to be significantly reduced. The study provides the rationale to explore hippocampal sparing in pediatric medulloblastoma in a prospective clinical trial.

Long-term outcomes and late toxicity of adult medulloblastoma treated with combined modality therapy: A contemporary single-institution experience

BACKGROUND

Medulloblastoma (MB) is a rare central nervous system malignancy of adults, with limited contemporary studies to define treatment guidelines and expected late toxicity.

METHODS

A single-center, retrospective study was conducted of patients age ≥18 years from 1997-2019 with MB and who were treated with postoperative radiotherapy. Late toxicity was defined as a minimum of 18 months from diagnosis. Overall survival (OS) and progression-free survival (PFS) were characterized using Kaplan-Meier and Cox regression analyses.

RESULTS

Fifty-nine patients met criteria, with median age of 25 years (range 18-62 y) and median follow-up of 6.5 years (range 0.7-23.1 y). At diagnosis, 68% were standard-risk, 88% Chang M0, and 22% with anaplastic histology. Gross total resection was achieved in 75%; median craniospinal irradiation dose was 30.6 Gy (relative biological effectiveness [RBE]), median total dose was 54.0 Gy (RBE), 80% received proton radiotherapy; 81% received chemotherapy. 5 year PFS and OS were 86.5% and 95.8%, respectively; 10 year PFS and OS were 83.9% and 90.7%, respectively. Anaplastic histology was associated with worse PFS (P = .04). Among eight recurrences, 25% presented after 5 years. Most common grade ≥2 late toxicities were anxiety/depressive symptoms (30%), motor dysfunction (25%), and ototoxicity (22%). Higher posterior fossa radiation dose was associated with increased risk of late toxicity, including worse cognitive dysfunction (P = .05).

CONCLUSIONS

Adults with MB have favorable survival outcomes, but late failures and toxicity are not uncommon. Better understanding of prognostic factors, possibly from molecular subtyping, may help to define more personalized treatments for patients with high risk of recurrence and long-term treatment sequelae.

Denosumab for craniofacial fibrous dysplasia: duration of efficacy and post-treatment effects

Denosumab has been advocated as a potential treatment for the rare skeletal disorder fibrous dysplasia (FD); however, there is limited data to support safety and efficacy, particularly after drug discontinuation. We report a case of successful treatment of aggressive craniofacial FD with denosumab, highlighting novel insights into the duration of efficacy, surrogate treatment markers, and discontinuation effects. A 13-year-old girl presented with persistent pain and expansion of a maxillary FD lesion, which was not responsive to repeated surgical procedures or bisphosphonates. Pre-treatment biopsy showed high RANKL expression and localization with proliferation markers. Denosumab therapy was associated with improved pain, decreased bone turnover markers, and increased lesion density on computed tomography scan. During 3.5 years of treatment, the patient developed increased non-lesional bone density, and after denosumab discontinuation, she developed hypercalcemia managed with bisphosphonates. Pain relief and lesion stability continued for 2 years following treatment, and symptom recurrence coincided with increased bone turnover markers and decreased lesion density back to pre-treatment levels. This case highlights the importance of considering the duration of efficacy when treating patients with FD and other nonresectable skeletal neoplasms that require long-term management.

Clinical outcomes of pediatric patients with autism spectrum disorder and other neurodevelopmental disorders and intracranial germ cell tumors

INTRODUCTION

Intracranial germ cell tumors (IGCTs) are rare tumors of the central nervous system with peak incidence around puberty. Given the developmental origins of IGCTs, we investigated the prevalence of neurodevelopmental disorders (NDDs) in patients with IGCTs and characterized outcomes for patients with NDD and IGCTs.

METHODS

A retrospective review of medical records was conducted for 111 patients diagnosed with IGCTs between 1998 and 2018 and evaluated at the Massachusetts General Hospital. Kaplan-Meier method and log-rank test was used for survival analyses. Cox regression analyses were performed for parameters associated with progression-free survival (PFS).

RESULTS

Median age at IGCT diagnosis was 12.8 years (range: 4.3-21.7) and median follow-up was 6.5 years (range: 0.2-20.5). Eighteen patients were diagnosed with NDDs prior to IGCT diagnosis, including five patients with autism spectrum disorder (ASD). Of the 67 patients with pure germinomas, four (6.0 %) had prior ASD diagnoses. Patients with NDD had significantly inferior PFS in the nongerminomatous germ cell tumor (NGGCT) cohort. On univariate and multivariable analyses, craniospinal irradiation (CSI) was significantly associated with improved PFS in the NGGCT cohort.

CONCLUSIONS

Our study found an ASD prevalence in the pure germinoma cohort more than threefold greater than the national prevalence, suggesting an association between ASD and pure germinomas. Furthermore, patients with NDD and NGGCT had worse PFS, possibly due to fewer patients with NDD receiving CSI. Future prospective studies with larger cohorts are needed to examine associations between NDDs and IGCTs, and further characterize outcomes for patients with NDDs and IGCTs.

Intellectual functioning among case-matched cohorts of children treated with proton or photon radiation for standard-risk medulloblastoma

BACKGROUND

Proton therapy may reduce cognitive deficits after radiotherapy among brain tumor survivors, although current data are limited to retrospective comparisons between historical cohorts. The authors compared intelligence quotient scores within a case-matched cohort of children with medulloblastoma treated with proton radiation (PRT) or photon radiation (XRT) over the same time period.

METHODS

Among 88 consecutive patients with standard-risk medulloblastoma treated with PRT or XRT at 2 institutions from 2000 to 2009, 50 were matched 1:1 (25 with PRT and 25 with XRT) according to age, gender, date of diagnosis, histology, radiation boost, and craniospinal irradiation dose. One-way analyses of variance were performed to compare the Full-Scale Intelligence Quotient (FSIQ) and associated index scores between the 2 cohorts.

RESULTS

Neurocognitive data were available for 37 survivors (17 with PRT and 20 with XRT) from the matched cohort. The mean age was 8.5 years (SD, 4.14 years). The median follow-up was 5.3 years (range, 1.0-11.4 years) and 4.6 years (range, 1.1-11.2 years) for the PRT and XRT cohorts, respectively (P = .193). Patients treated with PRT had significantly higher mean FSIQ (99.6 vs 86.2; P = .021), verbal (105.2 vs 88.6; P = .010), and nonverbal scores (103.1 vs 88.9; P = .011) than the XRT-treated cohort. Differences in processing speed (82.9 vs 77.2; P = .331) and working memory (97.0 vs 92.7; P = .388) were not statistically significant.

CONCLUSIONS

Radiotherapy-associated cognitive effects appear to be more attenuated after proton therapy. Comprehensive prospective studies are needed to appropriately evaluate the neurocognitive advantages of proton therapy.

Long-term health-related quality of life in pediatric brain tumor survivors receiving proton radiotherapy at <4 years of age

BACKGROUND

The purpose of this analysis is to report long-term health-related quality of life (HRQoL) among brain tumor survivors treated with proton therapy (PRT) at a very young age.

METHODS

Fifty-nine children <4 years old received PRT between 2000 and 2011. Forty families participated. HRQoL was assessed by child self-report (CSR; age ≥5) and parent proxy report (PPR; age 2+) using the PedsQL Core.

RESULTS

The median age was 2.5 years (range, 0.3-3.8) at PRT and 9.1 years (5.5-18) at last follow-up. The most common diagnoses were ependymoma (n = 22) and medulloblastoma (n = 7). Median follow-up is 6.7 years (3-15.4). Follow-up mean CSR and PPR scores were: total core (78.4 and 72.9), physical (82.9 and 75.2), psychosocial (76.0 and 71.6), emotional (74.4 and 70.7), social (81.2 and 75.1), and school (72.4 and 69.9). Parent-reported HRQoL fell within a previously defined range for healthy children in 37.5% of patients, and for children with severe health conditions in 45% of patients. PPR HRQoL was stable from baseline to last follow-up among all domains except for social functioning. History of gastrostomy tube was significantly associated with poorer CSR and PPR HRQoL on multivariable analysis. Ninety percent of children functioned in a regular classroom, 14 (36%) used a classroom aid, 9 (23%) used an outside tutor, and 18 (46%) had an individualized education plan.

CONCLUSION

Long-term HRQoL among brain tumor survivors treated with PRT at a very young age is variable, with over a third achieving HRQoL levels commensurate with healthy children.

KEY POINTS

1. One third of survivors reported long-term HRQoL scores comparable to those of healthy children.2. Treatment for hydrocephalus or a feeding tube was associated with significantly lower HRQoL.3. Total core HRQoL scores remained stable from baseline to last follow-up.

Clinical outcomes in a large pediatric cohort of patients with ependymoma treated with proton radiotherapy

BACKGROUND

Treatment for pediatric ependymoma includes surgical resection followed by local radiotherapy (RT). Proton RT (PRT) enables superior sparing of critical structures compared with photons, with potential to reduce late effects. We report mature outcomes, patterns of failure, and predictors of outcomes in patients treated with PRT.

METHODS

One hundred fifty patients (<22 y) with World Health Organization grades II/III ependymoma were treated with PRT between January 2001 and January 2019 at Massachusetts General Hospital. Demographic, tumor, and treatment-related characteristics were analyzed. Event-free survival (EFS), overall survival (OS), and local control (LC) were assessed.

RESULTS

Median follow-up was 6.5 years. EFS, OS, and LC for the intracranial cohort (n = 145) at 7 years were 63.4%, 82.6%, and 76.1%. Fifty-one patients recurred: 26 (51.0%) local failures, 19 (37.3%) distant failures, and 6 (11.8%) synchronous failures. One hundred sixteen patients (77.3%) underwent gross total resection (GTR), 5 (3.3%) underwent near total resection (NTR), and 29 (19.3%) underwent subtotal resection (STR). EFS for the intracranial cohort at 7 years for GTR/NTR and STR was 70.3% and 35.2%. With multivariate analysis, the effect of tumor excision persisted after controlling for tumor location. There was no adverse effect on disease control if surgery to RT interval was within 9 weeks of GTR/NTR.

CONCLUSION

PRT is effective and safe in pediatric ependymoma. Similar to previous studies, GTR/NTR was the most important prognostic factor. Intervals up to 9 weeks from surgery to PRT did not compromise disease outcomes. There was no LC benefit between patients treated with >54 Gray relative biological effectiveness (GyRBE) versus ≤54 GyRBE.

Effects of dexrazoxane on doxorubicin-related cardiotoxicity and second malignant neoplasms in children with osteosarcoma: a report from the Children's Oncology Group

Background

Dexrazoxane protects from lower-cumulative-dose doxorubicin cardiotoxicity, but the effect of dexrazoxane in children with sarcoma treated with higher-cumulative-dose doxorubicin is unknown.

Methods

We evaluated children with osteosarcoma (OS) on two Children's Oncology Group trials with higher dose doxorubicin (375-600 mg/m²) preceded by dexrazoxane (10:1 dexrazoxane:doxorubicin dosing). They were evaluated after the minimum expected treatment time (METT), defined as 28 weeks. Cardiotoxicity was identified by echocardiography and serum N-terminal pro-brain natriuretic peptide (NT-proBNP). Second malignant neoplasm (SMN) data was collected.

Results

All children had normal left ventricular (LV) systolic function as measured by LV fractional shortening and no heart failure. The end-diastolic septal thickness Z-scores (P < 0.01) and LV mass Z-scores (P < 0.01) were significantly smaller than normal for body-surface area in both sexes. The average LV mass Z-scores were significantly smaller for girls (P < 0.01) and marginally smaller for boys (P = 0.06). Girls had significantly smaller LV end-diastolic dimension Z-scores normalized to BSA (P < 0.01) compared to healthy controls and had significant increases in NT-proBNP. Four children developed SMNs as first events, a rate similar to historical controls.

Conclusions

Dexrazoxane prevented LV dysfunction and heart failure in children with OS receiving higher dose doxorubicin. However, LV structural changes were not fully prevented, especially in girls. As a result, hearts become abnormally small for body size, resulting in higher LV stress. Dexrazoxane did not increase the risk of SMN. Dexrazoxane should be used in this population, particularly for girls, to mitigate anthracycline-induced cardiotoxicity.

Trial registrations

ClinicalTrials.gov: NCT00003937 (P9754) registered 1 Nov 1999, and NCT00023998 (AOST0121) registered 13 Sept 2001.

Characteristics and Predictors for Secondary Leukemia and Myelodysplastic Syndrome in Ewing and Osteosarcoma Survivors

PURPOSE

Long-term survivors of Ewing sarcoma (ES) and osteosarcoma may be at risk for therapy-related acute leukemia or myelodysplastic syndrome (t-AL/MDS).

METHODS AND MATERIALS

We retrospectively reviewed the clinicopathologic characteristics of 1071 patients with osteosarcoma (n = 757) and ES (n = 314) who were treated between 1985 and 2014. Multivariable competing risk analysis was used to analyze predictors of t-AL/MDS, including a radiation dose (≥55.8 Gy vs <55.8 Gy) × disease site (pelvis/spine vs other) interaction term. A supplemental nested case-control study was conducted to assess the association between cumulative chemotherapy dose and t-AL/MDS.

RESULTS

The median follow-up for surviving patients was 97 months (range, 0.03-380). Twenty patients developed t-AL/MDS, all of whom received chemotherapy and 15 of whom were treated with radiation therapy. Radiation therapy to ≥55.8 Gy was associated with development of t-AL/MDS (adjusted hazard ratio, 2.89; 95% confidence interval [CI], 1.23-6.80; P = .015), and there was a significant radiation dose × disease site interaction term (adjusted hazard ratio, 6.70; 95% CI, 2.71-16.53; P_interaction < .001). The 5-year cumulative incidence of t-AL/MDS in patients receiving ≥55.8 Gy radiation therapy to the pelvis or spine was 5.0% (95% CI, 0.9-14.9) for osteosarcoma and 10.7% for ES (95% CI, 3.3-23.2). In our nested case-control study, cumulative doses of ifosfamide and etoposide were associated with development of t-AL/MDS.

CONCLUSIONS

Patients with osteosarcoma and ES receiving ≥55.8 Gy of radiation therapy to the pelvis or spine appear to be at increased risk for t-AL/MDS. Treatment with high cumulative doses of chemotherapy may further augment this risk.

Endocrine Deficiency As a Function of Radiation Dose to the Hypothalamus and Pituitary in Pediatric and Young Adult Patients With Brain Tumors

PURPOSE

There are sparse data defining the dose response of radiation therapy (RT) to the hypothalamus and pituitary in pediatric and young adult patients with brain tumors. We examined the correlation between RT dose to these structures and development of endocrine dysfunction in this population.

MATERIALS AND METHODS

Dosimetric and clinical data were collected from children and young adults (< 26 years of age) with brain tumors treated with proton RT on three prospective studies (2003 to 2016). Deficiencies of growth hormone (GH), thyroid hormone, adrenocorticotropic hormone, and gonadotropins were determined clinically and serologically. Incidence of deficiency was estimated using the Kaplan-Meier method. Multivariate models were constructed accounting for radiation dose and age.

RESULTS

Of 222 patients in the study, 189 were evaluable by actuarial analysis, with a median follow-up of 4.4 years (range, 0.1 to 13.3 years), with 31 patients (14%) excluded from actuarial analysis for having baseline hormone deficiency and two patients (0.9%) because of lack of follow-up. One hundred thirty patients (68.8%) with medulloblastoma were treated with craniospinal irradiation (CSI) and boost; most of the remaining patients (n = 56) received involved field RT, most commonly for ependymoma (13.8%; n = 26) and low-grade glioma (7.4%; n = 14). The 4-year actuarial rate of any hormone deficiency, growth hormone, thyroid hormone, adrenocorticotropic hormone, and gonadotropin deficiencies were 48.8%, 37.4%, 20.5%, 6.9%, and 4.1%, respectively. Age at start of RT, time interval since treatment, and median dose to the combined hypothalamus and pituitary were correlated with increased incidence of deficiency.

CONCLUSION

Median hypothalamic and pituitary radiation dose, younger age, and longer follow-up time were associated with increased rates of endocrinopathy in children and young adults treated with radiotherapy for brain tumors.

Quality of life in patients with proton-treated pediatric medulloblastoma: Results of a prospective assessment with 5-year follow-up

BACKGROUND

To the authors' knowledge, health-related quality of life (HRQOL) outcomes are not well described in patients with medulloblastoma. The use of proton radiotherapy (RT) may translate into an improved HRQOL. In the current study, the authors report long-term HRQOL in patients with proton-treated pediatric medulloblastoma.

METHODS

The current study was a prospective cohort HRQOL study of patients with medulloblastoma who were treated with proton RT and enrolled between August 5, 2002, and October 8, 2015. Both child report and parent-proxy report Pediatric Quality of Life Inventory (PedsQL) surveys were collected at baseline during RT and annually thereafter (score range on surveys of 0-100, with higher scores indicating better HRQOL). Patients were dichotomized by clinical/treatment variables and subgroups were compared. Mixed-model analysis was performed to determine the longitudinal trajectory of PedsQL scores. The Student t test was used to compare long-term HRQOL measures with published means from a healthy child population.

RESULTS

Survey data were evaluable for 116 patients with a median follow-up of 5 years (range, 1-10.6 years); the median age at the time of diagnosis was 7.6 years (range, 2.1-18.1 years). At baseline, children reported a total core score (TCS) of 65.9, which increased by 1.8 points annually (P<.001); parents reported a TCS of 59.1, which increased by 2.0 points annually. Posterior fossa syndrome adversely affected baseline scores, but these scores significantly improved with time. At the time of last follow-up, children reported a TCS of 76.3, which was 3.3 points lower than that of healthy children (P = .09); parents reported a TCS of 69, which was 11.9 points lower than that of parents of healthy children (P<.001). Increased follow-up time from diagnosis correlated with improved HRQOL scores.

CONCLUSIONS

HRQOL scores appear to increase over time after treatment in children treated with proton RT for medulloblastoma but remain lower compared with those of parent-proxy reports as well as published means from a healthy normative sample of children. Additional follow-up may translate into continued improvements in HRQOL. Cancer 2018. © 2018 American Cancer Society.

Early clinical observations on the use of imatinib mesylate in FOP: A report of seven cases

BACKGROUND

Fibrodysplasia ossificans progressiva (FOP) is an ultrarare genetic disorder of progressive, disabling heterotopic ossification (HO) for which there is presently no definitive treatment. Research studies have identified multiple potential targets for therapy in FOP, and novel drug candidates are being developed for testing in clinical trials. A complementary approach seeks to identify approved drugs that could be re-purposed for off-label use against defined targets in FOP. One such drug is imatinib mesylate, a tyrosine kinase inhibitor originally developed for use in patients with chronic myeloid leukemia (CML). Imatinib has the desirable effect of attacking multiple targets involved in the early hypoxic and inflammatory stages of FOP flare-ups, including HIF1-α, PDGFRα, c-KIT, and multiple MAP kinases.

RESULTS

Based on compelling biologic rationale, strong preclinical data, and a favorable safety profile, imatinib has been prescribed on an off-label basis in a non-trial setting in seven children with continuous FOP flare-ups, predominantly in the axial regions, and which were not responsive to standard-of-care regimens. Anecdotal reports in these seven isolated cases document that the medication was well-tolerated with a ubiquitous reported decrease in the intensity of flare-ups in the six children who took the medication.

CONCLUSIONS

These early clinical observations support the implementation of clinical trials in children with uncontrolled FOP flare-ups to determine if imatinib may ameliorate symptoms or alter the natural history of this debilitating and life-threatening disease.

Genetic Analysis of Giant Cell Lesions of the Maxillofacial and Axial/Appendicular Skeletons

PURPOSE

To compare the genetic and protein expression of giant cell lesions (GCLs) of the maxillofacial (MF) and axial/appendicular (AA) skeletons. We hypothesized that when grouped according to biologic behavior and not simply by location, MF and AA GCLs would exhibit common genetic characteristics.

MATERIALS AND METHODS

This was a prospective and retrospective study of patients with GCLs treated at Massachusetts General Hospital from 1993 to 2008. In a preliminary prospective study, fresh tissue from 6 aggressive tumors each from the MF and AA skeletons (n = 12 tumors) was obtained. RNA was extracted and amplified from giant cells (GCs) and stromal cells first separated by laser capture microdissection. Genes highly expressed by GCs and stroma at both locations were determined using an Affymetrix GeneChip analysis. As confirmation, a tissue microarray (TMA) was created retrospectively from representative tissue of preserved pathologic specimens to assess the protein expression of the commonly expressed genes found in the prospective study. Quantification of immunohistochemical staining of MF and AA lesions was performed using Aperio image analysis to determine whether immunoreactivity was predictive of aggressive or nonaggressive behavior.

RESULTS

Five highly ranked genes were found commonly in GCs and stroma at each location: matrix metalloproteinase-9 (MMP-9), cathepsin K (CTSK), T-cell immune regulator-1 (TCIRG1), C-type lectin domain family-11, and zinc finger protein-836. MF (n = 40; 32 aggressive) and AA (n = 48; 28 aggressive) paraffin-embedded tumors were included in the TMA. The proteins CTSK, MMP-9, and TCIRG1 were confirmed to have abundant expression within both MF and AA lesions. Only the staining levels for TCIRG1 within the GCs predicted the clinical behavior of the MF lesions.

CONCLUSIONS

MMP-9, CTSK, and TCIRG1 are commonly expressed by GCLs of the MF and AA skeletons. This supports the hypothesis that these lesions are similar but at different locations. TCIRG1 has not been previously associated with GCLs and could be a potential target for molecular diagnosis and/or therapy.

Incidence of CNS Injury for a Cohort of 111 Patients Treated With Proton Therapy for Medulloblastoma: LET and RBE Associations for Areas of Injury

BACKGROUND

Central nervous system (CNS) injury is a rare complication of radiation therapy for pediatric brain tumors, but its incidence with proton radiation therapy (PRT) is less well defined. Increased linear energy transfer (LET) and relative biological effectiveness (RBE) at the distal end of proton beams may influence this risk. We report the incidence of CNS injury in medulloblastoma patients treated with PRT and investigate correlations with LET and RBE values.

METHODS AND MATERIALS

We reviewed 111 consecutive patients treated with PRT for medulloblastoma between 2002 and 2011 and selected patients with clinical symptoms of CNS injury. Magnetic resonance imaging (MRI) findings for all patients were contoured on original planning scans (treatment change areas [TCA]). Dose and LET distributions were calculated for the treated plans using Monte Carlo system. RBE values were estimated based on LET-based published models.

RESULTS

At a median follow-up of 4.2 years, the 5-year cumulative incidence of CNS injury was 3.6% for any grade and 2.7% for grade 3+. Three of 4 symptomatic patients were treated with a whole posterior fossa boost. Eight of 10 defined TCAs had higher LET values than the target but statistically nonsignificant differences in RBE values (P=.12).

CONCLUSIONS

Central nervous system and brainstem injury incidence for PRT in this series is similar to that reported for photon radiation therapy. The risk of CNS injury was higher for whole posterior fossa boost than for involved field. Although no clear correlation with RBE values was found, numbers were small and additional investigation is warranted to better determine the relationship between injury and LET.

Proton therapy for pediatric and adolescent esthesioneuroblastoma

BACKGROUND

Esthesioneuroblastoma (EN) of the paranasal sinus comprises less than 3% of tumors of in pediatric and adolescent patients [1]. The collective adult literature indicates a critical role for radiotherapy in attaining cure [2], yet pediatric outcome data is limited. Radiation in pediatric patients with EN can cause significant morbidity due to the proximity of critical structures. Proton radiotherapy offers a potential dosimetric benefit that may improve long-term survival and toxicity outcomes in the pediatric population [3].

METHODS

We retrospectively identified eight patients treated for EN with proton radiotherapy from 2000-2013. Times to event clinical endpoints are summarized using the Kaplan-Meier methods and are from the date of radiotherapy completion. Toxicities are reviewed and graded according to CTCAE v. 4.0.

RESULTS

Median follow up was 4.6 years for survivors (range 0.8-9.4 years). The 4 year overall survival was 87.5%. Four of eight patients (one elective) had comprehensive neck radiotherapy. No local or regional failures were observed. Two patients failed distantly with diffuse leptomeningeal disease and intraparenchymal brain metastases, at 0.6 and 1.3 months respectively. Four patients developed radiation related late toxicities including endocrine dysfunction, two cases of grade 2 retinopathy and one case of grade 3 optic neuropathy.

CONCLUSIONS

In a limited cohort, proton radiotherapy appears to provide excellent locoregional disease control even in those patients with locally advanced disease and intracranial extension. Distant failure determined overall survival in our cohort. Toxicities were acceptable given disease location and extent.

Novel molecular pathways in Gorham disease: implications for treatment

Rapid advances in evidence-based treatment schedules are a hallmark of modern oncology. In rare neoplastic diseases, however, clinical expertise is hard to build and evidence based on randomized trials almost impossible to collect. Gorham disease is a rare form of lymphatic proliferation accompanied by osteolysis, which usually occurs in young adults. Despite the fact that the clinical course of Gorham disease is often devastating and occasionally fatal, insights into its biological background are sparse and standardized treatment unavailable. Interestingly, recent knowledge on the mechanisms of lymphangiogenesis may help elucidate the pathophysiology of Gorham disease and lead to novel treatment targets. Here, we discuss our current understanding of Gorham disease, discuss established and emerging therapeutic strategies, and attempt to frame a treatment rationale.

Do histologic criteria predict biologic behavior of giant cell lesions?

PURPOSE

To determine whether the clinical behavior of giant cell lesions (GCLs) or their anatomic location can be differentiated by histologic criteria alone.

MATERIALS AND METHODS

We performed a retrospective study of patients with GCLs treated at Massachusetts General Hospital between 1993 and 2008. Predictor variables were histologic parameters: number of giant cells (GCs) per high-power field, number of nuclei per GC, GC size, stromal cellularity, stromal type, presence of hemorrhage and reactive osteoid, and blinded pathologists' prediction of location and behavior. Outcome variables were clinical behavior (aggressive or nonaggressive) and GCL location, that is, maxillofacial (MF) or axial/appendicular (AA). Descriptive and bivariate statistics were computed with statistical significance set at P ≤ .05.

RESULTS

The sample included 88 subjects: 41 MF GCLs (35 aggressive) and 47 AA GCLs (28 aggressive). Aggressive AA lesions had more GCs per high-power field, larger mean GC size, and increased stromal cellularity, and they more frequently had a mononuclear stroma when compared with aggressive MF lesions (P < .05). There were no significant histologic differences between aggressive and nonaggressive MF lesions or between nonaggressive MF and nonaggressive AA lesions. Aggressive AA lesions had more nuclei/GC than nonaggressive AA lesions (P = .03). Using histologic criteria only, blinded pathologists predicted clinical behavior in only 45% of cases (κ = 0.19, P = .09). They predicted a lesion's location in 82% of cases with fair agreement (κ = 0.44, P < .01).

CONCLUSIONS

Results of this study indicate that histologic differences between aggressive and nonaggressive GCLs are insufficient for pathologists to differentiate them consistently regardless of location.

Outcome for adolescent and young adult patients with osteosarcoma: a report from the Children's Oncology Group

BACKGROUND

There are conflicting data regarding age as a prognostic factor in osteosarcoma. The authors conducted a study evaluating the impact of age on prognosis in children and young adults with osteosarcoma enrolled on North American cooperative group trials.

METHODS

Patients with high-grade osteosarcoma of any site enrolled on North American cooperative group trials CCG-7943, POG-9754, INT-0133, and AOST0121 were included in this study. Primary tumor site, age, sex, ethnicity, histologic response, and presence of metastatic disease at diagnosis were evaluated for their impact on overall survival (OS) and event-free survival (EFS).

RESULTS

A total of 1054 patients were eligible and had complete data available for the study. Age was not significantly associated with any other presenting covariate analyzed except sex. Age 18 or older was associated with a statistically significant poorer EFS (P = .019) and OS (P = .043). The 10-year EFS and OS in patients <10, 10 to 17, and ≥18 years old were 55%, 55%, 37% and 68%, 60%, 41%, respectively. The poorer EFS in patients ≥18 years old was because of an increased rate of relapse. Presence of metastatic disease at diagnosis, poor histologic response, and pelvic tumor site were also associated with a poorer prognosis. In multivariate analysis, age continued to be associated with poorer EFS (P = .019) and OS (P = .049).

CONCLUSIONS

In osteosarcoma, age 18 to 30 years is associated with a statistically significant poorer outcome because of an increased rate of relapse. Poorer outcome in adolescent and young adult patients is not explained by tumor location, histologic response, or metastatic disease at presentation.

Proton-based radiotherapy for unresectable or incompletely resected osteosarcoma

BACKGROUND

A study was undertaken to assess clinical outcome and the role of proton therapy for local control of osteosarcoma (OSA).

METHODS

All patients who received proton therapy or mixed photon-proton radiotherapy from 1983 to 2009 at the Massachusetts General Hospital were reviewed. Criteria for proton therapy were the need for high dose in the context of highly conformal radiotherapy of unresected or partially resected OSA, positive postoperative margins, postoperative imaging studies with macroscopic disease, or incomplete resection as defined by the surgeon. The primary endpoint was local control of the site treated; secondary endpoints were disease-free survival (DFS), overall survival (OS), long-term toxicity, and prognostic factors associated with clinical outcome.

RESULTS

Fifty-five patients with a median age of 29 years (range, 2-76 years) were offered proton therapy. The mean dose was 68.4 gray (Gy; standard deviation, 5.4 Gy). Of the total dose, 58.2% (range, 11%-100%) was delivered with protons. Local control after 3 and 5 years was 82% and 72%, respectively. The distant failure rate was 26% after 3 and 5 years. The 5-year DFS was 65%, and the 5-year OS was 67%. The extent of surgical resection did not correlate with outcome. Risk factors for local failure were ≥ 2 grade disease (P < .0001) and total treatment length (P = .008). Grade 3 to 4 late toxicity was seen in 30.1 % of patients. One patient died from treatment-associated acute lymphocytic leukemia, and 1 from secondary carcinoma of the maxilla.

CONCLUSIONS

Proton therapy to deliver high radiotherapy doses allows locally curative treatment for some patients with unresectable or incompletely resected OSA.

Platelet-derived growth factor receptor-beta in Gorham's disease

BACKGROUND

A 17-year-old male presented with pain in his lower-left chest. He had no significant medical history and was previously in good health. He had a fractured ninth left anterior rib and the tenth, eleventh and twelfth ribs were absent, which was thought to be a congenital anomaly. Several months later, he presented again with back pain, an enlarging mass in the lower-left chest wall, erosion of the lateral pedicles of the lower thoracic vertebrae and pleural effusion.

INVESTIGATIONS

Physical examination, chest X-ray, MRI of the spine, incisional biopsy, serial CT imaging of the hemithorax, immunohistochemistry, flow cytometry, and enzyme-linked immunosorbent assays.

DIAGNOSIS

Gorham's lymphangiomatosis with expression of platelet-derived growth factor receptor-beta and elevated circulating platelet-derived growth factor-BB.

MANAGEMENT

Spine stabilization, thalidomide, celecoxib, interferon-alpha2b, pamidronate, zoledronate, thoracotomy, pleurectomy, talc pleurodesis, and imatinib mesylate.

Diagnosis and treatment of childhood acute myelogenous leukemia

Acute myelogenous leukemia (AML) accounts for about 20% of the acute leukemias seen in children. In contrast to childhood acute lymphoblastic leukemia (ALL), there has only been a modest improvement in the cure rate of children with AML during the past two decades. Approximately 40% of children treated with chemotherapy alone are long-term survivors. The outcome is somewhat better for those children who are given bone marrow transplants from histocompatible sibling donors early in the first remission. During the last decade, however, new insights into the molecular basis of AML has increased our understanding of the pathogenesis and biology of this group of leukemias and are beginning to provide us with new therapeutic strategies.

Spinal cord compression in widely metastatic Wilms' tumor. Paraplegia in two children with anaplastic Wilms' tumor

Spinal cord compression in Wilms' tumor is a rare event, generally caused by invasion of the canal by paraspinal lesions or metastatically involved vertebral bodies. This case report reviews the clinical presentation, radiologic evaluation, and emergent therapy in two cases of spinal cord compromise involving patients with widely metastatic Wilms' tumor. One of these is the only known report of intradural metastasis in a child with this malignancy. Both cases illustrate the importance of anticipating and rapidly responding to neurologic complications that may arise in patients with aggressively metastatic Wilms' tumor.