Henry Mandeville

Integrated Molecular Meta-Analysis of 1,000 Pediatric High-Grade and Diffuse Intrinsic Pontine Glioma

Summary We collated data from 157 unpublished cases of pediatric high-grade glioma and diffuse intrinsic pontine glioma and 20 publicly available datasets in an integrated analysis of >1,000 cases. We identified co-segregating mutations in histone-mutant subgroups including loss of FBXW7 in H3.3G34R/V, TOP3A rearrangements in H3.3K27M, and BCOR mutations in H3.1K27M. Histone wild-type subgroups are refined by the presence of key oncogenic events or methylation profiles more closely resembling lower-grade tumors. Genomic aberrations increase with age, highlighting the infant population as biologically and clinically distinct. Uncommon pathway dysregulation is seen in small subsets of tumors, further defining the molecular diversity of the disease, opening up avenues for biological study and providing a basis for functionally defined future treatment stratification.

An emerging evidence base for PET-CT in the management of childhood rhabdomyosarcoma: systematic review

Introduction Rhabdomyosarcoma (RMS) management depends on risk stratification at diagnosis and treatment response. Assessment methods include CT, MRI, bone scintigraphy, histological analysis and bone marrow biopsy. Advanced functional imaging (FI) has potential to improve staging accuracy and management strategies. Methods and analysis We conducted a systematic review (PROSPERO 2013:CRD42013006128) of diagnostic accuracy and clinical effectiveness of FI in histologically proven paediatric RMS. PRISMA guidance was followed. We searched 10 databases to November 2013. Studies with ≥10 patients with RMS which compared positron emission tomography (PET), PET-CT or diffusion-weighted imaging (DWI) MRI to conventional imaging at any treatment stage were included. Study quality was assessed. Limited, heterogeneous effectiveness data required narrative synthesis, illustrated by plotting sensitivity and specificity in receiver operating curve (ROC) space. Results Eight studies (six PET-CT, two PET) with 272 RMS patients in total were included. No DWI-MRI studies met inclusion criteria. Pooled estimates were not calculated due to sparseness of data. Limited evidence indicated initial PET-CT results were predictive of survival. PET-CT changed management of 7/40 patients. Nodal involvement PET-CT: sensitivity ranged from 80% to 100%; specificity from 89% to 100%. Distant metastatic involvement: PET-CT sensitivity ranged from 95% to 100%; specificity from 80% to100%. Data on metastases in different sites were sparse. Limited data were found on outcome prediction by PET-CT response. Dissemination and ethics PET/PET-CT may increase initial staging accuracy in paediatric RMS, specifically in the detection of nodal involvement and distant metastatic spread. There is a need to further assess PET-CT for this population, ideally in a representative, unbiased and transparently selected cohort of patients.

Adverse events of local treatment in long-term head and neck rhabdomyosarcoma survivors after external beam radiotherapy or AMORE treatment

BACKGROUND Radiotherapy is a well-known cause of adverse events (AEs). To reduce AEs, an innovative local treatment was developed in Amsterdam: Ablative surgery, MOuld brachytherapy and surgical REconstruction (AMORE). AIMS (1) to determine the prevalence of AEs in HNRMS survivors and (2) to compare AEs between survivors treated with the international standard: external beam radiotherapy (EBRT-based: London) and survivors treated with AMORE if feasible, otherwise EBRT (AMORE-based: Amsterdam). METHODS All HNRMS survivors, treated in London or Amsterdam between January 1990 and December 2010 (n = 153), and alive ⩾ 2 years post-treatment were eligible (n = 113). A predefined list of AEs was assessed in a multidisciplinary clinic and graded according to the Common Terminology Criteria for Adverse Events. RESULTS Eighty HNRMS survivors attended the clinic (median follow-up 10.5 years); 63% experienced ⩾ 1 severe or disabling event, and 76% had ⩾ 5 AEs (any grade). Survivors with EBRT-based treatment were, after adjustment for site, age at diagnosis, and follow-up duration, at increased risk to develop any grade 3/4 event or ⩾ 5 AEs (any grade) compared with survivors with AMORE-based treatments (p = 0.032 and 0.01, respectively). Five year overall survival (source population) after EBRT-based treatment was 75.0%, after AMORE-based treatment 76.9%, p = 0.56. CONCLUSION This study may serve as a baseline inventory and can be used in future studies for prospective assessments of AEs following the introduction of novel local treatment modalities. AMORE-based local treatment resulted in similar overall survival and a reduction of AEs secondary to local treatment.

Non-coplanar trajectories to improve organ at risk sparing in volumetric modulated arc therapy for primary brain tumors

BACKGROUND AND PURPOSE To evaluate non-coplanar volumetric modulated arc radiotherapy (VMAT) trajectories for organ at risk (OAR) sparing in primary brain tumor radiotherapy. MATERIALS AND METHODS Fifteen patients were planned using coplanar VMAT and compared against non-coplanar VMAT plans for three trajectory optimization techniques. A geometric heuristic technique (GH) combined beam scoring and Dijkstras algorithm to minimize the importance-weighted sum of OAR volumes irradiated. Fluence optimization was used to perform a local search around coplanar and GH trajectories, producing fluence-based local search (FBLS) and FBLS+GH trajectories respectively. RESULTS GH, FBLS, and FBLS+GH trajectories reduced doses to the contralateral globe, optic nerve, hippocampus, temporal lobe, and cochlea. However, FBLS increased dose to the ipsilateral lens, optic nerve and globe. Compared to GH, FBLS+GH increased dose to the ipsilateral temporal lobe and hippocampus, contralateral optics, and the brainstem and body. GH and FBLS+GH trajectories reduced bilateral hippocampi normal tissue complication probability (p=0.028 and p=0.043, respectively). All techniques reduced PTV conformity; GH and FBLS+GH trajectories reduced homogeneity but less so for FBLS+GH. CONCLUSIONS The geometric heuristic technique best spared OARs and reduced normal tissue complication probability, however incorporating fluence information into non-coplanar trajectory optimization maintained PTV homogeneity.

Endocrine disorders among long-term survivors of childhood head and neck rhabdomyosarcoma

PURPOSE Head and neck rhabdomyosarcoma (HNRMS) survivors are at increased risk of developing pituitary dysfunction as an adverse event of radiotherapy. Our aim was to investigate the frequency and risk factors for pituitary dysfunction in these survivors. Secondly, we aimed to compare the prevalence of pituitary dysfunction between survivors treated with external beam radiation therapy (EBRT) and survivors treated with the ablative surgery, moulage technique after loading brachytherapy, and surgical reconstruction (AMORE) procedure. METHODS Eighty HNRMS survivors treated in London (EBRT based) and Amsterdam (AMORE based: AMORE if feasible, otherwise EBRT) in the period 1990-2010 and alive ≥ 2 years post-treatment were evaluated. Survivors were evaluated in multidisciplinary late-effects clinics, with measurement of linear growth, determination of thyroid function, and growth hormone parameters. Additional data, such as baseline characteristics, anthropometrics, pubertal stage, and the results of additional laboratory investigations, were retrieved from patient charts. RESULTS Pituitary dysfunction was diagnosed in 24 in 80 (30%) survivors, after a median follow-up time of 11 years. Median time to develop pituitary dysfunction after HNRMS diagnosis was 3.0 years. Risk factors were EBRT-based therapy (odds ratio [OR] 2.06; 95% confidence interval [CI] 1.79-2.46), parameningeal tumour site (OR 1.83; 95% CI 1.60-2.17) and embryonal RMS histology (OR 1.49; 95% CI 1.19-1.90). CONCLUSIONS Radiotherapy used for the treatment of HNRMS confers a significant risk of the development of pituitary dysfunction. AMORE-based treatment in children with HNRMS resulted in less pituitary dysfunction than treatment with conventional EBRT. Our findings underscore the importance of routine early endocrine follow-up in this specific population.

Individualized 131I-mIBG therapy in the management of refractory and relapsed neuroblastoma.

ObjectiveIodine-131-labelled meta-iodobenzylguanidine (131I-mIBG) therapy is an established treatment modality for relapsed/refractory neuroblastoma, most frequently administered according to fixed or weight-based criteria. We evaluate response and toxicity following a dosimetry-based, individualized approach. Materials and methodsA review of 44 treatments in 25 patients treated with 131I-mIBG therapy was performed. Patients received 131I-mIBG therapy following relapse (n=9), in refractory disease (n=12), or with surgically unresectable disease despite conventional treatment (n=4). Treatment schedule (including mIBG dose and number of administrations) was individualized according to the clinical status of the patient and dosimetry data from either a tracer study or previous administrations. Three-dimensional tumour dosimetry was also performed for eight patients. ResultsThe mean administered activity was 11089±7222 MBq and the mean whole-body dose for a single administration was 1.79±0.57 Gy. Tumour-absorbed doses varied considerably (3.70±3.37 mGy/MBq). CTCAE grade 3/4 neutropenia was documented following 82% treatments and grade 3/4 thrombocytopenia following 71% treatments. Further acute toxicity was found in 49% of patients. All acute toxicities resolved with appropriate therapy. The overall response rate was 58% (complete or partial response), with a further 29% of patients having stable disease. ConclusionA highly personalized approach combining patient-specific dosimetry and clinical judgement enables delivery of high activities that can be tolerated by patients, particularly with stem cell support. We report excellent response rates and acceptable toxicity following individualized 131I-mIBG therapy.

Hearing loss in survivors of childhood head and neck rhabdomyosarcoma: a long-term follow-up study

To determine the hearing status of survivors treated for head and neck rhabdomyosarcoma (HNRMS) at long‐term follow‐up.

Local Failure in Parameningeal Rhabdomyosarcoma Correlates With Poor Response to Induction Chemotherapy

BACKGROUND Local control remains a challenge in pediatric parameningeal rhabdomyosarcoma (PM-RMS), and survival after local failure (LF) is poor. Identifying patients with a high risk of LF is of great interest to clinicians. In this study, we examined whether tumor response to induction chemotherapy (CT) could predict LF in embryonal PM-RMS. METHODS We identified 24 patients with embryonal PM-RMS, age 2 to 18 years, with complete magnetic resonance imaging and gross residual disease after surgical resection. All patients received proton radiation therapy (RT), median dose 50.4 GyRBE (50.4-55.8 GyRBE). Tumor size was measured before initial CT and before RT. RESULTS With a median follow-up time of 4.1 years for survivors, LF was seen in 9 patients (37.5%). The median time from the initiation of CT to the start of RT was 4.8 weeks. Patients with LF had a similar initial (pre-CT) tumor volume compared with patients with local controlled (LC) (54 cm(3) vs 43 cm(3), P=.9) but a greater median volume before RT (pre-RT) (40 cm(3) vs 7 cm(3), P=.009) and a smaller median relative percent volume reduction (RPVR) in tumor size (0.4% vs 78%, P<.001). Older age (P=.05), larger pre-RT tumor volume (P=.03), and smaller RPVR (P=.003) were significantly associated with actuarial LF on univariate Cox analysis. CONCLUSIONS Poor response to induction CT appears to be associated with an increased risk of LF in pediatric embryonal PM-RMS.

Chemotherapy responsiveness in a patient with multiply relapsed ameloblastic fibro-odontosarcoma of the maxilla.

Ameloblastic fibro‐odontosarcoma (AFOS) is an extremely rare malignant odontogenic tumor. Complete surgical excision is the treatment of choice. Deaths due to disease recurrence and/or progression are documented. Here, we report the case of a 15‐year‐old female with multiple recurrent AFOS. She responded to chemotherapy with ifosfamide and doxorubicin consolidated by stereotactic reirradiation using cyberknife and remained in complete remission 14 months from the end of reirradiation therapy. Chemotherapy with ifosfamide and doxorubicin should be considered in advanced cases of AFOS. Pediatr Blood Cancer

Intensity-modulated arc therapy to improve radiation dose delivery in the treatment of abdominal neuroblastoma.

The standard European radiotherapy technique for children with neuroblastoma is a conventional parallel opposed pair. This frequently results in compromise on planning target volume coverage to stay within normal tissue tolerances. This study investigates the use of an intensity-modulated arc therapy (IMAT) technique to improve dose distribution and allow better protocol compliance. Among 20 previously treated patients, ten had received the full prescribed dose with conventional planning (protocol compliant) and ten had a compromise on planning target volume coverage (protocol noncompliant). All patients were replanned with IMAT. Dosimetric parameters of the conventional radiotherapy and IMAT were compared. The dose received by 98% of the planning target volume, homogeneity and conformity indices were all improved with IMAT (p < 0.001). IMAT would have enabled delivery of the full protocol dose in eight out of ten protocol-noncompliant patients. IMAT may improve outcomes through improved protocol compliance and better dose distributions.