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"Boop, Frederick"
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Biography: Frederick A. Boop MD
2022
Dr. Boop is the president of the 48th annual meeting of the ISPN. He has served Semmes-Murphey Clinic as a member of the Board of Directors, Chief of the pediatric neurosurgery division, and as pediatric neurosurgery fellowship director. He has held the JT Robertson endowed chair from The University of Tennessee Health Science Center (UTHSC) Department of Neurosurgery residency training program and the St. Jude endowed chair in pediatric neurosurgery where he is currently a member of the St. Jude Global Program. He is currently Emeritus Chair at UTHSC.
Journal Article
Proton therapy and limited surgery for paediatric and adolescent patients with craniopharyngioma (RT2CR): a single-arm, phase 2 study
2023
Compared with photon therapy, proton therapy reduces exposure of normal brain tissue in patients with craniopharyngioma, which might reduce cognitive deficits associated with radiotherapy. Because there are known physical differences between the two methods of radiotherapy, we aimed to estimate progression-free survival and overall survival distributions for paediatric and adolescent patients with craniopharyngioma treated with limited surgery and proton therapy, while monitoring for excessive CNS toxicity.
In this single-arm, phase 2 study, patients with craniopharyngioma at St Jude Children's Research Hospital (Memphis TN, USA) and University of Florida Health Proton Therapy Institute (Jacksonville, FL, USA) were recruited. Patients were eligible if they were aged 0–21 years at the time of enrolment and had not been treated with previous radiotherapeutic or intracystic therapies. Eligible patients were treated using passively scattered proton beams, 54 Gy (relative biological effect), and a 0·5 cm clinical target volume margin. Surgical treatment was individualised before proton therapy and included no surgery, single procedures with catheter and Ommaya reservoir placement through a burr hole or craniotomy, endoscopic resection, trans-sphenoidal resection, craniotomy, or multiple procedure types. After completing treatment, patients were evaluated clinically and by neuroimaging for tumour progression and evidence of necrosis, vasculopathy, permanent neurological deficits, vision loss, and endocrinopathy. Neurocognitive tests were administered at baseline and once a year for 5 years. Outcomes were compared with a historical cohort treated with surgery and photon therapy. The coprimary endpoints were progression-free survival and overall survival. Progression was defined as an increase in tumour dimensions on successive imaging evaluations more than 2 years after treatment. Survival and safety were also assessed in all patients who received photon therapy and limited surgery. This study is registered with ClinicalTrials.gov, NCT01419067.
Between Aug 22, 2011, and Jan 19, 2016, 94 patients were enrolled and treated with surgery and proton therapy, of whom 49 (52%) were female, 45 (48%) were male, 62 (66%) were White, 16 (17%) were Black, two (2%) were Asian, and 14 (15%) were other races, and median age was 9·39 years (IQR 6·39–13·38) at the time of radiotherapy. As of data cutoff (Feb 2, 2022), median follow-up was 7·52 years (IQR 6·28–8·53) for patients who did not have progression and 7·62 years (IQR 6·48–8·54) for the full cohort of 94 patients. 3-year progression-free survival was 96·8% (95% CI 90·4–99·0; p=0·89), with progression occurring in three of 94 patients. No deaths occurred at 3 years, such that overall survival was 100%. At 5 years, necrosis had occurred in two (2%) of 94 patients, severe vasculopathy in four (4%), and permanent neurological conditions in three (3%); decline in vision from normal to abnormal occurred in four (7%) of 54 patients with normal vision at baseline. The most common grade 3–4 adverse events were headache (six [6%] of 94 patients), seizure (five [5%]), and vascular disorders (six [6%]). No deaths occurred as of data cutoff.
Proton therapy did not improve survival outcomes in paediatric and adolescent patients with craniopharyngioma compared with a historical cohort, and severe complication rates were similar. However, cognitive outcomes with proton therapy were improved over photon therapy. Children and adolescents treated for craniopharyngioma using limited surgery and post-operative proton therapy have a high rate of tumour control and low rate of severe complications. The outcomes achieved with this treatment represent a new benchmark to which other regimens can be compared.
American Lebanese Syrian Associated Charities, American Cancer Society, the US National Cancer Institute, and Research to Prevent Blindness.
Journal Article
Review and update on pediatric ependymoma
by
Boop, Frederick A.
,
Boop, Scott H.
,
Shimony, Nir
in
Case-based Review
,
Medicine
,
Medicine & Public Health
2023
Since our last Special Annual Issue dedicated to the topic of ependymoma in 2009, critical advancements have been made in the understanding of this disease which is largely confined to childhood. In the era of molecular profiling, the prior classification of ependymoma based on histology has become largely irrelevant, with multiple new subtypes of this disease now being described in the newest 2021 WHO CNS Tumor Classification System. Despite our advancements in understanding the underlying biology of these tumors, the mainstays of treatment—gross total surgical resection followed by confocal radiation therapy—have continued to yield the best treatment results across multiple studies and centers. Here, we provide an update on our understanding of the advancements made in tumor biology, surgical, and oncologic management of this disease. As we move into an era of more personalized medicine, it is critical to reflect on our historical understanding of different disease entities, to better understand the future directions of our treatments.
Journal Article
The use of 5-aminolevulinic acid in resection of pediatric brain tumors: a critical review
by
Zhang, Chenran
,
Boop, Frederick A.
,
Ruge, John
in
Aminolevulinic acid
,
Brain cancer
,
Brain tumors
2019
The compound, 5-aminolevulinic acid (5-ALA) is approved for fluorescence-guided resections of malignant gliomas in Europe and other countries for use in adults, but not for children. The application of 5-ALA in children remains an off-label use. Several case reports on fluorescence-guided surgery use in children have been published, yet no prospective study has been conducted. Here we systematically review the reported studies and discuss the usefulness, application, and safety of 5-ALA use in resection of pediatric brain tumors.
Journal Article
Subtypes of medulloblastoma have distinct developmental origins
2010
Medulloblastoma subtypes identified
Medulloblastomas, a common type of malignant childhood brain tumour, are thought in the main to arise from the cerebellum, many of them involving aberrant signalling of a signalling pathway involving Sonic Hedgehog. There is substantial heterogeneity among medulloblastomas, however, and new work shows that a distinct subtype of medulloblastoma arises from the dorsal brainstem and is associated with altered Wnt signalling. Distinct molecular and clinical profiles of the subtypes have implications for future treatment. This suggests that subgroups of medulloblastoma are intrinsically different diseases, so therapeutic strategies may need to be tailored accordingly.
Medulloblastomas are the most common malignant childhood brain tumours and are thought to arise from the cerebellum. There is substantial heterogeneity among medulloblastomas and some are thought to arise following aberrant Sonic Hedgehog pathway activation. It is now shown that a distinct subtype of medulloblastoma arises from the dorsal brainstem and is associated with altered WNT signalling. Distinct molecular and clinical profiles of the subtypes have implications for future treatment.
Medulloblastoma encompasses a collection of clinically and molecularly diverse tumour subtypes that together comprise the most common malignant childhood brain tumour
1
,
2
,
3
,
4
. These tumours are thought to arise within the cerebellum, with approximately 25% originating from granule neuron precursor cells (GNPCs) after aberrant activation of the Sonic Hedgehog pathway (hereafter, SHH subtype)
3
,
4
,
5
,
6
,
7
,
8
. The pathological processes that drive heterogeneity among the other medulloblastoma subtypes are not known, hindering the development of much needed new therapies. Here we provide evidence that a discrete subtype of medulloblastoma that contains activating mutations in the WNT pathway effector
CTNNB1
(hereafter, WNT subtype)
1
,
3
,
4
arises outside the cerebellum from cells of the dorsal brainstem. We found that genes marking human WNT-subtype medulloblastomas are more frequently expressed in the lower rhombic lip (LRL) and embryonic dorsal brainstem than in the upper rhombic lip (URL) and developing cerebellum. Magnetic resonance imaging (MRI) and intra-operative reports showed that human WNT-subtype tumours infiltrate the dorsal brainstem, whereas SHH-subtype tumours are located within the cerebellar hemispheres. Activating mutations in
Ctnnb1
had little impact on progenitor cell populations in the cerebellum, but caused the abnormal accumulation of cells on the embryonic dorsal brainstem which included aberrantly proliferating Zic1
+
precursor cells. These lesions persisted in all mutant adult mice; moreover, in 15% of cases in which
Tp53
was concurrently deleted, they progressed to form medulloblastomas that recapitulated the anatomy and gene expression profiles of human WNT-subtype medulloblastoma. We provide the first evidence, to our knowledge, that subtypes of medulloblastoma have distinct cellular origins. Our data provide an explanation for the marked molecular and clinical differences between SHH- and WNT-subtype medulloblastomas and have profound implications for future research and treatment of this important childhood cancer.
Journal Article
The genomic landscape of diffuse intrinsic pontine glioma and pediatric non-brainstem high-grade glioma
2014
Suzanne Baker, Jinghui Zhang and colleagues report the identification of recurrent somatic mutations in the bone morphogenetic protein (BMP) receptor
ACVR1
in 32% of diffuse intrinsic pontine gliomas.
Pediatric high-grade glioma (HGG) is a devastating disease with a less than 20% survival rate 2 years after diagnosis
1
. We analyzed 127 pediatric HGGs, including diffuse intrinsic pontine gliomas (DIPGs) and non-brainstem HGGs (NBS-HGGs), by whole-genome, whole-exome and/or transcriptome sequencing. We identified recurrent somatic mutations in
ACVR1
exclusively in DIPGs (32%), in addition to previously reported frequent somatic mutations in histone H3 genes,
TP53
and
ATRX
, in both DIPGs and NBS-HGGs
2
,
3
,
4
,
5
. Structural variants generating fusion genes were found in 47% of DIPGs and NBS-HGGs, with recurrent fusions involving the neurotrophin receptor genes
NTRK1, NTRK2
and
NTRK3
in 40% of NBS-HGGs in infants. Mutations targeting receptor tyrosine kinase–RAS-PI3K signaling, histone modification or chromatin remodeling, and cell cycle regulation were found in 68%, 73% and 59% of pediatric HGGs, respectively, including in DIPGs and NBS-HGGs. This comprehensive analysis provides insights into the unique and shared pathways driving pediatric HGG within and outside the brainstem.
Journal Article
Shifting Strategies in the Treatment of Pediatric Craniopharyngioma
by
Roth, Jonathan
,
Merchant, Thomas E
,
Constantini, Shlomi
in
Brain cancer
,
Histology
,
Hospitals
2023
Purpose of ReviewCraniopharyngiomas represent one of the most challenging diseases to treat. Despite their benign histology, and after many decades of surgical experience and technological advancements, there is still no clear consensus regarding the most effective management for this tumor. Due to their location and aggressive local characteristics, purely surgical approaches all too often result in unacceptable morbidity.Recent FindingsPartial resection combined with radiation therapy results in similar control rates when compared to aggressive surgery, while also minimalizing the neuro-endocrinological morbidity.SummaryIn this manuscript, we describe the historical progression of the shifting strategies in the management of pediatric craniopharyngioma. Time has also altered our expectations for outcomes, evolving from purely morbidity and mortality to simple Glasgow Outcomes Scales, now to formal neuro-psychometric and quality of life data.
Journal Article
Radiotherapy alone for pediatric patients with craniopharyngioma
by
Pan, Haitao
,
Merchant, Thomas E.
,
Boop, Frederick A.
in
Adolescent
,
Body mass index
,
Bone imaging
2022
Purpose
Radiotherapy alone, without tumor-directed surgery, may be appropriate for selected patients with craniopharyngioma reducing the risks associated with neurosurgery. Understanding outcomes for patients with craniopharyngioma treated with radiotherapy alone will further refine patient selection and treatment options.
Methods
Since 2002, 13 children, adolescents and young adults, with craniopharyngioma were treated with radiotherapy alone and followed for disease control and functional outcomes at a single institution. The median age at treatment was 13 years (range, 3–21 years). All patients received 54 Gy/54 Gy(RBE) in 30 fractions. Five patients were treated with intensity-modulated photon therapy, four with passively scattered proton therapy, and four with intensity-modulated proton therapy.
Results
With a median follow-up of 5 years (range 3 months–14 years), all patients were alive. One experienced tumor progression 8.5 years after treatment. No significant changes in vision, hearing or neurologic function attributed to radiotherapy. Hormone deficiencies and body mass index were within the expected range at baseline and 5 years after treatment. There was no evidence of cognitive decline based on assessment of IQ, memory and attention. Unexpected complications included single cases of out-of-field malignancy, white matter changes, large vessel narrowing, and pontine capillary telangiectasia. Six patients had sphenoid bone abnormalities on follow-up imaging attributed to radiotherapy.
Conclusion
Radiotherapy alone is an important treatment option to consider when radical resection is contraindicated, or surgical intervention is not required to alleviate symptoms. Disease control and functional outcomes are excellent after radiation therapy alone in appropriately selected patients.
Journal Article
Management of Chiari malformations: opinions from different centers—a review
2019
Purpose
Surgical decision-making in Chiari malformation type I (CM-I) patients tends to depend on the presence of neurological signs and symptoms, syringomyelia, and/or scoliosis, but significant variability exists from center to center. Here, we review the symptoms of CM-I in children and provide an overview of the differences in opinion regarding surgical indications, preferred surgical techniques, and measures of outcome.
Methods
A review of the literature was performed to identify publications relevant to the surgical management of pediatric CM-I patients.
Results
Most surgeons agree that asymptomatic patients without syringomyelia should not undergo prophylactic surgery, while symptoms of brainstem compression and/or lower cranial nerve dysfunction warrant surgery. Patients between these extremes, however, remain controversial, as does selection of the most appropriate surgical technique.
Conclusions
The optimal surgical procedure for children with CM-I remains a point of contention, and widespread variability exists between and within centers.
Journal Article