Noninvasive treatment of cutaneous neurofibromas (cNFs): Results of a randomized prospective, direct comparison of four methods.

BACKGROUND: People with Neurofibromatosis Type 1 (NF1) suffer disfigurement and pain when hundreds to thousands of cutaneous neurofibromas (cNFs) appear and grow throughout life. Surgical removal of cNFs under anesthesia is the only standard therapy, leaving surgical scars. OBJECTIVE: Effective, minimally-invasive, safe, rapid, tolerable treatment(s) of small cNFs that may prevent tumor progression. METHODS: Safety, tolerability, and efficacy of 4 different treatments were compared in 309, 2-4 mm cNFs across 19 adults with Fitzpatrick skin types (FST) I-IV: radiofrequency (RF) needle coagulation, 755 nm alexandrite laser with suction, 980 nm diode laser, and intratumoral injection of 10 mg/mL deoxycholate. Regional pain, clinical responses, tumor height and volume (by 3D photography) were assessed before, 3 and 6 months post-treatment. Biopsies were obtained electively at 3 months. RESULTS: There was no scarring or adverse events > grade 2. Each modality significantly (P < .05) reduced or cleared cNFs, with large variation between tumors and participants. Alexandrite laser and deoxycholate were fast and least painful; 980 nm laser was most painful. Growth of cNFs was not stimulated by treatment(s) based on height and volume values at 3 and 6 months compared to baseline. LIMITATIONS: Intervention was a single treatment session; dosimetry has not been optimized. CONCLUSIONS: Small cNFs can be rapidly and safely treated without surgery.

Not without Context-A Multiple Methods Study on Evaluation and Correction of Automated Brain Tumor Segmentations by Experts.

RATIONALE AND OBJECTIVES: Brain tumor segmentations are integral to the clinical management of patients with glioblastoma, the deadliest primary brain tumor in adults. The manual delineation of tumors is time-consuming and highly provider-dependent. These two problems must be addressed by introducing automated, deep-learning-based segmentation tools. This study aimed to identify criteria experts use to evaluate the quality of automatically generated segmentations and their thought processes as they correct them. MATERIALS AND METHODS: Multiple methods were used to develop a detailed understanding of the complex factors that shape experts' perception of segmentation quality and their thought processes in correcting proposed segmentations. Data from a questionnaire and semistructured interview with neuro-oncologists and neuroradiologists were collected between August and December 2021 and analyzed using a combined deductive and inductive approach. RESULTS: Brain tumors are highly complex and ambiguous segmentation targets. Therefore, physicians rely heavily on the given context related to the patient and clinical context in evaluating the quality and need to correct brain tumor segmentation. Most importantly, the intended clinical application determines the segmentation quality criteria and editing decisions. Physicians' personal beliefs and preferences about the capabilities of AI algorithms and whether questionable areas should not be included are additional criteria influencing the perception of segmentation quality and appearance of an edited segmentation. CONCLUSION: Our findings on experts' perceptions of segmentation quality will allow the design of improved frameworks for expert-centered evaluation of brain tumor segmentation models. In particular, the knowledge presented here can inspire the development of brain tumor-specific metrics for segmentation model training and evaluation.

Neurotoxicity and management of primary and secondary central nervous system lymphoma after adoptive immunotherapy with CD19-directed chimeric antigen receptor T-cells.

BACKGROUND: Chimeric antigen receptor (CAR) T-cells targeting CD19 have been established as a leading engineered T-cell therapy for B-cell lymphomas; however, data for patients with central nervous system (CNS) involvement are limited. METHODS: We retrospectively report on CNS-specific toxicities, management, and CNS response of 45 consecutive CAR T-cell transfusions for patients with active CNS lymphoma at the Massachusetts General Hospital over a 5-year period. RESULTS: Our cohort includes 17 patients with primary CNS lymphoma (PCNSL; 1 patient with 2 CAR T-cell transfusions) and 27 patients with secondary CNS lymphoma (SCNSL). Mild ICANS (grade 1-2) was observed after 19/45 transfusions (42.2%) and severe immune effector cell-associated neurotoxicity syndrome (ICANS) (grade 3-4) after 7/45 transfusions (15.6%). A larger increase in C-reactive protein (CRP) levels and higher rates of ICANS were detected in SCNSL. Early fever and baseline C-reactive protein levels were associated with ICANS occurrence. CNS response was seen in 31 cases (68.9%), including a complete response of CNS disease in 18 cases (40.0%) which lasted for a median of 11.4 ±â€…4.5 months. Dexamethasone dose at time of lymphodepletion (but not at or after CAR T-cell transfusion) was associated with an increased risk for CNS progression (hazard ratios [HR] per mg/d: 1.16, P = .031). If bridging therapy was warranted, the use of ibrutinib translated into favorable CNS-progression-free survival (5 vs. 1 month, HR 0.28, CI 0.1-0.7; P = .010). CONCLUSIONS: CAR T-cells exhibit promising antitumor effects and a favorable safety profile in CNS lymphoma. Further evaluation of the role of bridging regimens and corticosteroids is warranted.

Current and Emerging Imaging Techniques for Neurofibromatosis Type 1-Associated Cutaneous Neurofibromas.

A consistent set of measurement techniques must be applied to reliably and reproducibly evaluate the efficacy of treatments for cutaneous neurofibromas (cNFs) in people with neurofibromatosis type 1 (NF1). cNFs are neurocutaneous tumors that are the most common tumor in people with NF1 and represent an area of unmet clinical need. This review presents the available data regarding approaches in use or development to identify, measure, and track cNFs, including calipers, digital imaging, and high-frequency ultrasound sonography. We also describe emerging technologies such as spatial frequency domain imaging and the application of imaging modalities such as optical coherence tomography that may enable the detection of early cNFs and prevention of tumor-associated morbidity.

Existing and Developing Preclinical Models for Neurofibromatosis Type 1-Related Cutaneous Neurofibromas.

Neurofibromatosis type 1 (NF1) is caused by a nonfunctional copy of the NF1 tumor suppressor gene that predisposes patients to the development of cutaneous neurofibromas (cNFs), the skin tumor that is the hallmark of this condition. Innumerable benign cNFs, each appearing by an independent somatic inactivation of the remaining functional NF1 allele, form in nearly all patients with NF1. One of the limitations in developing a treatment for cNFs is an incomplete understanding of the underlying pathophysiology and limitations in experimental modeling. Recent advances in preclinical in vitro and in vivo modeling have substantially enhanced our understanding of cNF biology and created unprecedented opportunities for therapeutic discovery. We discuss the current state of cNF preclinical in vitro and in vivo model systems, including two- and three-dimensional cell cultures, organoids, genetically engineered mice, patient-derived xenografts, and porcine models. We highlight the models' relationship to human cNFs and how they can be used to gain insight into cNF development and therapeutic discovery.

Target Product Profile for Cutaneous Neurofibromas: Clinical Trials to Prevent, Arrest, or Regress Cutaneous Neurofibromas.

Cutaneous neurofibromas (cNFs) are benign tumors of the skin that affect >95% of adults with neurofibromatosis type 1. Despite their benign histology, cNFs can significantly impact QOL due to disfigurement, pain, and pruritus. There are no approved therapies for cNFs. Existing treatments are limited to surgery or laser-based treatments that have had mixed success and cannot be readily applied to a large number of tumors. We review cNF treatment options that are currently available and under investigation, discuss the regulatory considerations specific to cNFs, and propose strategies to improve cNF clinical trial design and standardize clinical trial endpoints.

RAS Signaling Gone Awry in the Skin: The Complex Role of RAS in Cutaneous Neurofibroma Pathogenesis, Emerging Biological Insights.

Cutaneous neurofibromas (cNFs) are the most common tumor in people with the rasopathy neurofibromatosis type 1. They number in hundreds or even thousands throughout the body, and currently, there are no effective interventions to prevent or treat these skin tumors. To facilitate the identification of novel and effective therapies, essential studies including a more refined understanding of cNF biology and the role of RAS signaling and downstream effector pathways responsible for cNF initiation, growth, and maintenance are needed. This review highlights the current state of knowledge of RAS signaling in cNF pathogenesis and therapeutic development for cNF treatment.

Management of neurofibromatosis type 1-associated plexiform neurofibromas.

Plexiform Neurofibromas (PN) are a common manifestation of the genetic disorder neurofibromatosis type 1 (NF1). These benign nerve sheath tumors often cause significant morbidity, with treatment options limited historically to surgery. There have been tremendous advances over the past two decades in our understanding of PN, and the recent regulatory approvals of the MEK inhibitor selumetinib are reshaping the landscape for PN management. At present, there is no agreed upon PN definition, diagnostic evaluation, surveillance strategy, or clear indications for when to initiate treatment and selection of treatment modality. In this review, we address these questions via consensus recommendations from a panel of multidisciplinary NF1 experts.

Genetic testing to gain diagnostic clarity in neurofibromatosis type 2 and schwannomatosis.

Neurofibromatosis type 2 (NF2) and schwannomatosis (SWN) have distinct genetic etiologies but overlapping phenotypes. Genetic testing may be required for accurate diagnosis, which is critical for determining prognosis, screening recommendations, and treatment options. Our study aimed to compare the efficacy of germline-only versus paired (germline and tumor) genetic testing for clarifying the diagnosis in patients with features of NF2 and SWN. We performed a retrospective chart review of patients referred for NF2/SWN genetic testing at Massachusetts General Hospital from 2015 to 2020. Logistic regression analysis was performed to assess factors associated with diagnostic clarity. Overall, paired testing had 8.5 times greater odds of providing diagnostic clarity than germline-only testing (p < 0.01). Among patients who underwent paired testing, those who had analysis of two or more tumors had the greatest likelihood of gaining diagnostic clarity, with odds 13 times greater than patients who underwent germline-only testing (p < 0.01). Paired testing with analysis of one tumor significantly increased the odds of diagnostic clarity over germline-only testing by a factor of 6.5 (p < 0.01). These results have implications for genetic testing strategies and counseling patients about genetic testing utility. They also support the routine use of testing in individuals with suspected NF2 or SWN and improved insurance coverage for paired testing within this population.

Bone marrow drives central nervous system regeneration after radiation injury.

Nervous system injury is a frequent result of cancer therapy involving cranial irradiation, leaving patients with marked memory and other neurobehavioral disabilities. Here, we report an unanticipated link between bone marrow and brain in the setting of radiation injury. Specifically, we demonstrate that bone marrow-derived monocytes and macrophages are essential for structural and functional repair mechanisms, including regeneration of cerebral white matter and improvement in neurocognitive function. Using a granulocyte-colony stimulating factor (G-CSF) receptor knockout mouse model in combination with bone marrow cell transplantation, MRI, and neurocognitive functional assessments, we demonstrate that bone marrow-derived G-CSF-responsive cells home to the injured brain and are critical for altering neural progenitor cells and brain repair. Additionally, compared with untreated animals, animals that received G-CSF following radiation injury exhibited enhanced functional brain repair. Together, these results demonstrate that, in addition to its known role in defense and debris removal, the hematopoietic system provides critical regenerative drive to the brain that can be modulated by clinically available agents.