Faculty Bibliography

Perineural invasion (PNI), the neoplastic invasion of nerves, is a common pathological finding in head and neck cancer that is associated with poor clinical outcomes. PNI is a histological finding of tumor cell infiltration and is distinct from perineural tumor spread (PNTS), which is macroscopic tumor involvement along a nerve extending from the primary tumor that is by definition more advanced, being radiologically or clinically apparent. Despite widespread acknowledgement of the prognostic significance of PNI/PNTS, the mechanisms underlying its pathogenesis remain largely unknown, and specific therapies targeting nerve invasion are lacking. The use of radiation therapy for PNI/PNTS can improve local control and reduce devastating failures at the skull base. However, the optimal volumes to be delineated with respect to targeting cranial nerve pathways are not well defined, and radiation may carry risks of major toxicity secondary to the location of adjacent critical structures. Here we examine the pathogenesis of these phenomena, analyze the role of radiation in PNI/PNTS, and propose guidelines for radiation treatment design based on the best available evidence and the authors' collective experience in order to advance understanding and therapy of this ominous cancer phenotype.

BACKGROUND:Awareness of disease status has been identified as a factor in the treatment decision-making process. Women with recurrent ovarian cancer are facing the challenge of making treatment decisions throughout the disease trajectory. It is not understood how women with ovarian cancer perceive their disease and subsequently make treatment decisions. PURPOSE/OBJECTIVE:The purpose of this phenomenological study was to understand the lived experience of women with recurrent ovarian cancer, how they understood their disease and made their treatment decisions. METHODS:A qualitative design with a descriptive phenomenological method was used to conduct 2 in-depth interviews with 12 women (n = 24 interviews). Each interview was ∼60 minutes and was digitally recorded and professionally transcribed. Data collection focused on patients' understanding of their disease and how patients participated in treatment decisions. A modified version of Colaizzi's method of phenomenological reduction guided data analysis. RESULTS:Three themes emerged to describe the phenomenon of being aware of disease status: (1) perceiving recurrent ovarian cancer as a chronic illness, (2) perceived inability to make treatment decisions, and (3) enduring emotional distress. CONCLUSIONS AND IMPLICATIONS/CONCLUSIONS:This study revealed how 12 women conceptualized recurrent ovarian cancer as a chronic disease and their perceived inability to make treatment decisions because of lack of information and professional qualifications, resulting in enduring emotional distress. Future research should replicate the study to confirm the persistence of the themes for racially, ethnically, and religiously diverse patient samples and to improve understanding of awareness of disease status and decision-making processes of patients.

An auditory brainstem implant (ABI) is a surgically implanted central neural auditory prosthesis for the treatment of profound sensorineural hearing loss in children and adults who are not cochlear implant candidates due to a lack of anatomically intact cochlear nerves or implantable cochleae. The device consists of a multielectrode surface array which is placed within the lateral recess of the fourth ventricle along the brainstem and directly stimulates the cochlear nucleus, thereby bypassing the peripheral auditory system. In the United States, candidacy criteria for ABI include deaf patients with neurofibromatosis type 2 (NF2) who are 12 years or older undergoing first- or second-side vestibular schwannoma resection. In recent years, several non-NF2 indications for ABI have been explored, including bilateral cochlear nerve avulsion from trauma, complete ossification of the cochlea due to meningitis, or a severe cochlear malformation not amenable to cochlear implantation. In addition, growing experience with ABI in infants and children has been documented with encouraging outcomes. While cochlear implantation generally remains the first-line option for hearing rehabilitation in NF2 patients with stable tumors or post hearing preservation surgery where hearing is lost but a cochlear nerve remains accessible for stimulation, an ABI is the next alternative in cases where the cochlear nerve is absent and/or if the cochlea cannot be implanted. Herein, we review ABI device design, clinical evaluation, indications, operative technique, and outcomes as it relates to lateral skull base pathology.

The BRAF-V600E mutation is found in 15-20% of pediatric low grade gliomas (PLGG) and result in worse outcome and higher risk of transformation to high grade gliomas (PHGG). Although ongoing trials are assessing the role of BRAF inhibitors (BRAFi) in these children, data are still limited. We aimed to report overall response rates and predictors of outcome in childhood BRAF-V600E gliomas. We collected clinical, imaging and molecular information of patients treated with BRAFi outside trials from centers participating in the PLGG taskforce. Response was calculated by RANO criteria and follow up data were collected for all patients. Sixty-six patients were treated with BRAFi (55 PLGG and 11 PHGG); median follow-up time was 1.5 years (0.1-5y). In PLGG, objective response (tumor reduction of >25%) was observed in 77% compared to 15% in a cohort treated with conventional chemotherapy (pCDKN2A deletion was not associated with lack of response, while specifc enhancing patterns correlated strongly with response to BRAFi. Two-year PFS for the BRAF-V600E PLGG was 74% vs 47% for BRAFi vs chemotherapy, respectively (p=0.02). Our data reveal rapid, dramatic and sustained response of BRAF-V600E PLGG to BRAFi. These are in contrast to BRAF-V600E PHGG and non-enhancing PLGG. Additional molecular analyses are being performed to identify poor responders and emerging mechanisms of resistance in these tumors

OBJECTIVES/OBJECTIVE:Adequate treatment of laryngopharyngeal malignancy often incorporates radiation therapy. Structures surrounding laryngopharynx exposed to traditional radiation doses are susceptible to posttreatment toxicity. Among poorly understood sequelae is the rare manifestation of sternoclavicular joint (SCJ) osteoradionecrosis (ORN). METHODS:Three institutional encounters prompted a comprehensive literature search, generating three published case reports. Systematic extraction and analysis (n = 6) of demographics, cancer history, comorbidities, ORN presentation, imaging, and management established the largest series to investigate this pathology. RESULTS:Patients were males (6), 54 to 70 years old, smokers (4), with Hypertension/dyslipidemia, myocardial infarction/coronary artery disease, second primary (2), diabetes mellitus (1), and myelofibrosis(1). Four underwent total laryngectomy, one primary, three as salvage. Five patients had concurrent chemoradiation (≥70 Gy). All patients presented with swollen, tender neck wounds concerning for persistent/recurrent malignancy. Computed tomography (CT) demonstrated bone erosion (5 of 5) and increased bone scan uptake (2 of 2). All responded to surgical exploration with drainage alone (1), sequestrectomy (2), or bone resection with synovectomy (3). Complete healing took 2 months to 3 years. One unrelated patient death occurred before control of ORN was achieved. DISCUSSION/CONCLUSIONS:Given varied patient characteristics, synergistic risk factors exist that alter bone radiation threshold, resulting in irreversible ischemic damage and osteoradionecrosis. Vascular susceptibility and inability to repair may regulate that threshold. Understanding this relationship will facilitate early detection and intervention. CONCLUSION/CONCLUSIONS:Integrating cases of sternoclavicular joint ORN promotes awareness of atypical laryngopharyngeal radiation complications, elucidates contributing factors, educates physicians on presentation and management, and provides a platform for prospective investigation. LEVEL OF EVIDENCE/METHODS:4. Laryngoscope, 2018.

Intralabyrinthine schwannomas (ILS) are rare tumors that frequently cause sensorineural hearing loss. The development and increased use of magnetic resonance imaging in recent years have facilitated the diagnosis of these tumors that present with otherwise nondiscriminant symptoms such as tinnitus, vertigo, and hearing loss. The following is a review of the presentation, pathophysiology, imaging, and treatment with a focused discussion on auditory rehabilitation options of ILS.

A new category of hearing technology has emerged that comprises devices inserted deep into the ear canal. Although not implanted, they represent an extension of what is expected of a traditional hearing aid. There are advantages to these devices, but they are not suited for all individuals with hearing loss. This category consists of 2 devices currently available in the United States: Lyric (Phonak AG, Stafa, Switzerland) and Earlens (Earlens, Menlo Park, CA, USA).