title: Successful delivery of adjuvant external beam radiotherapy for ependymoma in a patient with Ondine׳s curse.
abstract: Ondine׳s curse is a rare, potentially life-threatening disorder characterized by loss of automatic breathing during sleep and preserved voluntary breathing. It is seldom encountered in the radiotherapy clinic but can pose significant technical challenges and safety concerns in the delivery of a prescribed radiation course. We report a unique case of successful delivery of radiotherapy for ependymoma in a patient with Ondine׳s curse. A 53-year-old gentleman presented with vertigo when lying down. Brain magnetic resonance imaging revealed an enhancing mass in the floor of the fourth ventricle. He underwent maximal safe resection. Pathology revealed ependymoma. The patient was referred for radiotherapy. Computed tomography simulation was performed in supine position with 3-point thermoplastic mask immobilization. Sequential TomoTherapy plans were developed. At first scheduled treatment, shortly after mask placement, his arms went limp and he was unresponsive. Vitals showed oxygen saturation 83%, pulse 127, and blood pressure 172/97mmHg. He was diagnosed with Ondine׳s curse thought secondary to previous brainstem damage; the combination of lying flat and pressure from the mask was causing him to go into respiratory arrest. As supine positioning did not seem clinically advisable, he was simulated in prone position. A RapidArc plan and a back-up conformal plan were developed. Prescriptions were modified to meet conservative organs-at-risk constraints. Several strategies were used to minimize uncertainties in set-up reproducibility associated with prone positioning. He tolerated prone RapidArc treatments well. The report highlights the importance of applying practical patient safety and treatment planning/delivery strategies in the management of this challenging case.
authors.affiliation: Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL.
authors.forename: Mehee
authors.initials: M
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, Rush University Medical Center, Chicago, IL.
authors.forename: Miranda
authors.initials: M
authors.lastname: Thoma
authors.affiliation: Department of Radiation Oncology, Rush University Medical Center, Chicago, IL.
authors.forename: George
authors.initials: G
authors.lastname: Tolekidis
authors.affiliation: Department of Neurosurgery, Rush University Medical Center, Chicago, IL.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Byrne
authors.affiliation: Department of Radiation Oncology, Rush University Medical Center, Chicago, IL; Department of Neurosurgery, Rush University Medical Center, Chicago, IL. Electronic address: aidnag_diaz@rush.edu.
authors.forename: Aidnag Z
authors.initials: AZ
authors.lastname: Diaz
mesh_terms: D001932:Brain Neoplasms / Q000150:complications / Q000532:radiotherapy* / Q000601:surgery; D004806:Ependymoma / Q000150:complications / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D020182:Sleep Apnea, Central / Q000209:etiology*
keywords: Ependymoma; Ondine׳s curse; Prone positioning; Radiotherapy