Browsing by Author "Ramirez-Fort, Marigdalia K."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Computational simulations establish a novel transducer array placement arrangement that extends delivery of therapeutic TTFields to the infratentorium of patients with brainstem gliomas
    (Elsevier, 2021-12-30) Ramirez-Fort, Marigdalia K.; Naveh, Ariel; McClelland, Shearwood, III.; Gilman, Casey K.; Fort, Migdalia; Mendez, Melissa; Matta, Jaime; Bomzon, Ze’ev; Lange, Christopher S.; Radiation Oncology, School of Medicine
    Background and purpose: Tumor treating fields (TTFields) are a non-invasive, efficacious treatment modality currently approved for supratentorial glioblastomas. Despite their ability to improve overall survival in supratentorial tumors, the current placement of arrays is limited to the supratentorial head, precluding its use in infratentorial tumors. Infratentorial malignancies are in need of new therapy modalities given their poor prognoses in both children and adults. The aim of this research is to determine whether rearrangement of TTFields may allow for management of infratentorial tumors. Materials and methods: Delivery of TTFields using Novocure's prototype Optune™ device human male head model was simulated based on brain MRIs from patients with brainstem gliomas to develop a novel array layout designed to extend adequate infratentorial coverage. Results: Array placement on the vertex, bilateral posterolateral occiput, and superior-posterior neck achieved intensities above 1.1 V/cm (average 1.7 V/cm; maximum 2.3 V/cm) in the vertical field direction and above 1 V/cm (average 2 V/cm; maximum 2.8 V/cm) in the horizontal field direction of the infratentorium. The calculated field intensity within the simulated tumors were in the therapeutic range and demonstrated the effective delivery of TTFields to the infratentorial brain. Conclusions: Our findings suggest that rearrangement of the TTFields standard array with placement of electrodes on the vertex, bilateral posterolateral occiput, and superior-posterior neck allows for adequate electric field distribution in the infratentorium that is within the therapeutic range.
  • Thumbnail Image
    Item
    Preservation of male fertility in patients undergoing pelvic irradiation
    (Elsevier, 2024-02-16) Ramirez-Fort, Marigdalia K.; Kardoust-Parizi, Mehdi; Flannigan, Ryan; Bach, Phil; Koch, Nicholas; Gilman, Casey; Suarez, Paula; Fort, Digna V.; McClelland, Shearwood, III; Lange, Christopher S.; Mulhall, John P.; Fort, Migdalia; Schlegel, Peter N.; Radiation Oncology, School of Medicine
    As the number of cancer survivors increases, so does the demand for preserving male fertility after radiation. It is important for healthcare providers to understand the pathophysiology of radiation-induced testicular injury, the techniques of fertility preservation both before and during radiation, and their role in counseling patients on the risks to their fertility and the means of mitigating these risks. Impaired spermatogenesis is a known testicular toxicity of radiation in both the acute and the late settings, as rapidly dividing spermatogonial germ cells are exquisitely sensitive to irradiation. The threshold for spermatogonial injury and subsequent impairment in spermatogenesis is ~ 0.1 Gy and the severity of gonadal injury is highly dose-dependent. Total doses < 4 Gy may allow for recovery of spermatogenesis and fertility potential, but with larger doses, recovery may be protracted or impossible. All patients undergoing gonadotoxic radiation therapy should be counseled on the possibility of future infertility, offered the opportunity for semen cryopreservation, and offered referral to a fertility specialist. In addition to this, every effort should be made to shield the testes (if not expected to contain tumor) during therapy.
  • Thumbnail Image
    Item
    The surgical nature of radiation oncology should be better reflected in pre-residency training
    (Elsevier, 2019-08-17) McClelland, Shearwood; Brown, Simon A.; Ramirez-Fort, Marigdalia K.; Jaboin, Jerry J.; Zellars, Richard C.; Radiation Oncology, School of Medicine