Taste and smell disturbances after brain irradiation: A dose–volume histogram analysis of a prospective observational study

Abstract

Purpose Radiation-induced taste and smell disturbances are prevalent in patients receiving brain radiotherapy, although the mechanisms underlying these toxicities are poorly understood. We report the results of a single institution prospective clinical trial aimed at correlating self-reported taste and smell disturbances with radiation dose delivered to defined areas within the brain and nasopharynx. Methods and Materials 22 patients with gliomas were enrolled on a prospective observational trial in which patients underwent a validated questionnaire assessing taste and smell disturbances at baseline, and at 3 and 6 weeks after commencement of brain radiotherapy. 14 patients with glioblastoma, 3 patients with grade 3 gliomas, and 5 patients with low grade gliomas participated. Median dose to tumor volume was 60 Gy (range 45–60 Gy). Dose volume histogram (DVH) analysis was performed for specific regions of interest (ROI) that were considered potential targets of radiation damage including the thalamus, temporal lobes, nasopharynx, olfactory groove, frontal pole and periventricular stem cell niche. The %v10 (percent of ROI receiving 10 Gy), %v40, and %v60 were calculated for each structure. Data from questionnaires and DVH were analyzed using stepwise regression. Results 20 of 22 patients submitted evaluable questionnaires that encompassed at least the entire radiotherapy course. 10 of 20 patients reported experiencing some degree of smell disturbance during radiotherapy, and 14 of 20 patients experienced taste disturbances. Patients reporting more severe taste toxicity also reported more severe toxicities with sense of smell (r2=0.60, p<0.006). Tumor location in the temporal lobe predicted for increased severity of taste toxicity (F3, 16=1.44, p<0.06). The nasopharynx was the only structure in which the DVH data predicted the presence of radiation-induced taste changes (r2=0.28, p<0.02). Conclusions Radiation-induced taste toxicity appears to be more common in temporal lobe tumors, and may be related to the dose received by the nasopharynx.

A brain-lesion pattern based algorithm for the diagnosis of posttraumatic olfactory loss

“…While the highly significant role of the olfactory bulb is very clear, less is known about a possible role of the temporal lobe pole in olfaction. Lesions induced by radiation have been found to be associated with decreased olfactory function (23) . In addition, specific deficits of the temporal lobe pole in primary progressive aphasia have been found to be related severe deficits in odour naming and matching.…”

Brain lesion-pattern analysis in patients with olfactory dysfunctions following head trauma

“…A role of the temporal lobe was seen as “linking odor object representations to transmodal networks, given its anatomical proximity to olfactory and visual object processing areas” ( Kasai et al, 2003 , Olofsson et al, 2013 , Olson et al, 2007 ). Lesions induced by radiation have been found to be associated with decreased olfactory function ( Leyrer et al, 2014 ) and deficits of the temporal lobe pole in primary progressive aphasia were related to severe deficits in odor naming and matching, which would be a compatible association provided the hypothesis that distorted input from a damaged lateral orbitofrontal cortex results in the report of a wrong perception.…”

Prevalence, clinical significance and possible correction of taste and smell abnormalities in patients with oncological diseases

“…Сухость во рту приводит к снижению вкусовых ощущений из-за ограниченной доставки раздражителей к хеморецепторам [80]. Современные исследования изменений вкусовых и обонятельных ощущений на фоне лучевой терапии в основном включают больных опухолями головы и шеи, хотя недавно появилась публикация о подобном исследовании с участием больных глиомой [81]. В среднем дисгевзия и дизосмия встречаются у 70 и 50 % больных соответственно.…”

“…Вопрос об изменении обоняния во время лучевой терапии остается спорным. Так, в некоторых публикациях приводится информация о субъективных жалобах пациентов на потерю обоняния [81], но в других работах при объективной оценке обоняния изменений выявлено не было [85]. Дискретной же оценки степени выраженности изменений не было представлено ни в одном исследовании.…”