Abnormal visual and olfactory sensations during radiation therapy: a prospective study

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

PURPOSE: Patients sometimes report phosphene and phantosmia during radiation therapy (RT). However, the detail features and related factors are not well understood. Our prospective study aimed to investigate the characteristics of phantosmias and phosphenes, to identify factors that influence the occurrence, intensity and hedonic (pleasantness/unpleasantness) ratings of such sensations during RT.

METHODS: We included a total of 106 patients (37 women), who underwent RT in regions of the brain, ear, nose, throat (ENT), and other areas of the body for a duration of 43 ± 5 days. Medical history and treatment parameters were collected in a structured medical interview. Olfactory function was measured using the Sniffin' Stick Odor Identification Test at baseline. Phantosmia and phosphene were recorded weekly based on a self-report questionnaire.

RESULTS: There were 37% of the patients experiencing phantosmias, 51% experiencing phosphenes, and 29% simultaneously experiencing both sensations. Phosphenes were typically perceived as a flashily blue, white and/or purple light, phantosmias were typically perceived as a chemical-like, metallic or burnt smell. Younger age (F = 7.81, p < 0.01), radiation in the brain region (χ 2 = 14.05, p = 0.02), absence of taste problems (χ 2 = 10.28, p = 0.01), and proton RT (χ 2 = 10.57, p = 0.01) were related to these abnormal sensations. History of chemical/dust exposure predicted lower intensity (B = -1.52, p = 0.02) and lower unpleasantness (B = 0.49, p = 0.03) of phantosmia. In contrast, disease (tumor) duration (B = 0.11, p < 0.01), food allergy (B = 2.77, p < 0.01), and epilepsy (B = -1.50, p = 0.02) influence phosphenes intensity. Analgesics intake predicted a higher pleasantness of the phosphenes (B = 0.47, p < 0.01).

CONCLUSIONS: Phantosmias and phosphenes are common during RT. The treatment settings and individual arousal level influence the occurrence, intensity and hedonic of such abnormal sensations. Phantosmias and phosphenes may involve more central neural than peripheral mechanism, and they could be elicited with activation of areas that are not regarded to be part of the olfactory or visual network.

Details

Original languageEnglish
Pages (from-to)936-949
Number of pages14
JournalStrahlentherapie und Onkologie
Volume199 (2023)
Issue number10
Early online date4 Jun 2023
Publication statusPublished - 4 Jun 2023
Peer-reviewedYes

External IDs

Scopus 85160818640
Mendeley 4307578c-541d-31dd-895d-49ca3aec67a5
WOS 001002428000001
ORCID /0000-0001-9713-0183/work/146645710

Keywords

Keywords

  • Phantosmia, Phosphene, Photon, Proton, Radiation therapy, Prospective Studies, Humans, Female, Phosphenes, Emotions, Olfaction Disorders/etiology, Smell

Library keywords