Olfactory Sensations During Proton and Photon Radiotherapy: A Multicenter Prospective Observational Study

Mizumoto, Masashi; Oshiro, Yoshiko; Sumiya, Taisuke; Miyamoto, Toshio; Baba, Keiichiro; Murakami, M.; Shimizu, Shunsuke; Iizumi, Takashi; Saito, Takashi; Makishima, Hirokazu; Numajiri, Haruko; Nakai, Kei; Okumura, Toshiyuki; Maruo, Kazushi; Sakae, Takeji; Sakurai, Hideyuki

doi:10.7759/cureus.22964

Cited by 6 publications

(28 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our recent research showed the patients who received total body irradiation (TBI) felt odor (14 of 32 patients) and 2 of 14 patients answered “ozone” as the type of smell without knowledge of ozone as a possible cause ( 26 ). These reports indicate that ozone may be cause of the odor, however various types of odors have been reported in these reports as well ( 26 , 27 ), and it is not possible to identify the cause of the odors as ozone alone.…”

Section: Discussionmentioning

confidence: 94%

“…There is less information about odor, but this may be caused by a small amount of ozone generated by irradiation. Ozone is often described as having a burnt or chemical odor, and these odors were common in and 2 of 14 patients answered "ozone" as the type of smell without knowledge of ozone as a possible cause (26). These reports indicate that ozone may be cause of the odor, however various types of odors have been reported in these reports as well (26, 27), and it is not possible to identify the cause of the odors as ozone alone.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Light flash and odor during proton beam therapy for pediatric patients: a prospective observational study

et al. 2022

Self Cite

View full text Add to dashboard Cite

Light flash and odor during radiation therapy are well-known phenomena, but the details are poorly understood, particularly in pediatric patients. Therefore, we conducted a prospective observational study of these events in pediatric patients (age ≤20 years old) who received radiotherapy at our center from January 2019 to November 2021. Light flash and odor were evaluated using a patient-reported checklist including the presence, strength, and duration of the phenomenon, and color of light or type of odor. 53 patients who received proton therapy (n=47) and photon radiotherapy (n=6) were enrolled in this study. The median age of the patients was 10, ranged from 5 to 20. The patients who was able to see the light flash was 4, and all of them received retina irradiation. This was equivalent to 57% of the patients who received radiotherapy to retina (n=7). The light was bright and colored mainly blue and purple, which seemed to be consistent with Cherenkov light. Odor was sensed by 9 (17%) patients, and seven patients of the 9 received nasal cavity irradiation. This was equivalent to 41% of the patients who received nasal cavity irradiation (n=17). Other 2 patients received proton therapy to brain tumor. The odors were mainly described as plastic, burnt and disinfectant, which may be caused by ozone generated during irradiation. These data suggest that pediatric patients with retinal and nasal cavity irradiation frequently sense light flashes or odor. So adequate care is necessary so that these patients are not worried about this phenomenon.

show abstract

Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Light flash and odor during proton beam therapy for pediatric patients: a prospective observational study

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…In previous studies, 27% of patients in whom the nasal cavity was included in the radiation field sensed odors and only 5% of patients in whom the nasal cavity was not included in the radiation field sensed odors [ 2 ]. An odor was sensed in 44% of TBI cases in the current study, which is a higher rate than that in radiotherapy other than TBI.…”

Section: Discussionmentioning

confidence: 99%

“…Visual abnormality was defined as unable to distinguish the colors on the chart with or without glasses, and abnormal olfactory sensation was confirmed by interview. A checklist was used with the same format as in previous studies to evaluate light and odor during TBI [ 1 , 2 ]. TBI was performed at 12 Gy in 6 fractions for 3 days, and TBI on the same day was performed with an interval of at least 6 hours.…”

Section: Methodsmentioning

confidence: 99%

“…Light flash and odor during radiotherapy are well-known phenomena among radiation oncologists. Two prospective observational studies have indicated that 56% of patients sensed a light flash during retina irradiation and 27% of patients sensed an odor during nasal cavity irradiation [ 1 , 2 ]. In our previous research, light flash and odor were felt with both X-ray and proton beam therapy, and pediatric patients (under 20 years old, median 10 years old) also sensed a light flash and odor with a certain probability (data not shown).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Abnormal sensation during total body irradiation: a prospective observational study

Mizumoto

Oshiro

Miyamoto

et al. 2022

Journal of Radiation Research

Self Cite

View full text Add to dashboard Cite

Light flash and odor during radiotherapy are well-known phenomena. Two prospective observational studies have indicated that 55% of patients observed a light flash during irradiation of the retina and 27% of patients sensed an odor during radiotherapy for the nasal cavity. A prospective observational study was performed in all patients at our hospital who received total body irradiation (TBI) between January 2019 to October 2021. Light flash and odor during TBI were examined using the same method as that used in previous studies. A total of 32 patients received TBI during the study period. The patients had a median age of 41 (18–60) years, and included 20 males and 12 females. A survey checklist showed that 14 patients (44%) sensed light and 14 patients (44%) sensed odor during TBI,. The color of the light during irradiation was yellow in six cases, white in four cases, and blue in four cases. The intensity of the light was 2–5 (median 3, 1 is very weak, 5 is very strong) and the time over which the light flash was felt was 4–60 s (median 10 s). Two patients each sensed smells of plastic, ozone and bleach, and others sensed one smell each. The intensity of the odor was 1–4 (median 3, 1 is very weak, 5 is very strong) and the time over which the odor was sensed was 1–25 s (median 3 s). We conclude that light flashes and odors are each sensed by 44% of patients during TBI. Various types of light flashes and odors were reported in this study.

show abstract

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

et al. 2023

View full text Add to dashboard Cite

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 (χ2 = 14.05, p = 0.02), absence of taste problems (χ2 = 10.28, p = 0.01), and proton RT (χ2 = 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.

show abstract

Olfactory Sensations During Proton and Photon Radiotherapy: A Multicenter Prospective Observational Study

Cited by 6 publications

References 14 publications

Light flash and odor during proton beam therapy for pediatric patients: a prospective observational study

Light flash and odor during proton beam therapy for pediatric patients: a prospective observational study

Abnormal sensation during total body irradiation: a prospective observational study

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

Contact Info

Product

Resources

About