Effects of radiotherapy on olfactory function in patients with head and neck cancer

Prospective observational cohort study of radiotherapy dose to the olfactory region and subsequent olfactory dysfunction in head and neck cancer patients at Chang Gung Memorial Hospital

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN14947812

Enrollment

Registered

2025-09-29

Start date

2021-01-12

Completion date

Unknown

Last updated

2026-02-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Head and neck cancers (including nasopharyngeal carcinoma, nasal cavity cancer, oral cavity cancer, tonsil cancer, hypopharyngeal cancer, laryngeal cancer, parotid cancer and palate cancer) Cancer

Interventions

All participants received standard-of-care intensity-modulated radiotherapy (IMRT), with some patients also receiving concurrent chemotherapy as clinically indicated. No additional interventions were

Eligibility

Sex/Gender

All

Age

18 Years to 100 Years

Inclusion criteria

Inclusion criteria: 1. Patients with histologically confirmed head and neck cancer scheduled for curative intensity modulated radiotherapy (IMRT) at Chang Gung Memorial Hospital 2. Provided written informed consent approved by the Chang Gung Medical Foundation IRB

Exclusion criteria

Exclusion criteria: 1. Severe nasal septal deviation with hypertrophic turbinate 2. Chronic rhinosinusitis with or without nasal polyps 3. History of head trauma 4. Prior radiotherapy to the head and neck region 5. Baseline olfactory dysfunction defined as Taiwan Smell Identification Test (TWSIT) score <40

Design outcomes

Primary

Measure	Time frame
The proportion of participants with olfactory dysfunction (TWSIT <40) measured using the Taiwan Smell Identification Test (TWSIT, score range 0–48) at baseline (pre-RT), end of radiotherapy, and at 1, 3, 6, and 12 months post-RT	—

Secondary

Measure	Time frame
1. Change in olfactory function measured using the change in TWSIT scores (continuous 0–48) from baseline to end of RT and to 1, 3, 6, and 12 months post-RT 2. Dose–response relationship measured using the association between mean olfactory-region radiation dose (Gy) and change in TWSIT scores measured using radiotherapy treatment plans at one timepoint 3. Dose threshold exploration measured using the identification of potential radiation dose cut-off values predictive of olfactory dysfunction using ROC analysis, measured using radiotherapy treatment plans at one timepoint 4. Regression analysis of odds measured using the logistic regression analysis of odds of post-RT olfactory dysfunction in relation to olfactory-region dose, adjusted for relevant covariates measured using radiotherapy treatment plans at one timepoint	—

Measure

Time frame

1. Change in olfactory function measured using the change in TWSIT scores (continuous 0–48) from baseline to end of RT and to 1, 3, 6, and 12 months post-RT 2. Dose–response relationship measured using the association between mean olfactory-region radiation dose (Gy) and change in TWSIT scores measured using radiotherapy treatment plans at one timepoint 3. Dose threshold exploration measured using the identification of potential radiation dose cut-off values predictive of olfactory dysfunction using ROC analysis, measured using radiotherapy treatment plans at one timepoint 4. Regression analysis of odds measured using the logistic regression analysis of odds of post-RT olfactory dysfunction in relation to olfactory-region dose, adjusted for relevant covariates measured using radiotherapy treatment plans at one timepoint

—

Countries

Taiwan

Contacts

Public ContactGeng He Chang

genghechang@gmail.com+886-5-3621000 ext.2076

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 19, 2026