Olfactory bulb volume and olfactory function after radiotherapy in patients with nasopharyngeal cancer

Bayram Veyseller; Berke Ozucer; Nazan Degirmenci; Defne Gurbuz; Makbule Tambas; Musa Altun; Fadullah Aksoy; Orhan Ozturan

doi:10.1016/j.anl.2014.02.004

Olfactory bulb volume and olfactory function after radiotherapy in patients with nasopharyngeal cancer

Auris Nasus Larynx. 2014 Oct;41(5):436-40. doi: 10.1016/j.anl.2014.02.004. Epub 2014 Apr 17.

Authors

Bayram Veyseller¹, Berke Ozucer², Nazan Degirmenci¹, Defne Gurbuz³, Makbule Tambas⁴, Musa Altun⁴, Fadullah Aksoy¹, Orhan Ozturan¹

Affiliations

¹ Bezmiâlem Vakif University, Medical Faculty, Department of Otolaryngology, Fatih, Istanbul, Turkey.
² Bezmiâlem Vakif University, Medical Faculty, Department of Otolaryngology, Fatih, Istanbul, Turkey. Electronic address: berkeozucer@gmail.com.
³ Okmeydanı Research and Training Hospital, Department of Radiology, Istanbul, Turkey.
⁴ Istanbul University, Istanbul Medical Faculty, Department of Oncology, Çapa, Istanbul, Turkey.

PMID: 24746667
DOI: 10.1016/j.anl.2014.02.004

Abstract

Objective: Radiotherapy is the primary method of treatment for nasopharyngeal cancer (NPC) and many side effects were reported in patients receiving radiation to this area. This study was conducted to evaluate the long-term effects of radiotherapy following NPC on olfactory bulb (OB) volume and olfactory function.

Methods: Twenty-four patients with NPC who received radiotherapy at least 12 months ago were recruited. Fourteen healthy subjects with similar demographical characteristics were recruited as the healthy control group. All volunteers were subjected to a nasoendoscopical examination, and abnormalities that could potentially cause olfactory dysfunction were the exclusion criteria from the study. An experienced radiologist segmented the MRI coronal, axial and sagittal slices manually for three-dimensional OB volume measurement in a blinded manner. Olfactory function was assessed using the Connecticut Chemosensory Clinical Research Center (CCCRC) test, and average score (0: worst, 7: best) was calculated as the total CCCRC olfactory score.

Results: The mean CCCRC score was 5.5 ± 1.1 for the nasopharyngeal cancer patients, whereas the mean score of healthy control group was 6.4 ± 0.4. There was a significant difference in the olfactory scores (p=0.003). The mean OB volume in the NPC group was 46.7 ± 12.1mm(3). Among the patients with NPC, the cisplatin receiving group had a mean OB volume of 47.2mm(3), whereas the cisplatin+docetaxel receiving group had a mean OB volume of 46.5mm(3), and they were similar. The MRI measurement of the healthy control group was 58.6 ± 13.8mm(3). The OB volumes of the healthy control group were significantly higher (p<0.05).

Conclusion: Radiotherapy following nasopharyngeal cancer results in a diminished OB volume and deteriorated olfactory function. Chemosensory olfactory dysfunction might be a contributing factor to lack of appetite, cancer cachexia and consequent lowered quality of life in NPC patients.

Keywords: Dysosmia; Nasopharynx cancer; Olfactory bulbus; Olfactory dysfunction; Olfactory function; Radiotherapy; Smell.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Carcinoma
Case-Control Studies
Female
Humans
Magnetic Resonance Imaging
Male
Middle Aged
Nasopharyngeal Carcinoma
Nasopharyngeal Neoplasms / radiotherapy*
Olfaction Disorders / etiology*
Olfaction Disorders / pathology
Olfactory Bulb / pathology
Olfactory Bulb / radiation effects*
Organ Size
Quality of Life
Radiotherapy / adverse effects*
Sensory Thresholds
Smell / radiation effects*