Early Changes in Apparent Diffusion Coefficient for Salivary Glands during Radiotherapy for Nasopharyngeal Carcinoma Associated with Xerostomia

• Published in: Korean journal of radiology Vol. 19; no. 2; pp. 328 - 333
• Main Authors: Zhang, Qing, Wei, Yu-Mei, Qi, Yuan-Gang, Li, Bao-Sheng
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Society of Radiology 01.03.2018; 대한영상의학회
• Subjects: Cancer; Exocrine glands; Neuroimaging and Head & Neck; Patients; Radiation therapy; 방사선과학; Diffusion-weighted imaging; Nasopharyngeal carcinoma; MR imaging; Parotid gland; Dry mouth; Head and neck; Radiation-induced complication; Quality of life
• ISSN: 1229-6929; 2005-8330
• DOI: 10.3348/kjr.2018.19.2.328

To evaluate the early changes in the apparent diffusion coefficient (ADC) of the salivary glands during radiotherapy (RT) and their association with the degree of xerostomia at 6 months after RT in patients with nasopharyngeal carcinoma (NPC). We enrolled 26 patients with NPC who underwent RT. Each patient underwent diffusion-weighted MRI of the salivary glands at rest and with gustatory stimulation within 1 week before RT and 2 weeks after the beginning of RT. The ADC at rest (ADC ) and increase and increase rate with stimulation (ADC , ADC ) of the submandibular and parotid glands were calculated. The differences in the variables' values between 2 weeks after the beginning of RT and baseline (ΔADC , ΔADC , and ΔADC ) were compared to the degree of xerostomia at 6 months after RT. The ADC of the submandibular and parotid glands were both significantly higher at 2 weeks after the beginning of RT than found at baseline (both < 0.01). The ADC and ADC for the parotid glands were both significantly lower at 2 weeks after the beginning of RT than found at baseline (both < 0.01). ΔADC and ΔADC of the parotid glands were associated with the degree of xerostomia at 6 months after RT ( = -0.61 and -0.72, both < 0.01). The ADCs of the salivary glands change early during RT. The differences in the ADC increase and increase rate of the parotid glands between 2 weeks after the beginning of RT and baseline were associated with the degree of xerostomia at 6 months after RT.