Radiological imaging features of the salivary glands in xerostomia induced by an immune checkpoint inhibitor

Kouji Katsura,Kaname Nohno,Marie Soga,Masaki Takamura,Takafumi Hayashi,Saori Funayama,Noboru Kaneko,Kayoko Ito,Taichi Kobayashi

doi:10.1007/s11282-020-00480-9

Abstract

The clinical features of xerostomia induced by immune checkpoint inhibitors (ICI) are similar to those of Sjögren’s syndrome (SS), whereas the immunohistological and serological features are known to differ from those of SS. However, the radiologic imaging features of salivary glands are not yet well known. We report a case of a 56-year-old male patient diagnosed with ICI-induced xerostomia. The patient underwent various imaging examinations to investigate the condition of the salivary glands, which indicated the following: (1) less specific findings on contrast-enhanced computed tomography, (2) mixed with intermediate and low signal intensity on both T1-weighted and fat-suppressed T2-weighted magnetic resonance imaging and poor “salt and pepper” appearance on magnetic resonance sialography, and (3) multiple ovoid hypoechoic areas with hyperechoic bands without acute sialadenitis on ultrasound. These radiologic imaging findings suggested remarkable lymphocyte infiltration, which could be a characteristic of ICI-induced xerostomia.

Highlights

To date, immune checkpoint inhibitors (ICI), including ipilimumab or nivolumab, are used for the treatment of various types of cancers
The clinical characteristics of patients with xerostomia induced by ICI, such as nivolumab, are similar to those of s syndrome (SS) patients, but the prevalence of SS-associated immunological markers such as antinuclear antibodies or anti-SSA in patients with ICI-induced xerostomia is low compared with patients with SS-induced xerostomia [6,7,8]
magnetic resonance imaging (MRI) of the parotid glands showing markedly high signal intensity as compared with that in the muscle and h apparent diffusion coefficient map of the parotid glands showing a markedly lower value than that in the muscle. i Diffusion-weighted MRI of the submandibular glands showing marked high signal intensity as compared with muscle and j apparent diffusion coefficient map of the submandibular glands showing marked lower value than muscle lymphocyte profile is different between these conditions, and the B-cell ratio of ICI-induced xerostomia is obviously lower than that of SS-induced xerostomia [7, 8]

Summary

Introduction

Immune checkpoint inhibitors (ICI), including ipilimumab or nivolumab, are used for the treatment of various types of cancers. The amount of stimulated saliva by Saxon test was 0.32 g/2 min, and the Schirmer test produced tears of 3 mm/5 min for the right eye and 2 mm/5 min for the left eye These results showed that salivary and lacrimal functions were decreasing markedly, the results of the serologic test were negative for SS (Fig. 2). D Transverse fine-blood flow color Doppler US images of the left submandibular gland showing no significant increased vascularity (T2WIfs), and it was replaced by multiple intermediatesignal lesions, including diffusely distributed small, low-signal spots. Diffusion-weighted image (DWI) and apparent diffusion coefficient (ADC) map showed salivary glands with a heterogeneous marked high signal intensity and a lower value than normal, respectively (Fig. 5g–j)

Discussion

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