18F-FDG-PET/CT in the quantification of photon radiation therapy-induced vasculitis

Austin J Borja; Emily C Hancin; Alexandra D Dreyfuss; Vincent Zhang; Toby Mathew; Chaitanya Rojulpote; Thomas J Werner; Shivaraj Patil; Karthik Gonuguntla; Alexander Lin; Steven J Feigenberg; Samuel Swisher-McClure; Abass Alavi; Mona-Elisabeth Revheim

¹⁸F-FDG-PET/CT in the quantification of photon radiation therapy-induced vasculitis

Am J Nucl Med Mol Imaging. 2020 Feb 25;10(1):66-73. eCollection 2020.

Authors

Austin J Borja^{1

2}, Emily C Hancin^{1

3}, Alexandra D Dreyfuss^{1

2}, Vincent Zhang¹, Toby Mathew¹, Chaitanya Rojulpote¹, Thomas J Werner¹, Shivaraj Patil^{1

4}, Karthik Gonuguntla^{1

4}, Alexander Lin⁵, Steven J Feigenberg⁵, Samuel Swisher-McClure⁵, Abass Alavi¹, Mona-Elisabeth Revheim^{1

6

7}

Affiliations

¹ Department of Radiology, University of Pennsylvania Philadelphia, PA, USA.
² Perelman School of Medicine at The University of Pennsylvania Philadelphia, PA, USA.
³ Lewis Katz School of Medicine at Temple University Philadelphia, PA, USA.
⁴ Department of Medicine, University of Connecticut Hartford, CT, USA.
⁵ Department of Radiation Oncology, University of Pennsylvania Philadelphia, PA, USA.
⁶ Division of Radiology and Nuclear Medicine, Oslo University Hospital Oslo, Norway.
⁷ Institute of Clinical Medicine, Faculty of Medicine, University of Oslo Oslo, Norway.

PMID: 32211220
PMCID: PMC7076303

Abstract

Radiation therapy (RT) is an important component of care for head and neck cancers (HNC). Photon RT vasculitis is a complication of incidental dose delivery to nearby vascular structures. However, optimal methods for early diagnosis are not clearly established. The aim of this study was to evaluate ¹⁸F-FDG-PET/CT in detecting radiation-induced vasculitis of the left common carotid (LCC) and the arch of the aorta (AoA) in patients treated for HNC. ¹⁸F-FDG-PET/CT scans obtained before RT (Pre-RT) and 3 months after RT (Post-RT) were retrospectively reviewed in 30 HNC patients (25 males, 5 females; average age 57.9±8.1 years) treated with photon RT. All subjects underwent ¹⁸F-FDG-PET/CT imaging 60 minutes after 5.0 MBq/kg ¹⁸F-FDG injection. Average standard uptake values (Avg SUVmean) of the LCC and AoA were obtained by global assessment. A two-tailed paired t-test was used to assess the difference in Avg SUVmean between pre- and post-RT imaging. Subjects demonstrated significant increased Avg SUVmean within the LCC post-RT (pre = 1.42, post = 1.65, P<0.001), with a mean increase of 0.23 SUV. Similarly, subjects exhibited higher ¹⁸F-FDG uptake in the AoA post-RT (pre = 1.44, post = 1.69, P<0.01), with a mean increase of 0.23 SUV. ¹⁸F-FDG-PET/CT may be used to detect and quantify photon RT vasculitis in HNC patients. Further investigation is warranted to evaluate the clinical implications of this pathology and the role for alternative treatment strategies in minimizing tissue toxicity.

Keywords: 18F-FDG; PET/CT; head and neck cancer; photon therapy; radiation therapy; vasculitis.