Diagnostic Performance of Diffusion-Weighted MRI and FDG PET/CT for Detecting the Local Recurrence of Head and Neck Squamous Cell Carcinoma

Abstract

IntroductionFor patients with head and neck squamous cell carcinoma (HNSCC), multidisciplinary treatment involving surgery, radiotherapy, and/or chemotherapy improves survival and quality of life (1, 2). Despite aggressive combined management, locoregional recurrence is observed in approximately 40% of patients (3). Physical examination after treatment can be compromised by post-treatment changes, as surgical intervention can change the normal anatomy and radiotherapy can cause edema, inflammation, fibrosis, and necrosis (4). Particularly in the early stages of treatment, posttreatment follow-up imaging is also a challenge. Differentiation of post-treatment changes from a recurrence of HNSCC is generally not possible on computed tomography (CT) or magnetic resonance imaging (MRI); recurrent tumors and post-treatment changes may show similar appearances on routine MRI. After contrast administration, mass-like enhancement of post-treatment changes may mimic recurrence (1). Conversely, some recurrent tumors do not show enhancements, and thus, they cannot be distinguished from post-treatment changes (5).Diffusion-weighted MRI (DW-MRI) is sensitive to the randomized (Brownian) motion of water molecules. This imaging technique uses two opposite gradients of similar strength along a particular diffusion direction. The first gradient stimulates dephasing, and the second gradient will completely rephase all stationary molecules. Consequently, the movement of protons in living tissues results in incomplete rephrasing and is then converted into a decrease in the signal intensity on the resulting image (6, 7). The apparent diffusion coefficient ( Bulgular: Nüks saptanan hastalarda ADC ortalama değerleri saptanmayan hastalarla karşılaştırıldığında istatistiksel olarak anlamlı derecede düşük bulunmuştur (0,773'e karşı 1,588 x10-3/mm 2 sırasıyla, p<0,001). Nüks saptanan hastalarda SUV max değerleri saptanmaya hastalara göre istatistiksel olarak anlamlı derecede yüksek bulundu (15,642' karşı 4,508 sırasıyla; p<0,001). Nüks saptanan hastalarda ADC ortalama ve SUV max değerleri arasında anlamlı bir korelasyon izlenmedi (p=0,278, r=0,341). Nüks saptanmayan hastalarda ADC ortalama ve SUV max değerleri arasında negatif korelasyon saptandı (p=0,019, r=-0,691).Sonuç: PET/BT ve DAG-MRG baş-boyun SCC hastalarında tedavi sonrası nüksü saptamada etkin yöntemlerdir. Baş-Boyun SCC hastaları tedavi sonrası DAG-MRG ile takip edilebilir ve nüks şüphesi olan hastalarda PET-BT takip protokolüne eklenebilir.Anahtar Kelimeler: Baş ve boyun kanseri; difüzyon ağırlıklı görüntüleme, görünür difüzyon katsayısı, pozitron emisyon tomografisi/bilgisayarlı tomografi, standardize tutulum değeri Objective: To compare the efficacy between diffusion-weighted magnetic resonance imaging (DW-MRI) and positron emission tomography/computed tomography (PET/CT) in detecting the local recurrence of head and neck squamous cell carcinoma (HNSCC) following treatment in the same patient group. Methods: Twenty-three patients who had biopsy-proven HNSCC were enrolled. All ...