¹⁸F-FDG-PET/CT Imaging in Advanced Glottic Cancer: A Tool for Clinical Decision in Comparison with Conventional Imaging

Abstract

This study assessed the role of 18F-FDG PET-CT (PET/CT) to detect the cartilage and paraglottic infiltration in advanced glottic cancer comparing the results with those of conventional imaging (CI) (contrast-enhanced computed tomography and/or magnetic resonance). In addition, we assessed the prognostic value of quantitative parameters, measured on baseline PET/CT, in terms of event-free survival (EFS) and overall survival (OS). We retrospectively analyzed 27 patients with glottic squamous cell carcinoma stage III and IVA, treated in our institute between 2010 and 2016, comparing PET/CT, performed for staging and radiotherapy planning, and CI findings. Cohen’s K was used to compare concordance between PET/CT and CI. Imaging findings were correlated with endoscopic evaluation and histological reports (gold standard (GS)). All lesions shown by CI were also detected by PET/CT imaging, and in 5 cases, a better definition of local infiltration was achieved with PET/CT than CI (5 CT). Sensitivity, specificity, and accuracy of PET/CT and CT were 95%, 86%, and 93% and 70%, 86%, and 74% for, respectively. MRI showed sensitivity and specificity of 100%. One false-negative (FN) cases and 1 false-positive (FP) case were observed with PET/CT with no difference compared to MRI (10 cases). Six FN cases and 1 FP case were observed with CT. Cohen’s K was 0.60 (PET vs. CI) and 0.80 (PET vs. GS). Patients were followed-up for at least 24 months to calculate EFS and OS. 13 local recurrence and 7 deaths were recorded. Among quantitative PET parameters, baseline MTV was the most powerful predictor of outcome. Our data suggest a reliable sensitivity and accuracy of PET/CT in the evaluation of local extension, proving a useful method for initial local staging in addition to the well-established role in lymph-node and distant sites assessment. Furthermore, pretreatment MTV provides better prognostic information than other PET/CT parameters.

The role of 18F-FDG PET/CT in the follow-up of laryngeal cancer after treatment

“…disease-free survival (p =0.03), while nodal SUV was not predictive. Castelli et al (23) and Paone et al (24) concluded that among many quantitative PET parameters, SUVmax did not show promising results as a good outcome predictor. However, Chun et al (25) claimed that there was a significant difference in SUVmax between cervical lymph nodes with and without extracapsular spread (6.39 ± 4.53 vs 1.21 ± 1.70; p < .001) in patients with laryngeal cancer who had undergone 18F-FDG PET/CT before the surgery.…”

Computed tomography in the assessment of cartilage invasion in locally advanced laryngeal cancer

“…In the last decade, numerous studies have been performed to assess and compare the value of different imaging techniques in the evaluation of cartilage invasion [7,[10][11][12][13][14][15][16][17][18][19][20][21][22][23]. However, most of those studies have significant drawbacks, mainly small sample sizes.…”

“…Other imaging tests can also be used to evaluate cartilage invasion. Paone et al found that PET/CT improves the detection of cartilage invasion and overall staging [11]. Dual-energy CT has been shown to improve the accuracy of cartilage invasion imaging By contrast, dynamic contrast-enhanced CT does not appear to improve diagnostic accuracy in assessing cartilage invasion [14].…”

“…There are several studies that compared CT imaging to histopathological evaluation in laryngeal cancer staging. However, most of those studies had small sample sizes, thus limiting the strength of the findings [7,[10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”

Nasal-Type NK/T-Cell Lymphoma Involvement of the Vocal Cord on FDG PET/CT

“…One case demonstrated a primary NK/T-cell lymphoma involving the larynx revealed on PET/CT, which exhibited a diffuse FDG uptake on supraglottic and glottic exophytic regions 14 . Asymmetric vocal cord FDG uptake should arouse a suspicion of primary neoplasm, 15 metastasis, 16 vocal paralysis (contralateral side uptake), 17 myofibroblastic tumor, 18 myxoma, 19 and sarcoidosis 20 . In our case, the ENKTL involved the left side of vocal cord, showing focal intense FDG uptake on PET/CT.…”