Is there a role for PET/CT parameters to differentiate thyroid cartilage invasion from penetration?

Total lesion glycolysis as a predictor of clinical T3-4a laryngeal cancer with laryngectomy or nonlaryngectomy

The purpose of the present study is to investigate whether the 18F-fluorodeoxyglucose (18F-FDG) uptake parameter is related to survival outcomes for patients with clinical T3-T4a laryngeal cancer with various definitive treatments including total laryngectomy (TL). Parameters of 18F-FDG uptake in the primary tumors of 46 cases which were assessed by positron emission tomography with computed tomography were enrolled in the present observation study. Monovariate or multivariate survival analyses were performed with log-rank test or Cox regression model, with the hazard ratio (HR) and 95% confidence interval (CI), respectively. Cutoff values of the 18F-FDG uptake parameters were determined by the lowest P-value for monovariate overall survival. In the monovariate analysis, both metabolic tumor volume ≥13.1 and total lesion glycolysis (TLG) ≥46.5 were significantly associated with shorter overall survival, and TLG ≥46.5 was also related to a reduction in distant metastasis-free survival. In the multivariate analysis adjusting for clinical T classification (cT4/cT3) and treatment group (TL/non-TL), TLG (≥46.5/<46.5) was associated with both poorer overall (HR: 3.16, 95% CI: 1.10-9.49) and distant metastasis-free (HR: 8.91, 95% CI: 1.93-62.6) survival. In conclusion, TLG is a predictor for survival in laryngeal cancer.

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

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.

A Critical Reappraisal of Primary and Recurrent Advanced Laryngeal Cancer Staging

Objectives:

Laryngeal squamous cell carcinoma (LSCC) can involve different anatomic subunits with peculiar surgical and prognostic implications. Despite conflicting outcomes for the same stage of disease, the current staging system considers different lesions in a single cluster. The aim of this study was to critically discuss clinical and pathologic staging of primary and recurrent advanced LSCC in order to define current staging pitfalls that impede a precise and tailored treatment strategy.

Methods:

Thirty patients who underwent total laryngectomy in the past 3 years for primary and recurrent advanced squamous cell LSCC were analyzed, comparing endoscopic, imaging, and pathologic findings. Involvement of the different laryngeal subunits, vocal-fold motility, and spreading pattern of the tumor were blindly analyzed. The diagnostic accuracy and differences between clinicoradiologic and pathologic findings were studied with standard statistical analysis.

Results:

Discordant staging was performed in 10% of patients, and thyroid and arytenoid cartilage were the major diagnostic pitfalls. Microscopic arytenoid involvement was significantly more present in case of vocal-fold fixation ( P = .028). Upstaging was influenced by paraglottic and pre-epiglottic space cancer involvement, posterior commissure, subglottic region, arytenoid cartilage, and penetration of thyroid cartilage; on the contrary, involvement of the inner cortex or extralaryngeal spread tended to be down-staged. Radiation-failed tumors less frequently involved the posterior third of the paraglottic space ( P = .022) and showed a significantly worse pattern of invasion ( P < .001).

Conclusions:

Even with the most recent technologies, 1 in 10 patients with advanced LSCC in this case series was differently staged on clinical examination, with cartilage involvement representing the main diagnostic pitfall.