The value of whole-body contrast-enhanced 18F-FDG PET/CT imaging in the diagnosis and staging of patients with laryngeal carcinoma

Comprehensive literature review of oral and intravenous contrast-enhanced PET/CT: a step forward?

The integration of diagnostic CT scans into PET/CT facilitates a comprehensive single examination, presenting potential advantages for patients seeking a thorough one-shot check-up. The introduction of iodinated contrast media during PET scanning raises theoretical concerns about potential interference with uptake quantification, due to the modification of tissue density on CT. Nevertheless, this impact appears generally insignificant for clinical use, compared to the intrinsic variability of standardized uptake values. On the other hand, with the growing indications of PET, especially 18F-FDG PET, contrast enhancement increases the diagnostic performances of the exam, and provides additional information. This improvement in performance achieved through contrast-enhanced PET/CT must be carefully evaluated considering the associated risks and side-effects stemming from the administration of iodinated contrast media. Within this article, we present a comprehensive literature review of contrast enhanced PET/CT, examining the potential impact of iodinated contrast media on quantification, additional side-effects and the pivotal clinically demonstrated benefits of an all-encompassing examination for patients. In conclusion, the clinical benefits of iodinated contrast media are mainly validated by the large diffusion in PET protocols. Contrary to positive oral contrast, which does not appear to offer any major advantage in patient management, intravenous iodine contrast media provides clinical benefits without significant artifact on images or quantification. However, studies on the benefit-risk balance for patients are still lacking.

The Prognostic and Diagnostic Value of [18F]FDG PET/CT in Untreated Laryngeal Carcinoma

This study aims to determine the diagnostic accuracy of staging PET/CT and neck MRI in patients with laryngeal carcinoma and to assess the value of PET/CT in predicting progression-free survival (PFS) and overall survival (OS). Sixty-eight patients who had both modalities performed before treatment between 2014 and 2021 were included in this study. The sensitivity and specificity of PET/CT and MRI were evaluated. PET/CT had 93.8% sensitivity, 58.3% specificity, and 75% accuracy for nodal metastasis, whereas MRI had 68.8%, 61.1%, and 64.7% accuracy, respectively. At a median follow-up of 51 months, 23 patients had developed disease progression and 17 patients had died. Univariate-survival analysis revealed all utilized PET parameters as significant prognostic factors for OS and PFS (p-value < 0.03 each). In multivariate analysis, metabolic-tumor volume (MTV) and total lesion glycolysis (TLG) predicted better PFS (p-value < 0.05 each). In conclusion, PET/CT improves the accuracy of nodal staging in laryngeal carcinoma over neck MRI and adds to the prognostication of survival outcomes through the use of several PET metrics.

Contrast-enhanced ultrasound for the preoperative assessment of laryngeal carcinoma: a preliminary study

BACKGROUND

Contrast-enhanced ultrasound (CEUS) is considered an attractive imaging technique to evaluate tumor microcirculation. However, the validity of CEUS for assessing laryngeal carcinoma is unclear.

PURPOSE

To compare the performance of CEUS with conventional US and contrast-enhanced computed tomography (CECT) in the diagnosis and preoperative T-staging of laryngeal carcinoma.

MATERIAL AND METHODS

Forty-one consecutive patients with laryngeal carcinoma underwent conventional high-frequency US, CEUS, and CECT before surgery. The CEUS characteristics of laryngeal carcinoma were recorded. The imaging findings of CEUS and conventional US were compared with CECT findings and the postoperative pathological examination.

RESULTS

CEUS showed hyperenhancement in 38 cases and isoenhancement in three cases. Homogeneous distribution of contrast agent was found in 20 cases and heterogeneous distribution in 21 cases, of which 16 cases showed local perfusion defects. In the enhanced phase, rapid entry was observed in 37 cases, synchronous entry was observed in two cases, and slow entry was observed in two cases. Rapid exit was observed in 25 cases and slow exit was observed in 16 cases. The pretherapeutic T-staging accuracy was not significantly different between conventional US, CEUS, and CECT (P ≥ 0.500). A high sensitivity and specificity were achieved by CEUS in the evaluation of involvement of thyroid cartilage.

CONCLUSION

Compared with conventional US and CECT, CEUS has a reliable initial T-staging accuracy and diagnostic properties for detecting laryngeal cartilage invasion.

Stage Migration and Survival Trends in Laryngeal Cancer

BACKGROUND

During the last two decades, significant advancements in the treatment of laryngeal cancer have occurred. Although survival of head and neck cancer patients has improved over time, the temporal trend of laryngeal cancer survival is an area of controversy.

METHODS

From 2004 to 2016, 77,527 patients who had laryngeal cancer treated with curative intent in the United States were identified in the National Cancer Database. Relative and observed survival rates were assessed for temporal trends. Multinomial logistic regression investigated the relationship between American Joint Committee on Cancer (AJCC) stage and increasing calendar year.

RESULTS

No significant improvement in 2- or 5-year observed survival (OS) or relative survival (RS) was observed. The 5-year RS ranged from 61.72 to 63.97%, and the 5-year OS ranged from 54.26 to 56.52%. With each increasing year, the proportion of stage 4 disease increased, with risk for stage 4 disease at the time of diagnosis increasing 2.2% annually (adjusted odds ratio [aOR], 1.022; 95% confidence interval [CI], 1.017-1.028; p < 0.001). This increase was driven by a 4.7% yearly increase in N2 disease (aOR, 1.047; 95% CI, 1.041-1.053; p < 0.001), with an annual 1.2% increase in T3 disease (aOR, 1.012; 95% CI, 1.007-1.018; p < 0.001) and a 1.2% increase in T4 disease (aOR, 1.012; 95% CI, 1.005-1.018; p < 0.001).

CONCLUSION

Despite advances in the field, laryngeal cancer survival in the United States is not improving over time. This may be due to an increase in the proportion of stage 4 disease, driven primarily by increasing nodal disease. To achieve survival improvement commensurate with scientific and technologic advances, efforts should be made to diagnose and treat laryngeal cancer at earlier stages to prevent further stage migration.

Salvage carbon dioxide transoral laser microsurgery for laryngeal cancer after (chemo)radiotherapy: a European Laryngological Society consensus statement

Purpose

To provide expert opinion and consensus on salvage carbon dioxide transoral laser microsurgery (CO₂ TOLMS) for recurrent laryngeal squamous cell carcinoma (LSCC) after (chemo)radiotherapy [(C)RT].

Methods

Expert members of the European Laryngological Society (ELS) Cancer and Dysplasia Committee were selected to create a dedicated panel on salvage CO₂ TOLMS for LSCC. A series of statements regarding the critical aspects of decision-making were drafted, circulated, and modified or excluded in accordance with the Delphi process.

Results

The expert panel reached full consensus on 19 statements through a total of three sequential evaluation rounds. These statements were focused on different aspects of salvage CO₂ TOLMS, with particular attention on preoperative diagnostic work-up, treatment indications, postoperative management, complications, functional outcomes, and follow-up.

Conclusion

Management of recurrent LSCC after (C)RT is challenging and is based on the need to find a balance between oncologic and functional outcomes. Salvage CO₂ TOLMS is a minimally invasive approach that can be applied to selected patients with strict and careful indications. Herein, a series of statements based on an ELS expert consensus aimed at guiding the main aspects of CO₂ TOLMS for LSCC in the salvage setting is presented.

Routine restaging after primary non-surgical treatment of laryngeal squamous cell carcinoma-a review

Purpose

Treatment of patients with laryngeal squamous cell carcinoma with radiotherapy or chemoradiation is an established alternative to laryngeal surgery in many cases, but particularly for advanced tumors without cartilage invasion. Imaging modalities face the challenge of distinguishing between posttherapeutic changes and residual disease in the complex anatomic subsite of the larynx. Guidelines concerning restaging of head and neck squamous cell carcinomas (HNSCC) are presented by the National Comprehensive Cancer Network (NCCN) and other national guidelines, but clearly defined recommendations for routine restaging particularly for laryngeal cancer are lacking.

Methods

A systematic search was carried out in PubMed to identify studies evaluating routine restaging methods after primary non-surgical treatment of laryngeal squamous cell carcinoma from 2009 to 2020.

Results

Only three studies were deemed eligible, as they included at least ≥50% patients with laryngeal squamous cell carcinoma and evaluated imaging modalities to detect residual cancer. The small number of studies in our review suggest restaging with fluoro-deoxy-glucose positron-emission tomography/computed tomography (FDG PET/CT) 3 months after initial treatment, followed by direct laryngoscopy with biopsy of the lesions identified by FDG PET/CT.

Conclusion

Studies evaluating restaging methods after organ-preserving non-surgical treatment of laryngeal carcinoma are limited. As radiotherapy (RT), chemoradiotherapy (CRT), systemic therapy followed by RT and radioimmunotherapy are established alternatives to surgical treatment, particularly in advanced laryngeal cancers, further studies are needed to assess and compare different imaging modalities (e.g. PET/CT, MRI, CT, ultrasound) and clinical diagnostic tools (e.g., video laryngoscopy, direct laryngoscopy) to offer patients safe and efficient restaging strategies. PET or PET/CT 3 months after initial treatment followed by direct laryngoscopy with biopsy of the identified lesions has the potential to reduce the number of unnecessary laryngoscopies.

Clinical Versus Pathologic Laryngeal Cancer Staging and the Impact of Stage Change on Outcomes

OBJECTIVES/HYPOTHESIS

Evaluate the impact and accuracy of clinical laryngeal cancer staging.

STUDY DESIGN

Retrospective cohort study.

METHODS

Two hundred sixty-five consecutive patients with laryngeal squamous cell carcinoma who underwent total laryngectomy from 2001 to 2017 were studied. Clinical versus pathologic tumor (T) and nodal (N) categories were compared. Logistic regression and Cox proportional hazards analyzed the association of stage change with perioperative factors and outcomes.

RESULTS

Forty-seven patients (17.7%, accuracy = 0.969 ± 0.010 [standard error]) changed between T1-2 and T3-4. Sixty-four patients (24.1%, accuracy = 0.866 ± 0.020) had inaccurate N category. Salvage patients were less likely to have stage change (downstage: odds ratio [OR] = 0.20, 95% confidence interval [CI]: 0.08-0.50, P < .001; upstage: OR = 0.41, 95% CI: 0.23-0.74, P = .003), but more likely to have inaccurate nodal category (39.8% vs. 11.7%, P < .001). Patients with stage change tended to have greater odds of positive/close margins (upstage: OR = 1.78, 95% CI: 0.91-3.5, P = .092) and chemotherapy (downstage: OR = 2.21, 95% CI: 0.80-6.14, P = .128; upstage: OR = 1.87, 95% CI: 0.85-4.11, P = .119). Stage change was associated with recurrence (P = .047) with downstaged patients less likely to recur (hazard ratio = 0.26, 95% CI: 0.08-0.82, P = .021). Stage change was not associated with positron emission tomography scan, subsite, time to surgery, or mortality.

CONCLUSIONS

A third of laryngeal cancer patients were downstaged or upstaged after laryngectomy with 18% and 24% of clinical T and N categories inaccurate, respectively. Stage change was less common for salvage patients and associated with risk of recurrence.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:559-565, 2021.

PET/CT Evaluation of Head and Neck Cancer of Unknown Primary

The diagnosis of carcinoma of unknown primary in the head and neck is made when there is a metastasis but no primary lesion is identified after physical exam and diagnostic CT or MR imaging. PET/CT is the first step in searching for a primary lesion, followed by more invasive techniques such as endoscopy and surgery. Knowledge of the different tumor histologic types, preferential locations of nodal spread, imaging pitfalls, and other special considerations such as cystic metastases can be helpful in the ultimate identification of primary tumors, which leads to improved overall patient survival.