Systematic review: Accuracy of imaging tests in the diagnosis of recurrent laryngeal carcinoma after radiotherapy

PET-CT detection of local residual laryngeal carcinoma after definitive (chemo)radiotherapy

BACKGROUND

Positron emission tomography and computed tomography (PET-CT) is currently recommended in evaluating the treatment response after (chemo)radiotherapy ([C]RT). In the larynx, post-treatment changes and physiological uptake make image interpretation more challenging compared to other head and neck sites. Previous research has not addressed imaging factors specifically in the larynx that would help in distinguishing the residual disease and explain the unique challenges of that anatomic area. The study cohorts are small and heterogenous. Our objective was to investigate the ability of PET-CT in diagnosing local residual laryngeal carcinoma, and to uncover imaging factors that could be used in differentiating the residual disease from post-treatment and physiological changes. In the same study cohort, we also aimed to uncover prognostic factors for local residual or recurrent disease.

METHODS

Our retrospective study cohort included 73 patients with T2-T4 laryngeal carcinoma undergoing (C)RT with curative intention, and post-treatment non-contrast-enhanced PET-CT at 2-6 months. Findings were compared between local residual and non-residual disease. Local residual disease was defined as a persistent tumor growth with no evidence of remission in between, confirmed by biopsy, and evident within 6 months from the end of RT. PET-CT was evaluated using a 3-step scale: negative, equivocal, and positive.

RESULTS

Nine (12%) had a local residual tumor and 11 (15%) developed local recurrence, based on the biopsy. The median follow-up of surviving patients was 64 months (range, 28-174). In univariate analysis, primary tumor diameter greater than 2.4 cm (median value), and vocal cord fixation were prognostic for local residual or recurrent disease. Sensitivity, specificity, PPV, and NPV were 100%, 75%, 36%, and 100%, respectively, when the equivocal interpretation was grouped with the positive interpretation. All local residuals, and 28% (18/64) non-residuals, had a primary tumor area SUV_max of over 4.0 (p < 0.001). CT showed a persistent mass at the primary tumor area in 56% of residuals, and in 23% of non-residuals (p > 0.05). By combining SUV_max>4.0 and mass, specificity improved to 91%.

CONCLUSIONS

NPV of post-treatment PET-CT in laryngeal carcinoma is high, but equivocal and positive results have low PPV and require further diagnostics. All local residuals had SUV_max over 4.0. The combination of SUV_max over 4.0 and mass on CT increased specificity, but the sensitivity was low.

Surgical Treatment of Early Glottic Cancer

The incidence of all head and neck malignancies is rising worldwide, with carcinoma of the larynx constituting approximately 1% of all cancers. Early glottic cancer responds quite favorably to surgical intervention due to its early presentation, coupled with the low rate of regional and distant metastases. This article focuses on various approaches to the surgical treatment of early glottic cancer. Details include the clinical and radiological evaluation of laryngeal cancer, the goals of treatment, current surgical options for early disease, approach to surgical resection margins and management of nodal disease, and complications associated with each treatment modality.

Diagnostic efficacy of positron emission computerized tomography scans in suspicious laryngeal findings postorgan preservation treatment

BACKGROUND

Larynx preservation protocols (LPP) for glottic primary squamous cell carcinoma has gained popularity worldwide. Direct laryngoscopy (DL) with biopsy is mandated when recurrence is suspected. The efficacy of 18Fluoro-deoxy-glucose positron emission computerized tomography (PET-CT) as alternative first-line diagnostic investigation in suspected recurrence was evaluated.

METHODS

A retrospective study of patients with suspicious fiber-optic findings at more than 12 weeks after LPP. Sensitivity, specificity, and the negative predictive value (NPV) of DL and PET-CT were compared.

RESULTS

Seventy-two patients presenting 105 cases of suspicious events were included in this study. Fifty-two events were initially investigated by DL and 53 events by PET-CT. The sensitivity of DL and PET-CT was 56.25% and 100%, respectively. The NPV was 84% for DL and 100% for PET-CT (p = 0.015).

CONCLUSION

Negative PET scans after LPP are highly accurate in ruling out recurrent/persistent disease and may spare the patient from negative biopsies.

Symptom-based remote assessment in post-treatment head and neck cancer surveillance: A prospective national study

OBJECTIVES

To report the incidence of locoregional recurrence in head and neck cancer (HNC) patients under surveillance following treatment undergoing symptom-based remote assessment.

DESIGN

A 16-week multicentre prospective cohort study.

SETTING

UK ENT departments.

PARTICIPANTS

HNC patients under surveillance following treatment undergoing symptom-based telephone assessment.

MAIN OUTCOME MEASURES

Incidence of locoregional recurrent HNC after minimum 6-month follow-up.

RESULTS

Data for 1078 cases were submitted by 16 centres, with follow-up data completed in 98.9% (n = 1066). Following telephone consultation, 83.7% of referrals had their face-to-face appointments deferred (n = 897/1072). New symptoms were reported by 11.6% (n = 124/1072) at telephone assessment; 72.6% (n = 90/124) of this group were called for urgent assessments, of whom 48.9% (n = 44/90) came directly for imaging without preceding clinical review. The sensitivity and specificity for new symptoms as an indicator of cancer recurrence were 35.3% and 89.4%, respectively, with a negative predictive value of 99.7% (p = .002). Locoregional cancer identification rates after a minimum of 6 months of further monitoring, when correlated with time since treatment, were 6.0% (n = 14/233) <1 year; 2.1% (n = 16/747) between 1 and 5 years; and 4.3% (n = 4/92) for those >5 years since treatment.

CONCLUSIONS

Telephone assessment, using patient-reported symptoms, to identify recurrent locoregional HNC was widely adopted during the initial peak of the COVID-19 pandemic in the United Kingdom. The majority of patients had no face-to-face reviews or investigations. New symptoms were significantly associated with the identification of locoregional recurrent cancers with a high specificity, but a low sensitivity may limit symptom assessment being used as the sole surveillance method.

The potential role of imaging techniques in avoiding neck dissection during salvage surgery after head and neck carcinoma treated with bioradiotherapy

OBJECTIVE

This study aimed to evaluate the effectiveness of computed tomography and positron emission tomography-computed tomography prior to salvage surgery after head and neck carcinoma treated with bioradiotherapy and to look at the role of neck dissection in this setting.

METHOD

This study was a retrospective chart review of a series of consecutive patients with locally advanced head and neck squamous cell carcinoma treated with bioradiotherapy. Radiological and pathological stages were compared to evaluate the accuracy of computed tomography and positron emission tomography-computed tomography in detecting occult neck metastasis in the context of recurrence of primary tumour. In order to assess the impact of neck dissection on survival, Kaplan-Meier survival curves after salvage surgery with and without neck dissection were derived.

RESULTS

A total of 268 patients were identified, of which 22 underwent salvage surgery. The negative predictive value of computed tomography and positron emission tomography-computed tomography was excellent. Neck dissection did not represent an improvement on overall, disease specific and regional recurrence free survival (p = 0.67, p = 0.91 and p = 0.62, respectively) amongst clinically and radiologically negative necks.

CONCLUSION

Conservative treatment of the neck should be considered when dealing with patients with primary site recurrence or persistent disease after bioradiotherapy without evidence of neck disease.

Salvage surgery for residual or recurrent laryngeal squamous cell carcinoma after (Chemo)radiotherapy: Oncological outcomes and prognostic factors

Nonsurgical primary treatment of early and advanced laryngeal squamous cell carcinoma, employing radiotherapy with or without chemotherapy, is considered a standard of care in many centers throughout the world. When patients have persistent or recurrent disease after non-surgical treatment, salvage surgery is frequently the only remaining potentially curative treatment. Depending on the extent of the residual/recurrent disease, different surgical salvage options are at the surgeon's disposal. In selected cases with limited local disease, salvage transoral laser microsurgery, transoral robotic surgery and open partial laryngectomies can be employed to achieve cure while preserving laryngeal function. For more advanced cases total laryngectomy is necessary. Identifying situations with unacceptable results from surgical salvage may guide future therapies.

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.

Comparison of diffusion-weighted MR imaging and 18F Fluorodeoxyglucose PET/CT in detection of residual or recurrent tumors and delineation of their local spread after (chemo) radiotherapy for head and neck squamous cell carcinoma

PURPOSE

To compare the diagnostic accuracy of diffusion-weighted magnetic resonance imaging (DW-MRI) and fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in detection of residual or recurrent tumors and their local extension in patients with head and neck squamous cell carcinoma after treatment with (chemo) radiotherapy (CRT).

METHOD

Twenty-five patients (17 men, 8 women, median age 64 years, range 49-79) who underwent surgical salvage for residual or recurrent tumors after CRT were included. The histopathologic analysis after the surgical salvage served as the gold standard.

RESULTS

Both DW-MRI and ¹⁸F-FDG PET/CT had a sensitivity of 92 % (23/25) in the detection of residual or recurrent tumors. MRI had a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting perineural spread of 62 % (5/8), 88 % (15/17), 71 % (5/7) and 83 % (15/18), respectively; in comparison, PET/CT did not detect any cases of perineural spread. The sensitivity, specificity, PPV and NPV of MRI in detecting muscle infiltration was 75 % (9/12), 77 % (10/13), 75 % (9/12) and 77 % (10/13) respectively, while the values for ¹⁸F-FDG PET/CT were 58 % (7/12), 69 % (9/13), 64 % (7/11) and 64 % (9/14).

CONCLUSIONS

DW-MRI- and ¹⁸F-FDG PET/CT-imaging have an identical detection rate of residual or recurrent tumors after (chemo) radiotherapy. MRI has a higher sensitivity in detecting local perineural spread, has a better accuracy in the detection of muscle infiltration and more accurately correlates the lesion size to the histopathologic specimen.

Chondroradionecrosis of the larynx

PURPOSE OF REVIEW

Purpose of the present review is to revise the literature of the last 18 months, looking for novelties or new trends in diagnosis and therapeutical approaches to a very uncommon complicaton.

RECENT FINDINGS

Some comorbidities as well as prior surgical laryngeal treatment and lifestyle factors are known to increase tissue susceptibility to radiation injury and to complications due to endotracheal intubation.

SUMMARY

Chondroradionecrosis (CRN) of the larynx is a rare and severe complication of radiotherapy and endotracheal intubation which can be fatal if not managed promptly. In recent years, the trend in oncological surgery is organ preservation even in the advanced stage of laryngeal malignancies. However, in certain stages of squamous cell carcinomas, radiotherapy is necessary as a first or second line of treatment. Endotracheal intubation has also been associated with chondronecrosis and it is thought to be secondary to excessive pressure of the endotracheal tube or its cuff on the cartilage itself. Clinical diagnosis of CRN is extremely difficult and should be placed in differential diagnosis with postradiation outcomes and cancer recurrence. PET is useful, but biopsy is still required to confirm the diagnosis. The use of the laryngeal mask airway should prevent this complication and is a reasonable choice through which to administer general anesthesia in selected patients.

Is C-11 Methionine PET an alternative to 18-F FDG-PET for identifying recurrent laryngeal cancer after radiotherapy?

OBJECTIVE

18F FDG-PET is superior to other imaging techniques in revealing residual laryngeal cancer after radiotherapy. Unfortunately, its specificity is low, due to FDG uptake in inflammation and in anaerobic conditions. PET imaging with the amino acid-based radiopharmaceutical C11-methionine (MET) should be less influenced by post-radiation conditions. The aim of this study was to investigate the potential of MET in diagnosing recurrent laryngeal cancer after radiotherapy as compared to 18F-FDG.

METHODS

Forty-eight patients with a clinical suspicion of local residual disease at least 3 months after completion of radiotherapy or chemoradiotherapy for a T2-4 laryngeal carcinoma, along with an indication for direct laryngoscopy, were included. They received MET-PET and FDG-PET prior to the direct laryngoscopy. One senior nuclear medicine physician assessed both the FDG-PET and MET-PET images visually for the degree of abnormal uptake. The gold standard was a biopsy-proven recurrence 12 months after PET. The nuclear physician had no access to the medical charts and was blinded to the results of the other PET. Sensitivity, specificity and positive and negative predictive value were calculated.

RESULTS

The sensitivity of FDG was 77.3% and the specificity 56.0% after the conservative reading, with these values equalling 54.5% and 76.0% for MET. The positive predictive value of FDG was 60.7% and the negative predictive value 73.7%. The PPV of MET was 66.7%, and the NPV was 65.5%. The McNemar test within diseased (sensitivity comparison) shows a p-value of 0.125, and the McNemar test within non-diseased (specificity comparison) shows a P-value of 0.180.

CONCLUSION

MET-PET is not superior to FDG-PET in terms of identifying recurrent laryngeal cancer.

Condroradionecrose de laringe após radioterapia

RESUMO Objetivo: estudar a condroradionecrose de laringe por complicação de radio-quimioterapia para tratamento do câncer de laringe e propor um fluxograma de tratamento com a utilização de câmara hiperbárica. Métodos: estudo retrospectivo de pacientes portadores de carcinoma de laringe admitidos em dois hospitais terciários num período de cinco anos. Resultados: de 131 pacientes portadores de câncer de laringe, 28 foram submetidos à radio e quimioterapia exclusiva e destes, três evoluíram com condroradionecrose. O tratamento destes pacientes foi realizado com câmara hiperbárica e com desbridamento cirúrgico, conforme proposição do fluxograma. Todos os pacientes tiveram a laringe preservada. Conclusão: a incidência de condroradionecrose de laringe por complicação de radioterapia e quimioterapia em nossa casuística foi de 10,7% e o tratamento com oxigenoterapia hiperbárica, com base no nosso fluxograma, foi efetivo no controle desta complicação.

Guidelines for the Surgical Management of Laryngeal Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to develop clinical practice guidelines for the surgical treatment of laryngeal cancer. This Task Force conducted a systematic search of the EMBASE, MEDLINE, Cochrane Library, and KoreaMed databases to identify relevant articles, using search terms selected according to the key questions. Evidence-based recommendations were then created on the basis of these articles. An external expert review and Delphi questionnaire were applied to reach consensus regarding the recommendations. The resulting guidelines focus on the surgical treatment of laryngeal cancer with the assumption that surgery is the selected treatment modality after a multidisciplinary discussion in any context. These guidelines do not, therefore, address non-surgical treatment such as radiation therapy or chemotherapy. The committee developed 62 evidence-based recommendations in 32 categories intended to assist clinicians during management of patients with laryngeal cancer and patients with laryngeal cancer, and counselors and health policy-makers.

Risk of Recurrence in Laryngeal Cancer

A cohort study was undertaken to analyze the risk of recurrence among 1616 patients with primary squamous cell carcinoma of the larynx from 1983 to 2010 at a single, tertiary academic center in Oslo, Norway. The cohort was followed from the date of diagnosis to September 2011. Competing risk regression analysis assessed the association between various risk factors and the risk of recurrence, where death was considered a competing event. Recurrence was observed in 368 patients (23%) during the study period. The majority (71%) of recurrences involved the location of the primary tumor. The overall risk of recurrence during the first three years after initiating treatment was 20.5%. Increased risk of recurrence was observed in patients with supraglottic cancer, younger patients, those with T2–T3 tumors and in patients treated in the earlier part of the study period. Significant factors for recurrence in glottic carcinomas were age, treatment in the earlier part of the study and T-status, whereas age was a significant factor in supraglottic cancer. N-status appeared less significant. In conclusion, follow-up of laryngeal squamous cell carcinoma should place particular emphasis on the site of the primary tumor, younger patients, cases of supraglottic cancer and T2-T4 primary tumors, especially during the first three years after treatment. More studies are needed to assess the impact of surgical versus non-surgical treatment, and eventually the significance of recurrence, for disease-specific and overall survival in cases of advanced laryngeal squamous cell carcinoma.

The role of ultrasound-guided transcutaneous tru-cut biopsy in diagnosing untreated and recurrent laryngo-hypopharyngeal masses

OBJECTIVE

To evaluate the diagnostic performance of Ultrasound-guided Transcutaneous Tru-Cut biopsy (USGTCB) of laryngo-hypopharyngeal masses suspicious for malignancy. Furthermore we investigated whether USGTCB is accurate for both untreated masses and suspected recurrences.

MATERIALS AND METHODS

From August 2004 to July 2014 we prospectively enrolled 66 patients for a total of 68 USGTCBs: 38 USGTCB were performed for a suspicious untreated mass and in 30 for a suspected recurrence. We calculated the sensitivity, specificity, positive predictive value and negative predictive value for all procedures and separately for untreated masses and suspected recurrences.

RESULTS

USGTCB diagnosed 57 malignancies (51 squamous cell carcinomas, 6 other tumors) and 11 benign lesions. There were no false positives reported, whereas five false negatives were observed: two in patients with an untreated mass, three in patients with a suspected recurrence. Overall, the sensitivity of the technique was 91.9% (95% confidence interval [CI]: 82.2-97.3%); the specificity was 100% (95% CI: 54.1-100%); positive and negative predictive values were 100% (95% CI: 93.7-100%) and 54.5% (95% CI: 23.5-83.1%) respectively, with similar performances in untreated masses and suspected recurrences of SCC.

CONCLUSION

USGTCB is an effective procedure for the histological diagnosis of laryngo-hypopharyngeal masses suspicious for malignancy in patients showing contraindications to biopsy via microlaryngoscopy under general, with similar performances for untreated masses and suspected recurrences.

Effectiveness of an (18)F-FDG-PET based strategy to optimize the diagnostic trajectory of suspected recurrent laryngeal carcinoma after radiotherapy: The RELAPS multicenter randomized trial

PURPOSE

The purpose of this study is to evaluate the efficacy of (18)F-FDG-PET as first-line diagnostic investigation, prior to performing a direct laryngoscopy with biopsy under general anesthesia, in patients suspected of recurrent laryngeal carcinoma after radiotherapy.

PATIENTS AND METHODS

150 patients suspected of recurrent T2-4 laryngeal carcinoma at least two months after prior (chemo)radiotherapy with curative intent for resectable disease were randomized to direct laryngoscopy (CWU: conventional workup strategy) or to (18)F-FDG-PET only followed by direct laryngoscopy if PET was assessed 'positive' or 'equivocal' (PWU: PET based workup strategy), to compare the effectiveness of these strategies. Primary endpoint was the number of indications for direct laryngoscopies classified as unnecessary based on absence of recurrence, both on direct laryngoscopy and on six month follow up. Safety endpoints comprised resectability of recurrent lesions and completeness of surgical margins following salvage laryngectomy.

RESULTS

Intention-to-treat analyses were performed on all randomized patients (CWU: n=74, PWU: n=76). Tumor recurrence was similar in both groups: 45 patients (30%; 21 CWU, 24 PWU) within six months. In 53 patients in the CWU arm (72%, 95% CI: 60-81) unnecessary direct laryngoscopies were performed compared to 22 in the PWU arm (29%, 95% CI: 19-40) (p<0·0001). The percentage of salvage laryngectomies (resectability) and positive surgical margins were similar between CWU and PWU (81%, 63% respectively, p=0·17, and 29%, 7%, respectively, p=0.20). The prevalence of the combination of local unresectability and positive margins is in the CWU group 24% and in the PWU group 8%. No difference (p=0.32) in disease specific survival between both groups was found.

CONCLUSION

In patients with suspected laryngeal carcinoma after radiotherapy, PET as the first diagnostic procedure can reduce the need for direct laryngoscopy by more than 50% without jeopardizing quality of treatment.

Should elective neck dissection be routinely performed in patients undergoing salvage total laryngectomy?

BACKGROUND

The prevalence of occult neck metastasis in patients undergoing salvage total laryngectomy remains unclear, and there is controversy regarding whether elective neck dissection should routinely be performed.

METHOD

A retrospective case note review of 32 consecutive patients undergoing salvage total laryngectomy in a tertiary centre was performed, in order to correlate pre-operative radiological staging with histopathological staging.

RESULTS

The median patient age was 61 years (range, 43-84 years). With regard to lymph node metastasis, 28 patients were pre-operatively clinically staged (following primary radiotherapy or chemoradiotherapy) as node-negative, 1 patient was staged as N1, two patients as N2c and one patient as N3. Fifty-two elective and seven therapeutic neck dissections were performed. Pathological analysis up-staged two patients from clinically node-negative (following primary radiotherapy or chemoradiotherapy) to pathologically node-positive (post-surgery). No clinically node-positive patients were down-staged. More than half of the patients suffered a post-operative fistula.

CONCLUSION

Pre-operative neck staging had a negative predictive value of 96 per cent. Given the increased complications associated with neck dissection in the salvage setting, consideration should be given to conservative management of the neck in clinically node-negative patients (staged following primary radiotherapy or chemoradiotherapy).

European Laryngological Society: ELS recommendations for the follow-up of patients treated for laryngeal cancer

It is accepted that the follow-up of patients who had treatment for laryngeal cancer is a fundamental part of their care. The reasons of post-treatment follow-up include evaluation of treatment response, early identification of recurrence, early detection of new primary tumours, monitoring and management of complications, optimisation of rehabilitation, promotion smoking and excessive alcohol cessation, provision of support to patients and their families, patient counselling and education. Controversies exist in how these aims are achieved. Increasing efforts are being made to rationalise the structure and timing of head and neck cancer follow-up clinics. The aim of this document is to analyse the current evidence for the need to follow up patients who have been treated for LC and provide an up to date, evidence-based statement which is meaningful and applicable to all European Health Care Systems. A working group of the Head and Neck Cancer Committee of the ELS was constituted in 2009. A review of the current published literature on the management and follow-up of laryngeal cancer was undertaken and statements are made based on critical appraisal of the literature and best current evidence. Category recommendations were based on the Oxford Centre for Evidence-Based Medicine. Statements include: length, frequency, setting, type of health professional, clinical assessment, screening investigations, patient's education, second primary tumours, and mode of treatment considerations including radiotherapy, chemo-radiation therapy, transoral surgery and open surgery. It also addresses specific recommendations regarding patients with persistent pain, new imaging techniques, tumour markers and narrow band imaging.

Imaging in head and neck squamous cell carcinoma: the potential role of PET/MRI

In head and neck oncology, the information provided by positron emission tomography (PET)/CT and MRI is often complementary because both the methods are based on different biophysical foundations. Therefore, combining diagnostic information from both modalities can provide additional diagnostic gain. Debates about integrated PET/MRI systems have become fashionable during the past few years, since the introduction and wide adoption of software-based multimodality image registration and fusion and the hardware implementation of integrated hybrid PET/MRI systems in pre-clinical and clinical settings. However, combining PET with MRI has proven to be technically and clinically more challenging than initially expected and, as such, research into the potential clinical role of PET/MRI in comparison with PET/CT, diffusion-weighted MRI (DW MRI) or the combination thereof is still ongoing. This review focuses on the clinical applications of PET/MRI in head and neck squamous cell carcinoma (HNSCC). We first discuss current evidence about the use of combined PET/CT and DW MRI, and, then, we explain the rationale and principles of PET/MR image fusion before summarizing the state-of-the-art knowledge regarding the diagnostic performance of PET/MRI in HNSCC. Feasibility and quantification issues, diagnostic pitfalls and challenges in clinical settings as well as ongoing research and potential future applications are also discussed.

Clinical Assessment and Treatment of the Dysfunctional Larynx after Radiation

Objective

To review the pathophysiology of early and late radiation-related tissue changes, methods to differentiate these changes from disease recurrence, and treatment of these changes in the irradiated larynx.

Data Sources

Peer-reviewed publications.

Review Methods

PubMed database search.

Conclusions/Implications for Practice

Early and late radiation-related changes in the larynx manifest variably between individual patients. Severe radiation-related tissue changes in the larynx and recurrent malignancy share many clinical characteristics, and the presence of malignancy must be considered in these patients. Positron emission tomography may help select patients who need operative biopsy to rule out recurrence. In patients with a cancer-free but dysfunctional larynx, both surgical and nonsurgical treatment options, including hyperbaric oxygen, are available for attempted salvage. Further investigation is needed before hyperbaric oxygen can be considered standard-of-care treatment for these patients.

Diagnostic accuracy of computed tomography findings for patients undergoing salvage total laryngectomy

CONCLUSIONS

Computed tomography (CT) imaging has clear limitations for the diagnosis of cartilage invasion or tumor spread in recurrent laryngeal cancer. Alternative methods of pretreatment assessment are needed for recurrent laryngeal cancer.

OBJECTIVES

The diagnosis and staging of recurrent laryngeal cancer, previously treated by radiation therapy (RT), remains challenging. Practically, surgeons need to depend on imaging to predict which patients will have a chance for conservation salvage laryngectomy. The purpose of the present study was to determine the accuracy of preoperative CT performed for recurrent laryngeal carcinoma evaluation following RT.

METHODS

This retrospective review identified 32 patients who underwent salvage total laryngectomy after RT from 1998 to 2010. For our radiologic classification of the thyroid cartilage, we analyzed the conditions as normal, sclerosis, invasion, penetration, and extralaryngeal spread and categorized the state of the arytenoids and cricoid into three possible conditions: normal, sclerosis, and destruction. Radiographic findings were correlated with pathology findings.

RESULTS

Sensitivity and specificity for the detection of the thyroid cartilage infiltration were 57% and 94%, 50% and 89% for the cricoid cartilage, and 33% and 76% for arytenoid cartilage, respectively. The accuracy of recurrent tumor classification was 59.4%. Three carcinomas were over-staged and 10 were under-staged.

Diffusion-weighted MR imaging including bi-exponential fitting for the detection of recurrent or residual tumour after (chemo)radiotherapy for laryngeal and hypopharyngeal cancers

OBJECTIVES

To assess whether diffusion-weighted magnetic resonance imaging (DW-MRI) including bi-exponential fitting helps to detect residual/recurrent tumours after (chemo)radiotherapy of laryngeal and hypopharyngeal carcinoma.

METHODS

Forty-six patients with newly-developed/worsening symptoms after (chemo)radiotherapy for laryngeal/hypopharyngeal cancers were prospectively imaged using conventional MRI and axial DW-MRI. Qualitative (visual assessment) and quantitative analysis (mono-exponentially: total apparent diffusion coefficient [ADC(T)], and bi-exponentially: perfusion fraction [F(P)] and true diffusion coefficient [ADC(D)]) were performed. Diffusion parameters of tumour versus post-therapeutic changes were compared, with final diagnosis based on histopathology and follow-up. Mann-Whitney U test was used for statistical analysis.

RESULTS

Qualitative DW-MRI combined with morphological images allowed the detection of tumour with a sensitivity of 94% and specificity 100%. ADC(T) and ADC(D) values were lower in tumour with values 120 ± 49 × 10(-5) mm(2)/s and 113 ± 50 × 10(-5) mm(2)/s, respectively, compared with post-therapeutic changes with values 182 ± 41 × 10(-5) mm(2)/s (P < 0.0002) and 160 ± 47 × 10(-5) mm(2)/s (P < 0.003), respectively. F(P) values were significantly lower in tumours than in non-tumours (13 ± 9% versus 31 ± 16%, P < 0.0002), with F(P) being the best quantitative parameter for differentiation between post-therapeutic changes and recurrence.

CONCLUSIONS

DW-MRI in combination with conventional MRI substantially improves detection and exclusion of tumour in patients with laryngeal and hypopharyngeal cancers after treatment with (chemo)radiotherapy on both qualitative and quantitative analysis, with F(P) being the best quantitative parameter in this context.

Diagnosis and treatment of recurrent laryngeal cancer following initial nonsurgical therapy

Surgery is the preferred modality for curative treatment of recurrent laryngeal cancer after failure of nonsurgical treatments. Patients with initial early-stage cancer experiencing recurrence following radiotherapy often have more advanced-stage tumors by the time the recurrence is recognized. About one third of such recurrent cancers are suitable for conservation surgery. Endoscopic resection with the CO(2) laser or open partial laryngectomy (partial vertical, supracricoid, or supraglottic laryngectomies) have been used. The outcomes of conservation surgery appear better than those after total laryngectomy, because of selection bias. Transoral laser surgery is currently used more frequently than open partial laryngectomy for treatment of early-stage recurrence, with outcomes equivalent to open surgery but with less associated morbidity. Laser surgery has also been employed for selective cases of advanced recurrent disease, but patient selection and expertise are required for application of this modality to rT3 tumors. In general, conservation laryngeal surgery is a safe and effective treatment for localized recurrences after radiotherapy for early-stage glottic cancer. Recurrent advanced-stage cancers should generally be treated by total laryngectomy.

¹⁸F-FDG PET/CT and MRI in the follow-up of head and neck squamous cell carcinoma

We evaluated the diagnostic performance of (18)F-FDG PET/CT and MRI for the assessment of head and neck squamous cell carcinoma (HNSCC) relapse. Since early treatment might prevent inoperable relapse, we also evaluated THE performance of early unenhanced (18)F-FDG PET/CT in residual tumor detection. The study was prospectively performed on 32 patients who underwent (18)F-FDG PET/CT and MRI before treatment and at 4 and 12 months after treatment. (18)F-FDG PET/CT was also performed 2 weeks after the end of radiotherapy. Histopathology or a minimum of 18 months follow-up were used as gold standard. Before treatment (18)F-FDG PET/CT and MRI detected all primary tumors except for two limited vocal fold lesions (sensitivity 94%). MRI was more sensitive than (18)F-FDG PET/CT for the detection of local extension sites (sensitivity 75 vs 58%), but at the cost of a higher rate of false positive results (positive predictive value 74 vs 86%). For relapse detection at 4 months, sensitivity was significantly higher for (18)F-FDG PET/CT (92%) than for MRI (70%), but the diagnostic performances were not significantly different at 12 months. For the detection of residual malignant tissue 2 weeks post-radiotherapy, sensitivity and specificity of (18)F-FDG PET/CT were respectively 86 and 85% (SUV cut-off value 5.8). (18)F-FDG PET/CT is effective in the differentiation between residual tumor and radiation-induced changes, as early as 2 weeks after treatment of a primary HNSCC. For follow-up, performance of (18)F-FDG PET/CT and MRI are similar except for a higher sensitivity of (18)F-FDG PET/CT at 4 months.

FDG PET with contrast-enhanced CT: a critical imaging tool for laryngeal carcinoma

Fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has evolved to be an essential imaging modality in the evaluation of laryngeal carcinoma. Although the modality has limited utility in assessing the extent of the primary tumor, FDG PET has proved to be superior to anatomic modalities in the detection of lymph node and distant metastases. The role of FDG PET in the evaluation of patients with laryngeal tumors that are clinically classified as N0 has not shown consistent usefulness because of the innate resolution limitations of the camera. In the posttherapy setting, however, FDG PET has consistently demonstrated a high negative predictive value in the identification of recurrent disease, both during the course of therapy and during long-term follow-up. In addition, contrast material-enhanced computed tomography (CT) in conjunction with FDG PET has demonstrated a complementary role by allowing for superior anatomic coregistration and therefore more definitive diagnosis. There is sufficient evidence that with further advances in PET technology, this modality will likely become more useful in the detection of small lesions and occult nodal disease, as well as in guiding the management of laryngeal carcinoma.

US-guided transcutaneous tru-cut biopsy of laryngo-hypopharyngeal lesions

OBJECTIVE

To evaluate the feasibility and performance of ultrasound-guided transcutaneous tru-cut biopsy (USGTCB) in selected patients (with stenosis of airways or difficult intubation or contraindication to general anaesthesia) with untreated or previously treated suspicious laryngo-hypopharyngeal masses.

METHODS

Biopsies were performed with a free-hand technique by a single radiologist. Thirty-six USGTCBs were scheduled in 34 patients (24 males, 10 females; age range 47-95 years). Two USGTCBs were not performed, as lesions were not detectable: therefore, 16 USGTCBs were performed for an untreated mass suspicious for malignancy and 18 were performed for a mass suspicious for recurrence after radiotherapy alone, or associated with endoscopic laser surgery or chemotherapy.

RESULTS

USGTCB diagnosed 25 squamous cell carcinomas (73.5%) and nine benign lesions (26.5%); no false positives and two false negatives were reported, both in patients previously treated with radiotherapy. The sensitivity, specificity, positive and negative predictive value of the technique was 92.5%, 100%, 100% and 77.7% respectively, with no major complications.

CONCLUSION

Although biopsy under microlaryngoscopy remains the "gold-standard" technique, USGTCB is feasible, carries the advantages of avoiding general anaesthesia, is suitable for outpatients and is cost-effective. If applied to selected patients, it could be considered for the histological diagnosis of both primary and recurrent laryngo-hypopharyngeal masses.

[18F]FLT-PET and [18F]FDG-PET in the evaluation of radiotherapy for laryngeal cancer

The evaluation of response to radiotherapy in patients with laryngeal cancer is a challenge because of the difficulty to differentiate between post-therapy changes and recurrent or residual tumor. Positron emission tomography is a non-invasive imaging tool that may be helpful in this differentiation. In this study, [(18)F]-fluoro-3'-deoxy-L-thymidine ([(18)F]FLT), a proliferation tracer is compared with 2-[(18)F]-fluoro-2-deoxy-D-glucose ([(18)F]FDG). Patients with primary laryngeal cancer, scheduled to undergo radiotherapy were included in this study. Patients underwent both [(18)F]FLT-PET and [(18)F]FDG-PET shortly before radiotherapy. Ten patients underwent [(18)F]FLT-PET and [(18)F]FDG-PET 2-3 months after radiotherapy. Scans were analyzed visually for areas of increased tracer uptake. The standardized uptake value (SUV) was measured as a semi-quantitative value of tracer uptake. Fourteen patients, all male, were included in this study. Both [(18)F]FLT-PET and [(18)F]FDG-PET showed increased tracer uptake in 12 out of 14 patients (86%). [(18)F]FDG uptake was significantly higher than [(18)F]FLT uptake (SUV(max): 4.5 vs. 2.4 (P=0.002); SUV(mean): 3.4 vs. 1.9 (P=0.002)). After radiotherapy, 3 patients had histologically proven residual or recurrent laryngeal cancer. [(18)F]FDG was true positive in 2 out of 3 patients, whereas [(18)F]FLT showed increased tracer uptake in only one. Of the remaining 7 patients, [(18)F]FLT was true negative in all, whereas [(18)F]FDG showed increased uptake in one (false positive). [(18)F]FLT-PET is feasible in visualizing laryngeal cancer and its evaluation of treatment. The overall uptake of this tracer is significantly lower as compared with [(18)F]FDG, but tumor to background ratios are comparable.

Detection of locoregional recurrent head and neck cancer after (chemo)radiotherapy using modern imaging

After radiotherapy with or without chemotherapy differentiation between residual and recurrent head and neck cancer and (chemo)radiation sequelae is often difficult. Currently, most physicians aggressively pursue potential recurrences, leading to a high rate of futile invasive diagnostic, e.g. examinations under general anaesthesia with taking of biopsies, and surgical procedures, e.g. planned neck dissections, and a waste of health care resources. Therefore, diagnostic techniques which reliably select patients who should undergo these procedures are warranted. Conventional imaging techniques are not reliable enough for this purpose. Potential imaging techniques to detect residual and recurrent locoregional disease after chemoradiation are (serial) CT or MRI and FDG-PET, eventually in combination with specific response criteria or scoring systems. Diffusion MRI and PET/CT may further improve these techniques. FDG-PET may help to select patients clinically suspected of recurrent laryngeal carcinoma after radiotherapy for direct laryngoscopy under general anaesthesia. It is not yet clear whether FDG-PET can reliable avoid futile routine evaluation by examination under general anaesthesia in oral and oropharyngeal cancer and planned neck dissection when a residual mass persists in the neck after (chemo)radiation. The most reliable scoring criteria and the optimal time interval between completion of radiation and FDG-PET still has to be assessed.

The cost-effectiveness of 18FDG-PET in selecting patients with suspicion of recurrent laryngeal carcinoma after radiotherapy for direct laryngoscopy

The aim of this study was to estimate the cost-effectiveness of ¹⁸FDG-PET in the selection for direct laryngoscopy in patients with suspicion of recurrent laryngeal carcinoma after radiotherapy. The direct medical costs of 30 patients with suspicion of a recurrence were calculated from the first visit where suspicion was raised until one year after. A conventional strategy, in which all these patients underwent direct laryngoscopy, was compared to an ¹⁸FDG-PET strategy in which only patients with a positive or equivocal ¹⁸FDG-PET underwent direct laryngoscopy. A sensitivity analysis was performed to examine the influence of the type of camera and ‘setting’. The mean costs of an ¹⁸FDG-PET strategy were €399 less than a direct laryngoscopy strategy. The type of camera and setting had no influence. In patients with suspicion for recurrent laryngeal carcinoma after radiotherapy, ¹⁸FDG-PET seems to be effective and less costly in selecting patients for direct laryngoscopy.