Contemporary Imaging and Reporting Strategies for Head and Neck Cancer: MRI, FDG PET/MRI, NI-RADS, and Carcinoma of Unknown Primary-AJR Expert Panel Narrative Review.

CT, MRI, and FDG PET/CT play major roles in the diagnosis, staging, treatment planning, and surveillance of head and neck cancers. Nonetheless, an evolving understanding of head and neck cancer pathogenesis, advances in imaging techniques, changing treatment regimens, and a lack of standardized guidelines have led to areas of uncertainty in the imaging of head and neck cancer. This narrative review aims to address four issues in the contemporary imaging of head and neck cancer. The first issue relates to the standard and advanced sequences that should be included in MRI protocols for head and neck cancer imaging. The second issue relates to approaches to surveillance imaging after treatment of head and neck cancer, including the choice of imaging modality, the frequency of surveillance imaging, and the role of standardized reporting through the Neck Imaging Reporting and Data System. The third issue relates to the role of imaging in the setting of neck carcinoma of unknown primary. The fourth issue relates to the role of simultaneous PET/MRI in head and neck cancer evaluation. The authors of this review provide consensus opinions for each issue.

Active upper aerodigestive tract hemorrhage in patients with head and neck cancers: the "dot-in-sludge" sign.

Active extravasation into the upper aerodigestive tract is a dramatic and potentially life-threatening complication in patients with head and neck cancers. It prompts presentation to the emergency room and subsequent urgent imaging to identify the source of hemorrhage. Imaging of these patients may be complicated by treatment-altered anatomy, posing a challenge to the emergency radiologist who needs to rapidly identify the presence of active hemorrhage and the potential source vessel. This retrospective review summarizes the clinical and imaging findings of 6 oropharyngeal and oral cavity squamous cell cancer (SCC) patients with active upper aerodigestive tract hemorrhage. Most patients had advanced stage disease and prior radiation therapy. All CECT or CTA exams on presentation demonstrated the "dot-in-sludge" sign of active extravasation, as demonstrated by a "dot" of avidly enhancing extravasated contrast material layered against a background "sludge" of non-enhancing debris in the lumen of the upper aerodigestive tract. Common sources of hemorrhage included the lingual, facial, and superior thyroidal arteries. Familiarity with these findings will help radiologists increase their accuracy and confidence in interpreting these urgent, complex examinations.

Personalizing Surveillance in Head and Neck Cancer.

Head and neck squamous cell carcinoma (HNSCC) encompasses a spectrum of heterogeneous diseases originating in the oral cavity, pharynx, and larynx. Within the United States, head and neck cancer (HNC) accounts for 66,470 new cases, or 3% of all malignancies, annually.1 The incidence of HNC is rising, largely driven by increases in oropharyngeal cancer.2-4 Recent molecular and clinical advancements, particularly with regard to molecular and tumor biology, reflect the heterogeneity of the subsites contained within the head and neck. Despite this, existing guidelines for post-treatment surveillance remain broad without much consideration given to different anatomic subsites and etiologic factors (such as human papillomavirus [HPV] status or tobacco exposure).5 Surveillance incorporating the physical examination, imaging, and emerging molecular biomarkers is an essential part of care for patients treated for HNC and allows for the detection of locoregional recurrence, distant metastases, and second primary malignancies aiming for better functional and survival outcomes. Additionally, it allows for evaluation and management of post-treatment complications.

Free Flap Fat Volume is Not Associated With Recurrence or Wound Complications in Oral Cancer.

Objective: Adipose stem cells (ASCs) have been shown in many preclinical studies to be potent suppressors of the immune system. Prior studies suggest that ASCs may promote cancer progression and wound healing. However, clinical studies investigating the effects of native, or fat-grafted adipose tissue on cancer recurrence have generated mixed results. We investigated whether adipose content in reconstructive free flaps for oral squamous cell carcinoma (OSCC) is associated with disease recurrence and/or reduction in wound complications. Study Design: Retrospective chart review. Setting: Academic medical center. Methods: We performed a review of 55 patients undergoing free flap reconstruction for OSCC over a 14-month period. Using texture analysis software, we measured the relative free flap fat volume (FFFV) in postoperative computed tomography scans and compared fat volume with patient survival, recurrence, and wound healing complications. Results: We report no difference in mean FFFV between patients with or without recurrence: 13.47 cm3 in cancer-free survivors and 17.99 cm3 in cases that recurred (p = .56). Two-year recurrence-free survival in patients with high and low FFFV was 61.0% and 59.1%, respectively (p = .917). Although only 9 patients had wound healing complications, we found no trend in the incidence of wound healing complications between patients with high versus low FFFV. Conclusion: FFFV is not associated with recurrence or wound healing in patients undergoing free flap reconstruction for OSCC, suggesting adipose content should not be of concern to the reconstructive surgeon.

NI-RADS to Predict Residual or Recurrent Head and Neck Squamous Cell Carcinoma.

American College of Radiology NI-RADS is a surveillance imaging template used to predict residual or recurrent tumor in the setting of head and neck cancer. The lexicon and imaging template provides a framework to standardize the interpretations and communications with referring physicians and provides linked management recommendations, which add value in patient care. Studies have shown reasonable interreader agreement and excellent discriminatory power among the different NI-RADS categories. This article reviews the literature associated with NI-RADS and serves as a practical guide for radiologists interested in using the NI-RADS surveillance template at their institution, highlighting frequently encountered pearls and pitfalls.

Posttreatment Magnetic Resonance Imaging Surveillance of Head and Neck Cancers.

Treatment strategies and recommended surveillance imaging differ for head and neck cancers depending on subsite and neoplasm type, and pose confusion for referring physicians and interpreting radiologists. The superior soft tissue resolution offered by magnetic resonance imaging is most useful in the surveillance of cancers with high propensities for intraorbital, intracranial, or perineural disease spread, which most commonly include those arising from the sinonasal cavities, nasopharynx, orbits, salivary glands, and the skin. This article discusses recommended surveillance protocoling and reviews treatment approaches, common posttreatment changes, and pearls for identifying disease recurrence in a subsite-based approach.

Comparison of 3D constructive interference in steady state (CISS) and T2 sampling perfection with application optimized contrasts using different flip angle evolution MR imaging of the intracranial trigeminal nerve and central skull base neuroforamina.

BACKGROUND AND PURPOSE: Due to surgical advancements, the accurate detection of perineural disease spread has become increasingly important in the management and prognostication of head and neck cancers, though MR evaluation has thus far been limited by technical and logistic challenges. The purpose of this study was to specifically evaluate the relative capability of 3D CISS and 3D T2-SPACE imaging to delineate the proximal intracranial divisions of the normal trigeminal nerve, an area important in determining the resectability of intracranial perineural disease. MATERIALS AND METHODS: A single center HIPAA-compliant, IRB approved retrospective review of 40 patients with clinical temporal bone/internal auditory canal MR imaging was conducted. 20 patients with 3D CISS images and 20 patients with 3D T2-SPACE images met inclusion criteria. Two radiologists scored the sequences on a 3-point scale based on ability to visualize anatomic structures surrounding the trigeminal nerve in Meckel's cave, intracranial trigeminal divisions, skull base neuroforamina, and proximal extracranial mandibular division. RESULTS: The following anatomic locations scored significantly better in the T2-SPACE sequence compared to the CISS sequence for both raters: intracranial V3 (p < .05), foramen ovale (p < .05), and extracranial V3 (p < .01). The average scores for the anterior Meckel's cave and foramen rotundum were higher for the T2-SPACE sequence, although not significantly. Percent interobserver agreement ranged from 50 to 90% and 65-100% for the different anatomic locations on the CISS and T2-SPACE sequences, respectively. CONCLUSION: 3D T2-SPACE was found to be superior to 3D CISS in the evaluation of the distal intracranial and extracranial portions of the normal trigeminal nerve.

Surgical Resection is Justifiable for Oral T4b Squamous Cell Cancers With Masticator Space Invasion.

OBJECTIVES: To examine survival endpoints in patients with tumor (T)4b oral cavity squamous cell carcinoma (OCSCC) with pathologically proven masticator space invasion treated with primary surgery followed by adjuvant therapy. STUDY DESIGN: Retrospective review at an academic cancer center. METHODS: Twenty-five patients with T4b OCSCC with pathologic masticator space invasion were treated with primary surgery from May 2012 to December 2016. Only patients with ≥ 2 years follow-up from date of surgery were included. Sixteen patients received adjuvant chemoradiation. RESULTS: Median follow-up time was 39 months from date of surgery. Overall survival (OS), disease-specific survival (DSS), and recurrence-free survival at 24 months were 44.0%, 63.2%, and 52.6%, respectively. On univariate analyses, adjuvant chemoradiation was associated with improved OS. Advanced age and prolonged length of hospital stay was associated with worse OS. CONCLUSION: For pT4b OCSCCA involving the masticator space, primary surgical resection followed by adjuvant chemoradiation demonstrates 24-month DSS of > 50% and OS of 44%. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E466-E472, 2021.

Outcomes and Predictive Value of Post-adjuvant Therapy PET/CT for Locally Advanced Oral Squamous Cell Carcinoma.

OBJECTIVES/HYPOTHESIS: For locally advanced oral squamous cell carcinoma (OSCC) treated by surgery and adjuvant therapy, consensus has yet to be reached on whether the optimal time to initiate surveillance positron emission tomography/computed tomography (PET/CT) scan is before or after adjuvant therapy. In this study, we characterize the utility of PET/CT scans obtained 3 months after adjuvant therapy. STUDY DESIGN: PET/CT scans were obtained for 220 patients with stage III, IVA, or IVB OSCC who underwent resection followed by adjuvant radiotherapy or chemoradiotherapy. METHODS: Using the Neck Imaging Reporting and Data System, PET/CT scans were dichotomized as suspicious (primary or neck category ≥3, or distant lesion present) versus nonsuspicious. We then computed differences in locoregional progression, distant progression, and overall survival; positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity; and success rate of salvage. RESULTS: Sixty-seven patients (30%) had suspicious PET/CT scans, which were significantly associated with local failure (hazard ratio [HR] 14.0, 95% confidence interval [CI] 7.3-26.6), distant failure (HR 18.4, 95% CI 9.6-35.3), and poorer overall survival (HR 9.5, 95% CI 5.0-17.9). Overall PPV, locoregional PPV, NPV, sensitivity, and specificity were 85%, 79%, 73%, 58%, and 92%, respectively. Among those with biopsy-confirmed progression, 37 patients (65%) underwent salvage therapy; four (11%) were without evidence of disease at last follow-up. CONCLUSIONS: For locally advanced OSCC, PET/CT scan 3 months after adjuvant therapy is strongly predictive of disease recurrence and survival, demonstrating improved performance over postoperative imaging in previous studies. Following a suspicious post-adjuvant therapy PET/CT scan, cure of locoregional recurrence is possible but unlikely. LEVEL OF EVIDENCE: 4 Laryngoscope, 2020.

Prognostic value of radiographically defined extranodal extension in human papillomavirus-associated locally advanced oropharyngeal carcinoma.

BACKGROUND: Pathologic extranodal extension (ENE) has traditionally guided the management of head and neck cancers. The prognostic value of radiographic ENE (rENE) in human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (HPV + OPX) is uncertain. METHODS: Patients with HPV + OPX with adequate pretreatment radiographic nodal evaluation from a single institution were analyzed. rENE status was determined by neuroradiologists' at time of diagnosis. Distant metastasis-free survival (DMFS), overall survival (OS), and locoregional recurrence-free survival (LRFS) were estimated using Kaplan-Meier methods. Cox proportional hazards models were fit to assess the impact of rENE on survival endpoints. RESULTS: Hundred sixty-eight patients with OPX + squamous cell carcinomas diagnosed between April 2008 and December 2014 were included for analysis with median follow-up of 3.3 years. Eighty-eight percent of patients received concurrent chemoradiotherapy. rENE was not prognostic; its presence in patients with HPV + OPX did not significantly impact OS, LRFS, or DMFS. CONCLUSIONS: In patients with HPV + OPX, rENE was not significantly associated with OS, LRFS, or DMFS.

Head and Neck: Skull Base Imaging.

There are a myriad of head and neck pathologies that extend from the extracranial to the intracranial compartment, traversing the skull base, and knowledge of the imaging appearance of this pathology is critical to practicing neurosurgeons. This article reviews some of the important inflammatory or acquired head and neck pathology along the skull base, neoplastic skull base lesions, and the intracranial extension of head and neck malignancy. Focus will be on the relevant anatomy, appropriate imaging protocols to evaluate these processes, as well as the differentiating imaging findings on computed tomography and magnetic resonance imaging.

Spontaneous Labyrinthine Hemorrhage: A Case Series.

OBJECTIVES: To describe patient characteristics, audiometric outcomes, and magnetic resonance imaging (MRI) signal patterns in patients with suspected labyrinthine hemorrhage. STUDY DESIGN: Retrospective review. SETTING: Tertiary medical center. SUBJECTS AND METHODS: Radiology database was queried for terms related to labyrinth hemorrhage or labyrinthitis and then selected for patients in which labyrinthine hemorrhage was suspected in the report. Eleven patients were identified and all treated at our institution. Blinded assessment of temporal bone MRI by 2 experienced neuroradiologists was performed and interrater reliability assessed. Patient demographics, medical comorbidities, and audiometric outcomes are described. RESULTS: Of the 11 patients identified, the median patient age was 60 years; 7 were female and 4 male. Ten of 11 patients presented with unilateral sudden sensorineural hearing loss (SNHL), and 8 of 11 had associated vertigo. One patient experienced vertigo without hearing loss. Of those presenting with sudden SNHL, 82% were left with nonserviceable American Academy of Otolaryngology-Head and Neck Surgery class D hearing. Interrater reliability for detecting T1 signal abnormalities was moderate but very good for detecting fluid attenuation inversion recovery (FLAIR) signal abnormalities. Most patients had existing hypertension. Average follow-up was 13.3 months. CONCLUSION: We present the largest cohort of patients with radiographic diagnosis of labyrinthine hemorrhage using T1 and FLAIR signal abnormalities on MRI. Most patients presented with a profound unilateral sudden SNHL that did not recover. Our findings are consistent with prior reports that abnormal FLAIR signal on MRI is a reliable marker for detecting inner ear injury and can potentially be used as a marker for poor prognosis.

Magnetic resonance cisternogram with intrathecal gadolinium with delayed imaging for difficult to diagnose cerebrospinal fluid leaks of anterior skull base.

BACKGROUND: Workup of cerebrospinal fluid (CSF) leaks can be challenging. Patients with intermittent or infrequent clear rhinorrhea that cannot be collected, those with questionable or multiple skull-base (SB) defects on imaging, and those with previous SB surgery can present diagnostic dilemmas. In this patient population, radiologic studies that allow repeat imaging over hours to days can increase the diagnostic yield. We report our experience with magnetic resonance cisternogram with intrathecal gadolinium (MRCgGd) in this patient population. METHODS: This study was a retrospective review of patients who underwent MRCgGd for workup of suspected CSF leaks at a tertiary care academic center. RESULTS: Over the past 3 years, 11 patients (10 females; mean age 50 years) underwent MRCgGd. Seven patients had suspected spontaneous CSF leaks from idiopathic intracranial hypertension and 2 had postsurgical defects. All patients had previous imaging that was indeterminate in localizing the site of the leak. Only 3 patients had positive beta-2 transferrin studies, all with multiple potential leak sites. MRCgGd confirmed the absence of leaks at 4 previously repaired SB defects, identified spinal canal leaks but no SB leaks in 2 patients (1 of whom had a nonleaking SB defect), and identified 5 patients with one or more SB leaks. Repeat imaging, from 30 minutes to 20 hours, was beneficial in identifying 4 leaks not confirmed in the immediate imaging, and ruling out leaks in 5 cases, therefore guiding further treatment. No complications occurred. CONCLUSION: MRCgGd is a useful diagnostic test in the workup of patients with difficult CSF leaks, with delayed imaging providing valuable diagnostic information.

Skull base fractures and their complications.

Basilar skull fractures are a relatively frequent occurrence in significant head trauma, and their detection is important, as even linear nondisplaced fractures can be associated with critical complications. The management of skull base fractures depends on the location and extent of these associated complications. This article reviews skull base anatomy; morphology of the common fracture patterns within the anterior, central, and posterior skull base; associated complications; imaging findings; and possible pitfalls in imaging of skull base trauma.

Pitfalls in the staging of cancer of the laryngeal squamous cell carcinoma.

Laryngeal carcinoma is a devastating malignancy that severely affects patients' quality of life, with compromise of ability to talk, breathe, and swallow. Accurate tumor staging is imperative, because treatment plans focus on laryngeal conservation therapy whenever possible. Although the mucosal extent of tumor and vocal cord mobility is best assessed with endoscopic evaluation, cross-sectional imaging is essential for accurate T-staging, because only cross-sectional imaging can assess the submucosal extent of the tumor, cartilage invasion, and extralaryngeal spread. This article reviews topics crucial for interpreting imaging studies of patients with laryngeal squamous cell carcinoma.