Nicolas Dulguerov

Detection and quantification of focal uptake in head and neck tumours: 18 F-FDG PET/MR versus PET/CT

PurposeOur objectives were to assess the quality of PET images and coregistered anatomic images obtained with PET/MR, to evaluate the detection of focal uptake and SUV, and to compare these findings with those of PET/CT in patients with head and neck tumours.MethodsThe study group comprised 32 consecutive patients with malignant head and neck tumours who underwent whole-body 18F-FDG PET/MR and PET/CT. PET images were reconstructed using the attenuation correction sequence for PET/MR and CT for PET/CT. Two experienced observers evaluated the anonymized data. They evaluated image and fusion quality, lesion conspicuity, anatomic location, number and size of categorized (benign versus assumed malignant) lesions with focal uptake. Region of interest (ROI) analysis was performed to determine SUVs of lesions and organs for both modalities. Statistical analysis considered data clustering due to multiple lesions per patient.ResultsPET/MR coregistration and image fusion was feasible in all patients. The analysis included 66 malignant lesions (tumours, metastatic lymph nodes and distant metastases), 136 benign lesions and 470 organ ROIs. There was no statistically significant difference between PET/MR and PET/CT regarding rating scores for image quality, fusion quality, lesion conspicuity or anatomic location, number of detected lesions and number of patients with and without malignant lesions. A high correlation was observed for SUVmean and SUVmax measured on PET/MR and PET/CT for malignant lesions, benign lesions and organs (ρ = 0.787 to 0.877, p < 0.001). SUVmean and SUVmax measured on PET/MR were significantly lower than on PET/CT for malignant tumours, metastatic neck nodes, benign lesions, bone marrow, and liver (p < 0.05). The main factor affecting the difference between SUVs in malignant lesions was tumour size (p < 0.01).ConclusionIn patients with head and neck tumours, PET/MR showed equivalent performance to PET/CT in terms of qualitative results. Comparison of SUVs revealed an excellent correlation for measurements on both modalities, but underestimation of SUVs measured on PET/MR as compared to PET/CT.

FDG-PET/CT pitfalls in oncological head and neck imaging

ObjectivesPositron emission tomography-computed tomography (PET/CT) with fluorine-18-fluorodeoxy-D-glucose (FDG) has evolved from a research modality to an invaluable tool in head and neck cancer imaging. However, interpretation of FDG PET/CT studies may be difficult due to the inherently complex anatomical landmarks, certain physiological variants and unusual patterns of high FDG uptake in the head and neck. The purpose of this article is to provide a comprehensive approach to key imaging features and interpretation pitfalls of FDG-PET/CT of the head and neck and how to avoid them.MethodsWe review the pathophysiological mechanisms leading to potentially false-positive and false-negative assessments, and we discuss the complementary use of high-resolution contrast-enhanced head and neck PET/CT (HR HN PET/CT) and additional cross-sectional imaging techniques, including ultrasound (US) and magnetic resonance imaging (MRI).ResultsThe commonly encountered false-positive PET/CT interpretation pitfalls are due to high FDG uptake by physiological causes, benign thyroid nodules, unilateral cranial nerve palsy and increased FDG uptake due to inflammation, recent chemoradiotherapy and surgery. False-negative findings are caused by lesion vicinity to structures with high glucose metabolism, obscuration of FDG uptake by dental hardware, inadequate PET scanner resolution and inherent low FDG-avidity of some tumours.ConclusionsThe interpreting physician must be aware of these unusual patterns of FDG uptake, as well as limitations of PET/CT as a modality, in order to avoid overdiagnosis of benign conditions as malignancy, as well as missing out on actual pathology.Teaching points• Knowledge of key imaging features of physiological and non-physiological FDG uptake is essential for the interpretation of head and neck PET/CT studies.• Precise anatomical evaluation and correlation with contrast-enhanced CT, US or MRI avoid PET/CT misinterpretation.• Awareness of unusual FDG uptake patterns avoids overdiagnosis of benign conditions as malignancy.

Apparent Diffusion Coefficient Histograms of Human Papillomavirus–Positive and Human Papillomavirus–Negative Head and Neck Squamous Cell Carcinoma: Assessment of Tumor Heterogeneity and Comparison with Histopathology

One hundred five consecutive patients with primary oropharyngeal and oral cavity head and neck squamous cell carcinoma underwent MR imaging with anatomic and DWI sequences. The collected tumor voxels from the contoured ROIs provided histograms from which position, dispersion, and form parameters were computed. Histogram data were correlated with histopathology, p16-immunohistochemistry, and polymerase chain reaction for human papillomavirus DNA. Diffusion phenotypes of human papillomavirus–positive and human papillomavirus–negative head and neck squamous cell carcinomas showed significant differences, which reflect their distinct degree of tumor heterogeneity. BACKGROUND AND PURPOSE: Head and neck squamous cell carcinoma associated with human papillomavirus infection represents a distinct tumor entity. We hypothesized that diffusion phenotypes based on the histogram analysis of ADC values reflect distinct degrees of tumor heterogeneity in human papillomavirus–positive and human papillomavirus–negative head and neck squamous cell carcinomas. MATERIALS AND METHODS: One hundred five consecutive patients (mean age, 64 years; range, 45–87 years) with primary oropharyngeal (n = 52) and oral cavity (n = 53) head and neck squamous cell carcinoma underwent MR imaging with anatomic and diffusion-weighted sequences (b = 0, b = 1000 s/mm2, monoexponential ADC calculation). The collected tumor voxels from the contoured ROIs provided histograms from which position, dispersion, and form parameters were computed. Histogram data were correlated with histopathology, p16-immunohistochemistry, and polymerase chain reaction for human papillomavirus DNA. RESULTS: There were 21 human papillomavirus–positive and 84 human papillomavirus–negative head and neck squamous cell carcinomas. At histopathology, human papillomavirus–positive cancers were more often nonkeratinizing (13/21, 62%) than human papillomavirus–negative cancers (19/84, 23%; P = .001), and their mitotic index was higher (71% versus 49%; P = .005). ROI-based mean and median ADCs were significantly lower in human papillomavirus–positive (1014 ± 178 × 10−6 mm2/s and 970 ± 187 × 10−6 mm2/s, respectively) than in human papillomavirus–negative tumors (1184 ± 168 × 10−6 mm2/s and 1161 ± 175 × 10−6 mm2/s, respectively; P < .001), whereas excess kurtosis and skewness were significantly higher in human papillomavirus–positive (1.934 ± 1.386 and 0.923 ± 0.510, respectively) than in human papillomavirus–negative tumors (0.643 ± 0.982 and 0.399 ± 0.516, respectively; P < .001). Human papillomavirus–negative head and neck squamous cell carcinoma had symmetric normally distributed ADC histograms, which corresponded histologically to heterogeneous tumors with variable cellularity, high stromal component, keratin pearls, and necrosis. Human papillomavirus–positive head and neck squamous cell carcinomas had leptokurtic skewed right histograms, which corresponded to homogeneous tumors with back-to-back densely packed cells, scant stromal component, and scattered comedonecrosis. CONCLUSIONS: Diffusion phenotypes of human papillomavirus–positive and human papillomavirus–negative head and neck squamous cell carcinomas show significant differences, which reflect their distinct degree of tumor heterogeneity.

Comparison of the incidence of osteoradionecrosis with conventional radiotherapy and intensity-modulated radiotherapy

Modern techniques of radiotherapy are supposed to decrease the incidence of osteoradionecrosis of the mandible (ORNM). The purpose of this study was to compare the incidence of ORNM after intensity‐modulated radiotherapy (IMRT) in comparison to conventional 3D conformal radiotherapy techniques (conventional RT).

The superficial musculoaponeurotic system flap in the prevention of Frey syndrome: A meta-analysis.

Evaluate the difference of the incidence in clinical Frey syndrome in studies comparing classical parotidectomy and parotidectomy with superficial musculoaponeurotic system (SMAS) flap elevation and suturing through meta‐analysis methodology.

Open Maximal Mucosa-Sparing Functional Total Laryngectomy

Background Total laryngectomy after (chemo)radiotherapy is associated with a high incidence of fistula and therefore flaps are advocated. The description of a transoral robotic total laryngectomy prompted us to develop similar minimally invasive open approaches for functional total laryngectomy. Methods A retrospective study of consecutive unselected patients with a dysfunctional larynx after (chemo)radiation that underwent open maximal mucosal-sparing functional total laryngectomy (MMSTL) between 2014 and 2016 is presented. The surgical technique is described, and the complications and functional outcome are reviewed. Results The cohorts included 10 patients who underwent open MMSTL. No pedicled flap was used. Only one postoperative fistula was noted (10%). All patients resumed oral diet and experienced a functional tracheo-esophageal voice. Conclusion MMSTL could be used to perform functional total laryngectomy without a robot and with minimal incidence of complications.

Pleomorphic Adenoma Originating from Heterotopic Salivary Tissue of the Upper Neck: A Diagnostic Pitfall

Pleomorphic adenoma directly arising in the neck is thought to originate from heterotopic salivary gland tissue. In this article, we present the case of a 55-year-old female patient with a histologically proven pleomorphic adenoma located at the left mandibular angle, anteriorly to the sternocleidomastoid muscle and posteroinferiorly to the submandibular gland. As the patient also had an ipsilateral thyroid nodule with coarse calcifications, clinical and radiological features suggested a possible level II metastatic lymph node. However, ultrasound-guided fine needle aspiration cytology and postsurgery histopathological examination revealed a pleomorphic adenoma arising from heterotopic salivary gland tissue unrelated to a benign thyroid nodule. In this article, we provide a review of the existing literature on heterotopic salivary gland tissue and related neoplasms and discuss their imaging presentation.

Synovial sarcoma of the hypopharynx in a pediatric patient: Case report.

Highlights • Synovial sarcoma (SS) is an extremely rare head and neck malignancy in the pediatric population.• Preoperative diagnosis of SS is challenging because of its nonspecific symptomatology, low clinical morbidity at presentation, lack of specific radiologic features, and physicians unfamiliarity.• We present this case to emphasize the correlation between histopathology diagnosis and clinical judgment to perform optimal treatment (surgical, chemo and/or radiotherapy) with preservation of pharyngeo-laryngeal function in the pediatric population.

Carotid artery by-pass and head and neck squamous cell carcinoma: Geneva's experience. Should we be afraid of the carotid artery?

1st Scientific Meeting of the Head and Neck Optical Diagnostics Society Colin Hopper, Adel K El-Naggar, Tahwinder Upile, Waseem Jerjes and HJCM Sterenborg Publication of this supplement was made possible with support from KARL STORZ Endoskope Meeting abstracts – A single PDF containing all abstracts in this Supplement is available here . http://www.biomedcentral.com/content/pdf/ 1758-3284-1-S1-info.pdf