Differentiation of pyriform sinus cancer from supraglottic laryngeal cancer by computed tomography

Contribuição da tomografia computadorizada no estadiamento do carcinoma de células escamosas da supraglote

OBJETIVO: Este trabalho tem como objetivos avaliar a influência da tomografia computadorizada no estadiamento local da classificação TNM dos tumores da supraglote e avaliar a concordância interobservadores na detecção da extensão tumoral. MATERIAIS E MÉTODOS: Foram avaliados, retrospectivamente, 39 pacientes com carcinoma de células escamosas da supraglote atendidos no Hospital Heliópolis entre 1988 e 1998. Os exames de tomografia computadorizada foram analisados por dois radiologistas individualmente. Para a avaliação da concordância interobservadores utilizou-se o índice kappa. RESULTADOS: A tomografia computadorizada foi determinante no estadiamento mais avançado em 38,5% dos casos, decorrente de extensão tumoral profunda não-identificada no exame clínico. CONCLUSÃO: A concordância interobservadores foi considerada ótima para as pregas vocais e subglote; boa para a supraglote, espaços paraglótico e pré-epiglótico, cartilagens cricóide e tireóide e para extensão tumoral extralaríngea; e regular para a base da língua.

Laryngeal imaging

Knowing the surgical options for treating laryngeal carcinomas and the factors that are used to select patients for radiation therapy leads to a more valuable and relevant interpretation of neck scans in patients with laryngeal tumors. Critical factors include tumor volume; cartilaginous invasion; spread across supraglottic-glottic-subglottic boundaries; infiltration of preepiglottic, paraglottic, and pharyngeal planes; and nodal disease. MR imaging offers greater sensitivity to cartilaginous invasion than CT but shows a higher rate of false-positive studies. Direct coronal MR imaging is often valuable in assessing these issues.

Laryngeal imaging

Knowing the surgical options for treating laryngeal carcinomas and the factors that are used to select patients for radiation therapy leads to a more comprehensive interpretation of neck scans in patients with laryngeal tumors (Table 6). Critical factors include tumor volume; cartilaginous invasion; spread across supraglottic-glottic-subglottic [table: see text] boundaries; infiltration of preepiglottic, paraglottic, and pharyngeal planes; and nodal disease. MR imaging offers greater sensitivity to cartilaginous invasion than CT but leads to a high rate of false-positive studies, which decreases its overall accuracy. Thin-section CT with multiplanar capability is competitive with direct coronal MR scanning and benefits from high specificity and submillimeter section thickness, if multidetector units are employed. Overall, the head and neck radiologist plays an invaluable role in assessing the extent of disease and therefore influences the appropriate selection from the available treatment options.

Radiologic diagnosis and staging of head and neck squamous cell carcinoma

The predominant extracranial head and neck cancer in adults is squamous cell carcinoma. The purpose of this article is to discuss the radiographic evaluation of these patients with CT scans or MR imaging before therapeutic intervention. Specific focus is given to the efficacy of CT scans and MR imaging, as an adjunct to clinical staging for evaluation of the primary tumor, and metastatic adenopathy. MR imaging, because of its improved soft tissue contrast and multiplanar capability, is probably superior to CT scans for evaluation of the primary tumor in patients with squamous cell carcinoma. CT scans, however, remain the gold standard for identifying metastatic adenopathy and in most institutions remain the study of choice for evaluating this patient population.

MRI of the hypopharynx with provocative maneuvers

The purpose of this study was to assess the validity of magnetic resonance (MR) functional images of the hypopharynx. Following T2-weighted spin-echo sequences during quiet respiration, contrast enhanced 2D-Turbo-FLASH sequences were obtained during Valsalva-maneuver, quiet respiration, A- and U-phonation, respectively. Tumor detection was clearly improved using functional MRI (sensitivity of 97.4%, specificity 83.3%, accuracy 95.5%) when compared with MRI during quiet respiration (sensitivity of 87.1%, specificity 33.3%, accuracy 80%). Rapid MR sequences such as 2D-Turbo FLASH allow functional imaging of the hypopharynx, thereby improving MR diagnosis of hypopharyngeal tumors.

Relative roles of computed tomography and endoscopy for determining the inferior extent of pyriform sinus carcinoma: correlative histopathologic study

Ten laryngopharyngectomy specimens were dissected to determine the relative accuracy of computed tomography (CT) and endoscopy under anesthesia for evaluating the inferior extent of pyriform sinus carcinoma. Endoscopic examination failed to detect involvement of the pyriform sinus apex in one patient, and considerably underestimated disease at this level in two others; CT accurately predicted the status of the apex in these three and all other patients. Endoscopy underestimated the inferior extent of tumor in six patients; CT revealed the inferior limit relative to the esophageal verge more accurately in all six of these submucosal extensions. Endoscopy revealed one case of mucosal spread to the esophageal verge not demonstrated by CT. Endoscopy and CT were both correct in revealing the esophageal verge to be involved (one case) and free of disease (two cases). This study also confirmed a common tendency of pyriform fossa cancer to spread through thyrohyoid membrane adjacent to the course of superior laryngeal neurovascular bundle (six cases). High-resolution CT, in experienced hands, is a useful adjunct to endoscopy for detecting submucosal, inferior extension of pyriform sinus carcinoma. This information can influence the choice of the lower margin of resection and method of pharyngeal reconstruction.

Magnetic resonance imaging of head and neck tumors

Magnetic resonance imaging has revolutionized the imaging of head and neck malignancies and is now rapidly replacing computed tomography as the study of choice in the majority of lesions in the head, neck, larynx, hypopharynx, oropharynx, paranasal sinuses, paranasopharynx, and skull base. CT scanning can be used in the same region; however, inflammation obtained in CT is not as clearly demonstrated and in some situations, such as malignancies of the tongue, the lesions may be missed entirely. There are still occasional difficult clinical problems when the two studies are complementary, but this situation will definitely be rare.

High resolution computed tomography: Part 3. The larynx and hypopharynx

High resolution computed tomography (CT) is a highly desirable addition to clinical examination of the larynx and hypopharynx. The anatomy and pathology of the larynx and hypopharynx is discussed and illustrated by CT.