The role of computed tomography in the management of cancer of the larynx

Revolutionizing lymph node metastasis imaging: the role of drug delivery systems and future perspectives

The deployment of imaging examinations has evolved into a robust approach for the diagnosis of lymph node metastasis (LNM). The advancement of technology, coupled with the introduction of innovative imaging drugs, has led to the incorporation of an increasingly diverse array of imaging techniques into clinical practice. Nonetheless, conventional methods of administering imaging agents persist in presenting certain drawbacks and side effects. The employment of controlled drug delivery systems (DDSs) as a conduit for transporting imaging agents offers a promising solution to ameliorate these limitations intrinsic to metastatic lymph node (LN) imaging, thereby augmenting diagnostic precision. Within the scope of this review, we elucidate the historical context of LN imaging and encapsulate the frequently employed DDSs in conjunction with a variety of imaging techniques, specifically for metastatic LN imaging. Moreover, we engage in a discourse on the conceptualization and practical application of fusing diagnosis and treatment by employing DDSs. Finally, we venture into prospective applications of DDSs in the realm of LNM imaging and share our perspective on the potential trajectory of DDS development.

50th anniversary of computed tomography: past and future applications in clinical neuroscience

Purpose: It has been 50 years since computed tomography was introduced to the worldwide neurologic medical and surgical community. In that time, tremendous advances in computer software and hardware, as well as creative changes in computerized tomographic (CT) hardware and tube technology, have dramatically improved the temporal and spatial resolution of CT. In this paper, I address what I feel are some of the most important impacts of CT in the field of clinical neuroscience over the last 50 years, as well as potential applications of CT that are on the horizon.

Approach: I have recounted from literature, colleagues, and personal recollection the historical impact of CT on neuroradiology practice and what appear to be near-term future applications.

Conclusions: Therapeutic applications beyond diagnosis, such as image-guided procedures, radiation, and surgical planning, and development of the field of theranostics have emerged and further increased the need for faster and more precise CT imaging. The integration of machine learning into the acquisition chain and radiologist tool kit has great implications for standardization, analysis, and diagnosis worldwide.

Pathologic Assessment of Computerized Tomography Accuracy for the Evaluation of the Laryngeal Cartilaginous Frame Work in Laryngopharyngeal Carcinomas

Sixty-six whole-organ sectioned laryngopharyngectomy specimens removed for cancer during a seven-year period were uniformly examined to determine the accuracy of preoperative high resolution computerized tomography (CT) for detection of cartilaginous involvement. Our results indicate that CT has a high overall specificity (88.2%) but a low sensitivity (47.1 %); we observed a high false-negative rate (26.5%) and a fairly low false-positive rate (5.9%). Massive cartilage destruction was easily assessed by CT, whereas both small macroscopic and microscopic neoplastic foci of cartilaginous invasion were missed on CT scans. Moreover, false-positive cases were mainly due to proximity of the tumor to the cartilage. Clinical implications of these results are discussed.

Computed Tomography in T1 Carcinoma of the Larynx

The findings at computed tomography (CT) were reviewed in 33 patients with laryngeal carcinoma classified as T1 at clinical examination. CT revealed extralaryngeal growth and thus changed the classification to T4 in 6 of the 20 patients with a supraglottic primary tumor, but in none of the 13 patients with a glottic tumor.

Staging of laryngeal cancer using 64-channel multidetector row CT: comparison of standard neck CT with dedicated breath-maneuver laryngeal CT

BACKGROUND AND PURPOSE

With a 64-channel multidetector row CT, imaging acquisition during speech, swallowing, or phonation has become feasible. However, the actual benefit of these additional focused images should be critically evaluated with respect to radiation dose. The purpose of this study was to determine if dedicated laryngeal CT using breath-holding and straw-blowing improved the accuracy of TNM-staging for patients with biopsy-proved laryngeal carcinomas in comparison with a standard neck CT.

MATERIALS AND METHODS

A total of 27 patients underwent a standard neck CT and a laryngeal CT with additional images acquired while patients held their breath or blew through a straw. Two radiologists interpreted the neck CT and later the laryngeal CT and assigned a TNM-stage for each case. These interpretations were compared with a TNM-stage determined by surgery and/or clinical examination for the individual patients. The accuracy of standard neck CT was compared with the accuracy of laryngeal CT.

RESULTS

The overall accuracy was not significantly different between standard neck CT and the additional laryngeal CT and was, in fact, lower in cases with additional larynx images. The accuracy of staging was slightly improved with the additional laryngeal CT for glottic cancers; however, it was decreased for supraglottic cancers. The accuracy of a dichotomous diagnosis of early-versus-advanced-stage cancer was 0.86 for the standard neck CT and 0.80 for the laryngeal CT. The readers' confidence levels did not improve with the use of the additional images.

CONCLUSIONS

In the era of isovoxel multidetector CT technology and judicious monitoring of radiation dose, a standard neck CT with coronal and sagittal reformats should suffice for the staging of laryngeal cancer.

O papel da tomografia computadorizada no estadiamento e tratamento cirúrgico do carcinoma epidermóide do seio piriforme

OBJETIVO: Determinar a real extensão das neoplasias do seio piriforme através da tomografia computadorizada após estadiamento clínico/endoscópico (seio piriforme, prega ariepiglótica, espaço paraglótico, glote, subglote, orofaringe, cartilagem tireóide, cartilagem cricóide, cartilagem aritenóide, esôfago cervical, extensão para tecidos moles extralaríngeos e musculatura pré-vertebral) e sua repercussão no planejamento cirúrgico. MÉTODO: O estudo incluiu pacientes portadores de carcinoma epidermóide de seio piriforme, atendidos no Departamento de Cabeça e Pescoço e Otorrinolaringologia do Hospital Heliópolis, Hosphel, São Paulo de 1988 e 2003. Foram avaliados os prontuários de 31 pacientes, sendo 29 (93,5%) do sexo masculino e dois (6,5%) do sexo feminino. A análise das tomografias foi realizada por três radiologistas individualmente e para o estudo da concordância interobservadores, foi utilizado o índice Kappa. RESULTADOS: A TC apresentou: forte concordância na avaliação de seio piriforme, prega ariepiglótica, espaço paraglótico e subglote; boa concordância para a orofaringe, glote, cartilagem cricóide, esôfago cervical e tecidos moles extralaríngeos; moderada para as cartilagens tireóide e aritenóide; fraca no estudo da musculatura pré-vertebral. CONCLUSÃO: A avaliação interobservadores das imagens do CEC do seio priforme determina o re-estadiamento TNM e conseqüente mudanças do paradigma cirúrgico.

Avaliação por tomografia computadorizada do envolvimento loco-regional do carcinoma espinocelular de corda vocal

No período de 1992 a 1998, foram avaliados, retrospectivamente, exames de tomografia computadorizada e prontuários de 22 pacientes com carcinoma espinocelular de corda vocal. Avaliou-se a concordância entre observadores para todos os casos e a acurácia e concordância entre os métodos para os casos operados, utilizando-se o índice kappa. A concordância foi excelente para o comprometimento tumoral das cartilagens tireóide, cricóide, extensão extralaríngea e estadiamento linfonodal; ótima para o envolvimento tumoral das cordas vocais, comissura posterior e espaço paraglótico; boa para o envolvimento tumoral da supraglote, subglote e estadiamento tumoral; regular para o envolvimento tumoral da comissura anterior e cartilagem aritenóide. A utilização simultânea da avaliação clínica e tomográfica para o estadiamento T obteve acurácia e concordância com achados patológicos de 89,47% e 84,9%, respectivamente, sendo superior à análise clínica isolada ou tomográfica. A acurácia e concordância patológica da tomografia computadorizada para o estadiamento N foi de 100%, sendo superior à avaliação clínica.

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.

Impact of cartilage invasion on treatment and prognosis of laryngeal cancer

Invasion of laryngeal cartilage has long been considered as a contraindication to radiation treatment and to all types of conservation surgery. With the advent of axial imaging techniques clarification of the submucosal extent of disease became possible. However, controversies regarding diagnosis (preferred modality, accuracy of detection of cartilage invasion) and treatment of cartilage invasion (Is cartilage invasion really a contraindication for irradiation treatment?) arose. Based on currently accepted criteria, CT appears to be more specific in detecting neoplastic cartilage invasion than MRI, but tends to underestimate invasion and may therefore result in undertreatment. Magnetic resonance has a higher sensitivity than CT for detection of cartilage invasion. The superiority of MRI lies in its ability to detect intracartilaginous tumor spread. Unfortunately, MR findings suggesting neoplastic cartilage invasion may be false positive in a considerable number of instances. Two MRI-dependent parameters appear to be significant as a prognostic factor for success of radiation therapy: tumor volume and abnormal MR signal pattern in cartilage. Minimal abnormal MR signal patterns in cartilage in patients with small tumors (under 5 cc) does not appear to be a very ominous finding for tumor recurrence after radiation therapy. On the other hand, abnormal MR signal pattern in cartilage combined with large tumor volume (above 5 cc) appears to worsen the prognosis significantly. If voice conservation surgery is being considered, MR imaging is useful for assessing those structures (such as cartilages) whose involvement would contraindicate partial laryngectomy. Magnetic resonance imaging appears to be the optimal method of examination in cooperative patients. If MRI fails or if it is contra-indicated, CT may still be recommended. The radiologist's experience with CT or MRI also determines the choice between the two modalities.

Three-dimensional photon treatment planning in carcinoma of the larynx

The role of three-dimensional (3-D) treatment planning in the definitive treatment of carcinoma of the larynx with radiation was evaluated at four institutions as part of an NCI contract. A total of 30 different treatment approaches were devised for two patients with larynx cancer. CT scans were obtained for both patients and various treatment planning tools were employed to optimize beam arrangements and to evaluate the resulting dose distribution. The effect on dose distribution of a number of factors was also examined: 1) the use of dose calculation algorithms which correct for tissue inhomogeneities, 2) the variation of the CT numbers used for inhomogeneity corrections to simulate inaccuracies in the knowledge of the CT numbers, and 3) the modification of beam energy. A multitude of data was used in plan evaluation and a numerical score was given to each plan to estimate the tumor control probability and the normal tissue complication probability. We found 3-D treatment planning to be of potential value in optimizing treatment plans in larynx cancer. Improved target coverage was achieved when complete information describing 3-D geometry of the anatomy was utilized. In some cases, the treatment planning tools employed, such as the beam's eye view, helped devise novel beam arrangements which were useful alternatives to standard techniques. We found little effect of change in CT number on dose distributions. A comparison between dose distributions calculated with tissue inhomogeneity corrections to those calculated without this correction showed little difference. We did find some improvement in the dose to the primary tumor volume at lower beam energies, but with an increased larynx volume potentially receiving doses above tolerance.

Cancer of the larynx: current concepts of diagnosis and treatment

Cancer of the larynx is a potentially fatal disease. Familiarity with current treatment, however, makes it potentially curable. This article discusses the available therapeutic options and their consequences.

Metastatic cancer to the larynx. Diagnosis and management

A case of metastatic tumor in the larynx following successful treatment of a breast carcinoma and a colon carcinoma is presented. The lesion was visible by indirect laryngoscopy, and computed tomography of the larynx assisted in delineating the extent of the disease. The separation of primary adenocarcinoma of the larynx from metastases is discussed, as is the identification of the origin of a metastasis where two separate primaries have existed. Other reports of cancer metastatsizing to the larynx are reviewed. Tumor spread to the larynx may be asymptomatic or may result in hoarseness, stridor and/or airway obstruction.

Computed tomography of the nasopharynx and neck

Computed tomography (CT) is unparalleled for evaluation of the nasopharynx and the neck in comparison with other radiologic modalities. Its ability to demonstrate soft tissue and bone abnormalities has established its role as a primary method of radiologic diagnosis, frequently obviating the need for further radiologic elaboration. Furthermore, in many cases, CT provides distinction among inflammatory, neoplastic, and traumatic conditions.

Framework invasion by laryngeal carcinomas

The accuracy of standard clinical and radiologic methods in detecting invasion of the laryngeal framework or the presence of a transglottic tumor was examined by comparing clinical and pathologic findings in a series of 50 randomly selected laryngectomies for squamous carcinoma. Forty-two of the patients had received radiation therapy as primary treatment. The presence of pain referred to the ear immediately before laryngectomy indicated invasion of the laryngeal framework or spread into the extralaryngeal soft tissues in 11 of 12 patients. Transglottic tumors were correctly identified in 10 of 14 patients from laryngeal tomograms, but seven additional tumors were incorrectly designated as transglottic. Both transglottic tumors and infraglottic extension were seriously underdiagnosed by direct laryngoscopy. Framework invasion was seen to be a feature of transglottic tumors 2 cm or more in diameter. The morphology of this process is described. Limited follow-up has already shown a pattern of early recurrence, frequently as cervical node metastases, that is significantly more common in patients with framework invasion.

Lipoma of the larynx imaged by conventional radiographic methods

Benign tumors of the larynx are rare lesions and seldom encountered by radiologists. They usually are small, most commonly being diagnosed by indirect or direct laryngoscopy. A case of a large benign lipoma arising from the larynx which was visualized radiographically is described. A definitive diagnosis, however, was only possible following surgical excision of the lesion.

Computed tomography in carcinoma of the larynx and piriform sinus

The conventional methods of examination do not furnish a complete picture of deep extension of carcinoma of the larynx and piriform sinus. Often the only sign of deep invasion is vocal cord fixation. The purpose of this study was to ascertain whether further information in this respect might be provided by computed tomography. The results of examinations by this technique were assessed on the basis of the findings in whole-organ serial sections in the transverse plane in 8 patients with laryngeal and 2 with piriform sinus carcinoma. In 2 further patients not undergoing operation, the findings yielded by CT were compared to the laryngoscopic assessment and the findings at a clinical follow-up after a full course of radiotherapy. CT adds valuable information on the deep invasion of the tumour, especially spread lateral to the arytenoid cartilage, to the laryngeal framework and outside the larynx.

The demonstration of cartilaginous involvement in laryngeal carcinoma by computerized tomography

Thirty-six patients with laryngeal carcinoma were investigated by computerized tomography (CT). In 8 patients invasion of cartilage was shown at subsequent pathological examination of the excised larynges. In all there were 14 areas of cartilage involvement, 11 of which could be diagnosed on retrospective examination of the CT scans. Involvement of tumour was shown either as areas of decreased density (chondrolysis) or areas of local increased density (chondrosclerosis) due to cartilage ossification. False positive and false negative evidence of cartilage involvement was recorded in the series, but the accuracy of diagnosis in positive terms was approximately 79%. Histological evidence is put forward that the presence of carcinoma in relation to the cartilage produces perichondritis, which enhances ossification and the latter process may then in itself facilitate invasion by the tumour. Previous radiotherapy may also be a factor in the causation of the perichondritis and ossification.

Computed tomography of the larynx: a clinical and pathologic study

Recent interest in the application of computed tomography (CT) to the evaluation of laryngeal tumors, and the fact that the larynx offers the unique opportunity of whole organ study after total laryngectomy, led to a prospective study of laryngoscopy, conventional tomography, and CT in relation to pathologic findings. The results showed that CT gives an exact assessment of laryngeal anatomy and tumor involvement, particularly in the paracordal and pre-epiglottic spaces. The laryngeal cartilages, which are not well demonstrated by any other means, are accurately delineated by CT. There is also good demonstration of the laryngeal surface of the epiglottis, including the anterior commissure, which is poorly shown by other radiologic methods and is sometimes poorly seen on laryngoscopy. Because CT and conventional tomography present images at 2 different planes, at right angles to each other, we believe that CT is entirely complementary to conventional tomography.

Computerized axial tomography in the assessment of thyroid cartilage invasion by laryngeal carcinoma: a prospective study

The purpose of this study was to assess the value of computerized axial tomography (CAT) in canine larynges that exhibit controlled surgical defects, and in 18 patients with biopsy-proved epidermoid carcinoma of the larynx who were studied prospectively. Five canine larynges with sequential surgical defects of 0 mm, 5 mm, 10 mm, and 15 mm were studied by CAT in order to evaluate our ability to identify defects in the thyroid cartilage. A 5-mm collimator with overlapping sections at 3-mm intervals and a 13-mm collimator with 5-mm overlapping sections were both used for each stage of the experiment. Results show significantly improved resolution with the 5-mm collimator compared with the 13-mm unit. In the human study group, results demonstrated excellent (100%) soft-tissue tumor site correlation. It appears from this study that we still lack a highly reliable radiographic technique for evaluating preoperatively with accuracy the integrity of the thyroid cartilage in the patient with carcinoma of the larynx.

The role of computed tomography in tumours of the larynx

A clinical study of computed tomography (CT) was undertaken in 35 patients with tumours involving the larynx. Twenty-seven had primary laryngeal neoplasms, five had tumours arising in adjacent structures but invading the larynx and three who had undergone total laryngectomy were investigated for possible recurrence. The findings were compared with conventional radiological methods and clinical assessment. Confirmation was obtained from laryngectomy specimens in four patients and at autopsy in one. CT provided additional preoperative information on 14 occasions. This included better delineation of submucosal tumour extent, invasion of the pre-epiglottic space and cartilage displacement in invasion.

The clinical application of computed tomography in the assessment of laryngo-pharyngeal carcinoma. (Preliminary report)

Computed axial tomography of the larynx offers a unique view of laryngeal structures which cannot be obtained by any other technique. Its applications are discussed and cases presented to demonstrate its usefulness.

Evaluation of computerized tomography, cinelaryngoscopy, and laryngography in determining the extent of laryngeal disease

A prospective study of over 100 cases comparing computerized tomography (CT) and correlating these studies with photographic motion picture studies of the larynx, conventional tomography and contrast laryngography has been performed. The authors give illustrative examples of cases in which the CT scan has been documented as providing equal and often times greater information concerning not only tumors, but also cystic lesions and traumatic lesions. With the newer technology, the reduced radiation (which is less than one half that of conventional tomography), and the decreased expense (now comparable to that of laryngography alone), eliminates the need for conventional laryngography and tomography examinations. The incorporation of motion picture documentation of the lesions allowing future comparative studies between the original lesion and the CT are recommended for a more accurate retrospective classification and assessment of therapeutic results.

Computed tomography of the normal larynx

A computed tomographic analysis of normal laryngeal anatomy was undertaken using cadaver larynxes. This was part of a larger project in which patients with laryngeal carcinoma were routinely evaluated in the computed tomographic (CT) body scanner. The appearance of normal laryngeal anatomy had to be delineated before disease processes of the larynx were evaluated, and this was accomplished using a computed tomographic technique with 5-mm slice thicknesses and a 3-mm overlap. The scan slices were then compared with anatomic sections taken at the same levels. The comparisons demonstrate an ideal level of accuracy that can be approached in the in-vivo larynx only with use of the latest-generation scanners. However, CT scanning is of immediate usefulness in the diagnosis of laryngeal pathology.