The effects of CT scanning on staging of tumours of the paranasal sinuses

Radiologic Features of Sinonasal Tumors

Imaging evaluation of sinonasal tumors is most often conducted with computed tomography, which excels at identifying the effects of these masses on adjacent osseous structures, and magnetic resonance imaging that is ideal for distinguishing pathologic masses from mucosal thickening and fluid that are common in the sinonasal spaces and depicting extension into the surrounding soft tissues, orbits, and intracranial compartment. Accordingly, the two studies are complementary exams and both are commonly utilized in the assessment of these masses. Less commonly, positron emission tomography can provide additional metabolic evaluation of potential metastatic disease in patients with malignant disease. While these imaging modalities are excellent for the portrayal of an abnormality, there is considerable overlap in the imaging appearance of these tumors and specific imaging manifestations linked to a particular tumor are frequently lacking. Therefore, while the mass may be readily identified, narrowing the differential diagnosis to a single specific entity is rare. Nevertheless, cross-sectional imaging plays an essential role in patient management and valuable guidance for successful biopsy or surgical resection in virtually all cases. This review emphasizes essential imaging manifestations that correlate with sinonasal tumors in general and highlight certain features that may implicate a specific disease process.

Clinical, radiological and surgical correlation in cancers of the paranasal sinuses

Clinical, radiological and CT findings for each adjacent subsite were tabulated and compared in 25 consecutive cases undergoing surgery for malignant lesions of the maxillo-ethmoid complex. It was found that tumour extensions into nose, palate, cheek and orbit were identified correctly in a high proportion of cases clinically and radiologically. Posterior extensions into infratemporal or pterygopalatine fossae were evident clinically in only one out of 5 cases. Clinical assessment failed to detect orbital invasion in 3 out of 7 cases, while CT missed orbital periosteal involvement in one case. CT overestimated spheno-ethmoidal extensions of tumour in 44% (8/18) cases.

Imaging of neoplasms of the paranasal sinuses

The assessment of sinonasal malignancies requires a multidisciplinary team approach.Advances in pretherapeutic imaging have significantly contributed to the managementof sinonasal tumors. CT and MR imaging play complementary roles in the assess-mentand staging of these malignancies by determining the presence or absence of exten-sionof disease into the skull base and its foramina, the orbit, and the intracranial compartment.

Retrospective assessment of computed tomographic imaging of feline sinonasal disease in 62 cats

Sixty-two cats with sinonasal disease were evaluated with computed tomography. Findings that may lead to a computed tomographic diagnosis of nasal neoplasia versus rhinitis included osteolysis of the paranasal bones, moderate to severe turbinate destruction, lysis of the nasal septum, the presence of a homogenous space occupying mass, and extension of the disease process into the orbit or facial soft tissues. These findings were not pathognomonic for neoplasia and may be associated with severe rhinitis; therefore, nasal biopsy was recommended. When compared with parallel radiographic studies, computed tomography was not more sensitive than radiographs at detecting the presence of nasal cavity abnormalities in cats with referable clinical signs but was more sensitive at localizing these changes and determining the extent of disease.

Imaging of neoplasms of the paranasal sinuses

The assessment of sinonasal malignancies requires a multidisciplinary team approach. Advances in pretherapeutic imaging have significantly contributed to the management of sinonasal tumors. CT and MR imaging play complementary roles in the assessment and staging of these malignancies by determining the presence or absence of extension of disease into the skull base and its foramina, the orbit, and the intracranial compartment.

Clinical classification and staging for primary malignancies of the maxillary antrum

A study of 51 patients with primary malignant maxillary sinus neoplasms was conducted. None of the patients had neck nodes and/or metastases, and each had 5-year follow-up. The tumors were staged according to the 1983 and 1988 American Joint Committee on Cancer staging systems for maxillary sinus cancers. There were 13 early stage (T1, T2) and 38 advanced (T3, T4) tumors in both systems. Cox regression analyses of survival curves showed increasingly worse prognoses for advanced tumors in both T-staging systems. Further analyses showed a significant difference in survival between T3 and T4 in the 1988, but not in the 1983 system. There were no significant differences in survival according to treatment modality or histological type of malignancy. We conclude that the 1988 system prognosticates successfully for T-stage (1 to 4) and demonstrates significant improvement in detecting T3 versus T4 differences compared to the 1983 system. The 1988 system applies equally for epidermoid cancer and other malignancies of the antrum.

Staging of base of tongue carcinoma by computed tomography

Staging of carcinoma of the base of the tongue according to the system adopted by the American Joint Committee on Cancer relies on clinical examination possibly augmented by multiple biopsies. Palpation of the tongue base can be difficult without anaesthesia due to retching and vomiting. Computed tomography can, however, accurately depict the deep structures of the base of the tongue without discomfort to the patient. It can also demonstrate the nodal stations of the neck. In 12 patients with primary carcinoma of the base of the tongue the clinical staging results were compared with the CT findings. In 10 of the 12 patients there was good correlation between tumour size and location, while only 2 patients showed a 1.0-1.5 cm discrepancy in the size estimate of the primary tumour. A total of 9 enlarged lymph nodes or nodal groups were only found by CT. The majority of positive nodal stations demonstrated only by CT were in the contralateral neck. Computed tomography is a valuable complement when staging tongue base carcinomas, particularly when evaluating the neck for lymph node metastasis.

Maxillary squamous cell carcinomas staged by computed tomography

In 72 patients with maxillary squamous cell carcinoma, computed tomography (CT) alone was used for T-staging according to the AJC classification. Five, 31, and 36 tumors were diagnosed as T2, T3, T4, respectively. In N0 patients with a minimum follow-up of 2 years, local control rates for T2, T3, and T4 tumors were 33% (1/3), 64% (16/25) and 38% (9/24), respectively. Addition of maxillectomy to treatment seemed to have improved the local prognoses in T3 and T4 tumors. High radiation doses of 60 Gy or more seemed to be beneficial for patients with T3 tumors and without maxillectomy. CT will be of great help in classifying tumors objectively. But more importantly, it will reveal resectability and dictate treatment of choice by delineating the tumor extent precisely.

Ameloblastomas of the jaws: radiological diagnosis and follow-up

Eleven of 57 tumours and cysts (19 per cent) seen at two major centres over a 4-year period were ameloblastomas, primary in eight and recurrent in three. Computed Tomography (CT) was the most sensitive imaging technique for detecting ameloblastomas. The radiological features were distinctive maxillary and mandibular pathology in primary cases and soft-tissue, maxillary sinus and asymmetrical deep tissue involvement in both primary and recurrent ameloblastomas. Following surgery and pathological confirmation, serial scans were combined with periodic clinical re-evaluation. We identified clinically occult recurrences in two cases and confirmed a clinically-suspected recurrence in one on the basis of the CT findings. Our protocol appears efficacious and is suggested for the necessary long-term follow-up in all pathologically verified ameloblastomas.

Role of the CT scanner in the management of cancer

Although the diagnostic scope of computed tomography has widened considerably in recent years, assessment of patients with suspected or known malignant disease remains the major reason for body CT referrals in the United Kingdom. This paper sets out to define important advantages and limitations of CT in cancer diagnosis, addressing the topics of primary diagnosis, staging, and patient follow up. There is relatively little information on the influence of CT on patient management in oncology but reported studies indicate that CT directly alters clinical decisions in 14-30% of patients. This aspect requires further evaluation and is of particular relevance when considering the appropriate use of high cost technology.

Patterns of relapse of squamous cell carcinoma of the maxillary sinus

Ninety-five M0 patients with squamous cell carcinoma of the maxillary sinus were treated mainly with combined surgery, radiation and chemotherapy. They were staged surgically according to the American Joint Committee TNM classification: 3 were T2N0, 55 T3N0, 27 T4N0 and 10 T3-4N1-3 patients. Relapse developed in 66 patients (69%): one (33%), 35 (64%), 22 (81%) and 8 (80%), respectively. All patients experienced relapse within 2 years after diagnosis. Local recurrence developed during the course of disease in 52 (79%) of the 66 patients who relapsed. Three patients with cervical relapse and one with local recurrence were successfully salvaged with rescue surgery. Local control achieved in 39 (41%) of the 95 patients: 2 (67%), 28 (51%), 7 (26%) and 3 (30%) in T2N0, T3N0, T4N0 and T3-4N1-3 patients, respectively. Autopsy findings of 17 patients are presented. An impact of computed tomography on staging of maxillary sinus tumors is discussed.

Computed tomography of the infratemporal fossa in primary jaw pathology

Due to the anatomical relationship of the jaws to the infratemporal fossa this area is readily involved in pathological processes of the jaw. Conventional radiographs play a limited role in demonstrating this region. A variety of primary diseases of the jaws, namely hereditary, developmental, infective, benign and malignant tumours with extension into the infratemporal fossa, are presented. Computed tomography is an excellent method for showing both osseous and soft-tissue components which include bony destruction, new bone formation, soft tissue calcification, inflammatory and malignant processes affecting the muscles and fat in the infratemporal fossa.

Evaluation of the role of computed tomography in radiotherapy treatment planning

The role of computed tomography (CT) in radiotherapy treatment planning was assessed in a series of 231 patients in whom treatment was planned with radical intent. For each patient, a treatment plan was produced by the best conventional techniques in use at the Middlesex Hospital. Each patient then underwent a CT scan in which the treatment conditions were closely simulated. As a result of the CT scan images, alteration was made to the planned treatment in 47% of 198 assessable patients. Large differences were seen in the usefulness of CT treatment planning for tumours in different sites, with the greatest contribution made to treatment of tumours of the sinuses and nasopharynx and of the bladder. Although its unit cost is high, computed tomography can be a very useful tool in radiotherapy treatment planning and can contribute uniquely to improved patient management for adequately selected patients.

CT evaluation of paranasal sinus tumours for cranio-facial resection

Twenty-two patients with tumours of the paranasal sinuses had computerised tomography performed prior to cranio-facial resection. The findings of CT, histology and operative appearances are compared and a 78% correlation found. The radical approach offered by cranio-facial resection allows more accurate confirmation of CT findings than hitherto possible. The particular importance of CT scanning in relation to tumours of paranasal sinuses is discussed.