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Biomedical subjects

T J Keane

Publications and source records attributed to T J Keane.

At least 55 records · Page 3Linked to original sources
PubMed1983

Cancer of the tonsil: results of radical radiation therapy with surgery in reserve.

Three hundred seventy-two patients with squamous cell carcinoma of the tonsil were treated with primary irradiation of curative intent. Surgery was saved for subsequent treatment failure. The overall survival was 38 percent at 5 years. Local control was 63 percent for all patients. T1 and T2 lesions were controlled in 87 percent and 68 percent of patients, respectively, and T3 lesions were controlled in 50 percent of patients. Patients with healthy (N0) nodes and those with mobile nodes had a high degree of regional control, but fixed nodes were controlled in only 37 percent of patients with radiation alone. The most common site of treatment failure was in the primary tumor, which accounted for 45 percent of relapses, and isolated nodal relapses were present in only 24 percent of patients. Subsequent surgery was possible in 47 percent of patients in whom initial treatment failed. A higher degree of subsequent control was obtained with more aggressive surgery compared with simple local resection. There was a high rate of second respiratory tract malignancy, in fact, after 2 years, patients were dying more commonly of their second respiratory tract malignancies than of cancer of the tonsil.

Adult↗
PubMed1983

Carcinoma of the hypopharynx results of primary radical radiation therapy.

The results of radiation therapy as applied to patients with squamous cell carcinoma of the hypopharynx seen during the period 1972-1976 at the Princess Margaret Hospital are presented. Approximately 2/3 of the patient population presented with disease involving the regional lymph nodes or with systemic metastases. Ninety percent (127/141) of all patients registered were treated primarily with radiation therapy with surgery reserved for the management of residual or recurrent disease only. Seventy-seven percent (98/127) of those who received radiation therapy were treated with radical intent. The uncorrected actuarial 5 year survival rate for those patients treated radically was 19%. Five year actuarial survival rates by the UICC TNM (1974) staging system, showed that nodal disease was the most significant determinant of survival. Five year survival rates were as follows: N0 36%; N1 20%; N2N30%. When considered within each nodal category the survival of the combined T1T2 group was not significantly different from the T3 category. Forty-five percent of those patients who failed with local or regional disease had an attempt at salvage surgery. Of these, 6/24 ultimately achieved local and regional control. Comparisons with other series in the literature are discussed and reasons for differences in published results are considered.

Carcinoma, Squamous Cell↗
PubMed1983

Supraglottic laryngeal carcinoma: an analysis of dose-time-volume factors in 410 patients.

Four hundred and ten patients with supraglottic laryngeal carcinoma treated with moderate dose radical radiotherapy with surgery for salvage (RRSS) were analyzed in detail to determine optimal dose-time-volume parameters to be used in the treatment of each stage of supraglottic carcinoma. In the RRSS group 41% are alive and well at 5 years, 38% died of their tumor and 21% of intercurrent disease. Presence or absence of nodal disease has a major impact on survival. Local control is approximately 70% in T1, T2N0 patients and approximately 50% in T3 and T4N0 patients. Seventeen percent of T1 and T2N0 patients failed in the initially negative neck. Ten major complications (2.4%) have been seen. Local control by irradiation was not influenced by dose or field size. Regional control in the initially negative neck was markedly increased with the use of larger irradiation field sizes. Field sizes of less than 7 X 7 cm resulted in an 18% neck failure rate as compared to 3% with larger field sizes (p = 0.00005). This particularly applied to early stage disease. As a result of the use of larger irradiation field sizes giving reduced neck failure rates, improvement in survival has been seen in early stage supraglottic patients. The results are compared with published results. There is no statistically significant dose response curve in any stage of supraglottic cancer over the dose range 1650-2300 ret. Optimal treatment factors for supraglottic cancer are discussed.

Carcinoma, Squamous Cell↗
PubMed1982

Lung density as measured by computerized tomography: implications for radiotherapy.

Accurate dose calculations for radiotherapy planning require a detailed knowledge of the internal anatomy of the patient both in terms of geometry and density. Computed tomography (CT) is presently the best means of providing these data. Fifty-eight patients who had scans of the thorax for radiotherapy planning were studied. The CT numbers were converted to relative electron densities and average lung densities were obtained for every patient. A linear correlation of lung density with age was found with the mean lung density of 0.35 at an age 5 years and 0.19 at an age of 80. The effect of scanning the patient under full inspiration, full expiration or normal shallow breathing conditions was analyzed. At the age of 5 years the expiration and inspiration average lung densities were 0.36 and 0.20, while at the age of 80 years they were 0.22 and 0.16, respectively. Respiratory volume changes were linearly correlated with changes in relative electron density. Differences in lung density between expiration and inspiration scans were found to demonstrate a similar trend with age as the relationship between vital capacity and age. The dosimetric and the possible clinical implications of lung density measurements for radiotherapy are considered. In particular, dose calculations were performed using scans taken under a number of different respiratory conditions. Doses calculated for a single cobalt-60 beam can differ by more than 25% when comparing a full inspiration scan to a normal breathing scan. A similar comparison for a parallel pair distribution on the lung yields a difference of about 3% while a typical three field technique for treating cancer of the esophagus shows a difference of nearly 10%.

Adolescent↗
PubMed1982

Carcinoid heart disease: diagnosis by two-dimensional echocardiography.

We prospectively studied 14 patients with the carcinoid syndrome to determine if two-dimensional echocardiography could detect the nature and extent of valvular abnormalities. Eight of the 14 patients had definite abnormalities of the right-sided cardiac valves. The tricuspid valve had a characteristic appearance, similar to previously described pathologic findings. The leaflets appeared diffusely thickened, shortened and stiff without evidence of commissural fusion. Saline contrast studies demonstrated tricuspid regurgitation, which corresponded to the severity of the tricuspid valve involvement. The pulmonary valve could only be adequately assessed in seven of 14 patients, and morphologic abnormalities similar to those in the tricuspid valve were found. Follow-up studies have shown progression of cardiac disease in six of eight patients. We conclude that two-dimensional echocardiography can detect the characteristic cardiac abnormalities in the carcinoid syndrome and may be a useful tool for following their progression.

Adult↗
PubMed1982

Combined radical radiation therapy and chemotherapy for primary squamous cell carcinoma of the anal canal.

Radical radiation therapy (5000 rads in 20 fractions in 4 weeks) combined with iv mitomycin (10 mg/m2) and 5-FU (1000 mg/m2/24 hours for 4 days) was used to treat 13 patients with locally advanced but operable squamous cell carcinoma of the anal canal. All patients achieved local control and retained anal continence, and none developed metastases. The patients were followed from 4 to 34 months (median, 12). Severe acute gastrointestinal toxic effects were seen in three patients; the same patients had significant thrombocytopenia or leukopenia. Treatment with this combined program may allow conservative management of squamous cell carcinoma of the anal canal and should be considered as an alternative to abdominoperineal resection.

Adult↗
PubMed1982

General principles of irradiation therapy as applied to head and neck cancer.

The general principles of irradiation therapy as applied to head and neck cancer are illustrated by discussion of typical radiation treatment planning for an early glottic carcinoma, carcinoma of the larynx with subglottic extension, a paranasal sinus carcinoma, and a localized tonsillar carcinoma. Each example shows how with modern techniques and careful planning radiation therapy can be directed homogeneously to any desired volume containing tumor but limiting the complications produced in the normal tissues. Homogeneous distribution of the dose of irradiation within the tumor is essential to avoid "cold" spots producing tumor recurrence and "hot" spots producing normal tissue complications. Improvements in technique of irradiation have halved the recurrence rate in T1 glottic cancer and reduced neck node recurrences in T1 supraglottic cancer from 19% to 3%. Techniques of implantation and the concept of therapeutic ratio are also discussed. The concepts of pre vs postoperative irradiation are discussed and the Toronto approach of delayed combined irradiation and surgery, which represents in our view the optimal combination of irradiation and surgery, is reviewed.

Brachytherapy↗
PubMed1982

Carcinoma of the hypopharynx.

This article provides an overview of the Toronto experience with carcinoma of the hypopharynx. The symptoms and clinical features of patients presenting with this disease are described. The majority of patients present with either advanced primary tumors or with disease already involving the regional lymph nodes. Survival for all patients presenting with this disease has not changed over a 16 year period. No patients presenting with bilateral or fixed nodal disease achieve five year survival. The results of radical treatment using different approaches are reviewed. Radical radiation therapy with surgery deferred for residual or recurrent disease offers a similar survival to routine combined treatment but preserves laryngeal function in 85% of those who survive five years. The prospects for improving the results of primary radical radiation therapy and our ability to surgically cure patients who fail radiation therapy are discussed.

Adult↗
PubMed1980

Combined treatment of squamous cell carcinoma of the anal canal: radical radiation therapy with 5-fluorouracil and mitomycin-C, a preliminary report.

Radical radiation therapy combined with 5-fluorouracil and mitomycin-C was studied in six patients with previously untreated operable squamous cell carcinoma of the anal canal. All six patients achieved local tumor control and have retained anal continence. There has been no evidence of late recurrence to date. This preliminary report demonstrates that this method of treatment warrants further study.

Adult↗