Radiation therapy of esophageal cancer: role of high dose rate brachytherapy.

Fifty untreated cases of squamous cell carcinoma arising from the middle one-third of the esophagus, with no apparent extraesophageal spread on a computed tomography (CT) scan and with a Karnofsky performance status of over 70, were treated by external beam irradiation to a dose of 3500 cGy/15 fractions/3 weeks. Twenty-five patients (Group A) received treatment with further external beam irradiation to a dose of 2000 cGy/10 fractions/2 weeks. Another group of 25 patients (Group B) received treatment with high dose rate intracavitary irradiation to a dose of 1200 cGy delivered in two sessions of 600 cGy each a week apart. All patients were assessed symptomatically, endoscopically, and radiologically every 3 months. There was marked difference at the end of 1 year in relief of dysphagia (37.5% in Group A vs. 70.6% in Group B), local control (25% in group A vs. 70.6% in group B) although the results were statistically insignificant (p greater than 0.05) and actuarial survival (44% in group A vs. 78% in group B) which was, however, significant statistically (z = 2.83). The cumulative radiation effect (CRE) by external beam irradiation was 1729 reu and by external beam and intracavitary irradiation 1741 reu, but the biological dose effect was better with external beam and intracavitary irradiation. Eight percent of patients treated by external beam and intracavitary irradiation had strictures in contrast to 4% treated by external beam irradiation alone. Moderate doses of external beam and intracavitary irradiation can give a better local response than external beam irradiation alone for the same biological dose in the treatment of esophageal carcinoma.

A newly developed immunofluorescence assay for simultaneous detection of antibodies to human immunodeficiency virus type 1 and type 2.

Immunofluorescence assays (IFA) that simultaneously distinguish between antibodies against closely related human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) infections have not been readily available. Serum specimens from 95 HIV-1-infected, 26 HIV-2-infected and 3 HIV-1/HIV-2 dually infected individuals and 106 seronegative blood donors were evaluated for the ability to serologically discriminate HIV-1 and HIV-2 infections by means of IFA employing three types of cells whose morphology varied within one field of microscopy. Mixtures of HIV-1-infected, HIV-2-infected and uninfected cells were used in the present study. In consequence, all serum specimens from individuals infected with HIV were confirmed to contain antibodies to HIV-1 and/or HIV-2. None of the sera from the blood donors were positive. Serum specimens from HIV-1-infected or HIV-2-infected individuals were diagnosed as single infection with HIV-1 (85/95) and HIV-2 (22/26), respectively, by this new assay. Although another 14 (10/95 and 4/26) were shown to be seropositive for both HIV-1-infected and HIV-2-infected cells, these results suggest that this assay is potentially simple and useful for screening and confirming both HIV-1 and HIV-2 infections simultaneously.