Atsushi Oouchi

Effect of radiation on the expression of carcinoembryonic antigen of human gastric adenocarcinoma cells

The changes of antigenic expression of cultured human gastric adenocarcinoma MKN45 cells caused by irradiation were investigated to elucidate the immune responses to localized irradiation. The expression of carcinoembryonic antigen (CEA) showed remarkable increases in the culture supernatant and on the surface of the membrane of irradiated cells. The expression of major histocompatibility complex Class I antigen on the membrane also was enhanced by irradiation. In addition, the irradiated cell groups, when analyzed using a CEA‐specific probe, showed remarkable increases in the CEA mRNA. These enhancements increased in the 10‐Gy and 15‐Gy irradiated populations compared with the 5‐Gy irradiated population. These results suggest that the enhancement of expression of CEA by radiation takes place at the CEA gene expression (mRNA) level but not at the protein level.

Radiotherapy for Kimura's disease: the optimum dosage.

PURPOSE To evaluate retrospectively the optimum dosage of irradiation for Kimuras disease. METHODS AND MATERIALS Twenty patients with Kimuras disease were treated with radiotherapy. The sex ratio was 19 males to 1 female. The mean ages at onset, initial treatment, and radiotherapy were 26.2, 29.5, and 32.2 years, respectively. Radiotherapy was mainly applied for residual or recurrent tumors. The eosinophil count increased by more than 10% in 18 of the 20 patients. In most instances, irradiation was given through a single field with dosages ranging from 20 to 44 Gy. RESULTS At the completion of radiotherapy, a marked response in tumor size was noted in all cases. The minimum follow-up was 48 months. Local control was obtained in 23 of 31 lesions (74.1%). At dosages of < or =25 Gy, 26-30 Gy, and > 30 Gy, local control was obtained in 2 of 8 (25.0%), 9 of 10 (90.0%), and 12 of 13 sites (92.3%), respectively. CONCLUSIONS Radiotherapy is an effective treatment for Kimuras disease. This strongly suggests that no surgical procedure other than a biopsy should be carried out. The radiation field should be limited to the lesion and swelling of the adjacent lymph nodes as much as possible, with a optimum dosage of 26-30 Gy regardless of tumor size.

Results of cesium needle interstitial implantation for carcinoma of the oral tongue

One hundred thirty previously untreated patients with invasive squamous cell carcinoma of the oral tongue received interstitial radiotherapy with curative intent using cesium needles. Ninety-nine patients were treated with interstitial radiotherapy alone and 31 patients received interstitial radiotherapy combined with external beam irradiation. The recurrence-free rates in the primary lesions were 94.4% (17/18) in T1, 91.2% (52/57) in T2, and 70.9% (22/31) in T3 lesions. The local recurrence-free rates with single-plane and two-plane implantation were good: 89.7% (70/78) and 85.7% (12/14), respectively. The rate of 64.2% (9/14) for volume implantation was significantly poorer (p < 0.05). It is evident that tumor volume is an important factor in the control of cancer following interstitial therapy. The overall incidence of ulceration of the tongue and mandibular complication was 20% (26/130) and 13% (17/130), respectively. Using both interstitial and external radiotherapy, the incidence was 22.5%, compared with 10.1% using interstitial radiotherapy alone. The mandibular complication incidence of 8.9% with single-plane implants was much lower than 20.8% for two-plane and 23.5% for volume implants. Interstitial radiotherapy is most suitable in T1 and T2 cases in which single-plane implantation is possible; for these patients interstitial radiotherapy, which has the advantage of preserving the structure and function of the tongue, should continue to be used in the future in spite of the progress in reconstructive surgery.

The effect of radiation on the expression of intercellular adhesion molecule-1 of human adenocarcinoma cells

PURPOSE To investigate the changes in antigenic expression of intercellular adhesion molecule-1 (ICAM-1) caused by ionizing radiation of cultured human adenocarcinoma cells. METHODS AND MATERIALS Human colonic BM314 and gastric MKN45 adenocarcinoma cells were irradiated to investigate the expression of ICAM-1 on the cell membrane and in the supernatant. In addition, the ICAM-1 gene expression (mRNA) was analyzed using a ICAM-1 cDNA as a probe. RESULTS The expression of ICAM-1 on the membrane was found to increase by irradiation. This effect was also observed in the supernatant. In addition, the irradiated cell population showed slight, but clear increases in ICAM-1 mRNA expression. CONCLUSIONS These results show that the enhancement of expression of ICAM-1 by radiation takes place at the ICAM-1 gene expression (mRNA) level. The results suggest that the low dose radiation may be useful for accumulating LFA-1 positive cytotoxic T lymphocytes (CTL) at the local tumor tissue, by which tumor cells may be attacked.

Results of External Irradiation and Low-Dose-Rate Intraluminal Brachytherapy for Esophageal Cancer

The results of definitive radiotherapy to elucidate the optimal doses of external irradiation (ERT) and low-dose-rate intraluminal brachytherapy (ILBT) were analyzed. Between 1979 and 1998, 100 patients with esophageal cancer were treated with ERT and ILBT. ERT was given at a dose of 40-65 Gy/25-32 fractions and ILBT at 10-24.3 Gy/2-3 fractions. The 5-year actuarial survival rate for all cases was 13%, and that for patients with tumors of 5 cm or less in length was 22.6%, while for patients with tumors longer than 5 cm the rate was 5% (p<0.005). In patients with tumors of 5 cm or less in length, the local control rate of those whose ILBT dose was 20 Gy or more was 83%, and for those with an ILBT dose of less than 20 Gy the control rate was 26.5% (p=0.014). In patients with tumors of 5 cm or less in length, the results of treatment with 60 Gy ERT and 20 Gy ILBT were promising and did not cause severe late complications.