[en] Radiation esophagitis sometimes interrupts the radiation therapy due to swallowing pain and dysplasia. We experienced three cases of radiation-induced esophagitis controlled with proton pump inhibitor (PPI). These cases suggested etiologic relationship radiation esophagitis and gastroesophageal reflux disease (GERD). We should consider PPI as treatment option for radiation esophagitis. (author)

[en] The purpose of this study is to evaluate the pain relief obtained by radiation therapy for painful bone metastases, with a special regard to general condition. Between June 1998 and May 2000, 54 patients with 86 painful bone metastases were treated with radiation therapy whose effects could be evaluated for a minimum period of 6 months or until death. Treatment schedules were 3 Gy/fraction/day (30-36 Gy/10-12 fractions) in usual cases (61 lesions), 4-8 Gy/fraction/day (8-20 Gy/1-5 fractions) in patients with a poor general condition (9 lesions), and 2 Gy/fraction/day (40-50 Gy/20-25 fractions) in lesions with a large radiation field (16 lesions). Complete pain relief without medication (CR) was achieved in 40 lesions (47%). Significant predictors for CR were primary site (p=0.0003), performance status (p=0.0060), pain score (p=00190), narcotic score (p<0.0001), and prognosis (p<0.0001), but no difference was found in CR among treatment schedules. No evidence of severe radiation-induced complication was seen. General condition (performance status and prognosis) has an influence on pain relief. Compared with the daily 2 Gy protocol, the daily 3 Gy protocol has the advantage of shorter treatment time. The treatment schedule should be assessed in patients with a large radiation field and/or poor general condition. Especially for the patients with poor general condition, combined pain medication should be considered. (author)

[en] In spite of the control of the water chemistry of SG secondary feed-water in PWR-SG, SG TSP BEC holes, which are the flow path of secondary water, are often clogged. In the past, the trending of BEC hole blockage rate has conducted by evaluating ECT original signals and visual inspections. However, the ECT original signals of deposits are diversified, it becomes difficult to analyze them with the existing evaluation method using the ECT original signals. In this regard, we have developed the secondary side visual inspection system, which enables the high-accuracy evaluation of BEC hole blockage rate, and new ECT signal evaluation method. (author)

[en] Purpose: To evaluate the quality of digitized radiation-planning images at different resolution and to determine the optimal resolution for digital storage. Methods and Materials: Twenty-five planning films were scanned and digitized using a film scanner at a resolution of 72 dots per inch (dpi) with 8-bit depth. The resolution of scanned images was reduced to 48, 36, 24, and 18 dpi using computer software. Image qualities of these five images (72, 48, 36, 24, and 18 dpi) were evaluated and given scores (4 = excellent; 3 = good; 2 = fair; and 1 = poor) by three radiation oncologists. An image data compression algorithm by the Joint Photographic Experts Group (JPEG) (not reversible and some information will be lost) was also evaluated. Results: The scores of digitized images with 72, 48, 36, 24, and 17 dpi resolution were 3.8 ± 0.3, 3.5 ± 0.3, 3.3 ± 0.5, 2.7 ± 0.5, and 1.6 ± 0.3, respectively. The quality of 36-dpi images were definitely worse compared to 72-dpi images, but were good enough as planning films. Digitized planning images with 72- and 36-dpi resolution requires about 800 and 200 KBytes, respectively. The JPEG compression algorithm produces little degradation in 36-dpi images at compression ratios of 5:1. Conclusion: The quality of digitized images with 36-dpi resolution was good enough as radiation-planning images and required 200 KBytes/image

[en] A retrospective analysis was performed to investigate the radioprotective effects of azelastine against radiation dermatitis for patients with head and neck cancers. The effects of azelastine were studied in 19 patients with laryngeal cancers treated by irradiation. As controls, 29 patients with laryngeal cancers treated by irradiation without the administration of azelastine were studied. All patients were irradiated using 3 MV linac X-rays. Azelastine was administered orally twice a day. Moist desquamation was observed in four of 29 control patients whereas no such moist desquamation developed after the administration of azelastine. Two cases of moist desquamation that developed before the administration of azelastine regressed during irradiation in patients placed on azelastine. Radiotherapy was completed without interruption in all patients treated with azelastine. No severe side effects were observed. Azelastine, administered orally, was a safe drug and has the potential of improving skin tolerance in irradiation therapy. (author)

[en] Definitive radiation therapy (RT) in 52 patients with the inoperable esophageal cancer was retrospectively evaluated with regard to irradiation field and combined chemotherapy. Treatments were divided into RT alone (n=19), RT with low-dose cisplatin (CDDP) (n=25), and RT with intermediate-dose CDDP group (n=8). Although initial recurrences were commonly observed in the primary sites, there were out-field lymph node failures in three patients with stage II disease, three with stage III, and one with stage IVa. Two-years cause specific survival rates of stage 0/I, II, III, and IVa were 100%, 64%, 14%, and 18% respectively. In 42 patients with II-IVa stages, the significant prognostic factors were performance status and clinical stage. Combined chemotherapy did not contribute significant improvement of survival rates for the inoperable esophageal cancer. Prophylactic irradiation for the lymph node metastases should be considered for patients with stage II and III diseases. (author)

[en] To improve the local control of T2-stage glottic carcinomas, we performed concomitant chemoradiation therapy with UFT (uracil and tegafur) and low dose cisplatin (CDDP). The predictive value of MR findings was also evaluated. Thirty six patients with T2N0-stage glottic carcinomas were included in this study. Tumors adjacent to the thyroid cartilage on MRI were classified as adjacent'', and undetectable tumors or tumors separate from the cartilage were classified as ''intact''. Radiation therapy with 64 Gy/32 fractions was delivered by 4 MV linear accelerator. Intravenous infusion of CDDP (4 mg/m²) and oral administration of UFT (450 mg/body) were continued concomitantly from day one of irradiation for four weeks. Kaplan-Meier methods were used to estimate the time to local recurrence distribution. Differences were determined using log-rank tests for univariate analysis. No severe acute and late adverse effects (grade 3 or more) were observed. Two-year local control rate with chemoradiation therapy was 82%. According to MR findings, local control rates were 95% for intact lesions (n=20) and 68% for adjacent lesions (n=16) (p=0.0249). Concomitant chemoradiation therapy with UFT and low dose CDDP was considered to be effective for T2-stage glottic carcinomas. However, the results were not enough for tumors adjacent to the thyroid cartilage on MRI. (author)

[en] Transmitted neutron spectra were measured for Fe slabs of 9.6 and 19.2 cm thick and 1 and 2 canned Na slabs of 15 cm thick (thickness of the stainless-steel can was 3 mm). The neutrons from the core of fast neutron source reactor ''YAYOI'' of the University of Tokyo were collimated and incident to the slabs. The intensity and the profile of the incident neutron beam was determined by a preliminary experiment. The transmitted neutrons were measured on the collimated axis and polar angle of 30⁰ and 45⁰ to the axis. Point-to-point Monte Carlo calculation was carried out for the purpose of comparison with experimental data. The results of the calculation showed good agreement to the experimental spectra. (author)

[en] Eddy Current Testing (ECT) technique is applied to PWR Steam Generator (SG) tubes during refueling outage inspection. Bobbin type probe is generally used for the inspection, but it cannot provide sufficient detectability for very tight cracks. NEL, R/D Tech (Canada) and AECL (Canada) jointly developed new ECT probe. The probe is transmit and receive type array probe. It has axial defect detection mode and circumferential defect detection mode. Its inspection speed is as fast as conventional bobbin probe, and detectability performance is same or better than performance of rotating pancake coil (RPC) probe, which is used for detailed inspection. As a tester of the new probe, we have developed new ECT tester TC7700. It is able to transmit composite wave from the 4 independent oscillators (simultaneous excitation system) compared with the conventional inspection system. As regarding for field inspection system, we have integrated Zetec (USA) probe positioner, probe pusher and R/D Tech TC7700. We are also developing new analysis software. The software has automated data screening function, which can deal with large amount of data compared with conventional bobbin probe. We plan to perform a large-scale field trial using the probe and new system in near future. (author)

[en] Purpose: The purpose of this study was to evaluate the incidence of radiation otomastoiditis, on using T₂-weighted magnetic resonance (MR) imaging, in relation to radiation fields, doses, intervals, and clinical symptoms after radiotherapy that included the temporal bone in the fields. Methods and Materials: We performed follow-up MR examinations at various intervals after radiotherapy including the temporal bones for 270 ears of 114 patients with various diseases of the head and neck and intracranial regions. The middle ear and mastoid air cells on T₂-weighted images were scored as follows; showing no high signal intensity, a local high signal intensity area, or a high signal intensity area occupying the entire middle ear and all mastoid air cells. The radiation fields as depicted on the lateral simulator films classed as anterior to the clival line, posterior to the clival line, or both. Results: The incidence of radiation otomastoiditis depicted on T₂-weighted MR images increased in the patients who had received irradiation doses of 50 Gy or more. In the patients with doses of less than 50 Gy, the incidence was 18% within 6 months following radiotherapy, 13% at between 6 and 12 months, and 8% after 12 months, whereas it was more than 50% at any period after radiotherapy in the patients with 50 Gy or more. The incidence of radiation otomastoiditis was quite high in the patients whose radiation fields included region both anterior and posterior to the clival line. Conclusion: The incidence of radiation otomastoiditis as demonstrated on T₂-weighted MR images is increased at irradiation doses of 50 Gy or more. To reduce the incidence of severe radiation otomastoiditis, the irradiation fields of the temporal bone when the dose is 50 Gy or more should be limited to as small as possible. The clival line is considered to be a good landmark in reducing the irradiation field when doses of 60-70 Gy are delivered in curative radiotherapy