Biomedical subjects

Yuzo Kikuchi

Publications and source records attributed to Yuzo Kikuchi.

7 recordsLinked to original sources

PubMed2006

Randomized phase II study of immunomodulator Z-100 in patients with stage IIIB cervical cancer with radiation therapy.

OBJECTIVE: To find the optimal dose of immunomodulator Z-100 in patients with stage IIIB squamous cell carcinoma of the cervix in combination with radiation therapy. METHODS: The patients were randomly assigned to the dosage levels of 2, 20 or 40 mug of Z-100. Z-100 was subcutaneously injected twice a week during radiotherapy and once in two weeks during the maintenance period. The response rate after radiotherapy was evaluated, and the optimal clinical dosage was then determined. Safety of Z-100 was evaluated during the radiation therapy and maintenance therapy. Survival was also evaluated. RESULTS: A total of 116 patients were entered. The adverse reactions were not dose-dependent and no serious toxicities were observed. The response rates were 72.2% (26/36) in the 2 microg group, 84.6% (33/39) in the 20 microg group and 94.3% (33/35) in the 40 microg group (P = 0.006). However, the survival was not significantly different. CONCLUSIONS: The optimal dose of Z-100 was determined to be 40 mug in combination with radiation therapy for stage IIIB cervical cancer. However, impact of Z-100 on survival must be determined by the placebo controlled randomized trial, because survival benefit was not observed in this small population study.

Adolescent↗

PubMed2006

Elective neck irradiation on ipsilateral side in patients with early tongue cancer for high-risk group with late cervical lymph node metastasis.

A prospective study was performed to assess the efficacy of elective neck irradiation (ENI) on the ipsilateral side in patients with early tongue cancer among a high-risk group with late cervical lymph node metastasis. Patients in the high-risk group had T2-tumors, excluding superficials or T1-tumors > or =19 mm in maximal diameter with invasion or ulcer. Between February 1989 and October 1997, 70 patients with tongue cancer of Stages I and II were enrolled in the present study (ENI group: 31, non-ENI group: 39). In a combination therapy of external beam irradiation and brachytherapy, the standard dose of interstitial brachytherapy for primary tumors was approximately 60 Gy. Irradiation was initiated with a 9-MeV electron beam at a dose of 50 Gy on the ipsilateral side of the neck only when the day of brachytherapy approached. Three patients (9.7%) in the ENI group had neck lymph node metastasis as did 5 (12.8%) in the non-ENI group (p= 0.684). In patients with ulceration, the incidence of subsequent lymph node metastasis was significantly higher (p=0.029). Neck lymph node metastasis occurred in 2 (16.7%) of 12 patients with ulcers in the ENI group and in 2 (66.7%) of 3 with ulcers in the non-ENI group. Although we could not demonstrate the significant efficacy of ENI in the high-risk group in this study, ENI decreased the neck lymph node metastasis. In addition, our results suggested that ENI particularly inhibits cervical lymph node metastasis in tongue tumor patients with ulcers.

Adult↗

PubMed2005

Development of a semi-automated superimposing image verification system using a template matching algorithm in radiotherapy.

To analyze shifts in the isocenter of images, we developed a semi-automated superimposing image-verification system that is capable of automatically quantifying shifts in the isocenter through image analysis with a personal computer (PC). The accuracy and usefulness of this software were examined through a comparison of nine portal images with a simulation image and by comparing nine portal images with a DRR image, using a human pelvic phantom. The difference between the known magnitude of shift and the magnitude of shift detected with this method was analyzed as detection error. When the portal images were compared with the simulation image, the 95% confidence interval (95% CI) of detection errors (mean+/-SD) was 0.57+/-0.36 mm (95% CI: 0.49-0.65 mm). When the portal images were compared with the DRR image, the respective figures were 0.68+/-0.38 mm (95% CI: 0.59-0.77 mm). No significant difference was noted between these two categories of comparison (N.S). The absolute detection error (mean+/-SD) in all directions was 0.34+/-0.34 mm for the comparison of portal images with the simulation image and 0.41+/-0.36 mm for the comparison of portal images with the DRR image. This system seems to be appropriate for verification of the treatment field by improving the accuracy of radiotherapy as a method of computer-assisted landmark recognition during image comparison.

Algorithms↗

PubMed2005

Development of computerized patient setup verification and correction system in radiotherapy.

Visual comparison of a reference image with a verification image is commonly used for setup verification in external beam radiation therapy. However, it sometimes lacks reproducibility and provides insufficient quantitative evidence. The present study was performed to develop computerized methods for determining landmarks to verify a portal image with digital reconstruction radiograph (DRR), and to investigate the clinical effectiveness of our method. Our computer algorithm consisted of three main procedures--preprocessing, determination of landmarks, and verification--none of which required manual operation. Finally, our system indicated the distance for setup correction. We evaluated the accuracy of our system using pelvic phantom images, and the maximum magnitude of error was shown to be 1.12 (n=9). The results indicated that the error range of our system was sufficiently small to examine patient positioning error, which should be less than 5 mm, as described in AAPM report TG40. Our system will aid operators in positioning patients accurately for external radiation therapy.

Algorithms↗

PubMed2005

Phase III double-blind randomized trial of radiation therapy for stage IIIb cervical cancer in combination with low- or high-dose Z-100: treatment with immunomodulator, more is not better.

BACKGROUND: To evaluate the efficacy of low or high-dose immunomodulator, Z-100, in combination with radiotherapy for cervical cancer. METHODS: Between 1995 and 1999, 221 patients with stage IIIb squamous cell carcinoma of the cervix were randomly assigned to treatment with Z-100 either at 0.2 microg or 40 microg in a double-blind manner in combination with radiotherapy. RESULTS: The 5-year survival of patients with high-dose and low-dose Z-100 was 41.5% (95% CI: 31.7-51.3%) and 58.2% (95% CI: 48.7-67.7%), respectively, showing a 30% reduction in the death rate (hazard ratio: 0.670 [95% CI: 0.458-0.980], P = 0.039). Survival of high-dose group was equivalent to the 4-year survival of the radiotherapy plus hydroxyurea arm (49.7%) of GOG120 study, and that of low-dose group was similar to the survival of the cisplatin-based chemoradiation arm. The progression-free survival was also significantly improved in favor of low-dose group (hazard ratio: 0.667 [95% CI: 0.447-0.997], P = 0.048). The survival of low-dose group was similar to the survival of the cisplatin-based chemoradiation arms of the GOG120 study. CONCLUSIONS: Unexpectedly, the survival of patients with advanced cervical cancer treated by lower dose of Z-100 in combination with radiotherapy was significantly better than those treated with higher dose Z-100, which was equivalent to the survival with radiotherapy alone. The hypothesis that lower dose of Z-100 enhances the efficacy of radiation therapy is now being tested by placebo-controlled randomized trial.

Adjuvants, Immunologic↗

PubMed2004

[Study of optimal imaging parameters for digitally reconstructed radiographs (DRR) in radiotherapy treatment planning using single-slice helical CT].

In recent years, by making digitally reconstructed radiographs (DRR) from helical CT images in the position check of an irradiation field, the verification performed by DRR, lineacgraphy (LG), or an electronic portal imaging device (EPID) has become possible. We examined the optimal parameters of single-slice helical scanning in DRR image construction and the usefulness of DRR replaced with the simulation film. We performed a section sensitivity profile at the Z-axis (SSPz) as evaluation of a physical characteristic of helical CT equipment and the form of image of DRR, fixed quantity evaluation of imaging distortion, and visual verification of images. It was determined that DRR was influenced by the partial volume effect depending on slice thickness and pitch, such that this influence occurred when slice thickness and pitch were large. Between a simulation film and DRR reconstructed using imaging parameters with a slice thickness of 3 mm, pitch of 1.0, and reconstruction slice thickness of 3 mm, coincidence was not complete. However, the distortion of DRR was small and the difference was not statistically; thus it was considered to be useful. In conclusion, we consider that DRR reconstructed using the parameters of single-slice helical scanning is useful for clinical evaluation in radiotherapy planning.

Humans↗

PubMed2004

[Online-conference using JGN.].

Telemedicine and online conference systems have some benefits so that equalizing medical level, improving efficiency of medical care and improving service for patients. It is possible to give advice and to support its medical projects stationed in other facility and to provide the same quality treatments for patients. In this paper, we set up an experimental network system to teleconference using JGN (Japan Gigabit Network) and tried to discussion alternatively for case study between Kanazawa university and Fukui red cross hospital, 70 km away. The JGN used in this study is an ultra-high-speed network for the purpose of research and development. Kanazawa university, and Fukui red cross hospital are connected by a 10 Mbps communication link of the JGN. We tried online conference on the experimental network using video chat system. In result, using video chat system, the average transmission rate of MRI images (256 X 256pixel, 16bit) is 0.2 s/frame.

Biomedical Research↗