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Biomedical subjects

M Sakura

Publications and source records attributed to M Sakura.

At least 19 recordsLinked to original sources
PubMed1995

[Determination of source position for four radiography systems with orthogonal projections in brachytherapy].

Four configurations of two X-ray tube positions are available for determining the position of a point using two orthogonal films. For each configuration, there are many formulas for calculating the coordinate of a point: the least squares methods with and without physical meaning, such as six sets of geometrical solutions, an approximation method with constant magnifications and so on. It is troublesome for a person in charge of treatment planning to directly derive a formula or select an appropriate formula from numerous ones for the four configurations. Thus, a method to easily apply the published formula for a configuration to the other three configurations is described in simulations and a clinical case using rotation matrixes of the right-handed coordinate system. Each diagonal element of the rotation matrixes is 1 or -1, and the other elements are 0.

Brachytherapy↗
PubMed1992

[Intraoperative radiotherapy for local recurrence of intrapelvic malignancies].

From 1986 to 1992, seventeen patients with recurrent intrapelvic malignancies have been treated with intraoperative radiotherapy (IOR) in Saitama Cancer Center. They were 8 males and 9 females. The age ranged 44 to 83 (mean:61.6). The primary organs involved were rectum in 7, urinary bladder in 5, uterine cervix in 3 and ovary in 2. Invasion of recurrent disease into bony pelvis was noted in all but one patient. A total of 27 IORs were done on 18 occasions for 17 patients. The mean radiation dose was 25.6 Gy (range: 12-30). The cones used were 4 to 7 (mean: 5.4) cm in diameter. Debulking surgery was performed in 13 patients just before IOR. Chemotherapy and/or external radiotherapy were done in addition to IOR in most of the cases. As of May 1992, 14 patients had died with a mean survival time of 10 months (range:0.5-29.8). IOR seems to be useful in controlling the intrapelvic recurrent disease and may warrant further investigation.

Adult↗
PubMed1991

Radiotherapy in inoperable stage I lung cancer.

In 38 cases of Stage I lung cancer, for which surgery was not indicated because of poor cardiopulmonary function or other reason, radical irradiation yielded excellent results. The five year survival rate was 42.1%, the 10-year survival rate 28.4% and the 15-year survival rate 17.1%. Postradiation complications which can be life-threatening, were acceptably low in incidence, and there was no radiation-related death. The results support the concept of radical irradiation being acceptable as a treatment modality for Stage I lung cancer if the patients concerned cannot have surgery because of poor cardiopulmonary function or some other reason.

Female↗
PubMed1991

Antibody response determined with antibody-dependent cell-mediated cytotoxicity (ADCC), neutralizing antibody, and varicella skin test in children with natural varicella and after varicella immunization.

Humoral and cellular immune responses were examined in 115 children with varicella and in 21 children who had been immunized with live varicella vaccine. Antibody determined with antibody-dependent cell-mediated cytotoxicity (ADCC) was detected earlier than neutralizing antibody (NT) in both groups. While humoral and cellular immunity were detected simultaneously in the natural varicella group, cellular immunity was detected earlier than humoral immunity in the immunized group. This suggests that ADCC, rather than NT, is involved in the early stages of recovery from varicella-zoster virus (VZV) infection.

Antibodies, Viral↗
PubMed1990

[Determination of the point position from two orthogonal X-ray photographs using least squares method and geometrical solutions].

Six sets of solutions for calculating the position of an interest point were obtained geometrically using four measured image coordinates on two X-ray photographs orthogonally projected. When the image coordinates had no error, all the solutions gave the same position without error. When an error occurred, the calculated positions differed from each other due to the propagation of error. Some solutions could not be used for this determination owing to a large propagation of error. Under conditions similar to those of clinical practice, the ratio of maximum error of position calculated by the six geometrical solutions to minimum error was about 426. The least squares method that we proposed gave results with less error. When one of the image coordinates could not be measured for some reason, the least squares method became automatically equivalent to one of the six geometrical solutions.

Image Processing, Computer-Assisted↗
PubMed1989

[Experiences in clinical application of an automated calculation system that determines the optimum intracavitary irradiation condition in the treatment of carcinomas of the uterine cervix].

An automated calculation system that determines the optimum intracavitary irradiation condition for treating carcinomas of the uterine cervix has been developed on the basis of the Manchester system. Using Vax-11 computer, the system has been successfully applied in treating 105 patients since December, 1984. Trouble with the system almost occurred during its use in the first year of its clinical application. One problem related to the method of calculation, which was quickly settled, and the other was mainly a human error. The calculation system has proven especially useful for radiotherapists.

Brachytherapy↗
PubMed1988

A method for calculating the optimum irradiation condition for intracavitary radiotherapy using quadratic programming.

A method of calculating optimum irradiation conditions for intracavitary radiotherapy using quadratic programming has been formulated and then modified for practical application. The allowable range of obtained dose, which is usually fixed in advance, is automatically computed to be as small as possible. The variance of the product of the activity and the irradiation time of the tandem source is also minimised to avoid the occurrence of cold and/or hot spots. Optimum irradiation conditions for conventional intracavitary radiotherapy of carcinoma of the uterine cervix were obtained on the basis of isodose curves passed through the points A of the Manchester system. Those for carcinoma of the other organs and special cases of carcinoma of the uterine cervix can be determined after consideration of the tumour state.

Brachytherapy↗
PubMed1988

[Intraoperative radiotherapy (IORT) in prostatic cancer].

Between February 1982 and February 1986, 30 patients with prostatic cancer received intraoperative radiotherapy (IORT). First 10 cases were treated by the transperineal approach, and after April 1983, 20 cases were done by the retropubic approach. We chose the retropubic approach, because it has advantages over the transperineal approach, which has a risk of rectal damage, lymph-adenectomy can not be performed and the patient can not sit down for a long time after the operation. In the IORT procedure for prostatic cancer by the retropubic approach, a longitudinal lower abdominal incision is made, and pushing down the bladder, the treatment cone is inserted to the prostate. We performed lymph-adenectomy at the same operation, if hard and large lymph-nodes were touched. Of 30 patients, 2 had stage B disease, 10 had stage C and 18 had stage D disease. The overall 5-year survival rate (Kaplan-Meier method) after IORT was 42.6% where as that the 31 cases seen (stage C: 6 cases, stage D: 25 cases) since the Center was founded (October 1975) until the introduction of IORT was 3.2%. Although no definite conclusion can be drawn because all cases received multidisciplinary therapy, IORT appears useful for the treatment of carcinoma of the prostate.

Adenocarcinoma↗
PubMed1987

[Intra-operative radiotherapy with excision of urinary bladder carcinoma].

From June, 1979 through Oct., 1986 forty patients (32 males and 8 females) with cancer of the urinary bladder have been treated by intraoperative radiotherapy (IORT) after surgical excision of their tumors. The five-year survival rate, by the Kaplan-Meier Method, was 100% in Grade I patients (n = 6), 56% in Grade II (n = 19), 49% in Grade III and 58% in all patients, respectively. Similarly, it was 62% for 33 patients in stages T1 and T2 of the disease and 42% for 7 patients graded T3 and T4 of only three patients out of eleven lost in this series, their deaths caused by urinary bladder cancer. IORT with a surgical excision of their bladder tumor provided excellent results in the control of recurrence.

Adult↗
PubMed1985

Synergic effect of cisplatin, Adriamycin, and cyclophosphamide combination chemotherapy and radiotherapy in non-small cell lung cancer.

61 patients with inoperable non-small cell lung cancer were treated by combination chemotherapy with cisplatin, Adriamycin and cyclophosphamide. 23 patients received radiotherapy in addition to the chemotherapy. 49 out of 55 adequately treated patients were evaluable for tumor response. Of 29 patients who received chemotherapy alone, 6 (21%) achieved partial responses. Of 20 patients who received combined chemotherapy and radiotherapy, 16 (80%) achieved complete or partial responses. The median survival time was 18 months for 22 patients treated with combined therapies.

Adult↗
PubMed1982

Computed tomography in the evaluation and treatment of endometrial carcinoma.

Since patients with endometrial carcinoma tend to be elderly, diabetic and hypertensive, individualization of treatment is very important. The therapy for each patient with endometrial carcinoma should be individualized and determined by the stage and factors predisposing to extrauterine spread of the tumor. Such risk factors include the grade of the tumor and depth of myometrial invasion. Unfortunately, staging based on pelvic examination is inaccurate in endometrial carcinoma and the depth of myometrial invasion cannot be assessed preoperatively. In order to assess its uses in the staging and treatment planning of endometrial cancer, CT was performed in 28 previously untreated patients with endometrial cancer. Twenty patients subsequently underwent surgery and the CT findings were correlated with the surgical and pathologic findings. CT proved to be useful in determining the depth of myometrial invasion and whether cervical involvement is present or not. Such information provided by CT helps to plan treatment more adequately and accurately for the individual patients.

Adult↗