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Takushi Dokiya

Publications and source records attributed to Takushi Dokiya.

4 recordsLinked to original sources
PubMed2006

Three-year results of treatment for prostate cancer with low-dose rate temporary iridium-192 brachytherapy.

AIM: To report the 3-year treatment results of definitive irradiation by using a temporary interstitial implant with low-dose rate iridium-192 with or without external beam radiotherapy in the treatment of localized prostate cancer. METHODS: One-hundred and forty-three patients with pathologically defined prostate carcinoma were treated from December 1997 to April 2003. The patients were classified into a low-risk group (T2, PSA 20 ng/mL or Gleason score>or=7). Low-risk patients were treated with low-dose-rate iridium brachytherapy as monotherapy delivering 70 Gy. High-risk patients were treated with the combination of brachytherapy and external beam radiotherapy delivering 40 Gy and 36 Gy, respectively. Kaplan-Meier estimates of prostate-specific antigen (PSA) progression-free survival rate were analysed. To assess the treatment quality in different periods, PSA progression-free survival rates in late era (year of 2000 and after) and in early era (before 2000) were compared. Morbidity was graded according to the Radiation Therapy Oncology Group grading scale. RESULTS: One hundred and nineteen patients were analysed, of which 86 patients underwent monotherapy with an iridium implant, and 33 were treated with the combination of external beam radiotherapy. Twenty-four patients were excluded from the analysis because the classification of risk group did not suit the criteria. The total (n=119) PSA progression-free survival rate at 3 years was 80.3%. The PSA progression-free survival rate at 3 years for the monotherapy group (n=86) and the combination therapy group (n=33) were 78.2% and 86.9%, respectively. There were 23 patients who were followed for more than 36 to 63 months, and, during this period, only 1 patient who received the monotherapy was diagnosed as PSA failure at 50 months. The 3-year PSA progression-free survival rate of monotherapy in late era was significantly higher than that in early era; however, no significant difference was seen in the combination treatment. Morbidity for the combination treatment was low; however, for the monotherapy, three patients developed severe rectal ulcers, and colostomies were made. CONCLUSIONS: The PSA progression-free survival rate after low-dose rate iridium-192 brachytherapy with or without external beam radiotherapy can be satisfactory and longer follow up is necessary to compare the efficacy of other treatments.

Adenocarcinoma↗
PubMed2005

[Pulmonary embolization of permanently implanted radioactive iodine-125 seeds for carcinoma of the prostate].

One year has passed since we started brachytherapy with radioactive iodine-125 seeds for carcinoma of the prostate. During the follow-up of patients, we have relatively frequently found migrated seeds in the lungs. Migrated seeds are reported to reach mainly the pulmonary artery and cause embolization without clinical symptoms. We counted the embolized seeds and determined the proportion of migrating seeds on chest X-ray exam. We found 47 cases of pulmonary embolization in our initial 100 cases. Less than half of the embolization were found in the chest X-ray exam performed on the next day after the implantation. We found more migrated seeds in the lower lung fields than in the upper and middle lung fields. Pulmonary embolization of implanted iodine-125 seeds is not unusual, and cases of prostate brachytherapy are likely to increase in Japan. We will have increased opportunities to observe chest X-ray films with migrated seeds in the future.

Aged↗
PubMed2005

[Experience of brachytherapy using I-125 seed permanent implants for localized prostate cancer].

PURPOSE: We report here our experience of brachytherapy using I-125 seeds for localized prostate cancer in 100 patients. MATERIALS AND METHODS: We carried out brachytherapy with I-125 seed permanent implants in 100 patients with localized prostate cancer between September 2003 and October 2004. Preplanning dosimetry was done using transrectal ultrasonic images obtained three or four weeks prior to treatment. Using transrectal ultrasound, we inserted I-125 seeds in the prostate through needles according to the preplanning diagram. We then examined the results on prostate CT performed one month later. RESULTS: It was necessary to describe transrectal ultrasonic image such as preplanning. There were several cases in which the source arrangement of the schedule was corrected immediately before the operation. In the examination after one month, the numerical value at the start of treatment initially was not satisfactory, but we eventually obtained a result that could to be evaluated. CONCLUSION: We carried out permanent implant brachytherapy for localized prostate cancer using I-125 seeds and reported our experience.

Aged↗