Biomedical subjects

Atsunori Yorozu

Publications and source records attributed to Atsunori Yorozu.

12 recordsLinked to original sources

PubMed2006

Predictive factors of acute urinary retention requiring catheterization following 125I prostate brachytherapy.

OBJECTIVE: To analyze predictive factors of acute urinary retention requiring catheterization after (125)I prostate brachytherapy. METHODS: A group of 227 consecutive patients with localized prostate cancer were treated with (125)I prostate brachytherapy between September 2003 and December 2004. The clinical, treatment-related and dosimetric factors were evaluated for the need for catheterization owing to urinary retention. RESULTS: Twelve patients (5.3%) required catheterization. The median time to onset was 2 days after implantation (range 1-7 days). Univariate analysis demonstrated that pre-implant ultrasound prostate volume, number of seeds, number of needles and neoadjuvant hormonal manipulation were predictive for catheterization. In multivariate analysis, the number of needles and neoadjuvant hormonal manipulation were significant independent predictive factors for catheterization (P = 0.002 and 0.025, respectively). The risk of catheterization in the cluster in which the number of needles was >24 was 4.07 times as high as that in the cluster in which the number of needles was < or =24 [11.3% versus 3.0%, P = 0.020; 95% confidence interval (CI) 1.24-13.36], and the risk in the hormonally manipulated patients was 7.05 times as high as that in the hormone-naïve patients (7.7% versus 1.2%, P = 0.034; 95% CI 0.89-55.64). CONCLUSION: Our data suggest that the number of needles and hormonal manipulation might be the strongest predictors for catheterization.

Aged↗

PubMed2006

Multi-institutional analysis of early squamous cell carcinoma of the hypopharynx treated with radical radiotherapy.

PURPOSE: To analyze the outcomes of patients with early hypopharyngeal cancer treated with radical radiotherapy (RT). METHODS AND MATERIALS: Ten institutions combined the data from 115 patients with Stage I-II hypopharyngeal squamous cell carcinoma treated with definitive RT between 1990 and 2001. The median patient age was 67 years; 99 patients were men and 16 were women. Of the 115 patients, 39 had Stage I and 76 had Stage II disease. Conventional fractionation was used in 98 patients and twice-daily RT in 17 patients; chemotherapy was combined with RT in 57 patients. The median follow-up period was 47 months. RESULTS: The overall and disease-specific 5-year survival rate for 95 patients without synchronous malignancies was 66.0% and 77.4%, respectively. The 5-year disease-specific survival rate by T stage was 95.8% for patients with T1 disease and 70.1% for patients with T2 disease (p=0.02). Of the 115 patients, local control with laryngeal voice preservation was achieved in 34 of 39 patients with T1 lesions, including 7 patients successfully salvaged, and in 56 of 76 patients with T2 lesions. Sixty-five patients (56.5%) had synchronous or metachronous cancers. Of the 115 patients, 19 died of hypopharyngeal cancer, 10 died of second primary cancers, and 14 died of other causes during the study and follow-up periods. CONCLUSIONS: Patients with early hypopharyngeal cancer tended to have a good prognosis after RT. However, second malignancies had an adverse effect on the overall outcomes of patients with early hypopharyngeal cancer.

Adult↗

PubMed2006

Serial changes of international prostate symptom score following I-125 prostate brachytherapy.

BACKGROUND: This study was conducted to assess serial changes in the International Prostate Symptom Score (IPSS) within the first 12 months after iodine-125 (I-125) prostate brachytherapy. METHODS: Between September 2003 and June 2004, a group of 103 patients with localized prostate cancer was treated with I-125 prostate brachytherapy, either alone (monotherapy; 60 patients) or in combination with external-beam radiotherapy (combined therapy; 43 patients). The IPSS was obtained at preimplant, and at 1, 6, and 12 months after treatment. The minimum IPSS follow-up for this study was 12 months. Dosimetry was based on computed tomography (CT) scan 1 month postimplant. Clinical, treatment-related, and dosimetric factors were assessed for correlations with the maximum IPSS increase (the peak IPSS minus the preimplant IPSS). RESULTS: The median preimplant IPSS was 7.0, with a median peak of 16 at 1 month. The IPSS returned to baseline in 42 patients (40.8%) and it returned to within 3 points of the baseline in 64 (62.1%) at 1-year follow-up. On univariate and multivariate analyses, the maximum IPSS increase was best predicted by lower preimplant IPSS, in both the monotherapy and combined therapy groups. CONCLUSION: In our series, IPSS after prostate brachytherapy peaked at 1 month and gradually returned to approximately baseline at 12 months.

Aged↗

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↗

PubMed2006

[Brachytherapy for prostate cancer].

This review article aims to overview modern prostate brachytherapy in Japan. Permanent transperineal prostate brachytherapy with I-125 started in September, 2003 in Japan. Brachytherapy has several advantages: the dose is adapted precisely to the tumor shape and size, and the long-lived isotope gives a higher tumor dose with less damage to normal tissue; less-time consuming for patients and staff: long-term results comparable to surgery or external beam series in the USA; and quality of life after brachytherapy also appealing. These advantages have brought about increasing use in Japan as well. Patients with a high probability of organ-confined disease and a low-risk group are appropriately treated with brachytherapy. Brachytherapy candidates with a significant risk of extraprostatic extension should be treated with supplemental external beam radiation therapy. High-dose-rate (HDR) brachytherapy with Ir-192 has preceded seed implants in Japan. HDR has some theoretical advantages. Long-term results of brachytherapy in the USA are comparable with surgery or external beam irradiation so far. We should develop more sophisticated brachytherapy techniques in Japan.

Brachytherapy↗

PubMed2005

The value of drip infusion cholangiography using multidetector-row helical CT in patients with choledocholithiasis.

The purposes of this study were to investigate the feasibility of drip infusion cholangiography computed tomography (CTCh) for choledocholithiasis and to compare the detection of the stone on CTCh with that of MR cholangiopancreatography (MRCP). CTCh examinations were performed after infusion of intravenous biliary contrast material (iotroxic acid meglumine, 100 ml) for patients with suspected biliary diseases and were reconstructed to maximum intensity projection (MIP) and multiplanar reformation (MPR). Of 432 patients who underwent CTCh, we identified 15 who underwent surgery or cholangioscopic removal for choledocholithiasis and 32 patients who underwent cholecystectomy due to cholecystolithiasis. Their MRCP images were compared with the CTCh images. The sensitivity and specificity of CTCh for detecting choledochal stones were 87% and 96% whereas those of MRCP were 80% and 88%. The sensitivity and specificity of CTCh for detecting gallstones were 78% and 100% whereas those of MRCP were 94% and 88%. CTCh allowed high sensitivity and specificity for detecting choledochal stones but diminished the detection for cholecystolithiasis compared with MRCP.

Adult↗

PubMed2005

Acute urinary morbidity following I-125 prostate brachytherapy.

BACKGROUND: In Japan, iodine-125 (I-125) prostate brachytherapy has been legally approved since July 2003, and this method is becoming more popular. The purpose of the present study was to assess acute urinary morbidity within the first 6 months after I-125 prostate brachytherapy. METHODS: A group of 130 consecutive patients with localized prostate cancer was treated with I-125 prostate brachytherapy between September 2003 and June 2004,either alone (monotherapy; 66 patients) or in combination with external-beam radiotherapy (combined therapy; 64 patients). Urinary morbidity was evaluated using the National Cancer Institute - Common Terminology Criteria for Adverse Events, version 3.0. RESULTS: During the follow-up, 111 patients (85.4%) developed some degree of urinary symptoms such as frequency, retention, dysuria, incontinence, or hematuria. Urinary frequency (73.1%) and retention (66.9%) were the most common, and showed no significant differences between the monotherapy group and combined therapy group (P = 0.352 and P = 0.630, respectively). Six patients (4.6%) required catheterization for urinary obstruction; the median time to onset was 1.5 days (range, 1-192 days). Five of these 6 patients received monotherapy and the other received combined therapy. CONCLUSION: Manifestations of acute urinary morbidity, especially frequency and retention, are relatively common but acceptable events after I-125 prostate brachytherapy.

Aged↗

PubMed2005

[Brachytherapy for prostate carcinoma].

This review aims to provide an overview of prostate brachytherapy and disseminate consensus guidelines formed by the American Brachytherapy Society. In Japan, permanent transperineal prostate brachytherapy with I-125 started in September 2003. Patients with high probability of organ-confined disease are appropriately treated with brachytherapy. Brachytherapy candidates with a significant risk of extraprostatic extension should be treated with supplemental external beam radiation therapy. The recommended prescription doses for monotherapy are 145 Gy. The corresponding boost doses after 40-50 Gy of external beam are 100-110 Gy. Dosimetric planning of the implant should be carried out for all patients before seed insertion. Post-implant dosimetry and evaluation must be performed on all patients. A dose-volume histogram of the prostate should be performed. The dose that covers 90% of the prostate volume, the percentage of prostate volume receiving 100%, 150%, and 200% of the prescribed dose, and the rectal dose and urethral dose should be reported. ABS recommends standardization of the reporting of brachytherapy-related prostate morbidity, including urinary, rectal, and sexual function. These morbidities should be correlated with the doses to normal tissues. High-dose-rate (HDR) brachytherapy with Ir- 192 has preceded seed implants in Japan. HDR has some theoretical advantages. We should develop techniques of both types of brachytherapy in Japan.

Brachytherapy↗

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

[Seed loss through the urinary tract and retrieval after prostate seed implant].

This study describes our experience with seed loss and retrieval through the urinary tract following seed implants for prostate cancer, and offers Japanese guidelines for safety and management. Two hundred consecutive patients were analyzed. All patients were preplanned with a modified peripheral loading technique and implanted with a Mick applicator under ultrasound guidance. All patients were instructed to return excreted seeds, if any, to our center. Seed loss occurred in 6% of patients and 0.13% of seeds. Seed loss tended to occur in the early period through either urine or ejaculation.

Brachytherapy↗

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↗

PubMed2003

[Radiotherapy for metastatic bone tumor].

There is good evidence that radiotherapy is effective in relieving bone pain due to metastatic tumor. For localized bone pain, external beam treatment will be successful in reducing pain in some 80% of patients. Many prospected randomized trials show single fractions as effective as more prolonged regimens both in terms of incidence and duration of pain relief. For scattered painful metastases, wide-field hemibody irradiation or the systemic administration of radioisotopes is effective.

Bone Neoplasms↗