Biomedical subjects

Takuhito Tada

Publications and source records attributed to Takuhito Tada.

11 recordsLinked to original sources

PubMed2006

Phase II study of etoposide and cisplatin with concurrent twice-daily thoracic radiotherapy followed by irinotecan and cisplatin in patients with limited-disease small-cell lung cancer: West Japan Thoracic Oncology Group 9902.

PURPOSE: We initially conducted a randomized phase II study to compare irinotecan and cisplatin (IP) versus irinotecan, cisplatin, and etoposide (IPE) after etoposide and cisplatin (EP) with concurrent twice-daily thoracic radiotherapy (TRT) in limited-disease small-cell lung cancer (LD-SCLC). We amended the protocol to evaluate IP after EP with concurrent twice-daily TRT in a single-arm phase II study because of an unacceptable toxicity in IPE. PATIENTS AND METHODS: Previously untreated patients with LD-SCLC were treated intravenously with etoposide 100 mg/m2 on days 1 through 3 and cisplatin 80 mg/m2 on day 1 with concurrent twice-daily TRT (1.5 Gy per fraction, a total dose of 45 Gy) beginning on day 2 followed by three cycles of irinotecan 60 mg/m2 on days 1, 8, and 15 and cisplatin 60 mg/m2 on day 1 of a 4-week cycle. RESULTS: Of the 51 patients enrolled, 49 patients were assessable for response and toxicity. The overall response rate and complete response rate were 88% and 41%, respectively. The median survival time for all patients was 23 months. The 2-year and 3-year survival rates were 49% and 29.7%, respectively. The median progression-free survival was 11.8 months. The major toxicities observed were neutropenia (grade 4, 84%), febrile neutropenia (grade 3, 31%), infection (grade 3 to 4, 33%), electrolytes imbalance (grade 3 to 4, 20%), and diarrhea (grade 3 to 4, 14%). CONCLUSION: EP with concurrent twice-daily TRT followed by the consolidation of IP appears to be an active regimen which deserves further phase III testing in patients with LD-SCLC.

Aged↗

PubMed2006

Relapse of stage I small cell lung cancer ten or more years after the start of treatment.

Most patients with small cell lung cancer (SCLC) usually show relapse within 1 or 2 years. Relapses after a 5-year disease-free survival are extremely rare. This report describes two patients with stage I SCLC in whom the disease recurred 10 or more years after the start of initial therapy. Because the recurrence of SCLC was noted in the mediastinal lymph nodes of the same side, we concluded that the patients had a late relapse of SCLC rather than a metachronous lung cancer.

Aged↗

PubMed2006

Usefulness of FDG-microPET for early evaluation of therapeutic effects on VX2 rabbit carcinoma.

PURPOSE: The aim of this study was to determine the potential use of high-resolution FDG-microPET for predicting the primary effects of radiotherapy and/or hyperthermia on tumor-bearing rabbits. METHODS: Twenty-eight VX2 xenografts in the thighs of rabbits were divided into the following 5 treatment groups: radiotherapy at a single dose of 10, 20 or 30 Gy, hyperthermia (43 degrees Celsius, 1 hour), and the combination of radiotherapy and hyperthermia (10 Gy + 43 degrees Celsius, 1 hour). FDG-microPET images were obtained by using a microPET P4 system at pretreatment and at 24 hours and 7 days after treatment. For the evaluation by FDG-microPET, tumor/muscle (T/M) ratios, retention index [RI = (T/M ratio at 120 min - T/M ratio at 60 min) / T/M ratio at 60 min], and time activity curve (TAC) were acquired. RESULTS: We divided the xenografts into a responder group (partial response + stable disease, n=14) and a non-responder group (progressive disease, n = 14). The T/M ratio at 24 hours after the treatment in the responder group was decreased remarkably with that at pre-treatment (p < 0.05), while in the non-responder group it showed no significant change between the time points. The RI and TAC patterns were comparable to T/M ratios in each treatment group. T/M ratios, RI, and TAC indicated marked changes at the time point of 24 hours in the responder group, although the tumors did not show any significant hange in volume at that time. Photomicrographs of sections showed that the number of viable tumor cells in the responder group decreased at 24 hours after treatment and that inflammatory cell infiltration was marked and almost all viable tumor cells had disappeared by day 7 after treatment. CONCLUSION: These results suggest that early evaluation by FDG-microPET, especially 24 hours after treatment, is useful to predict the primary effects of the treatment. Histological analysis showed that inflammatory cell infiltration at 7 days after treatment was considered to be a cause of accumulation of FDG in the tumors that showed a significant decrease in tumor cell number. This false-positive should be noted when predicting tumor response by FDG accumulation.

Animals↗

PubMed2006

Phase I study of weekly cisplatin, vinorelbine, and concurrent thoracic radiation therapy in patients with locally advanced non-small-cell lung cancer.

BACKGROUND: The combination of chemotherapy and thoracic radiation therapy (TRT) is considered as a standard treatment for locally advanced non-small-cell lung cancer (NSCLC). Although the frequent interaction of anticancer agents and irradiation may produce stronger radio-sensitizing effects, the daily administration of these agents is complicated. We therefore used weekly administration of these agents, and conducted a phase I study of weekly cisplatin, vinorelbine, and concurrent TRT. The purpose of this study was to identify the maximum tolerated dose (MTD), the dose-limiting toxicity (DLT), and the recommended dose of this treatment. METHODS: Patients with locally advanced NSCLC were enrolled in this study. Both cisplatin and vinorelbine were given intravenously on a weekly schedule for 6 weeks, starting on the first day of TRT, i.e., on days 1, 8, 15, 22, 29, and 36. The total dose of TRT was 60 Gy. The dose of cisplatin was fixed at 20 mg/m(2) per week. The starting dose of vinorelbine was 15 mg/m(2) per week (dose level 1). RESULTS: Nine patients were enrolled in this study. All three patients at dose level 1 experienced DLTs. We decreased the dose of vinorelbine to 10 mg/m(2) per week (dose level 0). Two of the six patients at dose level 0 experienced DLTs. Therefore, dose level 1 was considered as the MTD, and dose level 0 as the recommended dose. The DLTs of this treatment were esophagitis, fatigue, infection, and hyponatremia. CONCLUSION: The recommended dose of cisplatin is 20 mg/m(2) per week and that of vinorelbine is 10 mg/m(2) per week with standard TRT. A phase II study of this treatment is warranted.

Aged↗

PubMed2005

Non-small-cell lung cancer: reirradiation for loco-regional relapse previously treated with radiation therapy.

BACKGROUND: We evaluated the efficacy and toxicity of reirradiation for patients with loco-regional relapse of non-small-cell lung cancer after radiation therapy. METHODS: Between 1992 and 2002, 19 patients with loco-regional relapse underwent reirradiation. The median interval between the initial irradiation and reirradiation was 16 months, with a range of 5 to 60 months. The prescribed dose of reirradiation was 50 Gy in 25 fractions over 5 weeks for 18 patients and 60 Gy in 30 fractions over 6 weeks for 1 patient. RESULTS: Five patients could not receive the prescribed dose of reirradiation. The response rate was 43% among the 14 patients who received the prescribed dose of reirradiation. The overall 1-year and 2-year Kaplan-Meier survival rates were 26% and 11%, respectively, and the median survival time was 7.1 months. The median survival times associated with intervals between the initial irradiation and reirradiation of less than 12 months, 12-18 months, and more than 18 months were 2.1, 7.1, and 11.5 months, respectively. There were significant differences in survival between patients with an interval of less than 12 months and those with an interval of 12-18 months, and between those with an interval of less than 12 months and those with an interval of more than 18 months (generalized Wilcoxon method; P < 0.05 for both). Grade 3 radiation pneumonitis and grade 2 radiation esophagitis occurred in 1 and 3 patients, respectively. CONCLUSION: Reirradiation is considered to contribute to salvage in selected patients with relapsed non-small-cell lung cancer. Patients with a long interval after the initial irradiation are good candidates for reirradiation. On the other hand, patients with Eastern Cooperative Oncology Group (ECOG) performance status 3 were not good candidates.

Adenocarcinoma↗

PubMed2005

Non-small cell lung cancer: radiation therapy for locoregional recurrence after complete resection.

BACKGROUND: We investigated patterns of failure after radical radiation therapy in relation to the radiation field in patients with postsurgical locoregional recurrence of non-small cell lung cancer. METHODS: Between 1992 and 2002, 31 patients with locoregional recurrence were treated with radiation therapy. At the time of radiation therapy, the sites of recurrence were the bronchial stump, the regional lymph nodes, the chest wall, and both the regional lymph nodes and the chest wall in 7, 20, 3, and 1 patient, respectively. The prescribed dose was 60 Gy in 30 fractions over 6 weeks in all patients. RESULTS: The response rate was 87%. The overall 1-year, 2-year, and 4-year Kaplan-Meier survival rates were 61%, 30%, and 15%, respectively, and the median survival time was 14 months. Locoregional relapse with or without distant metastasis occurred in 15 patients (in-field, 7; marginal, 7; out-field, 1), and distant metastasis alone occurred in 7 patients. The sites of marginal relapse were the upper margin in two patients, the ipsilateral margin in one patient, the contralateral margin in one patient, and the lower margin in three patients, respectively (in one patient, the data for marginal relapse overlapped). In all patients with relapse on the lower margin, the mediastinal lymph nodes were dissected at the initial surgery. CONCLUSION: Postoperative recurrent non-small cell lung cancer showed distinctive features: the response rate was high, and the incidence of marginal relapse was also high, as in small cell lung cancer. The incidence of lower marginal relapse was high, in contrast to that in surgery-naive patients.

Aged↗

PubMed2005

Monitoring of respiratory movement of the diaphragm for gated radiotherapy.

PURPOSE: In order to obtain a respiratory signal for gated radiotherapy, diaphragm movement was monitored. MATERIALS AND METHODS: To obtain the diaphragm signal, an image brightness stabilizer for fluoroscopy of an X-ray simulator was used. The image brightness stabilizer output electric current in response to image brightness, which changed with diaphragm movement. The electric current was recorded as the diaphragm signal and compared with the abdominal wall signal, which was obtained by monitoring the height of the abdominal wall using a laser displacement sensor. RESULTS: A regular diaphragm signal was obtained in all of nine patients. At 70% expiration of the abdominal wall signal, the diaphragm signal ranged from 35% to 70% expiration (median, 55%). At 30% inspiration of the abdominal wall signal, the diaphragm signal ranged from 10% to 30% inspiration (median, 20%). CONCLUSION: A regular diaphragm signal could be conveniently obtained utilizing an image brightness stabilizer. The diaphragm signal tended to be delayed in comparison with the abdominal wall signal.

Diaphragm↗

PubMed2005

Close radiographic landmarks for spinal cord localization in treatment of thoracic malignancy.

BACKGROUND: On simulation radiographs of oblique fields, the spinal canal is estimated to be located on the deep surface of the tangential parts of the vertebral laminae within a width of the oblique diameter of the spinal canal. The aim of this study was to evaluate the accuracy of the estimated location of the spinal canal. MATERIALS AND METHODS: Beam's eye view digital simulation radiographs were produced using actual patient data from a computed tomography (CT) scanner. The spinal canal was projected onto the Beam's eye view image, and measurement of the distance between the tangential parts of the vertebral laminae and the anterior border of the spinal canal was performed. The oblique diameter on the axial CT image was compared to the measured distance. RESULTS: In all 10 patients, the tangential parts of the vertebral laminae were detectable on the Beam's eye view image. At all levels in all patients, the oblique diameter was slightly larger than or equal to the distance. With a gantry angle of 30 degrees the difference ranged from 0 to 2.5 mm (mean, 1.2 mm), from 0 to 1.0 mm (mean, 0.4 mm), and from 0 to 1.5 mm (mean, 0.4 mm) at levels T-1, T-4, and T-7, respectively. With a gantry angle of 45 degrees the difference ranged from 0 to 1.5 mm (mean, 0.8 mm), from 0 to 0.5 mm (mean, 0.3 mm), and from 0 to 1.0 mm (mean, 0.4 mm), respectively. CONCLUSION: The tangential parts of the vertebral laminae are useful landmarks, since the spinal canal location estimated using the tangential parts and measured oblique diameter of the spinal canal on the axial CT image is sufficiently accurate.

Aged↗

PubMed2005

Verification imaging using a computed radiography system for high-energy electron beam therapy.

PURPOSE: The aim of this study was to examine a method to more conveniently acquire verification images. A computed radiography (CR) system was employed using a photostimulable phosphor plate and diagnostic cassette used for taking diagnostic X-ray photographs. MATERIALS AND METHODS: Verification images were acquired using the diagnostic cassette and therapy cassette. Image processing parameters were adjusted to improve the image quality. Verification images were printed using optimum parameters, and 10 radiation technicians visually evaluated the images. The sign test was used, and image quality was evaluated using a two-sided test at a 5% level of significance. To assess its clinical value, a radiation oncologist evaluated patient verification images. RESULTS: Verification image quality was improved by the adjustment of image processing parameters. As a result of the image quality evaluation, there were no significant differences between the two types of cassette (p>0.05). In most of the clinical cases (98%), the verification images were useful. CONCLUSION: We found that good quality verification images were acquired by a CR system with a diagnostic cassette. This system is suitable for practical use to acquire daily verification images, and it is considered useful for maintaining quality assurance (QA) in high-energy electron beam therapy.

Humans↗

PubMedDate not supplied

Inhomogeneity correction in radiotherapy for lung cancer in multicenter clinical trials.

PURPOSE: Dose distribution in patients in past multicenter clinical trials was reviewed from the perspective of clinicians to evaluate the quality of treatment and to improve the quality of future clinical trials. MATERIALS AND METHODS: Thirty patients with stage III lung cancer, who had undergone radical radiation therapy in multicenter clinical trials were retrospectively reviewed. A two-dimensional treatment planning system using Clarkson integration was used to calculate correction factors at the primary lesions and at the mediastinal lymph nodes. RESULTS: Correction factors at the primary lesions ranged from 1.00 to 1.12 (mean, 1.06) and from 1.02 to 1.14 (mean, 1.06) in the AP/PA fields and in the oblique fields, respectively. The lowest values of correction factors at the mediastinal lymph nodes on the axial plane including the primary lesions ranged from 0.93 to 1.04 (mean, 0.98) and from 0.97 to 1.10 (mean, 1.02) in the AP/PA fields and in the oblique fields, respectively. In 14 patients whose primary tumor was located in the upper lung field, the correction factors at the subcarinal lymph nodes ranged from 0.90 to 1.01 (mean, 0.96) in the AP/PA fields. CONCLUSION: Delivered doses lower than those prescribed at the mediastinal lymph nodes should be taken into consideration to improve the quality of multicenter clinical trials.

Clinical Trials as Topic↗

PubMedDate not supplied

A single institutional subset analysis of the WJLCG study comparing concurrent and sequential chemoradiotherapy for stage III non-small-cell lung cancer.

PURPOSE: To supplement findings of the West Japan Lung Cancer Group (WJLCG) study, treatment outcomes in our institution were reviewed from the perspective of radiation oncology. MATERIALS AND METHODS: Chemotherapy consisted of cisplatin (80 mg/m2 on days 1 and 29), vindesine (3 mg/m2 on days 1, 8, 29, and 36), and mitomycin (8 mg/m2 on days 1 and 29). In the concurrent arm, radiation therapy began on day 2 with a dose of 56 Gy in 28 fractions over 6.8 weeks, with an interval of 10 days at 28 Gy. In the sequential arm, radiation therapy began on day 50 with a dose of 56 Gy in 28 fractions over 5.6 weeks, without an interval. RESULTS: Twenty-four patients in the concurrent arm and 25 patients in the sequential arm in our institution were eligible for the WJLCG study. In the concurrent arm, three patients could not receive the full dose of radiation therapy and 12 patients required interruption of radiation therapy for more than 4 days. The median survival time among per-protocol patients and in those with interruption or with incomplete radiation therapy was 28.9 months and 14.1 months, respectively (p = 0.02). In the sequential arm, one patient could not receive the full dose of radiation therapy and none of the patients required such interruption. Local relapse and distant metastases as the first site of relapse occurred in 12 (11 in-field, 1 marginal) and five patients, respectively, in the concurrent arm, and in eight (7 in-field, 1 marginal) and 11 patients, respectively, in the sequential arm. CONCLUSION: In the concurrent regimen, noncompletion or interruption of radiation therapy was frequent, and the prognosis of such patients was poor.

Adult↗