Biomedical subjects

Kenshiro Shiraishi

Publications and source records attributed to Kenshiro Shiraishi.

12 recordsLinked to original sources

PubMed2006

A retrospective study of radiotherapy for spinal bone metastases from hepatocellular carcinoma (HCC).

OBJECTIVE: To evaluate the therapeutic effects of radiotherapy on spinal bone metastases from hepatocellular carcinoma (HCC). METHODS: A retrospective review was conducted on 24 ambulatory patients with spinal bone metastases from HCC treated by radiotherapy from 1995 to 2004. Ambulatory rate and local progression-free rate after radiotherapy were analyzed. Eight (33%) of 24 patients had radiographic spinal cord compression from the spinal bone metastases before the treatment. Two (8.3%) of the 24 patients had some spinal deficits before the treatment. Biological equivalent dose (BED) with alpha/beta ratios of 10 ranged from 39 to 50.7 Gy (median 44.8 Gy). RESULTS: The median observation period was 5.1 months ranging from 0.9 to 36.0 months. Among the 24 patients, five (21%) underwent salvage therapies, while of the remaining 19 patients four (21%) became nonambulatory by the last follow-up. The ambulatory rates at 3 months and 6 months were 85 and 63%, respectively. The local progression-free rates at 3 months and 6 months were 53 and 47%, respectively. CONCLUSIONS: Radiotherapy with a BED of 39-50.7 Gy (median 44.8 Gy) is not sufficiently effective for the patients with spinal bone metastases from HCC to prevent paralysis. Dose escalation with a highly precise radiation technique will need to be evaluated.

Aged↗

PubMed2006

Treatment results of chemoradiation therapy for localized aggressive lymphomas: A retrospective 20-year study.

In this study we analyzed our cases of localized aggressive lymphoma treated in our institution during the last 20 years to compare the finding of this study with those of previous studies. Forty patients with Ann Arbor stage I-II aggressive lymphoma were treated with 3-6 cycles of a CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisolone) and radiation therapy (30 or 40 Gy with involved field). Between 1985 and 2003, 40 patients with stage I (N = 25) or stage II (N = 15) disease were treated. Chemotherapy mainly preceded radiotherapy, although the sequence of radiotherapy and chemotherapy was determined by individual physicians and patients' choice. Median and mean age was 50.5 and 48.6 years, respectively, at the time of diagnosis, with a male to female ratio of 19:21. Analyses were undertaken to determine (1) response to treatment according to age, international prognostic index (IPI), lactate dehydrogenase (LDH) value, serum interleukin 2 receptor (sIL-2R) value, cell type, stage, extent of maximum local disease, with or without mediastinal lymph nodes, number of sites, anatomic distribution, and irradiation dose, and (2) relapse patterns. Complete follow-up was obtained in all patients. The follow-up period of surviving 33 patients ranged from 24.7 to 180 months with a median of 69 and a mean of 72.7 months. A complete remission (CR) was achieved in 37 patients (93%). A study of relapse patterns after a CR showed that four patients had a first relapse within a radiation field and the other one patient had an extranodal distant relapse. Significant prognostic factors were not identified by multivariate analysis. Combined chemotherapy and radiation therapy is safe, highly effective, and probably curative for most patients with stage I-II aggressive lymphoma.

Adult↗

PubMed2006

Taste dysfunction in patients receiving radiotherapy.

BACKGROUND: Taste loss is a major cause of morbidity in patients undergoing head and neck irradiation. METHODS: In a prospective study, 51 patients undergoing radical head and neck irradiation at the Tokyo University Hospital were assessed for taste loss. Taste ability was measured by the taste threshold for the four basic tastes (sweet, sour, salt, and bitter qualities) plus another taste of "umami" quality using a filter-paper-disc method in patients before, during, and after radiotherapy (RT). RESULTS: All tastes declined on the fifth week after the start of RT and improved on the 11th week. Anatomic pathologic analyses in rats revealed that taste buds diminished completely on the sixth day after irradiation of 15 Gy in a single fraction, and the appearance of taste buds returned almost to the preirradiation state on the 28th day. CONCLUSIONS: The main cause of taste disorder resulting from RT was believed to be a disappearance of taste buds and not damage to the taste nerves.

Adult↗

PubMed2006

Treatment planning and dosimetry of a multi-axis dynamic arc technique for prostate cancer: A comparison with IMRT.

PURPOSE: Intensity-modulated radiation therapy (IMRT) allows greater dose conformity to the tumor target. However, IMRT, especially static delivery, usually requires more time to deliver a dose fraction than conventional external beam radiotherapy (EBRT). The authors have been using a "two-axis dynamic arc therapy" (2A-DAT) technique for prostate cancer treatment to make a concave dose distribution to spare the rectum and bladder while working with limited time and human resources. The objectives of this study were to (1) clinically implement the 2A-DAT technique, (2) evaluate the dosimetry in comparison with IMRT, and (3) analyze the initial treatment outcome. MATERIALS AND METHODS: The 2A-DAT consists of two dynamic arc therapies (DATs) with half rotation around two isocenters each in two separate symmetrical rhombi. Treatment planning is forward and on a trial-and-error basis. Thirty-four patients received 2A-DAT with a median prescribed dose of 70 Gy. RESULTS: Although inferior in dose uniformity, the 2A-DAT provided equivalent sparing of normal structures to IMRT. Daily fraction delivery time for the 34 patients ranged from 6.4 to 9.6 minutes, with an average of 7.4 minutes. Five-year survival and five-year prostate specific autigen (PSA) failure-free survival were 89.3% and 79.5%, respectively. Three patients developed grade 2 proctitis. CONCLUSION: This technique is a possible alternative to IMRT in EBRT of prostate cancer.

Aged↗

PubMed2006

Treatment results of preoperative concurrent chemoradiotherapy followed by surgery for stage III or IV esophageal squamous cell carcinoma.

PURPOSE: To evaluate the treatment outcome of preoperative neoadjuvant radiotherapy combined with chemotherapy (CTx) for 17 esophageal cancer patients. MATERIALS AND METHODS: Between 1992 and 2004, patients with locally advanced esophageal cancer (stage III or IV) before curative-intent surgery received radiotherapy (RT) combined with CTx (Cisplatin: 75 mg/m2, bolus infusion, and 5-fluorouracil (5-FU): 1,000 mg/m2/24 h, continuous infusion for 4 days) at a median total dose of 30 Gy (n=17). RESULTS: The median survival period was 13.8 months. The overall survival rates at 1, 2, and 3 years were 75%, 40%, and 20%, respectively. According to univariate analysis, no factor of worse prognosis was found. Pathological markedly (Grade 3) or moderately (Grade 2) effects were observed in 4 patients (24%) and 8 patients (47%), respectively. CONCLUSION: These results indicate that, although this regimen was effective in terms of pathological effect, it is unclear whether it made a contribution to the improvement of survival

Aged↗

PubMed2006

External beam radiotherapy to treat intra- and extra-hepatic dissemination of hepatocellular carcinoma after radiofrequency thermal ablation.

BACKGROUND: Radiofrequency ablation (RFA) is an alternative to percutaneous ethanol injection therapy (PEIT) for single non-surgical hepatocellular carcinoma. However, the risk of seeding along the needle track has been reported. METHODS: Seven patients presenting with neoplastic seeding after RFA or PEIT were treated with external beam radiotherapy using conventional fractionation. All patients underwent irradiation with a total dose in the range of 44-61 Gy (median and mode value: 50 Gy). RESULTS: An objective response to treatment was achieved in six of seven patients (86%). A complete response was obtained in two patients (29%). The median survival time was 14.7 months and the actuarial 1- and 2-year survivals were 67% and 50%, respectively. CONCLUSIONS: The response to treatment was relatively good without serious complications. Seeding from hepatocellular carcinoma is sensitive to external beam radiotherapy. It is useful in the treatment of these patients with 50 Gy in 25 fractions.

Aged↗

PubMed2005

Radiation therapy for portal venous invasion by hepatocellular carcinoma.

AIM: To clarify the efficacy and safety of three-dimensional conformal radiotherapy (3-D CRT) for this disease and to specify patient subgroups suitable for this treatment. METHODS: Fifty-two patients with HCC received PVI-targeted radiation therapy from January 1995 through December 2003. Portal venous invasion (PVI) was found in the second or lower order branches of the portal vein in 6 patients, in the first branch in 24 patients and in the main trunk in 22 patients. Child classifications of liver function before radiation therapy were A, B, and C for 19, 24 and 2 patients, respectively. All patients received three-dimensional conformal radiotherapy with a total dose ranging from 39 to 60 Gy (57.0 Gy in average). RESULTS: Overall survival rates at 1, 2, 3, 4, and 5 years were 45.1%, 25.3%, 15.2%, 10.1%, and 5.1%, respectively. Univariate analysis revealed that Child status, the number of tumor foci, tumor type, transcatheter arterial embolization (TAE) after radiation therapy were statistically significant prognostic factors. Multivariate analysis showed that the number of tumor foci and TAE after radiation therapy were statistically significant. CONCLUSION: The results of this study strongly suggest the efficacy of 3-D CRT as treatment for PVI in HCC. 3-D CRT is recommended in combination with post-radiation TAE for PVI of HCC with 5 tumor foci or less in the liver and with Child A liver function.

Adult↗

PubMed2005

Pathological changes after radiotherapy for primary pituitary carcinoma: a case report.

Pituitary carcinomas are extremely rare. The definition, diagnosis, therapy, and prognosis are controversial. So far, to our knowledge, there has been no report regarding pathological changes after radiotherapy for primary pituitary carcinoma. We reported a single case of a presumed prolactin staining pituitary carcinoma. We defined carcinoma by premorbid intracranial dissemination of the tumor. There were no proven extracranial metastases. The tumor was silent on PET scanning. The patient received external beam radiotherapy alone as primary therapy. Post-irradiation histology revealed that necrotic tissue made up approximately more than half. Tumor had viable cells. Probably approximately three-fifth of tumor cells were without alteration and approximately two-fifth were with degeneration. We confirmed that necrosis but no apoptosis were coexistent in the cells post irradiation for pituitary carcinoma.

Adenocarcinoma↗

PubMed2005

Comparison between conventional surgery and radiotherapy for FIGO stage I-II cervical carcinoma: a retrospective Japanese study.

PURPOSE: To compare treatment outcome results of conventional surgery vs. radiotherapy (RT) for carcinoma of the uterine cervix. MATERIALS AND METHODS: A retrospective analysis was conducted of 152 patients with uterine cervical cancer radically treated with surgery or high dose-rate intracavitary brachytherapy (HDR-ICBT) with or without external RT from June 1991 to May 2004. The median follow-up time was 43.5 months (range, 1.0-130.0 months). The median age was 53 years (range, 25-81 years). There were 13 patients (9%) in stage IA, 52 (34%) in stage IB, 24 (16%) in stage IIA, and 63 (41%) in stage IIB. The conventional surgery group included 115 patients (76%) who underwent hysterectomy with pelvic lymph node dissection. Of these, 72 (63%) received postoperative radiotherapy. Thirty-seven patients (24%) were assigned to the RT group. Of these, 14 (38%) received chemoradiotherapy. Three patients with stage I received ICBT-alone without external beam irradiation. RESULTS: The 5-year cause-specific survival (CSS) rates for surgery and RT were 79.9% and 82.3%, respectively; the difference between these two treatments was not statistically significant (P = 0.8524). The differences in the survival rates between the two treatments for each of the stage I or stage II patients were also not statistically significant (P = 0.8407 for stage I and P = 0.6418 for stage II). CONCLUSIONS: This retrospective study suggests that RT results in compatible survival with conventional surgery for patients with stage I-II cervical carcinoma.

Adenocarcinoma↗

PubMed2005

The experience of concurrent chemoradiation for Japanese patients with superficial esophageal squamous cell carcinoma: a retrospective study.

PURPOSE: To evaluate the treatment outcome of concurrent chemoradiation therapy (cCRT) for 13 clinically confirmed T1 esophageal cancer patients. METHODS: Between June 2000 and February 2004, patients with T1 esophageal cancer (tumor invading lamina propria or submucosa) received cCRT (50.4 Gy; CDDP: 75 mg/m2, day 1, bolus; 5-FU: 1000 mg/m2, days 1 to 4, continuous) (n = 13, T1 group). This treatment regimen was compared with the following 2 other groups treated during the same period: one was treated with radiation therapy alone for T1 disease (n = 5, RT-alone group); and the other group of patients consisted of those with T2 disease (tumor invading muscularis propria) who received the same cCRT regimen as the first T1 group (n = 9, T2 group). RESULTS: The overall survival rates at 1 and 3 years were in the T1 group, 75% and 75%; in the T2 group, 75% and 45% (P =0.2890); and in the RT-alone group, 60% and 40% (P = 0.2978). No treatment-related mortalities occurred in the T1 and RT-alone groups, but one patient in the T2 group died of radiation-induced pneumonitis. CONCLUSIONS: Although this study was not randomized, the results showed that cCRT is a safe and effective method for treating patients with superficial esophageal cancer.

Aged↗

PubMedDate not supplied

Intercomparison of dose distribution between gamma knife and C-arm-mounted linac.

Although the Gamma Knife is widely used as a standard tool of radiosurgery for intracranial diseases, recent innovations in medical accelerators have actualized equivalent dose distribution. Most commonly, multiple non-coplanar arc beams through a combination of gantry and couch rotations are used in linac-based radiosurgery, but beam entry geometry is different from that with the Gamma Knife. We have developed a C-arm-mounted medical accelerator and realized conical beam entry without couch rotation. A combination of several conical rotation beams with different C-arm angles comprises multi-orbit dynamic conical radiation therapy (MODCRT) and resembles radiation beam entry with the Gamma Knife. Intercomparison of dose distributions and dose-volume histograms for the same brain tumor demonstrated that MODCRT delivers a similar dose fall-off pattern to that obtained with the Gamma Knife, though the low-dose spread patterns differ.

Brain Neoplasms↗

PubMedDate not supplied

The intergroup/RTOG 85-01 concurrent chemoradiation regimen for Japanese esophageal cancer.

BACKGROUND/AIMS: To evaluate outcome of the U.S. RTOG/Intergroup Protocol 85-01 for 44 Japanese esophageal cancer patients. METHODOLOGY: Between 1996 and 2004, patients with esophageal cancer received the Intergroup concurrent chemoradiation therapy regimen for the primary treatment (n=44, group A). We compared the data with those of patients receiving radiotherapy (RT) combined with the weekly chemotherapy regimen (n=12, group B) and with those of patients receiving RT combined with the daily low-dose chemotherapy regimen (n=24, group C). RESULTS: The median survival period was 14.9 months in group A, 5.7 months in group B, and 6.3 months in group C. The survival rates at 1 and 3 years were 56% and 26% in group A, 42% and 21% in group B (p=0.3307), and 27% and 18% in group C (p=0.0462), respectively. CONCLUSIONS: The prognosis of patients who received the Intergroup regimen for esophageal cancer was significantly better than that of patients who received the daily low-dose chemotherapy regimen. The Intergroup regimen is well tolerable for the Japanese patients too.

Adult↗