Biomedical subjects

Y Shibamoto

Publications and source records attributed to Y Shibamoto.

At least 19 recordsLinked to original sources

PubMed2002

Comparison of 5-fluorouracil and 5-fluoro-2'-deoxyuridine as an effector in radiation-activated prodrugs.

The purpose of this study was to clarify whether 5-fluoro-2'-deoxyuridine (FdUrd) is superior to 5-fluorouracil (5-FU) as an effector in the radiation-activated prodrugs which we have been developing. The in vitro cytotoxicity of 5-FU and FdUrd was compared in two murine tumor and four human pancreatic cancer cell lines using a colony assay and in vivo efficacy was compared with SCCVII tumor using a growth delay time assay. FdUrd was slightly more hydrophilic than 5-FU. In vitro, FdUrd was more efficient than 5-FU in two lines, whereas 5-FU was more efficient in two lines and the two drugs were almost equal in efficacy in the remaining two. The concentration to reduce tumor cell survival to 50% after 24-h drug exposure was 5-32 microM for both 5-FU and FdUrd in murine lines, while it was 30-210 microM in human pancreatic cancer cell lines. The difference in relative efficacy of the two drugs among these cell lines could not be attributed to the rate of intracellular uptake of the compounds. FdUrd was less toxic than 5-FU in C3H/He mice, and FdUrd was less efficient than 5-FU in SCCVII tumors in vivo. These results suggest that FdUrd is not necessarily more potent than 5-FU, and development of the FdUrd prodrugs may not necessarily turn out to be fruitful.

Animals↗

PubMed2001

Definitive intraoperative very high-dose radiotherapy for localized osteosarcoma in the extremities.

PURPOSE: To evaluate the outcome and adverse effects in patients with osteosarcoma treated with very high-dose definitive intraoperative radiotherapy (IORT), with the intention of saving the affected limb. METHODS AND MATERIALS: Thirty-nine patients with osteosarcoma in their extremities were treated with definitive IORT. The irradiation field included the tumor plus an adequate wide margin and excluded the major vessels and nerves. Forty-five to 80 Gy of electrons or X-rays were delivered. The median follow-up of the surviving patients was 124 months. RESULTS: The cause-specific and relapse-free 5-year survival rate was 50% and 43%, respectively. Distant metastasis developed in 23 patients; 19 died and 4 were alive for >10 years. Nine local recurrences were found 4-29 months after IORT in the affected limb. No radiation-induced skin reaction or nerve palsy was observed in the patients treated with X-rays. Experiments using phantoms also confirmed that the scatter dose was below the toxic level in the IORT setting with X-rays. CONCLUSIONS: Very high-dose definitive IORT combined with preventive nailing and chemotherapy appeared to be a promising quality-of-life-oriented alternative to treating patients with osteosarcomas in the extremities, although the problem of recurrences from the surrounding unirradiated soft tissue remains to be solved.

Adolescent↗

PubMed2001

The effectiveness of an immobilization device in conformal radiotherapy for lung tumor: reduction of respiratory tumor movement and evaluation of the daily setup accuracy.

PURPOSE: To evaluate the daily setup accuracy and the reduction of respiratory tumor movement using a body frame in conformal therapy for solitary lung tumor. METHODS AND MATERIALS: Eighteen patients with a solitary lung tumor underwent conformal therapy using a body frame. The body shell of the frame was shaped to the patient's body contour. The respiratory tumor movement was estimated using fluoroscopy, and if it was greater than 5 mm, pressure was applied to the patient's abdomen with the goal of minimizing tumor movement. CT images were then obtained, and a treatment planning was made. A total dose of 40 or 48 Gy was delivered in 4 fractions. Portal films were obtained at each treatment, and the field displacements between them and the simulation films were measured for daily setup errors. The patients were repositioned if the setup error was greater than 3 mm. Correlations were analyzed between patient characteristics and the tumor movement, or the tumor movement reduction and the daily setup errors. RESULTS: Respiratory tumor movement ranged from 0 to 20 mm (mean 7.7 mm). The abdominal press reduced the tumor movement significantly from a range of 8 to 20 mm to a range of 2 to 11 mm (p = 0.0002). Daily setup errors were within 5 mm in 90%, 100%, and 93% of all verifications in left-right, anterior-posterior, and cranio-caudal directions, respectively. Patient repositioning was performed in 25% of all treatments. No significant correlation was detected between patient characteristics and tumor movement, tumor movement reduction, and the daily setup errors. CONCLUSIONS: The abdominal press was successful in reducing the respiratory tumor movement. Daily setup accuracy using the body frame was acceptable. Verification should be performed at each treatment in hypofractionated conformal therapy.

Adolescent↗

PubMed2001

Influence of interfraction interval on the efficacy and toxicity of hyperfractionated radiotherapy in combination with concurrent daily chemotherapy in stage III non-small-cell lung cancer.

PURPOSE: To investigate the influence of the interfraction interval (IFI) on treatment outcome and toxicity in hyperfractionated (HF) radiotherapy (RT) for Stage III non-small-cell lung cancer. METHODS AND MATERIALS: Data for 301 patients treated with 1.2 Gy b.i.d. to a total of 69.6 Gy and concurrent chemotherapy in our 3 prospective studies were analyzed. The chemotherapy regimen was either (1) 50 mg each of carboplatin and etoposide (CE) given on RT days (163 patients) or (2) 30 mg of CE on RT days and 100 mg of CE on Saturdays and Sundays during the RT course (138 patients). An IFI of 4.5-5 h or 5.5-6 h had been nonrandomly assigned for each patient, and this interval was kept throughout the treatment. RESULTS: No difference was observed in treatment outcome due to the chemotherapy protocol, and the 2 groups were combined. Patients treated with the shorter IFI had a better local control rate (38% at 5 years) and survival rate (30% at 5 years) than those treated with the longer interval (23% and 14%, respectively; p < 0.001). However, female patients and those with a high Karnofsky performance status score (KPS), weight loss of < or =5% in the previous 6 months, or Stage IIIA disease had been more often treated with the shorter IFI, and these characteristics were associated with better treatment outcome. In multivariate analysis, only gender, KPS, and weight change proved to be significant prognostic factors influencing both local control and survival, and the effect of IFI was not significant. The incidence of Grade 4 acute esophagitis tended to be higher in the shorter interval group (p = 0.072), but there were no differences in the incidence of late or other acute RT-related toxicities between the 2 groups. CONCLUSIONS: The possible influence of the IFI on local control and survival could not be verified using multivariate analysis. To better understand the influence of the IFI, randomized studies with more patients and wider ranges of intervals (e.g., 5 h vs. 8 h) seem to be necessary.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2001

Hyperfractionated radiation therapy and concurrent low-dose, daily carboplatin/etoposide with or without weekend carboplatin/etoposide chemotherapy in stage III non-small-cell lung cancer: a randomized trial.

PURPOSE: To investigate whether the addition of weekend chemotherapy consisting of carboplatin/etoposide to hyperfractionated radiation therapy (Hfx RT) and concurrent daily carboplatin/etoposide offers an advantage over the same Hfx RT/daily carboplatin/etoposide. METHODS AND MATERIALS: A total of 195 patients (Group I, 98; Group II, 97) were treated with either Hfx RT to a total tumor dose of 69.6 Gy via 1.2 Gy b.i.d. fractionation and daily 50 mg each of carboplatin and etoposide during the RT course (Group I) or the same Hfx RT with daily carboplatin/etoposide consisting of 30 mg each of carboplatin and etoposide and with weekend (Saturdays and Sundays) 100 mg each of carboplatin and etoposide during the RT course (Group II). RESULTS: No difference was found regarding median survival time and 5-year survival rates (20 vs. 22 months and 20% vs. 23%; p = 0.57). Median time to local progression was 20 and 19 months, respectively, while 5-year local progression-free survival rates were 28% and 27%, respectively (p = 0.66). Also, there was no difference regarding either median time to distant metastasis and 5-year distant metastasis-free survival (21 vs. 25 months and 29% vs. 34%, p = 0.29). There was no difference in the incidence of various nonhematologic toxicities between the two treatment groups, but patients treated with the weekend CHT had significantly more high-grade (> or = 3) hematologic toxicity (p = 0.0046). Late high-grade toxicity was not different between the two treatment groups. CONCLUSION: The addition of weekend carboplatin/etoposide did not improve results over those obtained with Hfx RT and concurrent low-dose, daily carboplatin/etoposide, but it led to a higher incidence of acute high-grade hematologic toxicity.

Adult↗

PubMed2001

Second cancers occurring in patients with early stage non-small-cell lung cancer treated with chest radiation therapy alone.

PURPOSE: To investigate the incidence of second cancers occurring in patients with early stage (I/II) non-small-cell lung cancer (NSCLC) treated with radiation therapy (RT) alone. PATIENTS AND METHODS: Seventy-eight patients had been treated with conventionally fractionated (CF) RT (1982 to 1987), and 116 patients had been treated with hyperfractionated (Hfx) RT (1988 to 1993). Tumor doses were 60 Gy for CF and 69.6 Gy (1.2 Gy bid) for Hfx. RESULTS: A total of 26 patients developed second cancers. The cumulative incidence of second cancer was 21.8% (SE, 4.7%) at 5 years and 34.8% (SE, 6.7%) at 10 years. For second lung cancers, it was 6.0% (SE, 2.8%) at 5 years and 14.2% (SE, 5.2%) at 10 years, and for second nonlung cancers, it was 16.3% (SE, 4.2%) at 5 years and 22.2% (SE, 5.7%) at 10 years. The rate of developing second cancer per patient per year was 4.3% (95% confidence intervals [CI], 2.7% to 5.9%), with the rates being 1.4% (CI, 0.5% to 2.3%) for the second lung cancers and 2.8% (CI, 1.5% to 4.1%) for second nonlung cancers. The rate of developing second cancers during the first and second 5-year period after RT (0 to 5 and 5 to 10 years) was 4.3% (CI, 2.4% to 6.2%) and 4.2% (CI, 0.6% to 7.8%), respectively, for all cancers. These rates were 1.0% (CI, 0.1% to 1.9%) and 2.2% (CI, 0% to 4.6%), respectively, for second lung cancers, and 3.2% (CI, 1.6% to 4.8%) and 1.5% (CI, 0% to 3.6%), respectively, for second nonlung cancers. CONCLUSION: Long-term survivors after RT alone for early stage NSCLC carry the same risk of developing second cancer, either lung or nonlung, as their counterparts treated surgically when the results of this study are compared with those of the published literature.

Aged↗

PubMed2001

In vivo evaluation of a novel antitumor prodrug, 1-(2'-oxopropyl)-5-fluorouracil (OFU001), which releases 5-fluorouracil upon hypoxic irradiation.

PURPOSE: We previously proposed that a prodrug of 5-fluorouracil (5-FU), OFU001, is activated through capturing of hydrated electrons produced by hypoxic irradiation. Because hydrated electrons are readily deactivated by oxygen, the 5-FU release occurs specifically upon hypoxic irradiation. In this study, we investigated the in vivo efficacy, pharmacokinetics, and toxicity of OFU001. METHODS AND MATERIALS: Female 10-week-old C3H/He mice bearing SCCVII tumors were used. To measure release of 5-FU from OFU001 in vivo, the mice were given 100 mg/kg of OFU001 intraperitoneally and irradiated. Thereafter, 5-FU levels in the tumor and serum were measured by high-performance liquid chromatography. To evaluate in vivo efficacy, OFU001 was administered 30 min before irradiation, and radiation-potentiating effects were investigated by means of a tumor growth delay assay and a 50% tumor control dose (TCD-50) assay. The lethal dose of OFU001 was evaluated in the same mice. RESULTS: Following administration of OFU001 and irradiation at 30 Gy, the average 5-FU levels in the tumor and serum were 179 ng/g and 83 ng/mL, respectively. Administration of OFU001 (100-200 mg/kg) to the tumor-bearing mice before a single dose of 15-Gy irradiation produced a mean tumor growth delay of 1-5 days as compared to radiation alone (although the delay was not significant). However, no additional growth delay was observed when OFU001 was combined with 5 radiation fractions of 4 Gy each. The enhancement ratio of OFU001 in the TCD-50 assay was 1.2. No mice died after administration of 0.6-1.2 g/kg of OFU001. CONCLUSIONS: OFU001 appears to work in vivo via the proposed mechanism of activation. Although the in vivo effect of this compound was not strong enough for clinical efficacy, these results should encourage further research on the development of prodrugs of more potent anticancer agents activated through the same mechanism.

Animals↗

PubMed2001

Absence of cervical radiation myelitis after hyperfractionated radiation therapy with and without concurrent chemotherapy for locally advanced, unresectable, nonmetastatic squamous cell carcinoma of the head and neck.

PURPOSE: To evaluate the risk of developing radiation myelitis after a cervical spinal cord dose of 50.6 Gy given via 1.1 Gy b.i.d. fractionation during a prospective, randomised trial of hyperfractionated radiation therapy (HFX RT) to a total dose of 77 Gy given in 70 fractions of 1.1 Gy b.i.d., with and without concurrent low-dose, daily cisplatin (CDDP) for head and neck cancer. METHODS: Of 130 patients with locally advanced, unresectable, nonmetastatic squamous cell carcinoma of the head and neck (SCC H&N) who entered a prospective, randomised trial, 101 patients received 50.6 Gy to a portion of their spinal cord and survived > 1 year following the beginning of therapy. Forty-five patients were treated with HFX RT alone and fifty-six patients also received CDDP. RESULTS: None of these 101 patients developed cervical radiation myelitis. Therefore, it was not possible to investigate the influence of potentially contributing factors on the occurrence of radiation myelitis, such as interfraction interval, cord length, and administration of concurrent CDDP. CONCLUSIONS: Given the increasing number of studies with both altered fractionated regimens and concurrent radio-chemotherapy in SCC H&N, new studies with more patients are needed to gain better insight into the risks of developing cervical radiation myelitis.

Adult↗

PubMed2001

Concurrent accelerated hyperfractionated radiation therapy and carboplatin/etoposide in patients with malignant glioma: long-term results of a phase II study.

PURPOSE: Feasibility, antitumor activity and toxicity of accelerated hyperfractionated radiation therapy (Acc Hfx RT) and concurrent carboplatin/etoposide (CBDCA/VP 16) chemotherapy were investigated in patients with malignant glioma. MATERIAL AND METHODS: Seventy-nine patients with either glioblastoma multiforme (GBM) (n = 61) or anaplastic astrocytome (AA) (n = 18) entered into a phase II study on the use of Acc Hfx RT with 60 Gy in 40 fractions in 20 treatment days over 4 weeks and concurrent CBDCA, 200 mg/m2, and VP 16, 200 mg/m2, both given once weekly during the RT course. RESULTS: The median survival time for all 79 patients was 14 months (11 and 44 months for GBM and AA patients, respectively), while the 2- and 4-year survival was respectively 33% and 11% for all patients, 13% and 1.6% for GBM patients, and 100% and 44% for AA patients (p < 0.0001). The median time to progression for all patients was 12 months (9 and 40 months for GBM and AA, respectively), while the 2- and 4-year progression-free survival (PFS) was respectively 28% and 10% (all patients), 10% and 1.7% (GBM) and 89% and 39% (AA) (p < 0.0001). Multivariate analysis showed that age, performance status, and preoperative size of tumor influenced survival in GBM. Only 5 (6%) patients experienced grade 3 leukopenia and 6 (8%) patients experienced grade 3 thrombocytopenia. No late RT-induced toxicity was observed to date. CONCLUSIONS: Although Acc Hfx RT/CBDCA + VP 16 was feasible and little toxic, it failed to improve survival/progression-free survival over that obtained with other currently used regimens. These results do not justify the investigation of this regimen in a phase III trial.

Adult↗

PubMed2001

Phase Ia study of a hypoxic cell sensitizer doranidazole (PR-350) in combination with conventional radiotherapy.

A phase Ia study of a 2-nitroimidazole nucleoside analog radiosensitizer doranidazole was conducted to evaluate its toxicity and pharmacokinetics in patients undergoing conventional external beam radiotherapy. Twenty-nine patients, aged 40-74 years, with a WHO performance status of 0-2 and with adequate organ functions, were entered in the study. Single administration of doranidazole was investigated first with 13 patients and then a course of five consecutive daily administrations was tested in 16 patients. Doranidazole was given i.v. 25 min before irradiation. Doranidazole doses of 400, 800, 1300 and 2000 mg/m2 were evaluated in the former study, and daily doses of 800, 1300 and 2000 mg/m2 were investigated in the latter study. All patients tolerated doranidazole administration. Although a transient decrease in the 24-h creatinine clearance rate was observed in five patients (one in the single administration study and four in the repeat administration study), this was not considered to be the dose-limiting toxicity. Other toxicities (hematological and gastrointestinal), which may not be related to doranidazole administration, were also mild and were not dose limiting. No neurotoxicity was observed. The average maximum concentration, area under the time-concentration curve and half-life of doranidazole in serum were 172-194 microg/ml, 502-582 microg x h/l and 4.2-4.6 h, respectively, at 2000 mg/m2. At the tested doses, administration of doranidazole was tolerable and achieved serum concentrations at which reasonable radiosensitization could be expected. A phase Ib/II study to evaluate the feasibility and efficacy of up to 30 repeat administrations seems to be warranted.

Adult↗

PubMed2001

Intracranial germinoma: radiation therapy with tumor volume-based dose selection.

PURPOSE: To prospectively investigate whether intracranial germinomas, except large ones, can be cured with radiation doses lower than 50 Gy and to determine 10-year follow-up results. MATERIALS AND METHODS: Between 1985 and 1995, 38 patients with intracranial germinoma diagnosed histologically or with established criteria were enrolled. Total radiation doses to the primary tumor site were 36 Gy after total removal, 40 Gy for tumors less than 2.5 cm in diameter, 45 Gy for those 2.5-4.0 cm, and 50 Gy for those greater than 4.0 cm, with 1.6-1.8-Gy daily fractions. Patients underwent irradiation of the primary tumor site or cerebrospinal axis (20-24 Gy), depending on findings at diagnosis. No chemotherapy was allowed. RESULTS: All patients completed radiation therapy. Thirty-five patients were treated according to protocol, and three with relatively slow tumor regression or presence of a cyst received additional radiation (5-7 Gy, 50-52 Gy total). Ten-year overall and relapse-free survival rates were 91% and 95%, respectively. Two patients developed meningeal dissemination, but none had local failure. Treatment complications included chordoma in one patient and internal carotid artery occlusion in another. No treatment-related decline of performance status was observed in the other patients. CONCLUSION: All tumor volume-based radiation doses were effective, without risk of local failure. Intracranial germinoma 4 cm or less in diameter can be cured with doses of 40-45 Gy. Investigation of further dose reduction seems worthwhile. Radiation therapy alone with these doses should be compared with ongoing chemotherapeutic protocols plus low-dose (24-30-Gy) irradiation in future studies.

Brain Neoplasms↗

PubMed2001

Intraarterial corticosteroid infusion following radiotherapy for primary central nervous system lymphoma: feasibility and preliminary result.

To utilize the high lympholytic effect of corticosteroids with minimal systemic adverse effects, we used intraarterial corticosteroid infusion in the treatment of 8 patients with primary central nervous system lymphoma (PCNSL). One patient had recurrent PCNSL, while the other patients had primary disease. Following standard radiotherapy with or without some systemic or intrathecal chemotherapy, prednisolone (60-100 mg in total) or dexamethazone (12 mg in total) was rapidly infused through the carotid arteries in all patients and also through the left vertebral artery in 5 patients. No acute or late complications of this treatment were observed. All 8 patients achieved complete or partial response. Four patients died of the disease, while the other 4 were alive with (1 patient) or without (3 patients) disease at 8-37 months after treatment, giving a 2-year survival rate of 55%. Intraarterial administration of high-dose corticosteroids appears to be a feasible treatment modality. This method may be used in preradiotherapy setting to evaluate response of PCNSL in future studies.

Adrenal Cortex Hormones↗

PubMed2000

Analysis of the clinical benefit of intraoperative radiotherapy in patients undergoing macroscopically curative resection for pancreatic cancer.

PURPOSE: To determine the survival of pancreatic cancer patients treated with intraoperative radiotherapy (IORT) and/or external beam radiation therapy (EBRT) following macroscopically curative resection. METHODS AND MATERIALS: One hundred and thirty-eight patients with pancreatic cancer who had undergone potentially curative total or regional pancreatectomy between 1980 and 1997 were retrospectively analyzed. Among the 138 patients, 98 had a pathologically negative surgical margin and the remaining 40 patients had a positive surgical margin. The usual EBRT dose was 45-55 Gy with a daily fraction of 1.5-2.0 Gy. The median IORT dose was 25 Gy in a single fraction. RESULTS: The 2-year cause-specific survival rate of patients with pathologically negative surgical margins was 19%, and that of patients with positive margins was 4% (p < 0.005). Although the median survival time (MST) of patients with negative margins treated with IORT and EBRT was significantly longer than that of those treated with operation alone (17 vs. 11 months), no significant difference in survival curves was observed. In patients with positive surgical margins in peripancreatic soft tissue, the difference between the survival curve of patients treated with surgery alone and that of those treated with surgery and radiation therapy was borderline significant (p < 0.10). Patients receiving intraarterial or intraportal infusion chemotherapy had significantly improved survival rates compared with those who did not receive it (p < 0.05). CONCLUSION: Although the MST was longer in patients with negative margins receiving IORT and EBRT than in those receiving no radiation, improved long-term survival by IORT and/or EBRT was not suggested. In patients with positive margins, our results obtained by IORT/EBRT were encouraging. Randomized studies with much higher patient numbers are necessary to define the role of IORT in curatively resected pancreatic cancer.

Adult↗

PubMed2000

Analysis of factors affecting the appearance of hepatocellular carcinoma in patients with chronic hepatitis C. A long term follow-up study after histologic diagnosis.

BACKGROUND: Hepatocellular carcinoma (HCC) occurs more frequently in patients with hepatitis C virus (HCV)-related chronic liver disease than those with hepatitis B virus-related disease. It is important to assess the factors affecting the development of HCC. METHODS: A long term follow-up study involving patients with chronic HCV was performed retrospectively. A total of 153 patients diagnosed between June 1981 and November 1990 with chronic HCV with or without cirrhosis by liver biopsy were enrolled in a long term follow-up study (average, 99.4 months) and the cumulative incidence rate of HCC and factors affecting the appearance of HCC were examined. RESULTS: The 5-year cumulative incidence rate was 9%, the 10-year cumulative incidence rate was 23%, and the 15-year cumulative incidence rate was 42%. The annual rate of incidence increased as the follow-up period progressed. The authors selected ten variables and investigated their effect on the incidence rate of HCC, including age, gender, habitual heavy drinking, positivity of antibody against hepatitis B virus surface antigen, treatment with interferon (IFN) during the follow-up period, maximum and minimum serum alanine aminotransferase levels during the follow-up period, histologic staging, grading, and irregular regeneration of hepatocytes. Of the 10 variables, age (> 50 years), habitual heavy drinking, and histologic staging were determined to be independent risk factors according to multivariate Cox proportional hazards regression analysis. IFN therapy by itself was not found to be an independent factor affecting the appearance of HCC. CONCLUSIONS: In patients with chronic HCV, the annual incidence rate of HCC appeared to increase as the follow-up period progressed. According to the results of the current study, the factors that independently affected the development of HCC were age, habitual heavy drinking, and histologic staging.

Adult↗

PubMed2000

Elective ipsilateral neck irradiation of patients with locally advanced maxillary sinus carcinoma.

BACKGROUND: The current study was conducted to investigate retrospectively whether elective ipsilateral neck irradiation (EINI) is effective in controlling subclinical neck disease in patients with locally advanced (T3 and T4) nonmetastatic (N0, M0) squamous cell carcinoma (SCC) of the maxilla. METHODS: Between 1987 and 1993 a total of 44 patients were treated with EINI. The primary tumor bed was treated with 60 grays (Gy) in patients undergoing radical maxillectomy or with 66 Gy in patients undergoing partial maxillectomy. The ipsilateral upper and lower neck (down to the clavicle) was treated with either opposing anteroposterior-posteroanterior fields or appositional electron fields. The dose of elective neck radiotherapy was 50 Gy in 25 daily fractions. RESULTS: The 5-year and 10-year survival rates (with standard error [SE]) were 66% (SE 7%) and 60% (SE 8%), respectively, whereas the 5-year and 10-year recurrence free survival rates both were 64% (SE 7%). The 10-year local recurrence free survival rate was 69% (SE 7%), whereas the 10-year regional recurrence free survival rate was 94% (SE 4%). Of the 2 patients who developed a recurrence in the neck, 1 was salvaged successfully by surgery, producing an ultimate 10-year regional recurrence free survival rate of 97%. The 10-year distant metastasis free survival rate was 91% (SE 4%). CONCLUSIONS: The findings of the current study appear to suggest the potential efficacy of EINI in patients with locally advanced, nonmetastatic SCC of the maxilla and that the high rate of control of cervical lymph nodes may lead to better overall survival than that reported in the majority of the recent series.

Carcinoma, Squamous Cell↗

PubMed2000

Radiosensitivity of human pancreatic cancer cells in vitro and in vivo, and the effect of a new hypoxic cell sensitizer, doranidazole.

BACKGROUND AND PURPOSE: A clinical study of the new 2-nitroimidazole nucleoside analogue doranidazole (PR-350) in combination with intraoperative radiotherapy is ongoing in Japan for localized unresectable pancreatic cancer. However, few data have been reported on the radiosensitivity and hypoxic fraction of human pancreatic cancers, and the efficacy of doranidazole against them. This study was undertaken to address these issues. MATERIALS AND METHODS: In vitro, four established human pancreatic cancer cell lines (SUIT-2, PANC-1, MIA PaCa-2 and BxPC-3) and murine SCCVII tumor cells (for comparison) were used. These cells were treated with 0.4 or 1 mM doranidazole for 45 mm prior to and during aerobic or hypoxic irradiation, and the cell survival was determined using the colony assay. In vivo, Balb/c nude mice bearing the pancreatic cancers (about 200 mg) on their backs received whole-body irradiation either after cervical dislocation, without physical restraint or anesthesia, or 20 min after intravenous injection of 100 mg/kg (0.4 mmol/kg) or 250 mg/kg (1 mmol/kg) of doranidazole. Following irradiation, the in vivo-in vitro assay was performed. The hypoxic fraction was estimated by the paired survival curve method. RESULTS: Regarding in vitro radiosensitivity, there were no characteristics common to the four pancreatic cancer cell lines. In vitro, doranidazole had no sensitizing effect under aerobic conditions, but under hypoxic conditions, its sensitizer enhancement ratio (SER) was 1.25-1.3 at 0. 4 mM and 1.4-1.55 at 1 mM against the four pancreatic cancer cell lines. These SERs were similar to those obtained in SCCVII cells. In vivo, the hypoxic fraction was 20% (95% CI, 11-38%) in SUIT-2, 14% (6.5-28%) in PANC-1, 10% (5.9-16%) in MIA PaCa-2, and 27% (15-46%) in BxPC-3 tumors. The SER of doranidazole was 1.15-1.3 at the dose of 100 mg/kg and 1.35-1.45 at 250 mg/kg. CONCLUSIONS: The four xenografted human pancreatic cancers had hypoxic fractions of 10-27% (mean: 18%). Doranidazole had definite in vitro and in vivo effects on all pancreatic cancer cell lines.

Animals↗

PubMed2000

Efficacy of conventional radiotherapy for recurrent meningioma.

Results of radiation therapy for 20 patients with recurrent meningioma were analyzed. The patients included 8 men and 12 women, with a median age of 55 years. All of the patients had undergone at least one operation prior to the reoperation preceding radiotherapy. Ten patients had benign meningiomas, while 4 and 6 patients had atypical and malignant meningiomas, respectively, at the time of radiotherapy. The median radiation dose was 59.4 Gy (range: 50-61.2 Gy). The local control rate at 5 years was 36% for all 20 patients (41% for benign meningiomas and 30% for atypical or malignant meningiomas). The 5-year survival rate was 47%. Excluding 2 patients whose follow-up period was shorter than the preradiotherapy interval from the previous operation, the postradiation recurrence-free period was longer than the preradiotherapy interval in 50% (9/18) of the patients. No serious complications of radiotherapy were observed. Radiotherapy seemed to be effective in controlling the tumor or delaying recurrence in at least half of the patients. However, higher doses of radiation, using sophisticated radiation techniques, may be necessary to obtain higher control rates.

Adolescent↗

PubMed2000

Long-term results of radiation therapy for pituitary adenoma.

PURPOSE: Local control for pituitary adenomas treated with external beam radiation therapy was retrospectively analyzed to evaluate the efficacy of radiation. MATERIALS AND METHODS: Thirty-eight patients treated with radiation therapy between 1979 and 1994 were analyzed. The median age was 46. Nineteen newly diagnosed tumors were treated with surgery and radiation therapy, while the others were recurrent cases. Twenty-two tumors were non-functioning, while 10 produced growth hormone (GH) and three each were prolactin-, and adrenocorticotropic hormone (ACTH)-producing tumors. The median-radiation dose was 50 Gy in 25 fractions. RESULTS: Non-functioning adenomas and prolactin-producing adenomas were completely controlled, judging from the absence of tumor progression on neuroimaging studies and clinical symptoms, and normalization of the serum prolactin level (< 25 ng/ml). On the other hand, local control was obtained in only one of the 3 patients with ACTH-producing adenomas, and the control rate at 10 years was only 46% for GH-producing adenomas. Panhypopituitarism developed in 35% of the patients after radiation therapy. No other serious complications were noted. CONCLUSION: Non-functioning pituitary adenomas and prolactin-producing adenomas were well controlled with external radiation therapy combined with surgery. However, dose escalation might be necessary to control GH-or ACTH-producing tumors. It is important to replace corticosteroid hormone and thyroid hormone in many patients.

Adolescent↗