Biomedical subjects

Hideo Tatsuzaki

Publications and source records attributed to Hideo Tatsuzaki.

7 recordsLinked to original sources

PubMed2006

AK-2123 (Sanazol) as a radiation sensitizer in the treatment of stage III cervical cancer: results of an IAEA multicentre randomised trial.

PURPOSE: AK-2123, a nitrotriazole hypoxic cell sensitizer, has reportedly improved results in head and neck cancers, uterine cervical cancers and other solid tumours when added to radical radiotherapy. A prospectively randomised trial was initiated by the International Atomic Energy Agency (IAEA) evaluating AK-2123 and radiotherapy in treatment of uterine cervical cancer stage III and IV. PATIENTS AND METHODS: A total of 462 patients were randomised from 8 centres. Patients from four centres were excluded due to lack of accrual, closing of the centre and insufficient documentation and reporting. The final study population consisted of 333 patients who were randomised between May 1995 and December 1998. Patients were randomised to either standard radical treatment (radiation therapy alone, RT) or standard radical radiotherapy and additional administration of AK-2123 (RT+AK-2123). The total dose of 45-50.8 Gy was delivered by 20-28 fractions in an overall time of 4-5 1/2 weeks, with further dose escalation by brachytherapy or external beam. In the study arm, patients received 0.6 g/sqm AK-2123 by intravenous administration before external beam radiotherapy, treating with AK-2123 on alternate days (e.g. Monday-Wednesday-Friday) during the entire course of external beam therapy. Following exclusion of 7 patients who did not undergo treatment, a total of 326 patients remained for evaluation. RESULTS: The rate of local tumour control was significantly higher in the group after radiotherapy and additional administration of AK-2123. Local tumour control was 61% (95/155) after AK-2123 and 46% (79/171) after radiotherapy alone (p=0.006). The actuarial survival at 60 months was 57% after RT+AK-2123, compared to 41% after RT (Log Rank p=0.01). AK-2123 did neither increase gastro-intestinal toxicity nor was it attributed to any haematological toxicity. A mild peripheral toxicity (Grade 1: 13% and Grade 2: 2%) usually completely reversible was infrequently seen after AK-2123 administration. CONCLUSION: We conclude that the addition of AK-2123 to radical radiotherapy significantly increases local tumour control and survival in advanced squamous cell cancer of the uterine cervix without the addition of any major toxicity.

Adult↗

PubMed2005

Regional hyperthermia combined with radiotherapy for uterine cervical cancers: a multi-institutional prospective randomized trial of the international atomic energy agency.

PURPOSE: Hyperthermia can be used to enhance the effects of radiation, and a combined treatment may, in some circumstances, be an advantage. Uterine cervical cancer is very common in developing countries. The control of locally advanced pelvic tumors is difficult with conventional treatment modalities. Based upon the biologic rationale and in view of the recent advances in heating and thermometry techniques, radiotherapy in combination with hyperthermia was investigated in a multi-institutional prospective randomized trial sponsored by the International Atomic Energy Agency. The primary purpose was to clarify whether the combination of hyperthermia and radiotherapy improves the rate of local control, compared with radiotherapy alone. METHODS AND MATERIALS: A total of 110 patients with biopsy-proven, locally advanced carcinoma of the uterine cervix were randomized to treatment by radiotherapy with or without hyperthermia. The patients were stratified by institution, stage, and histologic type. Each patient received external beam radiation therapy and brachytherapy. For the patients randomized to receive hyperthermia, a minimum of five sessions (60 min each, once per week) were administered, employing a radiofrequency (RF) capacitive heating device. Intratumoral temperature was measured at the first hyperthermic treatment, and at least once more during the course of treatment. The equipment and the policies and procedures at each participating institution except one (Pusan) were personally inspected at least once by the corresponding author, to ensure that quality assurance procedures were in place and were followed for treatment according to the protocol guidelines. The median follow-up period was 466 days for all the patients and 512 days for the surviving patients. RESULTS: The two arms were well balanced with regard to the patient factors, tumor factors, and treatment factors. The overall survival rate at 3 years was 73.2%, and the local control rate was 68.5%. There were no significant differences between the patients treated with or without hyperthermia, either with regard to the survival (p = 0.1893) or the rate of local control (p = 0.58). The survival was significantly worse among the patients with Stage IIb disease who received hyperthermia (p = 0.0162) although there was no difference in their rate of local control (p = 0.7988). Further analysis is necessary to determine if the difference in survival is due to a greater incidence of distant metastases or some other cause. Acute Grade 2-3 toxicity was seen in 10/55 patients (18%) treated by hyperthermia and in 2/55 of the patients (4%) treated without hyperthermia (p = 0.01). There was no significant difference in the late toxicity observed in the two arms. CONCLUSION: This prospective randomized study failed to show any benefit from the addition of hyperthermia to radiotherapy in the treatment of locally advanced carcinoma of the uterine cervix. The acute toxicity was significantly greater among the patients receiving hyperthermia, and the survival was significantly worse among the Stage IIb patients receiving hyperthermia even though there was no difference in the local control rate.

Adult↗

PubMed2004

Long-term changes in rabbit cornea after ionizing radiation.

PURPOSE: To investigate long-term changes in the cornea after ionizing irradiation in rabbits. METHODS: Mature albino rabbits (n = 4) were unilaterally irradiated with 20 Gy of x-rays. The contralateral eye served as a control. The rabbits were examined with slit-lamp biomicroscopy for 5 years. The eyes were then enucleated for histopathologic examinations with light microscopy and transmission electron microscopy. RESULTS: On biomicroscopy, there was no corneal abnormality during the 5-year follow-up period. On histopathology, no abnormality was observed in the corneal epithelium. In the endothelium, a vacuole-like structure was recognized by light microscopy, and transmission electron microscopy revealed marked enlargement of intercellular space and anamorphosis of the nuclei. CONCLUSION: Moderate x-ray irradiation to rabbit eye did not induce any long-term damage to the corneal epithelium, but the endothelium demonstrated persistent and irreversible damage, which was observed even 5 years after irradiation.

Animals↗

PubMed2003

Radiotherapy with or without mitomycin c in the treatment of locally advanced head and neck cancer: results of the IAEA multicentre randomised trial.

BACKGROUND AND PURPOSE: Single agent mitomycin c (MMC) has been shown to improve the outcome of radiotherapy in single institution trials. In order to confirm these findings in a broader worldwide setting, the International Atomic Energy Agency (IAEA) initiated a multicentre trial randomising between radiotherapy alone versus radiotherapy plus MMC. MATERIAL AND METHODS: Patients with advanced head and neck cancer were treated with primary curative radiotherapy (66 Gy in 33 fractions with five fractions per week) +/-a single injection (15 mg/m(2)) of MMC at the end of the first week of radiotherapy. Stratification parameters were tumour localization, T-stage, N-stage, and institution. A total of 558 patients were recruited in the trial from February 1996 to December 1999. Insufficient accrual and reporting led to the exclusion of three centres. The final study population consisted of 478 patients from seven centres. Patients had stage III (n=223) or stage IV (n=255) squamous cell carcinoma of the oral cavity (n=230), oropharynx (n=140), hypopharynx (n=65) or larynx (n=43). Prognostic factors like age, gender, site, size, differentiation and stage were well balanced between the two arms. RESULTS: The haematological side effects of MMC were very modest (<5% grade 3-4) and did not require any specific interventions. Furthermore, MMC did not enhance the incidence or severity of acute and late radiation side effects. Confluent mucositis and dry skin desquamation was common, occurring in 56% and 62% of patients, respectively. The overall 3-year primary locoregional tumour control, disease-specific and overall survival rates were 19, 36 and 30%, respectively. Gender, haemoglobin drop, tumour site, tumour and nodal stage were significant parameters for loco-regional tumour control. There was no significant effect of MMC on locoregional control or survival, except for the 161 N0 patients, where MMC resulted in a better loco-regional control (3-year estimate 16% vs. 29%, P=0.01). CONCLUSIONS: The study did not show any major influence of MMC on loco-regional tumour control, survival or morbidity after primary radiotherapy in stage III-IV head and neck cancer except in N0 patients where loco-regional control was significantly improved.

Adult↗

PubMed2002

Radiotherapy services in countries in transition: gross national income per capita as a significant factor.

BACKGROUND AND PURPOSE: The acquisition of radiotherapy by countries in transition (CITs) is an evolutionary process from having no resources whatsoever, to meeting the standards adopted by well-developed countries. The influence of the economic ability of a country to acquire and sustain this technology has intuitively been accepted as a major factor but has not before been subjected to analysis for a large group of countries. This information has been analysed to provide guidance to countries commencing and expanding radiotherapy services. MATERIAL AND METHODS: The number of linear accelerators and (60)Co megavoltage teletherapy machines in 72 CITs, those with gross national income per capita (GNI/cap)<$12000 per annum (pa) and a sample of 12 countries with GNI/cap>$12000 pa were expressed as machines per million population (MEV/mil) and used as an index of the ability of the country to provide a service. This figure was related to GNI/cap. The average populations of 24 further countries without radiotherapy were compared with 21 countries with radiotherapy facilities having the same range of GNI/cap. RESULTS: The relationship log(10) MEV/mil=-2.90+0.85 log(10) GNI/cap was identified between the machines and income. Also verified was that small low income countries were less likely to have the technology than those with large populations. CONCLUSIONS: The increase in the number of teletherapy machines is closely linked to the GNI/cap of a country. Our sample of well developed countries failed to demonstrate a levelling off of equipment acquisition with income. In the lower income group, smaller countries were less likely to have radiotherapy services than those with large populations.

Developing Countries↗

PubMed2002

Recommendations for implementation of high dose rate 192Ir brachytherapy in developing countries by the Advisory Group of International Atomic Energy Agency.

PURPOSE: To provide recommendations for the implementation of high dose rate (HDR) 192Ir brachytherapy technology in developing countries. METHODS: An Advisory Group Meeting of the International Atomic Energy Agency (IAEA) met to address the implementation of HDR 192Ir brachytherapy technology in developing countries. These recommendations reflect only the personal opinions of the authors and do not necessarily represent the opinion of the IAEA. RESULTS: An HDR treatment system should be purchased as a complete unit that includes the 192Ir radioactive source, source loading unit, applicators, treatment planning system, and control console. Infrastructure support may require additional or improved buildings and procurement of or access to new imaging facilities. A supportive budget is needed for quarterly source replacement and the annual maintenance necessary to keep the system operational. The radiation oncologist, medical physicist, and technologist should be specially trained before HDR can be introduced. Training for the oncologist and medical physicist is an ongoing process as new techniques or sites of treatment are introduced. Procedures for quality assurance (QA) of patient treatment, and the planning system must be introduced. Emergency procedures with adequate training of all associated personnel must be in place. CONCLUSIONS: The decision to select HDR in preference to alternate methods of brachytherapy is influenced by the ability of the machine to treat a wide variety of clinical sites. In departments with personnel and budgetary resources to support this equipment appropriately, economic advantage becomes evident only if large numbers of patients are treated. Intangible benefits of source safety, personnel safety, and easy adaptation to fluctuating demand for treatments also require consideration when evaluating the need to introduce this treatment system.

Brachytherapy↗

PubMed2002

Sanazole as a sensitizer of hypoxic cells with radical radiation in the treatment of advanced cancer of cervix an Indian experience.

AK-2123, is a nitrotriazole with a potential to sensitize hypoxic tissue to radiation. Cancer of cervix in advanced stages are predominantly treated with radiation. These are the tumours which harbour a large hypoxic core. This is an Indian experience of the multicentric trial. Patients were randomized to control and AK-2123 arm. 49 patients were randomized to each group. Patients received external radiation with telecobalt to a dose of 50 Gy in five weeks. Those in the study arm received 600 mg/m2, on alternate days. The patients were further treated with intracavitory radiation a dose of 20 Gy. The total dose of 70 Gy was achieved. Patients in the study arm had a complete response of 71.43% (35 of 49) while only 21 of 49 (42.86%) responded in the control group. The overall survival at two years was 72.2% for the study group and 32.43% for control. Neuropathy, a drug related toxicity was transient except, in one patient, which has persisted. AK-2123, has shown significant radiation sensitizing potential.

Adult↗