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PubMed1981

[Comparative evaluation of hydroxyproline in urine and in serum as a possible clinical parameter for radiation-induced destruction of connective tissue due to fractionated radiation therapy (author's transl)].

In the course of postoperative fractionated radiation therapy hydroxyproline was evaluated as a biochemical parameter of radiation damage in 60 patients with different tumour diseases. At different times before, during and after therapy, hydroxyproline in serum was evaluated according to the method of Dabew and Struck, hydroxyproline in urine according to the test combination "hypronosticon" (Organon-Technika). There was no correlation to be found between hydroxyproline in serum or urine, clinical course of disease and radiation dose. Possible explanations were discussed.

Cobalt Radioisotopes↗

PubMed1980

Initial events in radiation-induced atheromatosis. IV. Lipid composition of radiation-induced plaques.

Ionizing irradiation produced atheromas in the carotid arteries of hypercholesteremic rabbits which received a 0.5% cholesterol diet during 6 weeks. During this relatively short feeding period no atheromas were formed in the nonirradiated carotid arteries. When the animals received this diet for 5 months or a 2% cholesterol diet for 3 months also diet-induced atheromatosis could be found in the latter blood-vessels. A comparison was made between the lipid composition of the diet-induced and the radiation-induced fatty plaques. In all types of plaques the neutral lipids formed about 75 percent of the total lipids, esterified cholesterol being formed the main part of it followed by free cholesterol, phosphatidylcholine and sphingomyelin. A great similarity exists between the lipid composition of the diet-induced fatty plaques of the carotid artery, the aorta and the radiation-induced fatty plaque. It is concluded that radiation is one of the initiating factors in the atheromatous process of the large blood-vessels, leading to lipid infiltration because of injury to the endothelium.

Animals↗

PubMed1993

Rational integration of radiation and chemotherapy in patients with unresectable stage IIIA or IIIB NSCLC. Results from the Lung Cancer Study Group, Eastern Cooperative Oncology Group, and Radiation Therapy Oncology Group.

About 40 percent of all patients diagnosed with non-small-cell lung cancer (NSCLC) have locally advanced stage IIIA or IIIB disease. Such disease is at the borderline of anatomic resectability and associated with poor survival prospects with any present therapy. The Lung Cancer Study Group, Eastern Cooperative Oncology Group, and Radiation Therapy Oncology Group, among other North American clinical cooperative groups, have integrated radiation and chemotherapy in an attempt to prolong survival and, in some cases, cure patients with unresectable NSCLC. These two modalities have been given sequentially, concurrently, and in an alternating fashion with varying degrees of success. Trials employing cisplatin-containing chemotherapy have produced more positive results than those using other regimens, although this is not invariably so. Clearly, better treatments are needed for local and systemic disease. This paper considers possible mechanisms for combining radiation and chemotherapy, reviews the status of recent and current clinical trials, and outlines some directions for future research.

Antineoplastic Agents↗

PubMed1996

Radiation therapy for early glottic carcinoma (T1N0M0). The final results of prospective randomized study concerning radiation field.

PURPOSE: To investigate the effect of radiation field on the local control of early glottic carcinoma by prospective randomized study. PATIENTS AND METHODS: From May 1982 through February 1992, a total of 273 patients with early glottic carcinoma (T1N0M0) was treated at our department with a wedge filter technique using a shell to improve the dose distribution and immobilization during radiotherapy with 4 MV X-ray. Patients were randomly allocated to either treatment group A (radiation field size: 5 x 5 cm) or B (6 x 6 cm) using bilateral parallel opposed portals. Total radiation dose administered was 60 Gy in 30 fractions over a 6-week period. RESULTS: The 5-year recurrence-free survival rates were 88% in groups A and B (no significant difference). Minor chronic complication such as persistent arytenoid edema lasting more than 6 months or benign polypoid lesion of vocal cord was more frequently observed in group B (23%) than in group A (17%) (p = 0.038) while acute mucosal reaction and skin reaction showed no significant differences. CONCLUSION: A small field (5 x 5 cm) with an appropriate angle of wedge filter and shell fixing device is recommended to avoid adverse effect with keeping local control of early glottic carcinoma.

Actuarial Analysis↗

PubMed1977

[Radiation therapy in patients with electronic cardiac pacemakers: interferences with the pacemaker's function by ionizing radiation and other sources of disturbances (author's transl)].

In the course of radiation therapy and connected diagnostical measures ionizing radiation and other sources of disturbance may interfere with the function of permanent pacemakers. The conditions of such hazards are investigated in theory and practice making allowance for the different susceptibility to trouble of various models of permanent pacemakers. It appears that no extension of long-term follow-up of the cardiac pacemaker's function is needed with regard to possible late effects of ionizing radiation, but that the follow-up of pacemaker-patients during their first period of treatment should not be neglected, since other sources of electronic interference may be present. Routine checks as radiotherapy installations should also include possible sources of disturbance to electronic pacemakers.

Aged↗

PubMed1998

Bax protein expression correlates with radiation-induced apoptosis in radiation therapy for cervical carcinoma.

BACKGROUND: Bax protein serves as a positive regulator of apoptosis by forming heterodimers with bcl-2 protein, thereby promoting cell survival. It is unclear whether the regulation of apoptosis reported in many studies is applicable to the apoptotic phenomenon observed in conventional fractionated radiation therapy for cervical carcinoma. METHODS: The authors assessed the relation between apoptosis and the expression of Bax and bcl-2 protein in fractionated radiation therapy for cervical carcinoma by using in situ nick end labeling (ISEL) and immunohistochemical methods. RESULTS: Specimens were excised from the cervical tumors of 20 patients before and after administration of a total irradiation dose of 9 gray (Gy). The apoptotic cell index (AI) in tumor cells was 0.22% before irradiation and 1.20% after the administration of the 9 Gy, which represented a significant increase (P=0.0004). The positive rate of Bax protein increased from 15% (in 3 of 20 patients) before irradiation to 60% (in 12 of 20 patients) after the 9 Gy was administered, a statistically significant change (P=0.0126). In addition, there was a significant correlation between Bax protein expression and apoptosis positivity after the 9 Gy was administered (P=0.018). CONCLUSIONS: These results suggest that Bax protein is associated with apoptosis induced by fractionated radiation therapy.

Apoptosis↗

PubMed1977

The application in radiation therapy of substances which modify cellular radiation response.

Compounds to be considered as potential adjuvants in radiotherapy should indicate a strong mechanistic rationale for a differential response between tumor and normal tissues. Drugs which selectively radiosensitize hypoxic cells might be exploited in radiotherapy to increase the sterilization of resistant hypoxic areas of solid tumors which have outgrown their vascular supply. Several compounds have been shown to selectively radiosensitize hypoxic mammalian cells in vitro but their application in clinical studies in presently limited by their toxicity at the high drug dosages required to effect the sensitization. Phase I and Phase II clinical studies have now been completed with the sensitizer, metronidazole. This drug was tolerated by patients at dosages of 6 g/m2 three times a week for 3 weeks with a minimum of side effects, and survival of patients with glioblastoma multiforme treated with fractionated radiotherapy was significantly increased when the sensitizer was used in combination with the radiation. Drugs which selectively radioprotect oxygenated cells might also be exploited in therapy be permitting the use of higher radiation doses and thereby incurring more damage to the resistant hypoxic cells in tumours. Again, drug toxicity appears to be a limiting factor with this approach. If toxicities are not additive, combinations of radiosensitizers and radioprotectors might prove more effective than either individual approach.

Amifostine↗

PubMed1978

[The indication of radiation treatment for irradiated chicken on the basis of the radiation--induced loss of protein sulfhydryl groups (author's transl)].

A spectrophotometric technique for the identification of irradiated chicken (gallus domesticus) and doses ranging between 0.1 and 2.5 Mrad is described. Spectrophotometric determination of the sulfhydryl content in the animal tissue before (control) and after using 6,6'-Dithiodinicotinic acid is applied. Ionizing radiation causes a permant loss of sulfhydryl groups in the animal tissue such as chicken. Irradiation at room temperature and storing at -18 degrees C over a period of approximately one month does not show restitution or repair of the sulfhydryl loss. The dose-effect relation for this radiation-induced decrease of the sulfhydryl content can be described best by a double exponential function. Irradiation conditions, preparation of protein suspension from chicken, spectrometric investigations and other experimental details are reported. The results of all will be discussed in detail.

Animals↗

PubMed1993

Radiation-induced chromosomal aberrations in the bone marrow of mice exposed to various doses of gamma radiation.

The occurrence of chromosomal aberrations was studied at 1-14 days post-exposure in female BALB/c mice exposed to various doses of gamma radiation. The frequency of abnormal cells, chromatid and chromosome breaks, dicentrics, centric rings, acentric fragments and total aberrations increased with exposure dose, and it was highest at 7 Gy. A peak was recorded on day 1 post-exposure with a gradual decline thereafter. The chromosomal aberration yield reached a nadir on day 14 post-irradiation, without restoration to the control level. The best fit for the present data was by a linear-quadratic relationship between dose of radiation and the frequency of chromosomal aberrations.

Animals↗

PubMed2003

Differentiation between recurrent tumor and radiation necrosis in a child with anaplastic ependymoma after chemotherapy and radiation therapy.

BACKGROUND: In patients after treatment for malignant brain tumors, a clear distinction between tumor recurrence and radiation necrosis can be challenging. This case report describes the diagnostic workup in a child with anaplastic ependymoma and inconclusive MRI (magnetic resonance imaging) and PET (positron emission tomography) findings. CASE REPORT: 1.5 years after resection, hyperfractionated radiotherapy and chemotherapy of an anaplastic ependymoma in the right parietal region, the cranial MRI of an 11-year-old girl showed multiple small contrast-enhanced lesions in the frontal cortex. In the following months, these lesions increased in number and size and neurologic symptoms developed. Diagnostic workup included repeated MRI scans, PET with an (18)F-amino acid and (18)F-fluorodeoxyglucose (FDG), as well as a brain biopsy. RESULTS: Amino acid PET, performed when the lesions were still small, showed multiple small areas of mild uptake in close correlation to the MRI lesions. Although not typical, this result was suspicious of tumor seeding, the more since the lesions appeared in gray matter areas outside the high-dose-rate irradiation field. A biopsy, performed 6 months later when the clinical appearance worsened, showed no tumor tissue. FDG PET, performed after the size and number of the lesions had increased, showed no intensely increased glucose metabolism, a high-grade recurrent tumor was therefore very unlikely. In the following months, the clinical picture stabilized. CONCLUSION: The final interpretation of the lesions was multiple focal radiation necrosis based on perfusion abnormalities after chemotherapy and conformal hyperfractionated radiotherapy, probably due to an individually enhanced vulnerability of the cerebral vessels.

Biopsy↗

PubMed1984

Chronic damage after radiation therapy: challenge to radiation biology.

After local irradiation of the heart or the recto-sigmoid of rats, chronic radiation damage develops after several months, leading to well-defined clinical syndromes of fatal pericarditis and myocardial necrosis or fatal ileus. In both organs, the LD-50 is below 20 Gy, and a pronounced split dose recovery has been measured with fractionated irradiation. In both organs, the primary radiation damage appears to be to the capillaries, which then leads to secondary parenchymal atrophy. Damage to structured vessels and fibrosis was only seen in areas of necrosis, which in the gut might be precipitated by secondary trauma to the atrophic mucosa.

Animals↗

PubMedDate not supplied

Estimation of radiation dose received during treatment of in-stent restenosis using ionizing radiation.

BACKGROUND: Angioplasty is a widely accepted procedure for the treatment of coronary artery disease. However, restenosis of the treated vessel occurs in 30% of patients within 6 months. Intravascular brachytherapy (IVB) is used to inhibit the formation of new tissue growth at the vessel treatment site. IVB protocols using either gamma ray or beta particle emitting isotopes have been tested and approved. However, very little data are available on resultant whole-body dose and the potential for long-term radiation effects. METHODS: Using thermoluminescence dosimetry (TLD) devices, specifically lithium fluoride (LiF) doped with Mg, Cu, and P, the radiation dose on the surface of patients undergoing IVB was measured. The TLDs were positioned on the body to obtain a measure of the gamma dose at selected anatomic locations. Additionally, the skin dose from fluoroscopy was estimated. RESULTS: Measurements indicate that the average body dose on the skin surface from all TLDs, clinical requirements, and gamma source configurations varies from 0.95 mSv (95 mrem) at the head to 27.06 mSv (2706 mrem) at the sternal notch. For beta sources, the dose varied from 0.11 mSv (11.4 mrem) at the head to 0.49 mSv (49.5 mrem) at the sternal notch. The fluoroscopy contribution of dose to the body dose (15-min exposure time) was 0.10 mSv (10 mrem) at the head and 2.57 mSv (257 mrem) to the sternal notch. CONCLUSIONS: The results suggest that surface skin exposures from gamma sources used in IVB pose acceptable risks considering the medical benefits of the procedures.

Brachytherapy↗

PubMed1998

Radiation-induced impairment of bone healing in the rat femur: effects of radiation dose, sequence and interval between surgery and irradiation.

BACKGROUND AND PURPOSE: Impairment of osseous healing in treatment combining surgery and radiotherapy is a frequent complication. Its dependence on sequence and interval was studied in a defined experimental model. MATERIALS AND METHODS: The effect of pre- and postoperative irradiation by single doses of X-rays on osseous closure of a 1.2 mm drill hole in the rat femur was measured 6 or 7 weeks after surgery in histological sections using morphometrical methods. RESULTS: Irradiation delivered between 1 day and 6 months before surgery resulted in a reduction of bone healing following very similar dose response relationships; there was no evidence of any slow repair of latent radiation damage. Radiosensitivity of bone healing during the first 3 days after surgery was not different from preoperative irradiation; however, irradiation 4 days or later after surgery failed to reduce osseous healing even after very high radiation doses. CONCLUSION: Tolerance increases enormously if radiotherapy is given later than 4 days after surgery. This has great implications for combined radiotherapy and surgery schedules involving bone reconstruction, but may be even more important for radiotherapy applied to prevent heterotopic ossification after total hip arthroplasty. Biologically, target cell regeneration alone is insufficient to account for the drastic rise in radiotolerance; it must be accompanied by an increase in cellular resistance due to differentiation.

Animals↗

PubMed1997

Radiation techniques for the treatment of Hodgkin's disease with combined modality therapy or radiation alone.

This article reviews radiation techniques including field arrangements, anatomic borders, and doses for the treatment of Hodgkin's disease when radiotherapy is being used as the sole treatment and when it is part of a planned combined modality program with chemotherapy. We describe the techniques currently in use at Duke University Medical Center. Particular emphasis is placed on the evidence regarding the appropriate extent of the treatment field and the doses of radiation necessary to achieve local control. These issues assume increasing importance as we attempt to maintain high cure rates for Hodgkin's disease but lower the frequency of serious long-term complications.

Adult↗

PubMed2001

[Body build and radiation exposure in static roentgen studies (I): A contribution for determining a national reference dose value. Promoted by the Federal Office for Radiation Protection (St.Sch 4163)].

PURPOSE: To contribute data on radiation exposure in static x-ray procedures and to compare them with anthropometric parameters. METHOD: 121 chest x-rays and 100 lumbar spine examinations were carried out and the dose-area product (DAP) measured for each of the projections. Additionally, body height, body weight and the sagittal and transversal diameters of the examined regions were recorded. Dose measurements were statistically evaluated and the following data determined: Frequency distribution, median, 25%- and 75%-percentiles as well as correlations with sex, body weight and diameters. RESULTS: Median DAP was 13 (men: 16; women: 11) resp. 50 (62; 37) cGycm2 with pa resp lateral chest x-ray. Values were closely correlated with body weight (r = 0.704/0.659) and diameter of the chest (r = 0.657/0.579). Median DAP was 175 (239; 126) resp 531 (670; 361) cGycm2 with ap resp lateral lumbar spine examinations. Values were closely correlated with body weight (r = 0.678/0.666) and diameter of the abdomen (r = 0.664/0.658). CONCLUSIONS: DAP of chest x-rays and lumbar spine examinations is strongly influenced by the constitution of the patients. Men are nearly twice as largely exposed to radiation as women.

Adult↗

PubMed1985

[Calculation of radiation dose in changes in solar UV-B radiation with regard to keratitis photoelectrica].

With the help of the keratitis action spectrum and the solar spectrum for various elevations, the intensity of solar radiation that produces keratitis is calculated depending on altitude for terrain with and without snow cover. There is a 17-fold increase in midday solar intensity from winter to summer. In summer the intensity increases by 16% for every 1000 meters of altitude. For a subject observing snow-covered terrain, the intensity is 16 times greater than when the same terrain is observed without snow cover. For clinically observed cases of photoelectric keratitis caused by solar radiation it is possible to calculate the doses involved. They range between 1200 J/m2 and 5600 J/m2. These values are discussed in terms of a threshold dose, and it is concluded that this threshold dose is much higher than in the case of short-term irradiation such as occurs during welding. The difference between these two threshold doses is presumably explained by a repair mechanism.

Altitude↗

PubMedDate not supplied

Epidemiological studies on disturbances of human fetal development in areas with various doses of natural background radiation. II. Relationship between incidences of hydatidiform mole, malignant hydatidiform mole, and chorionepithelioma and gonad dose equivalent rate of natural background radiation.

The relationships between gonad dose equivalent rates and incidences of chorionic disease (i.e., hydatidiform mole, malignant hydatidiform mole, and chorionepithelioma) were analyzed with Kendall's rank correlation and regression methods. Data used were from 11 prefectures of Japan with various dose rates of natural background ionizing radiation between the years 1974 to 1976. The results suggested an association of the incidence of chorionic disease with the radiation dose rate in the very low dose-rate range.

Adult↗

PubMed2006

Accreditation and quality assurance for Radiation Therapy Oncology Group: Multicenter clinical trials using Stereotactic Body Radiation Therapy in lung cancer.

Starting in 2002, the Radiation Therapy Oncology Group in North America began the process of developing multicenter prospective trials in lung cancer using Stereotactic Body Radiation Therapy (SBRT). Much of the work was based on the prospective single institution trials from Indiana University that had been presented and published. In late 2004, RTOG 0236 using SBRT for medically inoperable patients with clinical stage I non-small cell lung cancer (NSCLC) was activated for accrual. Prior to activation, representatives from the Lung, Image-Guided Therapy, Physics, and Radiobiology Committees met on regular occasions to design the multicenter study and quality assurance measures. SBRT is not a black box, and the essence of the therapy had to be distilled via guidelines. Issues related to patient selection, method of dosimetry construction, equipment requirements, motion assessments and control, site accreditation, data exchange, and follow-up policies were worked out by compromise and consensus. RTOG 0236 has nearly completed its accrual. The Lung Committee has initiated the development of several other trials, each building on the last, to investigate the therapy in central tumors, in combinations with systemic therapy, in operable patients, and in lung metastases patients. The guidelines developed for RTOG 0236 will be refined to take advantage of more modern innovations including heterogeneity corrections and intensity modulation when appropriate. The development of RTOG 0618 using SBRT in operable patients with early stage NSCLC is a testament to both the enthusiasm from already published works and prospective multicenter clinical testing using SBRT techniques.

Accreditation↗