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At least 379 records · Page 21Linked to original sources
PubMed2001

Correlation between lung fibrosis and radiation therapy dose after concurrent radiation therapy and chemotherapy for limited small cell lung cancer.

PURPOSE: To evaluate the relationship between physician-identified radiographic fibrosis, lung tissue physical density change, and radiation dose after concurrent radiation therapy and chemotherapy for limited small cell lung cancer. MATERIALS AND METHODS: Fibrosis volumes of different severity levels were delineated on computed tomography (CT) images obtained at 1-year follow-up of 21 patients with complete response to concurrent radiation therapy and chemotherapy for limited small cell lung carcinoma. Delivered treatments were reconstructed with a three-dimensional treatment planning system and geometrically registered to the follow-up CT images. Tissue physical density change and radiation dose were computed for each voxel within each fibrosis volume and within normal lung. Patient responses were grouped per radiation and chemotherapy protocol. RESULTS: A significant correlation was noted between fibrosis grade and tissue physical density change and fibrosis grade. For doses less than 30 Gy, the probability of observing fibrosis was less than 2% with conventional fractionation and less than 4% with accelerated fractionation. Physical lung density change also showed a threshold of 30-35 Gy. For doses of 30-55 Gy and cisplatin and etoposide (PE) chemotherapy, fibrosis probability was 2.0 times greater for accelerated fractionation compared with conventional fractionation (P < .005) and was correlated to increasing dose for both fractionation schedules. CONCLUSION: Lung tissue physical density changes correlated well with fibrosis incidence, and both increased with increasing dose greater than a threshold of 30-35 Gy. With concurrent PE chemotherapy, fibrosis probability was twice as great with accelerated fractionation as with once-daily fractionation.

Absorptiometry, Photon↗
PubMedDate not supplied

Analysis of radiation pneumonitis and radiation-induced lung fibrosis in breast cancer patients after breast conservation treatment.

We examined radiation pneumonitis in breast cancer patients after breast conservation treatment (BCT) and analysed the degree of radiation-induced lung fibrosis by computed tomographies of the chest (chest CT). Fifty-two breast cancer patients were treated with BCT, including breast irradiation and chemotherapy. These patients symptomatic of radiation pneumonitis were examined every two to four weeks. Chest X-rays and chest CT were performed about one year after irradiation. symptoms due to radiation pneumonitis was registered in 9.6% of patients. lungs showed fibrotic changes by chest CT in 90% of the cases. Concurrent or alternative chemotherapy increased the incidence of symptomatic radiation pneumonitis and, to a certain extent, the degree of fibrotic change in the lung after BCT.

Adult↗
PubMed2005

Chemoradiation for ductal pancreatic carcinoma: principles of combining chemotherapy with radiation, definition of target volume and radiation dose.

Review of the role of chemoradiotherapy in the treatment of locally advanced pancreatic cancer with a specific focus on the technical feasibility and the integration of chemoradiotherapy into multimodal treatment concepts. Combined chemoradiotherapy of pancreatic cancer is a safe treatment with an acceptable profile of side effects when applied with modern planning and radiation techniques as well as considering tissue tolerance. Conventionally fractionated radiation regimens with total doses of 45-50 Gy and small-volume boost radiation with 5.4 Gy have found the greatest acceptance. Locoregional lymphatic drainage should be included in the planning of target volumes because the risk of tumor involvement and local or loco-regional recurrence is high. Up to now, 5-fluorouracil has been considered the "standard" agent for concurrent chemoradiotherapy. The role of gemcitabine given concurrently with radiation has not yet been defined, since high local efficacy may also be accompanied by enhanced toxicities. In addition, no dose or administration form has been determined to be "standard" up to now. The focus of presently ongoing research is to define an effective and feasible regimen of concurrent chemoradiotherapy. While preliminary results indicate promising results using gemcitabine-based chemoradiotherapy, reliable data derived from mature phase III trials are greatly needed. Intensity-modulated radiotherapy has been developed to improve target-specific radiation and to reduce organ toxicity. Its clinical relevance still needs to be defined.

Antimetabolites, Antineoplastic↗
PubMed1987

[The development of radiation necrosis of the brain after radiation therapy].

Examination by questionnaire of 102 institutions utilizing radiation therapy throughout the country revealed 97 cases of radiation necrosis of the brain, 41 cases of which have received only one course of radiation therapy with either high energy x-rays or 60Co gamma-rays and that have been histologically confirmed for necrosis. The dose fractionation relationship causing necrosis presumed by Strandquvist's diagram proved to be located along the line with the slope of 0.44 from the interception of 9.9 Gy with a single irradiation. Our own experience of brain tumor and cancer of the paranasal sinus told 2 with developed necrosis (incidence, 0.6%) of 325 cases on radiation therapy at a dose of 50-60 Gy and 5 (incidence, 2.0%) of 253 cases on radiation therapy at a dose of more than 60 Gy.

Brain↗
PubMed1993

[Radiation accidents and radiation disasters].

Accidents and disasters involving ionizing radiation are rare. Such accidents may occur not only at nuclear power stations but also in medicine and in industry. Only fairly large radiation doses can give acute medical effects. Symptoms and signs depend on the actual dose, and on what parts of the body are irradiated. In connection with a radiation accident, the main points are to recognize in the first place that radiation may be involved, and to have some knowledge of the actual source. Risk of localized irradiation from industrial sources, especially of hands, is a problem that is often overlooked. The paper reviews the principles for action by local health officers, the pathogenesis of radiation injury and early medical management. Some information is also given on the Norwegian system of contingency preparedness against nuclear accidents.

Accidents↗
PubMedDate not supplied

[Effects of previous small-dose irradiation on blood reaction and survival of mice after subsequent radiation and combined radiation-thermal injuries].

CBA x C57BL6 mice pre-exposed to 5 cGy gamma-irradiation then inflicted to LD70/30 acute radiation or combined injuries (radiation + thermal burn). In such protocol of the experiments preliminary "adaptive" dose radiation did not modify low 30-day survival rate and did not render an influence to the mean survival time. Leucopenia level and bone marrow devastation in 3 days after sublethal irradiation (4 Gy) or combined injury was similar in mice pre-exposed to low dose radiation (5 cGy) and in their unexposed controls. "Adaptive" dose radiation decreased leukocytes' number within the phase of hemopoiesis recovery (in 14 day after sublethal irradiation or combined injury).

Animals↗
PubMed1999

Occupational radiation exposure and mortality: second analysis of the National Registry for Radiation Workers.

The National Registry for Radiation Workers (NRRW) is the largest epidemiological study of UK radiation workers. Following the first analysis published in 1992, a second analysis has been conducted using an enlarged cohort of 124,743 workers, updated dosimetry and personal data for some workers, and a longer follow-up. Overall levels of mortality were found to be less than those expected from national rates; the standardised mortality ratio for all causes was 82, increasing to 89 after adjusting for social class. This 'healthy worker effect' was particularly strong for lung cancer and for some smoking-related non-malignant diseases. Analysis of potential radiation effects involved testing for any trend in mortality risk with external dose, after adjusting for likely confounding factors. For leukaemia, excluding chronic lymphatic leukaemia (CLL), the central estimate of excess relative risk (ERR) per Sv was similar to that estimated for the Japanese atomic bomb survivors at low doses (without the incorporation of a dose-rate correction factor); the corresponding 90% confidence limits for this trend were tighter than in the first analysis, ranging from just under four times the risk estimated at low doses from the Japanese atomic bomb survivors to about zero. For the grouping of all malignancies other than leukaemia, the central estimate of the trend in risk with dose was closer to zero than in the first analysis; also, the 90% confidence limits were tighter than before and included zero. Since results for lung cancer and non-malignant smoking-related diseases suggested the possibility of confounding by smoking, an examination was made, as in the first analysis, of all malignancies other than leukaemia and lung cancer. In this instance the central estimate of the ERR per Sv was similar to that from the A-bomb data (without the incorporation of a dose-rate correction factor), with a 90% confidence interval ranging from about four times the A-bomb value to less than zero. For multiple myeloma there was an indication of an increasing trend in risk with external dose (p = 0.06), although the evidence for this trend disappeared after omitting workers monitored for exposure to internal emitters. The second NRRW analysis provides stronger inferences than the first on occupational radiation exposure and cancer mortality; the 90% confidence intervals for the risk per unit dose are tighter than before, and now exclude values which are greater than four times those seen among the Japanese A-bomb survivors, although they are also generally consistent with an observation of no raised risk. Furthermore, there is evidence, of borderline statistical significance, of an increasing risk for leukaemia excluding CLL, and, as with solid cancers, the data are consistent with the A-bomb findings.

Cohort Studies↗
PubMed2006

Radiation protection and safety in medical use of ionising radiation in Republic of Bulgaria--harmonization of the national legislation with Euratom directives.

From February 2002 to November 2003 the National Centre of Radiobiology and Radiation Protection conducted a PHARE twinning project 'Radiation Protection and Safety at Medical Use of Ionising Radiation'. The main purposes of the project were the harmonization of Bulgarian legislation in the field of radiation protection with EC Directives 96/29 and 97/43 Euratom, and the establishment of appropriate institutional infrastructure and administrative framework for their implementation. This paper presents the main results of the project: elaboration of Ordinance for Protection of Individuals from Medical Exposure; performance of a national survey of distribution of patient doses in diagnostic radiology and of administered activities in nuclear medicine and establishment of national reference levels for the most common diagnostic procedures.

Bulgaria↗
PubMedDate not supplied

[The grounds of interspices difference in radiation-genetic effects of low-level radiation].

Radiation-genetic effects are characterized by large quantitative difference. After the low dose radiation appearance of mutation is the largest in Drosophila, substantially lower in mice, especially if irradiation was protracted, and practically absent in humans. As the possible grounds of this difference the author consider the existence of non-specific repair mechanism, which has arouse during evolution for diminution of different detrimental impacts, including ionizing radiation. The efficacy of such mechanism of natural protection is determined by the efficacy of the repair mechanisms, which is elevated in compliance with specific life span, which is of necessity for its maintenance. The evolution has led to maximal development of this mechanism in human beings, and it is proved in particular in prevention of the hereditary effect of low-level radiation.

Animals↗
PubMed1987

[Radiation burden in heart catheter studies--significance of measures for reducing scatter radiation].

During diagnostic and, more particularly, therapeutic intervention, such as transluminal coronary angioplasty, the operator may be exposed to a considerable degree of scatter radiation. In our study, we measured the level of radiation exposure of the head, unprotected knees and lower legs. A flexible lead screen, attached to the catheterization table (0.5 mm Pb) reduced scatter radiation of the lower legs by 95%. In addition, scatter radiation exposure of the head decreased by 54% by covering the patient with a rubber leaden blanket (0.25 mm Pb). Finally, the use of these supplementary yet simple measures did not hinder or interfere with the examination procedure in any way.

Cardiac Catheterization↗
PubMed1979

Carcinoma of the esophagus: pretreatment assessment, correlation of radiation treatment parameters with survival, and identification and management of radiation treatment failure.

Between January 1969 and February 1975, 344 patients with carcinoma of the esophagus were managed primarily at the Princess Margaret Hospital, Toronto. One hundred sixty-eight (168) of the patients were treated palliatively and 176 of the patients were treated by radical doses of radiation, surgical resection or both. Survival of the radical treatment group was biphasic, the steeper component being identical to the survival of the palliative treatment group, thereby representing a group of patients that did not respond to radical treatment. Analysis of pretreatment assessment parameters indicated that all patients with T1 lesions (length less than or equal to 5 cm, circumference incomplete) and all patients with Stage I disease responded to treatment. Patients who were female, age greater than or equal to 70 years, N0 or had well differentiated squamous cell histology, responded to treatment in at least 80% of cases. No patient with extralymphatic distant metastases responded to treatment. The presence of other major disease did not affect response to treatment. Thirty patients had surgical resections and their survival was not significantly greater than the 146 patients who had radical radiation alone. Survival analysis revealed an optimum range of nominal standard dose (NSD) of 1602--1714 rets (median 1679 rets) for patients treated by radiation alone. An optimum port size (area) of 100--140 cm2 was observed for patients receiving 5000 rads and supervoltage irradiation gave a significantly improved survival in comparison with megavoltage irradiation. Sixty-seven percent (67%) of patients treated by radical doses or radiation developed esophageal strictures postradiation and on the basis of radiological, endoscopic or histological evidence 75% of these strictures were considered to be associated with the persistence of malignancy. On the basis of postmortem examinations (32) and death certificates there was overall an 80% failure to control the disease locally and 95% of strictures were associated with persistence of malignancy in the esophagus. Thirty-one of the 146 patients receiving radical radiation alone had palliation for esophageal obstruction following radiotherapy. The construction of a physiological bypass (e.g., colon) resulted in a mean survival of 215 days which was much longer than the survival observed with rigid esophageal tubes (35 days) or gastrostomy tubes (58 days).

Aged↗
PubMed1988

Sensitivity of cultured cells to gamma radiation in a patient exhibiting marked in vivo radiation sensitivity.

An apparently normal 13-year-old girl developed multiple severe complications over several years after radiation therapy for Stage IIB Hodgkin's disease, including hypothyroidism, esophageal stenosis, restrictive lung and pericardial disease, extrahepatic biliary fibrosis, and sudden death presumed secondary to a myocardial infarction. Cultured skin fibroblast cells from the patient exhibited marked sensitivity to gamma radiation in vitro. The D0 of the radiation survival curve (the inverse of the straight line portion of the curve and that dose of radiation which theoretically leads to one lethal hit per cell) was 89 cGy, compared to a mean D0 for nine normal individuals of 155 cGy, and 85 cGy for two patients with the radiation sensitive disease ataxia-telangiectasia (AT). Profound clinical heterogeneity in response to cancer therapeutic agents may exist, with some individuals who show no signs or symptoms of DNA repair deficiency (for example, as is manifested by individuals with AT) exhibiting marked in vivo and in vitro sensitivity to certain DNA-damaging agents.

Adolescent↗
PubMed1997

Radiation myelopathy after chemotherapy and radiation therapy for fallopian tube carcinoma.

Radiation myelopathy is a severe consequence of radiation to the spinal cord which rarely occurs with standard doses of radiation. This entity commonly results in different degrees of sensory and motor deficits. Diagnosis of radiation myelopathy in women with gynecologic malignancies may increase with the concomitant use of chemotherapy and radiation therapy. This paper reports the effect of this combination therapy in a 60-year-old woman with fallopian tube carcinoma.

Fallopian Tube Neoplasms↗
PubMed1985

Radiation necrosis of the brain: time of onset and incidence related to total dose and fractionation of radiation.

Clinical deterioration during or after brain irradiation may be due to progression of neoplasm or radiation induced necrosis of the neoplasm and/or of normal brain tissues, or a combination of all. Eight patients with histologically documented radiation induced lesions of the brain are included in this study. The radiation therapy included the fractional schedule, group A, who received 280 to 300 rads daily, to a total dose of 4500 to 5000 rads and weekly exposure did not exceed 900 rads. Group B patients were exposed to 850 rads, daily dose on day 1, 3, 21 and 23 to a total dose of 3400 rads. The incidence of radiation induced lesions of brain was 3.4% in patients group A and 8.7% in group B patients (without statistical significance). The median time of onset of these lesions after completion of radiation therapy was significantly shorter in group B patients (8.5 months) as opposed to group A patients (21 months).

Brain↗
PubMed1993

Treatment and long-term outcome of chronic radiation esophagitis after radiation therapy for head and neck tumors. A report of 13 cases.

The natural history of chronic radiation esophagitis occurring in previously normal esophagus is still unknown. We describe here the long-term outcome of chronic esophagitis arising after neck irradiation for oropharynx and larynx carcinomas in 13 consecutive adult patients. The first clinical signs of radiation esophagitis were dysphagia or impossibility of oral intake, which appeared within 26 months (range 2-120 months) after the end of radiation for pyriform fossae carcinoma (N = 5), tonsil carcinoma (N = 2), larynx carcinoma (N = 2), pharynx carcinoma (N = 2), base of the tongue (N = 1), and thyroid carcinomas (N = 1). During upper endoscopy, an esophageal stenosis was found in 11 cases and was associated with ulceration in three cases. An isolated esophageal ulceration was present in only two cases. Chronic radiation esophagitis diagnosis was confirmed by histology and surgery in seven cases. In the last six cases, diagnosis was supported by the absence of first cancer relapses within a median follow-up of two years (16 months to nine years) and by endoscopic findings. Seven patients received parenteral or enteral nutrition. Ten patients were treated by peroral dilatations. These treatments allowed nearly normal oral diet in 11/13 patients. Only one patient was lost of follow-up after 20 months. Four patients died from chronic radiation esophagitis. One of these patients died from massive hemorrhage after peroral dilatation. Four patients died of a second carcinoma with no first cancer recurrence. Four patients were alive after six months to nine years of follow-up. Moderate dysphagia was still present, allowing nearly normal oral feeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1998

Energy loss due to radiation in postmortem cooling. Part A: quantitative estimation of radiation using the Stefan-Boltzmann law.

Conduction and convection are assumed to account for most of the energy loss from the dead body to the (cooler) environment. There are no quantitative estimations in the literature for the contribution of radiation to heat loss. The aim of the present paper was to estimate the radiation energy loss in postmortem cooling. The Stefan-Boltzmann law is used and combined with a single-exponential model for the cooling process of the skin derived from experimental data of Lyle and Cleveland (1956). The influence of various factors (e.g. skin temperature, environmental temperature, body mass and body height) on the amount of radiation emitted was investigated. The radiation energy is quantitatively described as a function of time. The radiation energy loss ranged from approximately 200 kJ in small (165 cm) and lean (50 kg) bodies at room temperature (20 degrees C) to approximately 600 kJ in tall (185 cm) and over-weight (100 kg) bodies at outdoor temperature (5 degrees C) in the first hour postmortem.

Body Constitution↗
PubMed1998

A randomized controlled clinical trial on the efficacy of radiation therapy in the control of subfoveal choroidal neovascularization in age-related macular degeneration: radiation versus observation.

BACKGROUND: The results of several pilot studies concerning radiation therapy for age-related subfoveal choroidal neovascularization (CNV) have been published recently. Although positive treatment results have been described, it is not known whether this therapy alters the natural course of eyes with neovascular age-related macular degeneration (AMD). A randomized controlled clinical trial was conducted in which radiation therapy was compared with observation in patients with subfoveal neovascular AMD. METHODS: Seventy-four patients with a recent drop in central vision due to subfoveal age-related CNV were randomized to either radiation treatment or observation. Patients with either classic, occult or mixed type CNV were included. Eyes in the treatment group received a radiation dose of 24 Gy in four fractions of 6 Gy. Evaluation of data concerning visual acuity (VA) and fluorescein angiography occurred at 3, 6 and 12 months after inclusion. RESULTS: At 12 months of follow-up 52.2% of the observation group versus 32.0% of the irradiation group had lost 3 or more lines of VA (P = 0.03, log rank test). More severe visual decline, 6 lines or more, was observed in 40.9% of the observation versus 8.8% in the irradiation group (P = 0.002 using log rank test). At 12 months 39.6% of the observation group and 20.0% of the treatment group had VA of less than 0.1 (P = 0.08, log rank test). The size of the CNV membrane doubled in 25.2% of eyes in the observation group versus 20.0% in the treatment group at least 12 months (P = 0.5, log rank test). No side effects were observed. CONCLUSION: Preservation of VA was significantly better in the treatment group compared with the control group at 12 months. Nevertheless we noted a drop in central vision of 3 or more lines in a substantial proportion of the treatment group. Radiation therapy does not prevent visual loss in all patients with age-related subfoveal CNV, and whether the treatment benefit at 12 months will persist has to be awaited.

Aged↗
PubMed1983

Radiation induced sarcomas of bone following therapeutic radiation.

Because of new therapeutic trends of multi-modality and the importance of late effects, we have updated our series of radiation induced bone sarcomas seen at Memorial Sloan-Kettering Cancer Center over the past four decades. A total of 37 cases of bone sarcoma arising from normal bone in the irradiated field was analyzed. The median for latent period from irradiation to diagnosis of bone sarcoma was 11 years with a minimum latent period of four years. The median radiation dose for the bone sarcoma was 6000 rad in 6 weeks with a minimum total radiation dose of 3000 rad in 3 weeks. We have found nine patients who developed bone sarcomas in the radiation field after successful treatment of Hodgkin's disease. Criteria for radiation induced bone sarcomas and the magnitude of the risk of bone sarcomas are briefly discussed.

Bone Neoplasms↗