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PubMed2004

Effects of ionising radiation exposure on plants, fish and mammals: relevant data for environmental radiation protection.

In order to develop a framework for the assessment of the environmental impact of radiation, it is necessary to establish the relationship between exposure (dose rate, accumulated dose) and the effects that may be induced in plants and animals. With this purpose in mind, the data available on effects induced by ionising radiation in various wildlife groups have been reviewed as part of the FASSET project. This paper has highlighted that the available information on the effects of low dose rate, continuous irradiation (< 10(3) microGy h(-1)) is reasonable for plants, fish and mammals, but is scarce or non-existent for other wildlife groups. Thus, the effects induced in plants, fish and mammals after chronic exposure to radiation are presented in this paper. The fragmentary nature of the available, relevant information has made it very difficult to characterise the desired dose rate-response relationships in any detail. However, it can be broadly concluded that, although minor effects may be seen at lower dose rates in the most sensitive species and systems, the threshold for statistically significant effects in most studies is about 10(2) microGy h(-1). The responses then increase progressively with increasing dose rate and usually become very clear at dose rates > 10(3) microGy h(-1) sustained for a large fraction of the lifespan.

Animals↗
PubMed1964

RADIATION PROTECTION IN CANADA. IV. FACTORS OF IMPORTANCE IN MINIMIZING RADIATION EXPOSURE OF PATIENTS, OPERATORS AND OTHERS INVOLVED IN DIAGNOSTIC AND THERAPEUTIC RADIOLOGY.

Factors that may reduce the dose of radiation, from diagnostic and therapeutic x-ray procedures, to the patient and to the occupational and non-occupational worker are outlined. Suitable basic radiation measuring apparatus is described. It is recommended that, in diagnostic radiography, relatively high kilovoltage, proper cones, collimation and adequate filtration be used. Some specific recommendations are made concerning fluoroscopic, photoroentgen and portable x-ray examinations. Film monitoring of personnel is advisable. Examples are given of protective devices to lessen the dosage to the occupational worker. It is the responsibility of the radiologist or physician in charge to ensure that the x-ray equipment is safe to operate and the radiation dose to the patient is kept to a minimum. The roentgen output for all radiographic examinations should be known by the responsible user.

Canada↗
PubMed1999

Enhanced radiation late effects and cellular radiation sensitivity in an ATM heterozygous breast cancer patient.

We observed severe late effects in a patient treated with radiation therapy for breast cancer. Radiation survival studies of patient fibroblasts show an enhanced cellular radiation sensitivity (Do = 0.95 Gy). Genetic analysis reveals that the patient is heterozygous for a mutated ATM gene. Protein truncation test (PTT) and sequence analysis identified a truncation within the leucine zipper domain, corresponding to a fragment previously reported to exhibit dominant negative function. These findings demonstrate that ATM heterozygosity may be associated with enhanced clinical radiation sensitivity and suggest a clinical relevance to this truncation that results in a dominant negative-acting protein.

Adenocarcinoma, Mucinous↗
PubMed1999

Radiation safety in the cardiac catheterization laboratory: operational radiation safety.

The goal of the catheterization laboratory radiation safety program is to facilitate invasive cardiology while simultaneously reducing staff risks to an acceptable level. Achieving this goal requires a balance between the value of catheterization to the patient and the associated radiation risk to the staff. This article introduces the principles of radiation protection as applied in the catheterization laboratory. Prudent conformance to these principles will appropriately reduce radiation risk. Cathet. Cardiovasc. Intervent. 47:347-353, 1999.

Air Pollution, Radioactive↗
PubMed1975

Delayed cerebrovascular consequences of therapeutic radiation. A clinicopathologic study of a stroke associated with radiation-related carotid arteriopathy.

A young woman, successfully treated for Hodgkin's disease with radiation and MOPP chemotherapy, incurred a devastating stroke months after radiation therapy to the neck and other areas. There was no premonitory clinical history of cerebrovascular attacks. Autopsy showed unilateral thrombotic occlusion of the internal carotid artery unassociated with neoplastic or fibrotic annular constriction of the vessel. There was medial thickening and fibroblastic proliferation within the carotid artery. Areas of focal elastic membrane degeneration involved the cervical portions of the carotid. Thrombus was organized to the damaged vessel wall and was propagated into the intracranial vessels. Aneurysm formation and arterial hemorrhages were absent. These vascular changes occurred in an area of extensive radiation (7200 rads). Pathoanatomical studies in this patient indicate that radiation-induced vascular changes were associated with a "delayed" stroke.

Adult↗
PubMed1978

Radiation nephritis following combined abdominal radiation and chemotherapy (bleomycin-vinblastine).

A 29-year-old man presented with acute glomerulonephritis five weeks following completion of combined chemotherapy (bleomycin-vinblastine) and abdominal radiation for testicular carcinoma. There was no evidence for a post-infectious cause or a systemic collagen disorder. The renal biopsy showed changes consistent with radiation nephritis. The combined radiation and chemotherapy may have, by additive or synergistic action, caused the early appearance of radiation nephritis.

Adult↗
PubMed1981

The radiation-induced inactivation of microorganisms in non-aqueous suspension: The effect of selected alcohols and paraffins on the radiation sensitivity of aerated Bacillus pumilus spores.

The effect of model compounds comprising alcohols and paraffins on the radiation sensitivity of B pumilus spores has been carried out with the aim of understanding the radiation-induced inactivation of microorganisms when suspended in non-aqueous medium. This study is a prerequisite to the undertaking of radiation sterilization of non-aqueous pharmaceuticals. Spores of B. pumilus E601 mounted on kaolin powder were suspended in the appropriate organic agent and gamma irradiated under oxic conditions. Spores suspended in paraffins displayed increased radiation response over that for aerated buffered suspensions. Values of inactivation constant ranged between 2X and 5X for that buffer. Less pronounced modification of response was obtained for the alcohols. The results reveal a marked tendency for response to increase with decreasing polarity of the suspending fluid. The partial miscibility of the alcohols in water enabled the examining of the transition from the response characteristic of aerated buffered suspensions to those of the spores in pure organic liquids.

Alcohols↗
PubMed2003

[Staffing levels in medical radiation physics in radiation therapy in Germany. Summary of a questionnaire].

To get a general idea of the actual staffing level situation in medical radiation physics in 1999 a survey was carried out by the task-group "Personalbedarf" of Deutsche Gesellschaft für Medizinische Physik (DGMP) among all DGMP-members who are active in this field. Main components for equipment and activities are defined in Report 8 and 10 of DGMP for staffing requirements in medical radiation physics. 322 forms were sent out, 173 of them have been evaluated. From the answers regarding equipment and activities numbers for staff are calculated by the methods given in Report 8 and 10 for this spot check target and compared with effective staffing levels. The data of the spot check are then extrapolated on total Germany. The result is a calculated deficit of 865 medical physicists for the whole physics staff, 166 of them in radiation therapy. From the age distribution of DGMP-members and the calculated deficit resulted a training capacity of about 100 medical physicists at all per year (19 in radiation therapy) if the deficit shall be cut back in 10 years.

Austria↗
PubMed2004

Radiation-induced temporary hair loss as a radiation damage only occurring in patients who had the combination of MDCT and DSA.

As imaging technologies become increasingly advanced, it is possible to obtain detailed morphological information as well as functional imaging data. In some imaging technologies, the radiation dose increases with the ability to obtain better images or more detailed information. We encountered three cases of temporary bandage-shaped hair loss, which was caused by perfusion studies of the head by multi-detector row computed tomography (MDCT) for evaluation of cerebral blood flow in patients with vascular disorders. In all three patients with temporary hair loss, two angiographies of the head had been performed in the period of serial CT examinations. This suggested the possibility that radiation exposure from angiography performed in serial examinations, combined with the perfusion studies of the head with MDCT, played an important role in this temporary, bandage-shaped hair loss. Radiologists should be aware that a cumulative or multiplier effect of radiation exposure from multiple diagnostic techniques may result in hair loss and other types of radiation complications.

Adult↗
PubMed1991

Ionizing radiation and genetic risks. II. Nature of radiation-induced mutations in experimental mammalian in vivo systems.

This paper reviews data on the nature of spontaneous and radiation-induced mutations in the mouse. The data are from studies using a variety of endpoints scorable at the morphological or the biochemical level and include pre-selected as well as unselected loci at which mutations can lead to recessive or dominant phenotypes. The loci used in the morphological recessive specific-locus tests permit the recovery of a wide spectrum of induced changes. Important variables that affect the nature of radiation-induced mutations (assessed primarily using tests for viability of homozygotes) include: germ cell stage, type of irradiation and the locus. Most of the results pertain to irradiated stem cell spermatogonia. The data on morphological specific-locus mutations show that overall, more than two-thirds of the X- or gamma-ray-induced mutations are lethal when homozygous. This proportion may be lower for those that occur spontaneously, but the numbers of tested mutants are small. For spontaneous mutations, there is evidence for the occurrence of mosaics and for proviral insertions. Most or all tested induced enzyme activity variants, dominant visibles (recovered in specific-locus experiments) and dominant skeletal mutations are lethal when homozygous and this is true of 50% of dominant cataract mutations, but again, the numbers of tested mutants are small. Electrophoretic mobility variants, which are known to be due to base-pair changes, are seldom induced by irradiation. At the histocompatibility loci, no radiation-induced mutations have been recovered, presumably because deletions are incompatible with survival even in heterozygotes. All these findings are consistent with the view that in mouse germ cells, most radiation-induced mutations are DNA deletions. Some mutations (in the morphological specific-locus tests) which had previously been inferred to be deletions on the basis of genetic analyses have now been shown to be DNA deletions by molecular methods. However, the possibility cannot be excluded that at least a small proportion of induced mutations may be intragenic changes. The data on the rates of induction of recessive lethals and of dominant skeletal and dominant cataract mutations (and proportions of the latter two which are homozygous lethal) can be used to estimate the proportions of recessive lethals which are expressed as skeletal abnormalities or cataracts. These calculations show that about 10% of recessive lethals manifest themselves as skeletal and less than 0.2% as cataract mutations.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Dose-response for local control with hyperfractionated radiation therapy in advanced carcinomas of the upper aerodigestive tracts: preliminary report of radiation therapy oncology group protocol 83-13.

A prospective, randomized Phase Ilate/II trial of hyperfractionated radiation therapy was conducted: 1.2 Gy minimum tumor dose was administered twice daily with a minimum interval of 4 hr, 5 days per week. Patients with Stage III and IV carcinomas of the oral cavity, oropharynx, nasopharynx, hypopharynx, and supraglottic larynx were stratified by site, presence or absence of nodal metastases, and performance status. They were assigned to four total doses between 67.2 Gy and 81.6 Gy to all known tumors. The highest dose arm was opened after preliminary assessment indicated acceptable late morbidity rates with the three lower doses. Of 479 patients entered, 260 patients were randomized to the three lower total doses and 237 were analyzed for this preliminary report: 63 were assigned to receive 67.2 Gy, 58 to 72.0 Gy, and 116 to 76.8 Gy. Estimates of grade 4 necrosis at 2 years were 10.0%, 5.1%, and 13.9%, respectively, for patients who received total doses of 67.2 Gy, 72.0 Gy, and 76.8 Gy. There was a suggestion of a trend toward increased local control at 24 months (Kaplan-Meier estimates of 25% for 67.2 Gy, 37% for 72.0 Gy, and 42% for 76.8 Gy) (p = .08). No difference was observed in survival. Assessment of the results using Cox regression models to correct for slight inequalities of pretreatment prognostic variables supported a total dose-tumor control relationship (p = .054). Results for the lowest dose arm were comparable to previous RTOG studies of common fractionation with similar total doses. The higher local control rates with 72.0 and 76.8 Gy using hyperfractionated radiation therapy suggest an improvement in outcome with radiation therapy for advanced carcinomas of the upper aerodigestive tracts. These preliminary findings have led to a Phase III comparison of hyperfractionated radiation therapy with 1.2 Gy b.i.d. with standard fractionation.

Adult↗
PubMed1992

Long-term radiation complications following conservative surgery (CS) and radiation therapy (RT) in patients with early stage breast cancer.

The frequency of brachial plexopathy, rib fracture, tissue necrosis, pericarditis, and second non-breast malignancies occurring in the treatment field among 1624 patients with early stage breast cancer treated with conservative surgery and radiation therapy at the Joint Center for Radiation Therapy between 1968 and 1985 is reported. The median follow-up time for survivors was 79 months (range 5-233 months). Brachial plexopathy was related to the use of a third field, the use of chemotherapy and the total dose to the axilla. Brachial plexopathy developed in 20 of 1117 women (1.8%) who received supraclavicular irradiation with or without axillary irradiation. The median time to its occurrence was 10.5 months (range 1.5-77 mo), and the majority (80%) of cases completely resolved. Among patients treated with a three-field technique, the incidence of brachial plexopathy was 1.3% (13/991) in patients treated with a dose to the axilla of less than or equal to 50 Gy, compared with 5.6% (7/126) in women treated with an axillary dose of greater than 50 Gy. The incidence of brachial plexopathy was 4.5% (15/330) among patients receiving chemotherapy, compared with 0.6% (5/787) when chemotherapy was not used (p less than 0.0001). Rib fracture was seen in 29 patients (1.8%), at a median time of 12 months following treatment (range 1-57). In all cases, the rib fracture healed without intervention. The incidence of rib fracture was 2.2% (28/1300) among patients treated on a 4 MV linear accelerator, compared with 0.4% (1/276) for patients treated on a 6 or 8 MV machine (p = 0.05). Of patients treated on a 4 MV machine, 0.4% (1/279) developed a rib fracture when a whole breast dose of 45 Gy or less was given, 1.4% (10/725) after receiving between 45 and 50 Gy, and 5.7% (17/296) following 50 Gy or higher. Tissue necrosis requiring surgical correction developed in three patients (0.18%) 22, 25, and 114 months after treatment. Presumed pericarditis (requiring hospitalization) was seen in 0.4% of women (3/831) who received radiation therapy to the left breast 2, 2, and 11 months after the start of treatment. Three women (0.18%) developed sarcomas in the treatments field at 72, 107, and 110 months, for a 10-year actuarial rate of 0.8%. Two of these sarcomas developed in areas of probable match-line overlap. One patient (0.06%) developed an in-field basal cell carcinoma at 42 months. In conclusion, the risk of significant complications following conservative surgery and radiation therapy for early stage breast cancer is low.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed2004

A prospective study on radiation pneumonitis following conformal radiation therapy in non-small-cell lung cancer: clinical and dosimetric factors analysis.

BACKGROUND AND PURPOSE: Clinical and dosimetric prognostic factors for radiation pneumonitis (RP) have been reported after three-dimensional conformal radiotherapy (3D-CRT) in patients with non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Ninety-six patients who received 3D-CRT for stage IA to IIIB NSCLC were evaluated prospectively. Surgery was performed before radiation in 51% of the patients (n = 49). RP was diagnosed six-eight weeks after 3D-CRT using the Lent-Soma classification. Factors evaluated included treatment factors such as total mean lung dose (MLD), and dose-volume histogram (DVH) thresholds for several radiation dose steps. These thresholds were originally determined from the median of the irradiated lung volume at each step. RESULTS: Six patients could not be evaluated for RP six weeks after 3D-CRT. Of the 90 remaining patients, 40 (44%) had RP (i.e. grade > or =1) at 6 weeks, including 7 patients (7.8%) with severe RP (grade > or =2). Regarding the whole toxicity (grade > or =1), age (> or =60 years), MLD, V20 and V30 were significantly related to RP. DVH thresholds determined for radiation doses from 20 to 40 Gy were also predictive of RP. Considering only severe RP (grade > or =2), only MLD, V20 and V30 remained associated with increased acute pulmonary toxicity. CONCLUSIONS: In this study, dosimetric factors (MLD, V20, V30) and age (> or =60 years) were predictive of RP regarding the whole pulmonary toxicity (grade > or =1). In addition, thresholds from 20 to 40 Gy, based on a stratification according to the median of the percentage of irradiated lung volume, were also predictive factors. They may, therefore, help discriminate patients at high and low risk for RP. However, only MLD, V20 and V30 remained associated with severe RP (grade > or =2), probably due to the small number of severe events in our series.

Adult↗
PubMed2006

A prospective phase II study of adjuvant postoperative radiation therapy following nodal surgery in malignant melanoma-Trans Tasman Radiation Oncology Group (TROG) Study 96.06.

BACKGROUND: The role of adjuvant postoperative therapy after resection of localised malignant melanoma involving regional lymph nodes remains controversial. There are no randomised trials that confirm that postoperative radiation conveys a benefit in terms of regional control or survival. METHODS: Two hundred and thirty-four patients with melanoma involving lymph nodes were registered on a prospective study to evaluate the effect of postoperative radiation therapy. The regimen consisted of 48Gy in 20 fractions to the nodal basin using recommended treatment guidelines for each of the major node sites. The primary endpoints were regional in-field relapse and late toxicity. Secondary endpoints were adjacent relapse, distant relapse, overall survival, progression-free survival and time to in-field progression. RESULTS: Adjuvant radiation therapy was well tolerated by all of the patients. As the first site of relapse, regional in-field relapses occurred in 16/234 patients (6.8%). The overall survival was 36% at 5 years. The progression-free survival and regional control rates were 27% and 91%, respectively, at 5 years. Patients with more than 2 nodes involved had a significantly worse outcome in terms of distant relapse, overall and progression-free survival. CONCLUSION: We believe that adjuvant radiation therapy following nodal surgery could offer a possible benefit in terms of regional control. These results require confirmation in a randomised trial.

Adult↗
PubMed2000

Ionizing radiation and genetic risks. XII. The concept of "potential recoverability correction factor" (PRCF) and its use for predicting the risk of radiation-inducible genetic disease in human live births.

Genetic risks of radiation exposure of humans are generally expressed as expected increases in the frequencies of genetic diseases over those that occur naturally in the population as a result of spontaneous mutations. Since human data on radiation-induced germ cell mutations and genetic diseases remain scanty, the rates derived from the induced frequencies of mutations in mouse genes are used for this purpose. Such an extrapolation from mouse data to the risk of genetic diseases will be valid only if the average rates of inducible mutations in human genes of interest and the average rates of induced mutations in mice are similar. Advances in knowledge of human genetic diseases and in molecular studies of radiation-induced mutations in experimental systems now question the validity of the above extrapolation. In fact, they (i) support the view that only in a limited number of genes in the human genome, induced mutations may be compatible with viability and hence recoverable in live births and (ii) suggest that the average rate of induced mutations in human genes of interest from the disease point of view will be lower than that assumed from mouse results. Since, at present, there is no alternative to the use of mouse data on induced mutation rates, there is a need to bridge the gap between these and the risk of potentially inducible genetic diseases in human live births. In this paper, we advance the concept of what we refer to here as "the potential recoverability correction factor" (PRCF) to bridge the above gap in risk estimation and present a method to estimate PRCF. In developing the concept of PRCF, we first used the available information on radiation-induced mutations recovered in experimental studies to define some criteria for assessing potential recoverability of induced mutations and then applied these to human genes on a gene-by-gene basis. The analysis permitted us to estimate unweighted PRCFs (i.e. the fraction of genes among the total studied that might contribute to recoverable induced mutations) and weighted PRCFs (i.e. PRCFs weighted by the incidences of the respective diseases). The estimates are: 0.15 (weighted) to 0.30 (unweighted) for autosomal dominant and X-linked diseases and 0.02 (weighted) to 0.09 (unweighted) for chronic multifactorial diseases. The PRCF calculations are unnecessary for autosomal recessive diseases since the risks projected for the first few generations even without using PRCFs are already very small. For congenital abnormalities, PRCFs cannot be reliably estimated. With the incorporation of PRCF into the equation used for predicting risk, the risk per unit dose becomes the product of four quantities (risk per unit dose=Px(1/DD)xMCxPRCF) where P is the baseline frequency of the genetic disease, 1/DD is the relative mutation risk per unit dose, MC is the mutation component and PRCF is the disease-class-specific potential recoverability correction factor instead of the first three (as has been the case thus far). Since PRCF is a fraction, it is obvious that the estimate of risk obtained with the revised risk equation will be smaller than previously calculated values.

Genetic Diseases, Inborn↗
PubMed1994

Radiation-induced changes in long-term survivors of childhood cancer after treatment with radiation therapy.

This article has provided an account of the delayed effects after successful treatment for childhood cancer. Particular emphasis has been placed on sequelae induced by radiation therapy. Chemotherapy-related complications that may simulate or aggravate these sequelae also are recorded. The alterations induced by radiation therapy and chemotherapy are not limited to the organs and tissues described in this article. Subtle, and at times psychologically devastating, sequelae also may be encountered (eg, sterility due to radiation and chemotherapeutic effects on the gonads). However, an attempt has been made only to identify those complications that may be more readily detected by means of radiographic studies. It is recommended that ongoing surveillance of the long-term successfully treated childhood cancer survivor be conducted in order to detect such complications. Early detection will assist in implementing appropriate treatment, minimizing delayed effects, and maximizing the quality of life. Periodic radiographic studies of previously radiated areas at regular intervals therefore appears appropriate.

Brain Diseases↗
PubMed2001

The role of androgen ablation in patients with biochemical or local failure after definitive radiation therapy: a survey of practice patterns of urologists and radiation oncologists in the United States.

To identify therapeutic patterns for putative prostate cancer treatment failures and the role played by androgen ablation therapy in these patients, a questionnaire study was undertaken with urologists and radiation oncologists who had attended a brachytherapy forum at the Seattle Prostate Institute (SPI). Hypothetical questions were asked about recommendations the physicians would give to a patient demonstrating biochemical or local failure after external-beam radiation therapy. Most of the physicians queried were in private practice; 53% were radiation oncologists and 47% were urologists. The respondents' recommendations for a hypothetical patient, who was 45 to 65 years of age, with a biopsy-proven local recurrence was treatment with androgen ablation (35% of respondents), radical prostatectomy (25%), interstitial brachytherapy (20%), and observation (19%). In the 65- to 75-year-old patient with a local recurrence, the respondents recommended observation (43%), androgen ablation (35%), interstitial brachytherapy (17%), and radical prostatectomy (4%). In patients receiving androgen ablation for a biochemical failure alone, there was no consensus on whether to use luteinizing hormone-releasing hormone agonist alone, total androgen ablation, orchiectomy, or intermittent androgen ablation. Criteria that prompted physicians to initiate androgen ablation were based on the rate of prostate-specific antigen (PSA) increase (67%), an absolute PSA number (24%), or clinical failure (9%). In the younger patient with a local recurrence, local intervention with radical prostatectomy or interstitial brachytherapy was recommended most often, followed by androgen ablation, then by observation. In the older patient, observation was recommended most often, followed closely by androgen ablation. Overall, there was a lack of consensus on how to deliver androgen ablation. However, there was remarkable agreement between urologists and radiation oncologists on virtually all issues queried.

Age Factors↗