Intradural extramedullary metastasis: a review of literature and case report.

Introduction: Intradural extramedullary (IDEM) metastatic disease is infrequently encountered by spine surgeons and consequently poorly understood. Discovery often corresponds with the onset of neurologic symptoms and no consensus exists regarding the importance of complete resection or anticipated postoperative outcome. We aim to elucidate treatment methodologies that exist in the literature.

Intraoperative Use of External Fixator Attachments for Reduction of Lower Extremity Fractures and Dislocations.

The mainstay of complex open lower extremity fractures and dislocations is the temporizing external fixator. We propose the use of external fixator attachments that allow for the reduction of fractures and dislocations intraoperatively. By using external fixator carbon fiber rods, the surgeon is able to create a capital "T" (sweet T) shaped attachment and connect this to a Schanz pin.

Accounting for shared and unshared dosimetric uncertainties in the dose response for ultrasound-detected thyroid nodules after exposure to radioactive fallout.

Dosimetic uncertainties, particularly those that are shared among subgroups of a study population, can bias, distort or reduce the slope or significance of a dose response. Exposure estimates in studies of health risks from environmental radiation exposures are generally highly uncertain and thus, susceptible to these methodological limitations. An analysis was published in 2008 concerning radiation-related thyroid nodule prevalence in a study population of 2,994 villagers under the age of 21 years old between August 1949 and September 1962 and who lived downwind from the Semipalatinsk Nuclear Test Site in Kazakhstan.

Uncertainties in estimating health risks associated with exposure to ionising radiation.

The information for the present discussion on the uncertainties associated with estimation of radiation risks and probability of disease causation was assembled for the recently published NCRP Report No. 171 on this topic. This memorandum provides a timely overview of the topic, given that quantitative uncertainty analysis is the state of the art in health risk assessment and given its potential importance to developments in radiation protection.

RadRAT: a radiation risk assessment tool for lifetime cancer risk projection.

Risk projection methods allow for timely assessment of the potential magnitude of radiation-related cancer risks following low-dose radiation exposures. The estimation of such risks directly through observational studies would generally require infeasibly large studies and long-term follow-up to achieve reasonable statistical power. We developed an online radiation risk assessment tool (RadRAT) which can be used to estimate the lifetime risk of radiation-related cancer with uncertainty intervals following a user-specified exposure history (https://irep.

Lauriston S. Taylor lecture: Radiation Protection and Public Policy in an Uncertain World.

Ionizing radiation is a known, well-documented, and reasonably well-quantified human cancer risk factor based on a remarkably consistent body of dose-response information from epidemiological studies of exposed populations supported by experimental studies using animal and cellular models. This fact is largely ascribable to the relative ease, compared to other carcinogens, of estimating radiation dose to organs and local tissues. Statistical models for radiation-related cancer risk are increasingly relevant to both radiation protection policy and the adjudication of compensation claims for cancers diagnosed following occupational and environmental exposures to ionizing radiation, as discussed in a number of expert committee reports of national and international organizations concerned with radiation-related risks.

Mortality from cardiovascular diseases in the Semipalatinsk historical cohort, 1960-1999, and its relationship to radiation exposure.

The data on risk of mortality from cardiovascular disease due to radiation exposure at low or medium doses are inconsistent. This paper reports an analysis of the Semipalatinsk historical cohort exposed to radioactive fallout from nuclear testing in the vicinity of the Semipalatinsk Nuclear Test Site, Kazakhstan. The cohort study, which includes 19,545 persons of exposed and comparison villages in the Semipalatinsk region, had been set up in the 1960s and comprises 582,656 person-years of follow-up between 1960 and 1999.

Associations of ionizing radiation and breast cancer-related serum hormone and growth factor levels in cancer-free female A-bomb survivors.

Levels of exposure to ionizing radiation are increasing for women worldwide due to the widespread use of CT and other radiologic diagnostic modalities. Exposure to ionizing radiation as well as increased levels of estradiol and other sex hormones are acknowledged breast cancer risk factors, but the effects of whole-body radiation on serum hormone levels in cancer-free women are unknown. This study examined whether ionizing radiation exposure is associated with levels of serum hormones and other markers that may mediate radiation-associated breast cancer risk.

Behavior and food consumption pattern of the population exposed in 1949-1962 to fallout from Semipalatinsk nuclear test site in Kazakhstan.

The relationship between radiation exposure from nuclear weapons testing fallout and thyroid disease in a group of 2,994 subjects has been the subject of study by the US National Cancer Institute. In that study, radiation doses to the thyroid were estimated for residents of villages in Kazakhstan possibly exposed to deposition of radioactive fallout from nuclear testing conducted by the Soviet Union at the Semipalatinsk Nuclear Test Site in Kazakhstan between 1949 and 1962. The study subjects included individuals of both Kazakh and Russian origin who were exposed during childhood and adolescence.

Breast cancer risk from different mammography screening practices.

Mammography screening is an accepted procedure for early detection of breast tumors among asymptomatic women. Since this procedure involves the use of X rays, it is itself potentially carcinogenic. Although there is general consensus about the benefit of screening for older women, screening practices differ between countries.

Cancer mortality among women frequently exposed to radiographic examinations for spinal disorders.

We studied cancer mortality in a cohort of 5,573 women with scoliosis and other spine disorders who were diagnosed between 1912 and 1965 and were exposed to frequent diagnostic X-ray procedures. Patients were identified from medical records in 14 orthopedic medical centers in the United States and followed for vital status and address through December 31, 2004, using publicly available regional, state and nationwide databases. Causes of death were obtained from death certificates or through linkage with the National Death Index (NDI).

Projected lifetime cancer risks from exposure to regional radioactive fallout in the Marshall Islands.

Radioactive fallout from nuclear test detonations during 1946-1958 at Bikini and Enewetak Atolls in the Marshall Islands (MI) exposed populations living elsewhere in the MI archipelago. A comprehensive analysis, presented in seven companion papers, has produced estimates of tissue-specific radiation absorbed dose to MI residents at all historically inhabited atolls from internal (ingested) and external irradiation resulting from exposure to radioactive fallout, by calendar year, and by age of the population at time of exposure. The present report deals, for the first time, with the implications of these doses for cancer risk among exposed members of the MI population.

Radiation doses and cancer risks in the Marshall Islands associated with exposure to radioactive fallout from Bikini and Enewetak nuclear weapons tests: summary.

Nuclear weapons testing conducted at Bikini and Enewetak Atolls during 1946-1958 resulted in exposures of the resident population of the present-day Republic of the Marshall Islands to radioactive fallout. This paper summarizes the results of a thorough and systematic reconstruction of radiation doses to that population, by year, age at exposure, and atoll of residence, and the related cancer risks. Detailed methods and results are presented in a series of companion papers in this volume.

Projected cancer risks from computed tomographic scans performed in the United States in 2007.

Background: The use of computed tomographic (CT) scans in the United States (US) has increased more than 3-fold since 1993 to approximately 70 million scans annually. Despite the great medical benefits, there is concern about the potential radiation-related cancer risk. We conducted detailed estimates of the future cancer risks from current CT scan use in the US according to age, sex, and scan type.

Incidence of carcinoma of the major salivary glands according to the WHO classification, 1992 to 2006: a population-based study in the United States.

Background: Carcinomas of the major salivary glands (M-SGC) comprise a morphologically diverse group of rare tumors of largely unknown cause. To gain insight into etiology, we evaluated incidence of M-SGC using the WHO classification schema (WHO-2005).

Methods: We calculated age-adjusted incidence rates (IR) and IR ratios (IRR) for M-SGC diagnosed between 1992 and 2006 in the Surveillance, Epidemiology and End Results Program.

Low-dose extrapolation of radiation health risks: some implications of uncertainty for radiation protection at low doses.

Ionizing radiation is a known and well-quantified human cancer risk factor, based on a remarkably consistent body of information from epidemiological studies of exposed populations. Typical examples of risk estimation include use of Japanese atomic bomb survivor data to estimate future risk from radiation-related cancer among American patients receiving multiple computed tomography scans, persons affected by radioactive fallout, or persons whose livelihoods involve some radiation exposure, such as x-ray technicians, interventional radiologists, or shipyard workers. Our estimates of radiation-related risk are uncertain, reflecting statistical variation and our imperfect understanding of crucial assumptions that must be made if we are to apply existing epidemiological data to particular situations.

Thyroid nodules, polymorphic variants in DNA repair and RET-related genes, and interaction with ionizing radiation exposure from nuclear tests in Kazakhstan.

Risk factors for thyroid cancer remain largely unknown except for ionizing radiation exposure during childhood and a history of benign thyroid nodules. Because thyroid nodules are more common than thyroid cancers and are associated with thyroid cancer risk, we evaluated several polymorphisms potentially relevant to thyroid tumors and assessed interaction with ionizing radiation exposure to the thyroid gland. Thyroid nodules were detected in 1998 by ultrasound screening of 2997 persons who lived near the Semipalatinsk nuclear test site in Kazakhstan when they were children (1949-1962).

Interactive RadioEpidemiological Program (IREP): a web-based tool for estimating probability of causation/assigned share of radiogenic cancers.

The Interactive RadioEpidemiological Program (IREP) is a Web-based, interactive computer code that is used to estimate the probability that a given cancer in an individual was induced by given exposures to ionizing radiation. IREP was developed by a Working Group of the National Cancer Institute and Centers for Disease Control and Prevention, and was adopted and modified by the National Institute for Occupational Safety and Health (NIOSH) for use in adjudicating claims for compensation for cancer under the Energy Employees Occupational Illness Compensation Program Act of 2000. In this paper, the quantity calculated in IREP is referred to as "probability of causation/assigned share" (PC/AS).

Multiple diagnostic X-rays for spine deformities and risk of breast cancer.

Background: Ionizing radiation is a well-established human mammary carcinogen. Women historically monitored by radiography at young ages for abnormal spinal curvature are an exposed population suitable for investigating radiation-related risk and its variation by modifying factors. In this historic cohort, 95% of daily dose increments (when exposure to the breast occurred) were under 2.

A case-control study in Hiroshima and Nagasaki examining non-radiation risk factors for thyroid cancer.

Background: Because little is known about the etiology of thyroid cancer in Japan, we conducted a case-control study of thyroid cancer and lifestyle and other risk factors. The present report focuses on medical history, family history, smoking and alcohol drinking, and their interactions with radiation exposure.

Methods: Thyroid cancer cases reported to the Hiroshima and Nagasaki tumor registries during 1970-1986 were histologically reviewed by pathologists.

Thyroid cancer in childhood cancer survivors: a detailed evaluation of radiation dose response and its modifiers.

Radiation exposure at a young age is a strong risk factor for thyroid cancer. We conducted a nested case-control study of 69 thyroid cancer cases and 265 controls from a cohort of 14,054 childhood cancer survivors to evaluate the shape of the radiation dose-response relationship, in particular at high doses, and to assess modification of the radiation effects by patient and treatment characteristics. We considered several types of statistical models to estimate the excess relative risk (ERR), mainly guided by radiobiological models.

Heterozygous individuals bearing a founder mutation in the XPA DNA repair gene comprise nearly 1% of the Japanese population.

Individuals who are homozygotes for mutations in DNA repair genes are at high risk for cancer. It is not well documented, however, if the heterozygous carriers of the mutation are also predisposed to cancer. To address the issue, xeroderma pigmentosum (XP) in Japan is an interesting candidate because of three major reasons: XP is an autosomal recessive disorder with an enormously elevated risk of skin cancer, the frequency of XP patients is higher in Japan than in other parts of the world, and more than half of Japanese XP patients are homozygous for the same founder mutation in the XPA gene.

External dose estimates for Dolon village: application of the U.S./Russian joint methodology.

Methods to estimate external dose from radioactive fallout from nuclear tests have for many years depended on two types of data: measurements of exposure rate in air and an empirically derived power function to describe the change in exposure rate with time, Over the last four years, a working group with American and Russian participation has developed a bi-national joint methodology that offers an improved capability for estimating external dose. In this method, external dose is estimated using exposure rate functions derived from data from American nuclear tests similar in construction to SNTS (Semipalatinsk Nuclear Test Site) devices. For example, in this paper, we derive doses for test #1 (August 29, 1949) at the SNTS using an exposure rate function for the U.