Collateral radiation

There is a possibility of radiation being emitted by other parts of the laser system, such as the power supply. This radiation associated with the operation of the laser system is called collateralradiation.The limits on this collateral radiation are (fromTable VI,21 CFR 1040.1) ... 

Accessible emission level—The magnitude of accessible laser or collateral radiation of a specific wavelength or emission duration at a particular point as measured by appropriate methods and devices of the radiation to which human access is possible in accordance with the definitions of the laser s hazard classification. 

An aperture is an opening in the protective housing, shielding enclosure of a product that controls the amount of light admitted. In a laser system, the aperture controls the laser and collateral radiation that is emitted, which also allows human exposure to the radiation. 

Collateral radiation is the extraneous radiation (such as secondary beams from optics, flash lamp light, RF radiation, and X-rays) that is not the intended laser beam as a result of the operation of the product or any of its components. System indicator lights would not normally be considered sources of collateral radiation. 

Most recently, a phase-I-study defined a dose of 13-ris-retinoic acid that was tolerable in patients after myeloablative therapy, and a phase-III-trial showed that postconsolidation therapy with 13-cis-retinoic acid improved EFS for patients with high-risk neuroblastoma [7]. Preclinical studies in neuroblastoma indicate that ATRA or 13-cw-RA can antagonize cytotoxic chemotherapy and radiation, such that use of 13-cis-RA in neuroblastoma is limited to maintenance after completion of cytotoxic chemotherapy and radiation. It is likely that recurrent disease seen during or after 13-cis-RA therapy in neuroblastoma is due to tumor cell resistance to retinoid-mediated differentiation induction. Studies in neuroblastoma cell lines resistant to 13-cw-RA and ATRA have shown that they can be sensitive, and in some cases collaterally hypersensitive, to the cytotoxic retinoid fenretinide. Here, fenretinide induces tumor cell cytotoxicity rather than differentiation, acts independently from RA receptors, and in initial phase-I-trials has been well tolerated. Clinical trials of fenretinide, alone and in combination with ceramide modulators, are in development. 

Inspection Upon inspection, pronounced cases of ascites are characterized by marked protrusion of the abdomen. The umbilicus becomes everted or bulging. The distance between the navel and the symphysis appears diminished as a result of caudal displacement of the former. With large quantities of ascitic fluid, the abdominal skin is taut and shiny. In long-standing cases of ascites, striae distensae, together with expanded collateral veins radiating from the navel, may be visible. Increased ascitic pressure sometimes causes the occurrence of a hernia (inguinal, femoral, umbilical or cicatricial). (S. fig. 16.7) (41, 48, 57)... 

Treatment planning requires a multi-disciplinary team with clear leadership and accountability to ensure that the screening, diagnostic and treatment procedures are conducted in a seamless fashion. The essential steps include (1) calculation of target liver mass to be infused and tumor burden (2) visceral angiography to map out tumor-perfusing vessels and embolize collaterals (3) assessment of pulmonary shunt (4) determination of the optimal therapeutic dose (5) room preparation (6) radiation monitoring and safety procedures (6) calculation of residual activity and efficiency of delivery. 

When contemplating LGI embolization there are some unique aspects of the history that need to be investigated. Knowing the past surgical history is important since prior intestinal surgery may have disrupted potential arterial collateral pathways and will increase the risk of an ischemic complication. If the patient has had radiation therapy to the... 

NAS. Reliability Centered Maintenance Guide for Facilities and Collateral Equipment, February 2000. National Council on Radiation Protection. Report Number 48 Radiation protection for medical and allied health personnel. Washington, DC NCRP, 1976. 

As such, OncoSiF offers an alternative to external beam radiation therapy, a course of treatment requiring 30 treatments over a 6-week period, with substantial collateral damage to healthy tissues, and a number of unpleasant treatment-related side effects. 

In our series, we have found a high incidence (44%) of anatomical variants in the pediatric population. Technical difficulties of retrograde sclerotherapy were seen in type IVb, collaterals from segmental renal veins to the internal spermatic vein with a competent ostial valve (12% of our cases, failure rate 50%) and in type V, double renal veins (14% of our cases, failure rate 33%). Our overall results (feilure rate 10%) are comparable to the recently reported pediatric series [35,36], in the radiological and surgical literature. The issue of radiation related to interventional procedure has been addressed in the literature. If the... 

Conversely the administration of NO donors to irradiated tissue could further increase the effects of radiation and this might be tailored in order to avoid collateral damage to normal surrounding tissues. 

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