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Antineoplastic Drugs during Pregnancy
Published in “Bert” Bertis Britt Little, Drugs and Pregnancy, 2022
The MOST IMPORTANT risk to manage is minimization of embryo-fetal exposure to ionizing radiation. Many diagnostic tests can be performed safely during pregnancy because most diagnostic X-ray procedures expose the fetus to no or very low-dose radiation (i.e., < 1 rad per procedure). The general guideline applies to pelvic neoplasms. The general “rule of thumb” has been that fetal or embryonic radiation exposure of less than 5 “skin” rads is associated with little to no risk. The exception to this is the critical period of neural plate development (days 10–18 post-conception), with the threshold for significant risk being as high as 15–20 “skin” rads (Brent, 1987). Skin rads are the amount of radiation delivered to the mother’s skin surface. Therefore, procedures that involve little to no radiation exposure to the pelvic region can be safely performed. Specifically, barium enemas, pyelography, chest films, and non-pelvic computerized tomography may safely be performed, if deemed necessary during the initial diagnosis of malignancies during pregnancy. Diagnostic modalities such as magnetic resonance imaging and ultrasonography are often able to provide the same diagnostic information as X-ray studies and carry no known risk to the fetus or embryo. Diagnostic techniques such as cystoscopy and sigmoidoscopy may be performed safely until the end of the second trimester. (Pentheroudakis and Pavlidis, 2006).
Principles and Basic Concepts in Radiation Dosimetry
Published in W. P. M. Mayles, A. E. Nahum, J.-C. Rosenwald, Handbook of Radiotherapy Physics, 2021
It was not until 1950 that the International Commission on Radiation Units and Measurements (ICRU) formalised the definition of dose in terms of ‘the quantity of energy absorbed per unit mass (ergs per gram) of irradiated material at the point of interest' (ICRU 1951). In 1954, the ICRU finally approved the term absorbed dose, with its unit the rad defined as ‘100 ergs per gram'. The modern unit, the gray (Gy), is exactly 100 rad (1 cGy = 1 rad). The meaning and formal definition of absorbed dose were further refined, and its modern form (see Section 5.3.1) given in ICRU report 33 (ICRU 1980) and carried through to report 60 (ICRU 1998) and report 85, revised as report 85a (ICRU 2011).
Fluoroscopy Quality Assurance and Quality Control Program
Published in Robert J. Parelli, Principles of Fluoroscopic Image Intensification and Television Systems, 2020
Test tools: Dosimeter, homogeneous phantom (13–50 nCkg_1/frame intensifier for 9-in. mode; approximately 7 nCkg_1/frame at intensifier for 6-in. mode). High-quality, relatively low-noise images are needed for cardiac diagnosis. Large number of frames/sec., 30-60 in about 10 sec. for each view or injection. Patient entrance exposures range from 50 to 150 Rads or more.
Can a prostate biopsy be safely deferred on PI-RADS 1,2 or 3 lesions seen on pre-biopsy mp-MRI?
Published in Arab Journal of Urology, 2023
Rickaz Abdul Raheem, Ahsen Razzaq, Victoria Beraud, Richard Menzies-Wilson, Rakan Odeh, Imoh Ibiok, Prashant Mulawkar, Henry Andrews, Iqbal Anjum, Khaled Hosny, Tom Leslie
A retrospective cohort study was conducted by reviewing the reports of mp-MRI prostate scans done in biopsy naïve patients at Milton Keynes University Hospital (MKUH) from 1/8/2017 to 31/7/2018. Scans that were reported as PI-RADS 1, 2 or 3 lesions were identified and included in the study, as well as those reported as ‘normal MRI’ or ‘no abnormalities detected’. All the MRIs were performed using a 1.5 T scanner and PI-RADS v2 was used for reporting. All these mp-MRI scans were reported by experienced radiologists. Transrectal ultrasound-guided prostate biopsies were performed by consultant urologists and an experienced associate specialist in urology. Cognitive fusion has been used if a target was identified. Pathology specimens had been reported by experienced consultant pathologists. All the MRI scans and histology reports were discussed in the Urology cancer MDT in the same hospital.
Low dose ionizing radiation and the immune response: what is the role of non-targeted effects?
Published in International Journal of Radiation Biology, 2021
Annum Dawood, Carmel Mothersill, Colin Seymour
Russ et al. (1919) investigated the effects of small doses of radiation (1/200 rad) in rats where the whole body was shielded and only the rat’s heart was irradiated, which decreased the lymphocyte number in blood circulation. This was presumed to be an indirect effect on lymphocytes as no aggregate or alteration was observed in directly irradiated tissue. A low dose was used in this study, but whether dose units of 1/200 rad for 12 seconds were delivered daily for two months remains unclear and roughly converts to a cumulative equivalent dose of 5 mrad or 0.05 mGy according to modern dosimetry. Compared to other work around this time, this study was better with regard to the reporting of units of Rad which can be directly converted to the modern unit, Gray, since both are measures of energy absorbed per unit mass.
Prostatectomy with or without post-operative radiotherapy: long-term adverse effects and quality of life
Published in Scandinavian Journal of Urology, 2021
Kari Vatne Monsen, Sophie D. Fosså, Alv A. Dahl, Tor Å. Myklebust, Sigbjørn Smeland, Andreas Stensvold
Due to the heterogeneity of study designs and used questionnaires, comparisons between the above studies and our findings are problematic. Nevertheless, our findings support the general view of higher prevalence and more severe AEs in irradiated than in non-irradiated men, though RAD-related deterioration of sexual and bowel dysfunctions/problems seems less in our patients than described in the above mentioned literature. Worsening in reported Symptom Burden must also be interpreted on the background of age-related normal changes among men in the general population: After the age of 60 years, urinary, bowel and sexual dysfunctions are not uncommon [21]. In our study the largest declines are observed within the urinary and sexual domain, in line with age-related reduced post-RP recovery in elderly Norwegian men [22]. We confirmed Sanda et al.’s [23] observation of improved urinary irritation/obstruction after RP, this development in our study probably being counteracted by post-RP RAD due to radiation-induced fibrotic tissue changes [24,25].