MEDICAL USES FOR RADIATION Andres Perez P.1 Level 4 MT10

RADIATION FOR MEDICAL USE  In medicine it is required to utilize X-rays in order for a doctor to properly diagnose a disease, such as Cancer, but also, it can be used for radiotherapy in order to try and cure a disease.  Radiation is very helpful in the Medical Field, it has MANY benefits that allow it to be a most commonly used treatment & diagnostic, especially when it comes to Cancer.  But while it may have many benefits, it also has quite a few risks that come along with utilizing it.  If used improperly and unprofessionally, it is MOST likely that the disease would only become even worse and the consequences could be very fatal.

DIAGNOSIS WITH RADIATION Diagnostic Radiology: CT Scan:  Use of X-rays to examine patients  X-rays penetrate flesh, & bone on photographic film  In some cases the images are captured & processed electronically.  Radiation from a machine passes through patient  Parts of Body Commonly Examined:  Chest  Limbs  Teeth  Doses are fairly low  For Example: About 0.1 mSv from chest exam.  The use has increased considerably in recent years.  Make up approximately 5% of all procedures (in developed countries)  A fan-shaped beam of X-rays is rotated around the patient and registered on the opposite side by a row of detectors.  An image of a slice or section through the patient is then reconstructed by a computer and expresses superior diagnostic info.  Doses can be an order of magnitude or more higher than those from conventional X-ray exams.

INTERVENTIONAL RADIOLOGY  Diagnostic procedure that gives the highest doses.  If it is not controlled carefully, it can lead to similarly high doses to surgeons.  The physician uses a series of X-rays to “see” into the patient in real time while performing a procedure inside the patient.  Allows a procedure on an internal organ to be done without the complicated surgery that might have been needed to get to the organ.  Procedures can give patient doses in the range mSv  Doses from procedures have been high enough to cause “deterministic effects” in patients & surgeons alike.

NUCLEAR MEDICINE  The patient is given a radionuclide in a carrying substance, which is preferentially taken up by the tissue or organ under study.  Administration may be by injection, ingestion, or inhalation  The radionuclide emits gamma rays  When used to treat instead of diagnosis, much greater activities are given to the patient and much higher doses are given to the target tissues or organs.  Treatment of an overactive thyroid gland-hyperthyroidsim-is probably the most common therapeutic procedure(the radionuclide used is iodine-131)  Many make us of the radionuclide techetium-99m  Has a half-life of 6hours  Gives off gamma rays with an energy of 0.14MeV  Can be conveniently prepared in the hospital  Readily labels a variety of carrying substances  Although they may have short half- lives, taking to account of the fact that activity still remains in the body of the patient that received the radionuclide for a while after the procedure, is advised.

RADIOTHERAPY  Technique used to cure Cancers or at least alleviate the most distressing symptoms, by killing cancerous cells.  A beam of high energy X-rays, gamma rays or electrons is directed towards the diseased tissue so it can receive a high dose while sparing the surrounding healthy tissue.  If tumor is deep in the body, beam is pointed at it from several directions to reduce the incidental damage.  Brachytherapy:  Another form of treatment, in which a radiation source is placed in/on the body for a short period (is used for some cancers.)  Since radiotherapy doses are strong, this treatment is only used when the outlook for a cure or relief is good and when other methods for treatment would be less effective.  Although it can cure the original cancer, it may possibly cause cancer in other tissues or “adverse hereditary effects in subsequent generations.”  Most people who receive this therapy are:  Past the age to have children  Too old for delayed cancers to occur

RADIOTHERAPY  Its aim is to maximize the effectiveness of treatment while minimizing the opposing side effects.  Tumors need absorbed doses of “tens of gray” to kill the cancer cells successfully.  Prescribed doses to tissues are typically in the range Gy normally given in fractions over a period of several weeks.  Considerable care is required to deliver accurate doses.  Too low or too high doses may lead to incomplete treatment or unacceptable side-effects.  Consequences may be grave.  A miscalibrated radiotherapy beam in Costa Rica in 1996 resulted in more than 100 patients receiving higher doses then intended; leading to death or serious injury.

CAUTIONS WITH RADIATION Guidance Levels for Medical Exposure Methods of Minimizing Doses  Its very important to avoid unnecessary exposures and keep the essential exposures as low as possible.  Decision to prescribe an X- ray exam is a matter of medical judgment made in the best interests of the patient.  The dose to the patient should be the lowest possible compatible with accurate diagnosis.  Use of good equipment  Well-maintained, properly adjusted, & skillfully operated  Having a programmer of quality in the X-ray Department.  Young people do not have many X-rays and the likelihood of needing an examination increases with age.  This implies a lower probability, in general, of any consequential cancers being expressed.

WORKS CITED  pdf pdf