About Us ::
Company History and Information
K&S Associates was founded in 1974 by Bob King and Tom Slowey as an organization to provide Medical Physics consultation services. Bob came to Vanderbilt University Medical Center in 1967 having several years experience at Brookhaven National Laboratory as a staff physicist. Bob received his Masters of Science degree from Vanderbilt University and was appointed Director of the Division of Physics and Biomedical Engineering of the Department of Radiology in 1970. Tom Slowey came to Vanderbilt University in 1969 as a junior in an undergraduate engineering program after receiving two years of credit from the University of Tennessee extension in Nashville. Tom was hired by the Division of Radiation Therapy to train as an assistant physicist and to maintain a Varian Clinac 6, a Cobalt 60 unit, a treatment planning computer and a dose scanner. Tom received a BE in electronic engineering from Vanderbilt in 1970 and was appointed Associate Director of the Division of Physics in 1971. Tom and Bob provided consulting services to area institutions and physicians in diagnostic and therapy physics over the period from 1971 to 1974 while members of the faculty and staff of Vanderbilt University Medical School. After K&S was formed in 1974, Bob remained at Vanderbilt while Tom resigned from Vanderbilt and managed the consultation services with two physics technologists and a dosimetrist, Vivian Denton. Vivian trained at Vanderbilt University Medical Center in dosimetry and maintained her registry as a radiologic technologist and as a radiation therapist. Vivian was then hired by K&S Associates to be in the position of Vice President and Quality Manager.
The business started by providing a full range of services including radiological compliance evaluations of diagnostic x-ray units, nuclear medicine services, personnel monitoring, treatment planning services, linear accelerator maintenance, diagnostic and therapy shielding design services, survey meter calibrations, calibrations of radiation therapy units and license preparation.
The business grew slowly during the first few years. In 1978, Bob became interested in other business activities and sold his interest in K&S to Tom Slowey. By the early 1980's, K&S was serving over 100 institutions in Tennessee, Kentucky, Alabama and Mississippi and was providing clinical medical physics and treatment planning consulting services to local area cancer centers.
In October 1981, Victoreen Instrument Company suspended operation as an Accredited Dosimetry Calibration Laboratory (ADCL) accredited by the American Association of Physicist in Medicine (AAPM). ADCL's provide precision radiation instrument calibrations for medical institutions which are directly traceable to the National Institute of Standards and Technology (NIST). This event created a crisis in obtaining medical calibrations since the other two accredited laboratories - Memorial Sloan Kettering Institute in New York and MD Anderson Cancer Center of the University of Texas in Houston - could not handle the demand for calibration services. In November 1981, K&S decided to design and build a calibration laboratory and apply for AAPM Accreditation. The lab was completed by mid summer of 1982 and was accredited by the AAPM in September of 1982.
In 1987, the K&S AAPM ADCL accreditation was extended to include low dose rate (LDR) brachytherapy calibrations. In 1992 the AAPM accredited K&S for high dose rate (HDR) Iridium-192 calibrations of well type chambers and was added to the services offered by K&S.
K&S was accredited by the Health Physics Society (HPS) in 1994 to provide radiation survey instrument calibrations for Cesium-137 for rates from 0.5 mR/h to 1000 R/h.
During the same year the diagnostic x-ray dosimeter calibrations were expanded to included diagnostic beams (3 phase, 12 pulse) at diagnostic rates (0.5 to 5 R/s) and extended to mammography with both W/Al and Mo/Mo beams. Noninvasive kVp meter calibrations for both mammography and general radiography were also added during 1994 -1995.
In 2001 K&S Associates became accredited by The American Association for Laboratory Accreditation - A2LA.
Effective January 1st, 2009, K&S became a wholly owned subsidiary of PTW-Freiburg - the German manufacturer of high-quality dosimetry and QA equipment for diagnostic and therapeutic radiation machines. While this change substantially increases the resources of K&S, the company remains an independent accredited entity and continues to provide services for all customers and all types of instruments.
K&S currently offers the broadest range of precision calibration and dosimetry services available covering energies from 10 kVp to 250 kVp x-rays, Cesium 137 and Cobalt 60, LDR (Iodine 125, Palladium 103, Cesium 137, Iridium 192) and Iridium 192 HDR brachytherapy. K&S offers diagnostic x-ray beam calibrations covering mammography, general radiography, fluoroscopic, and CT plus noninvasive kVp meter calibrations over the same range.
K&S is accredited by The American Association for Laboratory Accreditation - A2LA in accordance with recognized International Standard ISO/IEC 17025:2005 and also meets the requirements of ANSI/NCSL Z540-1-1994 and has an in-depth quality management program to provide equipment calibrations and services. Also K&S participates in a NIST measurement quality assurance program that exceeds the requirements for proficiency testing under MQSA.
The newest addition to our services is providing TLD dosimetry measurement services. K&S offers accredited custom TLD dose measurement services for diagnostic and therapeutic patients using chips sealed in polyethylene with a stated uncertainty of 5% for single chip measurements. In the future K&S plans to be able to provide dose measurement services using new nanodot technology. Also K&S provides calibrations of light meters, kVp meters, Unfors units, Reuter Stokes units, Triad systems, plus several other services.
K&S evaluates the performance of all dosimetry and survey instruments submitted for calibration under a protocol approved by the AAPM or HPS and determines whether it is fit for calibration. We perform this evaluation as an independent agent on behalf of the user and are not biased toward any instrument manufacturer. K&S always tests and, if appropriate, replaces batteries. We perform any required mechanical adjustments as needed and perform minor repairs, many times at no charge to the customer. We offer repairs on many instruments and expedite shipping to the manufacturer on those that we cannot repair. We also offer triaxial cable repairs and replacements.