Radiation Dose Chart

Imaging Sciences International (I-Cat) Response to NewYork Times Article

by Mr. Dick Greenan

I have had numerous requests for a rebuttal to the NY Times debacle http://www.nytimes.com/2010/11/23/us/23scan.html?_r=1&pagewanted=all, so to put things into perspective, here are my two cents!

The article “Radiation Worries for Children in Dentists’ Chairs” by Walt Bogdanich  (and Jo Craven McGinty)http://topics.nytimes.com/top/reference/timestopics/people/b/walt_bogdanich/index.html?inline=nyt-per is just another in his series of sensationalist, inflammatory investigative articles on medical and dental radiation and a style of reporting not new to Bogdanich.  He is a past Investigative Producer for “60 Minutes” on CBS and ABC!   Familiarize yourself with a few of his other works in his “Articles” in the above Bogdanich link.

But unfortunately in this article, he has dedicated only 3 sentences to the clinical benefits of CBCT technology and decided to further perpetuate and capitalize on the public’s phobia with radiation, airports not excluded!

Are there any CBCT users out there that didn’t want a CBCT on them selves?   Or on a family member, regardless of age?  Why is that?   Because you understand that the minimal risk of that exposure is far outweighed by the benefits.  Would you offer these services to your family and not to your patients?  Of course not.  Could you ever go back to practicing dentistry without this modality?  I have not met a practicing, wet-fingered clinician yet that would. Every user has a list of success stories attributed to their CBCT.

The Effective Radiation Dosage value is used today in order to quantify the level of risk from different x-ray procedures and compare them to naturally occurring sources of radiation.  The unit for this Effective Dosage Radiation is the microsievert (uSv).   We are obviously exposed to radiation from natural sources every day.  On average we are exposed to an effective dose of about 8 uSv per day from naturally occurring radioactive materials and cosmic radiation from outer space. High altitude long-haul commercial airline flights give an added dose of 30 uSv.

To compare, the radiation exposure from an average CBCT scan equates to 8-10 days natural radiation exposure. A regular Medical CT scan is the equivalent of 10 months natural radiation exposure.

So what does it all mean?  We are inundated with such comparisons, often conflicting, due to the myriad of variables, age of the research, age of the equipment and software used, phantom/model construction, etc. and the fact that the formulas used are not true science but based on theoretic tissue weights.   Just ten years ago, the radiation physicists thought they had it all figured out and then in 2007, they changed the weight factors, significantly, once again!  All based on theory!

Where does this leave you and your patient?    I have enclosed a good, average, comparison by two leading university oral and maxillofacial radiologists (not manufacturers!), which, puts things into perspective - for those of you who like numbers.

 

We readily accept the radiation burden in an fmx because of the obvious benefits.   But we have a problem with a 3D technology that uses 4 times LESS exposure?  The potential benefits of CBCT in dentistry are undisputed and have been supported in numerous university-based studies for the last 9 years.

But our Bogdanich stated “. . . there is little independent research to validate these claims”.    He needs to do some proper research but unfortunately that is not headlines material and Bogdanich and is ilk would be out of work.

He obviously didn’t go any further than the manufacturer’s sales literature.  If he were to truly do his due diligence he would discover a myriad of university based research and clinical based articles on the benefits of this growing technology.

And not just based on the adult population but in a recent Pediatr Dent. Jul-Aug;32(4):304-9.  http://www.ncbi.nlm.nih.gov/pubmed/20836949 article as well.  “The pediatric dental community can benefit from the amount of additional information provided by CBCT. The benefits of CBCT imaging must be weighed against the radiation risk to the pediatric patient and the complexity of the pathology.”  The radiation risk that we deal with daily.

Regarding Bogdanich’s slam on CE courses, State mandated hours aren’t the only things driving us to courses but professional curiosity to expand our knowledge.  And if we incorporate specific technologies that will enhance our abilities, skills and patient care, well, this is a cost that society has paid in the past and will continue to pay.  They call it progress.

CBCT allows us to see so much more, more accurately, more defined and in many cases, offering a greater choice in treatment plans.

An accurate diagnosis, successful treatment plan and outcome should be engineered on a strong foundation.  That foundation breeds confidence and success.  Your foundation will vary due to your patient, training, experience, phase II options, adjunctive health-care providers and equipment you have at your disposal.

When we order any X-ray exam, we have made the determination that the benefit outweighs the risk.  A CBCT scan is ultimately the patient’s decision to make, but the risk of such exams are much less than those risks we commonly accept in daily life.

Dick Greenan
Imaging Systems, Inc.
President

Curriculum Vitae:
Mr. Richard W. Greenan is an internationally known X-ray authority and holds degrees and certificates from Franklin Pierce College, Boston University and the USN Dental Technician, Electricity and Electronics and Dental Repair Schools. Formerly a USCG Dental X-ray Technologist, X-ray Specialist and X-ray Products Manager for the S.S. White Co., Ritter X-ray Co., Denar Corp., Quint Sectograph Corp., and J. Morita Corp., Mr. Greenan is President of Imaging Systems, Inc., the Academy for Advanced Radiographic Studies, author of A Practical Atlas of TMJ and Cephalometric Radiology, A Practical Guide to TMJ and Cephalometric Radiology, is published in numerous journals and has contributory chapters in The Bimler Cephalometric Analysis, (Drs. G.B. Bastien, J.W. Truitt), and Advanced Orthopedic and Orthodontic Therapy (Drs. G.B. Bastien, J.W. Truitt).  In addition to accruing over 4000 hours of continuing education in Radiology, TMJ and Orthodontics/Orthopaedics, Mr. Greenan has been a featured speaker at the American Academy of Implant Dentistry, the American Association of Orthodontists, American Equilibration Society, American Association for Functional Orthodontics, the American Academy of Head, Neck and Facial Pain Annual meetings and is a member of the American Academy of Oral and Maxillofacial Radiology, the International Association of Dentomaxillofacial Radiology, the International College of Cranio-Mandibular Orthopedics, the Academy of Osseointegration and the International Association for Orthodontics.  Mr. Greenan presents highly acclaimed and dynamic programs on Dental Radiography.