CT Scans & Kid’s risk for cancer

The Use of Computed Tomography in Pediatrics and the Associated Radiation Exposure and Estimated Cancer Risk
Diana L. Miglioretti, PhD, et al.
JAMA Pediatr. 2013;167(8):700-707.

Importance  Increased use of computed tomography (CT) in pediatrics raises concerns about cancer risk from exposure to ionizing radiation.

Objectives  To quantify trends in the use of CT in pediatrics and the associated radiation exposure and cancer risk.

Participants  The use of CT was evaluated for children younger than 15 years of age from 1996 to 2010, including 4 857 736 child-years of observation. Radiation doses were calculated for 744 CT scans performed between 2001 and 2011.

Main Outcomes and Measures  Rates of CT use, organ and effective doses, and projected lifetime attributable risks of cancer.

Results  The use of CT doubled for children younger than 5 years of age and tripled for children 5 to 14 years of age between 1996 and 2005, remained stable between 2006 and 2007, and then began to decline. Effective doses varied from 0.03 to 69.2 mSv per scan. An effective dose of 20 mSv or higher was delivered by 14% to 25% of abdomen/pelvis scans, 6% to 14% of spine scans, and 3% to 8% of chest scans. Projected lifetime attributable risks of solid cancer were higher for younger patients and girls than for older patients and boys, and they were also higher for patients who underwent CT scans of the abdomen/pelvis or spine than for patients who underwent other types of CT scans. For girls, a radiation-induced solid cancer is projected to result from every 300 to 390 abdomen/pelvis scans, 330 to 480 chest scans, and 270 to 800 spine scans, depending on age. The risk of leukemia was highest from head scans for children younger than 5 years of age at a rate of 1.9 cases per 10 000 CT scans. Nationally, 4 million pediatric CT scans of the head, abdomen/pelvis, chest, or spine performed each year are projected to cause 4870 future cancers. Reducing the highest 25% of doses to the median might prevent 43% of these cancers.

Conclusions and Relevance  The increased use of CT in pediatrics, combined with the wide variability in radiation doses, has resulted in many children receiving a high-dose examination. Dose-reduction strategies targeted to the highest quartile of doses could dramatically reduce the number of radiation-induced cancers.

journalistic version:


related paper:


You don’t need cognitive stimulation

John Zeisel on ‘hopeful aging’
Jul 7, 2013

Creative means discovery, creative means learning, creative means invention, creative means comprehension.
We’re always in search of understanding.

You can’t learn, be innovative, discover, be creative with banality.
Playing bingo isn’t going to cut it. It’s not interesting enough.
Looking at a Matisse and saying, “What is this painting about?” — that’s interesting enough.

Sudoku, crossword puzzles — mental exercise is not what I’m talking about.
It doesn’t do it. The term that’s used for those is ‘cognitive stimulation.’
You don’t need cognitive stimulation. You have to have meaning in your life. If it’s meaningful, it will stimulate you.

Is there anything else we can do to help our brains age well?
The basic three are sleep, diet and exercise.

The second level of intervention is stress reduction and creative endeavors: the arts, learning. The learning can be anything. It can be based on aptitudes and skills you already have, or you can also learn new skills. All kinds of learning are as essential as stress reduction.

The biggest misconception is that people with dementia can’t learn.
There are four learning systems in the brain.
One is called episodic learning: there’s an event in my life and I remember what happened.
The second is semantic learning, like learning a word out of context.
Then there’s emotional learning, which revolves around relating to others.
Then the final one is procedural learning, which we learn by repetition, by doing something. It’s how you learn to ride a bike or sign your signature.

People with dementia lose some ability with the first two, but they do not lose their abilities for emotional and procedural learning.

To Keep Your Brain Nimble As You Age, Stretch It


Headed To Mars? Watch Out For Cosmic Rays

Headed To Mars? Watch Out For Cosmic Rays
May 30, 2013

The bulk of the radiation was caused by galactic cosmic rays — beams of high energy ions that we don’t know how to shield against. Hassler says there’s really only one way to minimize the damage caused by these rays: “Go quickly.”

The shortest possible trip to Mars with current technology would take about six months. During that time an astronaut would experience about four times more radiation than someone on the International Space Station.

“An astronaut on ISS for, say six months would receive on the order of maybe 80 millisieverts, compared with the 330 we receive on our way to Mars,” Hassler says.

The average American is only exposed to about 6 millisieverts of radiation per year.
An abdominal CT scan subjects a patient to 10 millisieverts.
The dose from a long journey through open space is much higher. Calculating cancer risk from radiation exposure is tricky, but basic estimates suggest a trip to Mars would increase your risk of getting cancer by about 1.5 percent.

“What this paper does is place foursquare in front of the NASA leadership [that] there’s no cause for delay, at least as far as radiation is concerned,” Zubrin says. “We should now set our course for Mars.”

Therapeutic Effects of Lowering Cholesterol

Therapeutic Effects of Lowering Cholesterol
in: CURRENT Medical Dx & Tx 2014, Fifty-Third Edition > Chapter 28. Lipid Disorders
Robert B. Baron, MD, MS

Reducing cholesterol levels in healthy middle-aged men without CHD (primary prevention) reduces their risk in proportion to the reduction in LDL cholesterol and the increase in HDL cholesterol.
Treated adults have statistically significant and clinically important reductions in the rates of myocardial infarctions, new cases of angina, and need for coronary artery bypass procedures.

Rosuvastatin … JUPITER … a combined end point of myocardial infarction, stroke, revascularization, hospitalization for unstable angina, or death from cardiovascular causes in both men and women. The NNT for 1 year to prevent one event was 169.

Primary prevention studies have found a less consistent effect on total mortality.
The JUPITER trial … reduction in death from any cause. The NNT for 1 year was 400.

In patients with CHD, the benefits of cholesterol lowering are clearer.
The NNT to prevent a non-fatal myocardial infarction or a coronary artery disease death in these three studies were between 12 and 34. Aggressive cholesterol lowering with these agents causes regression of atherosclerotic plaques in some patients, reduces the progression of atherosclerosis in saphenous vein grafts, and can slow or reverse carotid artery atherosclerosis.
Meta-analysis suggests that this latter effect results in a significant decrease in strokes.
Results with other classes of medications have been less consistent.
For example, gemfibrozil treatment …

The disparities in results between primary and secondary prevention studies highlight several important points.
The benefits and adverse effects of cholesterol lowering may be specific to each type of drug; the clinician cannot assume that the effects will generalize to other classes of medication.
Second, the net benefits from cholesterol lowering depend on the underlying risk of CHD and of other disease.
In patients with atherosclerosis, morbidity and mortality rates associated with CHD are high, and measures that reduce it are more likely to be beneficial even if they have no effect—or even slightly harmful effects—on other diseases.

Green tea and coffee: reduced risk of stroke

The impact of green tea and coffee consumption on the reduced risk of stroke incidence in Japanese population: the Japan public health center-based study cohort.
Stroke. 2013 May;44(5):1369-74.
Kokubo Y, et al.

CONCLUSIONS:  Higher green tea and coffee consumption were inversely associated with risk of CVD and stroke in general population.

Comment in:

  • Response to letter regarding article, “The impact of green tea and coffee consumption on the reduced risk of stroke incidence in Japanese population: the Japan public health center-based study cohort”. [Stroke. 2013]
  • Letter by Chen regarding article, “The impact of green tea and coffee consumption on the reduced risk of stroke incidence in Japanese population: the Japan public health center-based study cohort”. [Stroke. 2013]

journalistic version:
A Daily Habit Of Green Tea Or Coffee Cuts Stroke Risk
March 15, 2013

Kokubo says that green tea contains compounds known as catechins, which help regulate blood pressure and help improve blood flow.
The compounds also seem to promote an anti-inflammatory effect.
Kokubo says coffee, which contains caffeine and compounds known as quinides, likely influences our health through different mechanisms.

Treatment of Blood Cholesterol

2013 ACC/AHA Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults
Circulation. November 12, 2013


New Cholesterol Guidelines Could Put More Americans On Statins 
November 13, 2013

Dr. Sidney Smith, at the University of North Carolina, was one of the guideline writers.
The American College of Cardiology and the American Heart Association have been sifting the evidence for four years to come up with the most up-to-date advice.

a high dose of statins, drugs such as Lipitor, Zocor or Crestor, or their generic equivalents.
They cost from $4 to $150 a month.

If you’re an adult under 75 and don’t have any of these risks, your doctor should check your odds of suffering a heart attack or stroke in the next 10 years, using a new risk calculator. If your 10-year risk is seven and a half percent or higher, the guidelines say you should be on a moderate dose of statin.

Dr. Sidney Smith says the new guidelines should actually make life simpler for doctors and patients because most don’t have to worry about starting a statin if their cholesterol reaches a certain point or about getting it down, through drugs, to a specific number target. But others think the new guidelines are more complicated.

DR. STEVEN ATLAS: Much more complex.
That’s Dr. Steven Atlas, a primary care doctor in Boston, who actually thinks new cholesterol guidelines are overdue.


US Doctors Urge Wider Use Of Cholesterol Drugs
by The Associated Press. November 12, 2013
Roughly half the cholesterol panel members have financial ties to makers of heart drugs, but panel leaders said no one with industry connections could vote on the recommendations.

“It is practically impossible to find a large group of outside experts in the field who have no relationships to industry,” said Dr. George Mensah of the heart institute.


Shift In Cholesterol Advice Could Double Statin Use
November 12, 2013

Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk: A Systematic Review and Meta-analysis


Preparing for Your Test