Radiology & Imaging

Medical Physicists: CT Scans Safe

Mayo Clinic professor of radiological physics Cynthia McCollough calls last fall's news from Cedars-Sinai Medical Center the straw that broke the camel's back for the CT scan community, at least when it comes to public perception.

Oncology & Cancer

Lung cancer scans: False alarms amid lives saved

(AP) -- Full results of a big study that showed some smokers' lives could be saved by screening with lung scans now reveal more clearly what the risks are: There's a good chance of a false alarm.

Oncology & Cancer

Study shows chemoradiotherapy prior to surgery improves survival

Researchers from Boston University School of Medicine (BUSM) have found that patients with node negative T3 and T4 non-small lung cancer who underwent chemotherapy before surgery had more than three times the survival rate ...

Health

Gov't says full-body scanners at airports are safe

(AP) -- They look a little like giant refrigerators and pack a radiation dose big enough to peer through clothing for bombs or weapons, yet too minuscule to be harmful, federal officials insist. As the government rolls out ...

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Absorbed dose

Absorbed dose (also known as total ionizing dose, TID) is a measure of the energy deposited in a medium by ionizing radiation. It is equal to the energy deposited per unit mass of medium, and so has the unit J/kg, which is given the special name Gray (Gy).

Note that the absorbed dose is not a good indicator of the likely biological effect. 1 Gy of alpha radiation would be much more biologically damaging than 1 Gy of photon radiation for example. Appropriate weighting factors can be applied reflecting the different relative biological effects to find the equivalent dose.

The risk of stochastic effects due to radiation exposure can be quantified using the effective dose, which is a weighted average of the equivalent dose to each organ depending upon its radiosensitivity.

When ionising radiation is used to treat cancer, the doctor will usually prescribe the radiotherapy treatment in Gy. When risk from ionising radiation is being discussed, a related unit, the sievert is used.

This text uses material from Wikipedia, licensed under CC BY-SA