PET imaging before radiation not ideal for determining boost radiation doses

November 3, 2009

(PHILADELPHIA) Positron emission tomography (PET) imaging of non-small cell lung cancer prior to receiving radiation therapy should not be the basis for determining areas that may benefit from higher doses of radiation, according to research presented by investigators at Thomas Jefferson University Hospital at the 51st ASTRO Annual Meeting (Abstract #2583/B-186).

Some studies suggest that areas that have the highest amount of hypermetabolic activity on PET scan before treatment are the areas most likely to have increased activity after treatment, according to Nitin Ohri, M.D., a resident in Oncology at Thomas Jefferson University Hospital. Dr. Ohri analyzed this theory in the Jefferson patient population.

"Investigators are looking to PET imaging find ways to predict if any part of the tumor would benefit from a higher radiation dose," Dr. Ohri said. "I wanted to see if residual activity on a scan after treatment correlates with the activity pattern on a scan done before treatment."

Dr. Ohri looked at the PET scans of 43 patients, of which 15 had significant activity on the scans both before and after treatment. He set up a coordinate system that divided tumors into nine regions or 17 regions for larger tumors. He then correlated the activity in the regions both before and after treatment.

He found that in some patients, the activity pattern was in similar regions before and after treatment. However, there were some patients who showed activity in completely different areas after treatment than there was before treatment.

"It's not sufficient to increase the dose to areas that are especially active on PET imaging before treatment and expect that to improve the control rate," Dr. Ohri said. "It may be more appropriate to do a scan halfway through treatment and plan additional radiation dose around that."

Source: Thomas Jefferson University (news : web)

Explore further: New scans improve treatment accuracy

Related Stories

New scans improve treatment accuracy

September 14, 2006

Australian doctors say they have developed new scans that can that quickly show whether breast cancer cells are responding to therapy.

Post-treatment PET scans can reassure cervical cancer patients

November 20, 2007

Whole-body PET (positron emission tomography) scans done three months after completion of cervical cancer therapy can ensure that patients are disease-free or warn that further interventions are needed, according to a study ...

One scan per patient is not always enough

October 19, 2009

Seven medical imaging groups wrote a joint letter to the Centers for Medicare and Medicaid Services (CMS) to formally request coverage of two fluorodeoxyglucose (FDG) positron emission tomography (PET) scans for a patient ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.