It's one-third the thickness of a human hair, yet its potential

to shrink inoperable liver tumors is now offering relief in a

big way to TUH patients.

Called Selective Internal Radiation (SIR) Spheres, these tiny

beads -- charged with a special radioactive element called

Yttrium 90 -- are injected into the body by the tens of

millions and guided directly into the tumor, where they work

to melt it away.

Offering patients a less painful, potent way to treat primary

liver cancer, SIR-Sphere therapy offers several advantages

over traditional alternatives, explains Gary Cohen, MD, Chief
of Vascular Interventional Radiology. Cohen recently

performed this innovative procedure for the first time at

Temple, aided by Alan Maurer, MD, Director of Nuclear

Medicine.

"Prior to the development of SIR-Sphere Therapy, the

standard treatment had been chemoembolization," said

Cohen, where surgeons insert a catheter into one of the

main arteries of the liver and inject a cocktail of

chemotherapeutic agents and particles to shrink a tumor

and block the blood flow feeding it.

This type of treatment offers limited success because of its

inability to sustain a long enough "dwell time" in the liver

for the chemotherapuetic agents. It also has the potential

to cause extreme pain that can last for weeks.

By contrast, SIR-Sphere Therapy has a 90 percent

response rate and can be less painful because of its ability

to deliver a higher dose of radiation without subjecting

nearby healthy tissue to harmful levels of radiation.

"By introducing it directly into the tumor, the radiation will

spread out in just a small area and won't affect other

parts of the body," explained Cohen.

Unlike chemoembolization, which requires an overnight

stay in the hospital coupled with heavy medication,

patients who receive SIR-Sphere Therapy go home the

same day and experience minimal side effects.

While its potential is inspiring -- the therapy has also

been effective in treating metastatic lesions in the colon

and breast -- the results achieved with SIR-Sphere

Therapy require a tremendous amount of pre-treatment

homework to achieve.

During a patient's initial consult, Cohen and his team

carefully review the patient's latest scans and lab-test

results to determine eligibility for the novel therapy.

Potential patients are sent to Nuclear Medicine, where

they undergo additional testing to determine blood flow

variables -- including detailed data on how blood is

supplied to the tumor. Patients who have more than

one vascular path leading from the tumor to other parts
of the body are not eligible for SIR-Sphere Therapy

because additional pathways could allow the

radioactive spheres to spread to healthy tissue.

For those deemed appropriate candidates, the delicate

procedure can take up to six hours. It begins by slowly

threading a catheter through a major artery in the groin

to the site of the liver tumor -- which then serves as the

portal through which the healing spheres will travel.
While the procedure relies on the delicate precision of the
interventional oncologist, Cohen sees the procedure as

a balanced collaboration between Interventional

Radiology and Nuclear Medicine.

"While I am delivering the therapy, the Nuclear Medicine

team performs vital calculations to determine what dose

of Yttrium-90 is necessary, and to makes sure it's safely

handled and delivered," said Cohen.

After the therapy is administered, recovery time is brief.

"Patients tolerate the therapy extremely well," said

Cohen. "They come out of the room hungry and want to

eat. It's almost miraculous."

While the treatment is being heralded as the next big

thing in interventional oncology, Cohen cautions that

SIR-Sphere Therapy is not a cure. Its primary use is to

help enhance the quality of life for patients with limited

treatment options.

"This is for patients for whom chemotherapy or

transplantation are not an option," said Cohen. "The goal

is to help the patient remain as comfortable as possible

for as long as possible while attempting to shrink the

tumor enough so they could possibly undergo a

curative procedure."

-- Steven Bates