Columbia University Medical Center

Racing Against Time: Doctors Collaborate to Help Pregnant Woman with Brain Tumor

mannequin

A mannequin was used to design measures to reduce the amount of radiation that reached a woman’s fetus during treatment for a brain tumor.

In early 2013, Pamela Sternberg of Washington Heights was diagnosed with glioblastoma, a particularly aggressive type of brain cancer. Complicating matters, Ms. Sternberg was 22 weeks pregnant. Doctors told her she had a year to live, and she could not receive any treatment while pregnant.

Lassman_Sternberg resized for Newsroom

Pamela Sternberg with Andrew Lassman

So Ms. Sternberg sought a second opinion. After consulting with neuro-oncologist Andrew B. Lassman, MD, she was offered an unconventional option: to receive radiation during her pregnancy, giving her a chance to save her own life and keep her baby. Dr. Lassman is the John Harris Associate Professor of Neurology at Columbia and chief of neuro-oncology at NewYork-Presbyterian Hospital/Columbia University Medical Center.

Center for Radiological Research

Center for Radiological Research staff

Fast-growing glioblastomas are extremely rare in pregnant women, so Dr. Lassman and his colleagues had to come up with an entirely new way to treat the patient. It took the combined ingenuity of a team of neuro-oncologists, maternal-fetal medicine specialists, radiation oncologists, medical physicists, biophysicists, machinists, and ethicists to make this unorthodox approach possible.

First, Tony Wang, MD, assistant professor of radiation oncology, was enlisted to design a treatment plan, using a mannequin with a radiation detector in its abdomen to measure the dose that would reach the fetus. The mannequin was provided by the Center for Radiological Research, which was enlisted to design and build extra safety measures to reduce the amount of radiation that reached the fetus.

“It was inevitable that a certain amount of radiation would reach the fetus,” says David Brenner, PhD, DSc, the Higgins Professor of Radiation Biophysics and director of the Center for Radiological Research, “but it was important to keep that to the absolute minimum possible.”

Although radiotherapy accelerators are shielded, some stray radiation still leaks through to the patient. The challenge for Dr. Brenner and his colleagues was to develop additional shielding to be placed between the accelerator and the fetus—a task far more complicated that it sounds.

When taking X-rays, dentists use lead aprons to shield the patient’s body from stray radiation. That was not an option here. “Dental X-rays are low energy, so it’s feasible to shield against them with a simple lead apron,” says Dr. Brenner. “The radiation used in radiation therapy is much higher energy. For that, we needed a different, more efficient shield.”

A much more efficient shield: Dr. Brenner’s team calculated that they would need a “sandwich” of three types of metals, beginning with a two-inch layer of lead. When lead is exposed to high-energy radiation, it does its job of shielding, but it also produces its own secondary radiation, so a second, quarter-inch layer of carbon steel was needed to reduce this secondary radiation. In turn, the steel is efficient but produces its own secondary radiation, so a third layer of aluminum was used to reduce the secondary radiation from the steel.

To build this one-of-kind radiation shield, Dr. Brenner turned to the Design and Instrument Shop in the Center for Radiological Research, a pioneer in the design and construction of radiology devices since it was founded by a student of Marie Curie in 1915. Within two weeks, the finished shield, weighing in at 500 pounds, was delivered by special crane to the radiation oncology suite.

Ms. Sternberg then received radiation therapy five days a week for six weeks. According to measurements taken by the physics team, the shield reduced the fetus’s radiation exposure by about 15 percent. Overall, the fetus was likely exposed to less radiation that one would get flying in an airplane.

For the safety of both mother and child, maternal-fetal medicine specialist Anita LaSala, MD, decided to induce labor at 35 weeks. On June 19, 2013, Ms. Sternberg gave birth to a healthy 6-pound boy named Timmy. More than a year later, Timmy is thriving, and his mother’s cancer is controlled. She receives biweekly immune-based infusions as part of a phase 1 clinical trial led by Dr. Lassman at the Herbert Irving Comprehensive Cancer Center. This experimental drug is in addition to the standard treatment of radiotherapy and chemotherapy.

“There is hope in seemingly hopeless situations,” Ms. Sternberg, now 38, was quoted as saying in an article in the New York Daily News. “Not that I haven’t had my moments, but I do feel hopeful.”

 

 

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