Radiologists may have to make only minor changes to their practices to adjust to the new international standards for lung cancer staging, but a lecture covering their implications was still controversial enough to send sparks flying Aug. 4 at the International Association for the Study of Lung Cancer meeting in San Francisco.

The point of contention during a question and answer session arose after plenary lecturer Dr. Ned Patz, a thoracic radiologist from Duke University in North Carolina, recommended noncontrast thoracic CT for staging. He had advised some 2000 physicians in the audience that whether to use contrast enhancement is a hotly debated question. That point proved true when Dr. John C. Ruckdeschel, CEO of the Nevada Cancer Institute, took to the microphone to challenge the recommendation.

“I’m flabbergasted by your recommendation that we do noncontrast CT as the initial staging study,” Ruckdeschel said. “In 30 years of sitting with surgeons every week, time and again we see these low-bid community CTs that are uncontrasted and worse than a chest x-ray. I am petrified that your slide will make it out into the community.”

In his defense, Patz referred to a study performed by his group at Duke to compare blinded readings of staging CT for lung cancers performed with and without contrast.

“Granted that it was in a tertiary care institution with thoracic radiologists doing it on the best equipment, but after 120 patients, our statistician told us to stop because the results were so highly statistically significant,” he said. “I understand your concern, but we could not find a difference [between the contrast and noncontrast studies].”

In the lecture, Patz noted that radiologists are actually moving away from both contrast and noncontrast CT for staging. FDG PET/CT has become the modality of choice for staging. Its application obviates dedicated thoracic CT or a nuclear bone scan, he said.

Initial diagnosis is still usually based on chest x-rays. They provide an enormous amount of information for staging the disease, he said.

Policies vary from hospital to hospital on the need for brain imaging. Data suggest that about 10% of asymptomatic patients will have brain metastases, but the clinical value of characterizing their presence is uncertain, Patz said.