A doctor, who performed nearly 100 botched prostate cancer procedures at Philadelphia's VA Medical Center, has been sanctioned by The Nuclear Regulatory Commission.

The agency said Dr. Gary Kao cannot take part in agency-related activities without undergoing more training after he performed 91 procedures in which veterans received incorrect doses from radioactive seeds implanted in the prostate to kill cancer cells.

The commission found many of Kao's patients received insufficient doses because he implanted seeds in nearby organs or surrounding tissue.

Kao told a Senate panel in 2009 that he acted in patients' best interest. A phone message left for Kao's lawyer was not immediately returned.

A medical physicist was also sanctioned Wednesday.

The Associated Press contributed to this report.