BALTIMORE (AP) - A Maryland doctor filed an $800 million lawsuit against a cell phone maker and a telecommunications company, claiming years of using the wireless devices caused his brain cancer. Chris Newman, 41, brought the suit agains Motorola Inc. and Verizon Communications on Tuesday in Baltimore City Circuit Court.The Food and Drug Administration said there is no evidence that radiation from cellular telephones poses a health risk. However, the FDA has also said there is no proof that cell phones are risk-free. The malignant tumor was discovered in March 1998 behind Newman's right ear. Newman's attotrney, Joanne Suder, said here client, a neurologist, used wireless phones at least several times a day between 1992 and 1998. "Because of the nature of his work he had to be in touch with patients on a minute-to-minute basis," Suder said.