Doriot Anthony Dwyer, a renowned flutist who broke down gender barriers with her appointment as principal flute of the Boston Symphony Orchestra in 1952, a post she held for nearly four decades, died on Saturday in Lawrence, Kan., where she lived near her daughter. She was 98.

Her death was announced by the Boston Symphony.

Ms. Dwyer was only the second woman to win a principal chair with a major American orchestra, after Helen Kotas, the principal horn of the Chicago Symphony Orchestra from 1941 until 1948.

Ms. Dwyer was 30 when the vacancy in Boston was announced. After thorough training, she had accumulated extensive experience ranging from freelancing in an orchestra that went on tour with Frank Sinatra to playing with the National Symphony Orchestra in Washington as second flute.

At the time, she was second flute with the Los Angeles Philharmonic, and during the summers played principal with the Hollywood Bowl Orchestra, directed by Bruno Walter, who had chosen her.