Graduating in engineering at London University in 1933, he later entered the medical school of the Middlesex Hospital, qualifying in 1938. He held a house surgeon's appointment at the West London Hospital and then became resident medical officer at the Radium Institute in 1931. In 1939 he joined the RAMC and was captured in the evacuation of France in 1940, spending the rest of the war as a prisoner. On his return to England after the defeat of Germany, he was appointed assistant radio-therapist at the Middlesex Hospital, being seconded for six months to the Fondation Curie in Paris. In 1949 he was appointed consultant radio-therapist to the Portsmouth Group of hospitals and established a clinic equipped with two 2000-curie cobalt units. He was fluent in French and German, frank, fearless and full of energy and drive, a bonny fighter not easily thwarted of his legitimate objectives. Gunderson died suddenly at the age of 48, while on holiday in Italy, on 14 February 1962. A memorial service was held in Portsmouth Cathedral on 28 February 1962. He was married only a short time before he died.