 The so-called Finsen lamp became widely used in for phototherapy, and derivatives of it became used when experimenting with other types of radiotherapy.Modifications were made to Finsen's original design, and it found its most common forms in the Finsen-Reyn lamp and Finsen-Lomholt lamp .By 1905, it was estimated that fully 50 percent of the cases of lupus were successfully healed by Finsen's methods.