For the parametric representation
(1)
 
(2)

the catacaustic of this curve from the radiant point is given by
(3)
 
(4)

Eliminating gives the Cartesian equation
(5)

Therefore, since
(6)

is the equation of a cardioid, the catacaustic of the cissoid of Diocles for radiant point at is a cardioid with .