The 22-year-old was snapped up by QPR on the final day of the January transfer window, but he failed to feature in a single first-team game.
Now Dellatorre's agent has confirmed that he will be moving back to Brazil.
"He is returning from London now and on June 12 he will present himself at Atletico Paranaense," agent Augusto Nogueira told Globo Esporte.
"Dellatorre didn't have the chance to play because he had a muscle injury and had to stop for two months. The club decided not to buy him, so he is returning to his club Atletico Paranaense."
On the player's future, Nogueira added: "Right now Paranaense is his focus, if any opportunity comes up, the president will decide."