Dunne joined the R's on a one-year deal in the summer and activated a further 12 months after making 37 appearances in all competitions for the Championship club.
The former Manchester City man has been a regular in the league's joint meanest defence and Dunne is glad to have put his fitness problems behind him.
"I am delighted. After missing a year through injury, to come back and play so many games is great," he told the club's official website.
"There is naturally always that worry that the injury may go again, so to play as regularly as I have has been brilliant. If we can kick on now and finish on a high, that would be the ultimate end to the season.
"What we have to do now is try to get as many points on the board as possible, and also to mentally prepare ourselves for the play-offs. When they come around we've got to make sure we're in good form.
"We were disappointed not to win on Saturday against Blackpool but our performances haven't been too bad recently, and if we can keep that up and continue to win games then we'll go into those play-offs full of belief and full of spirit.
"The aim from the start of this season was to win promotion to the Premier League and that remains the case. That's all we're concentrating on at the moment.
"Whatever happens at the end of May, we'll prepare accordingly for next season and for whatever challenge that brings."
QPR are sitting in third place in the Championship, nine points off an automatic promotion place, with seven games remaining.