Acne Medicine Alternative: PDT Vs Levulan Blue Light?

I am a 38 year old mexican female. I had a miscarriage 3 years ago, which most likely triggered cystic acne breakouts I get every month, around my period. About 6 months ago, I went on Doxycline and Spironalacton, which greatly controlled the acne, although I still get occasional whiteheads and blackheads. I don't want to be on medication forever, so I consulted with my dermatologist, who suggested several treatments. One of these is PDT, but she's also worried about discoloration. I went somwhere for a second opinion, and the nurse said I should have Levulan with the DUSA blue light. She said she uses it on dark patients and has never seen anyone hyperpigment. What do you think about the blue light vs. PDT? Which should I go for?