Probably cannot wash it. However, it can be freshened (dust removed) by running through a dryer.
You can carefully test a spot by dampening a cloth and rubbing gently over a small, inconspicuous area. If you used an inkjet printer and regular fabric (not the type you purchase at the store ready for printing), then I seriously doubt you can wash the quilt without having all the photos disappear. Perhaps you could re-do the photos on correctly treated fabric and hand applique them over the old ones?