BOSTON (AP) — State public health officials awarded Friday the first 20 licenses to operate medical marijuana dispensaries, the first in Massachusetts under a voter-approved law.

The 20 were chosen by the Department of Public Health out of 100 finalists. The dispensaries, which officials said could begin opening by the summer, will be allowed to grow and sell marijuana for patients with certain medical conditions including cancer, multiple sclerosis and Parkinson’s disease.