Integrated Oncology Network (ION), a portfolio company of Silver Oak Services Partners, has announced it acquired e+CancerCare (e+).

e+, based in Nashville, Tenn., is an operator of outpatient cancer care centers across 10 states.

ION, based in Corona del Mar, Calif., is a radiation oncology management and cancer center development company that now owns and manages more than 50 treatment centers in 17 states.

Silver Oak, based in Evanston, Ill., is a private equity investment firm focusing on middle-market healthcare, business and consumer services companies.

McGuireWoods served as counsel and legal advisor to ION in connection with the transaction.

Financial terms of the acquisition were not disclosed.