BOSTON — The failure of the Department of Children and Families to keep track of a missing 5-year-old boy whose family had been under its supervision is inexcusable but has given the state an opportunity to re-examine the agency and make changes, Gov. Deval Patrick said Monday.

Patrick met with representatives of the Child Welfare League of America, which he had asked to conduct an independent review of the state agency. He later told reporters he asked the league to report back to him by the spring, allowing time for lawmakers to pass any proposed legislation that might emerge from the review.

Jeremiah Oliver of Fitchburg has not been seen by relatives since September and is feared dead. Police learned he was missing in December. His mother and her boyfriend face charges in connection with his disappearance.

The state’s child advocate, Gail Garinger, who conducted a separate investigation, said in a report last week that the social worker assigned to the family had not made required monthly visits to the home. The social worker, a supervisor and area manager were later fired.

The case has focused attention on the caseload of social workers and the leadership of the agency.

“Nothing can excuse the misrepresentations made and the other failures in the lack of oversight of Jeremiah Oliver and his family,” Patrick said. “The people responsible for that have been dismissed.”

Patrick said staffing and caseload issues are separate, but no less serious.

“I think we have a great opportunity presented, ironically, by this terrible tragedy, to rethink and reinvigorate the department,” he said.

DCF Commissioner Olga Roche, who testified last week at a legislative oversight hearing, did not appear with the governor and Health and Human Services Secretary John Polanowicz at Monday’s news conference. But Patrick insisted he maintained confidence in Roche.

“I think she has shown that she is prepared to step up and be accountable and hold those who are directly responsible for these failures accountable,” Patrick said. “And we need her right now to help us get from here to the end of this department-wide review.”

Garinger’s report found that during a 12-month period ending in November, the statewide completion rate for required monthly visits was 82.5 percent, implying that nearly one in five home visits had been missed during that period. Patrick said while that number was a red flag, it was too early to draw conclusions from it because visits are often held outside the home, such as at schools or DCF offices.