A local department that enters into a voluntary continuing services and support agreement with a program participant shall file a petition for review of the agreement and the program participant’s case plan in accordance with § 16.1-283.3. If no subsequent hearings are held by the court to review the agreement and case plan after the initial review hearing held pursuant to § 16.1-283.3, the local department shall conduct administrative reviews of the case for the remaining term of the voluntary continuing services and support agreement no less than every six months.