How can I return distinct results from my linq query?

var query = from ada in db.ApplicantDetails.Where(predicate)
                    join vdv in db.VacancyDetails on ada.VacancyID equals vdv.VacancyID
                    join adag in db.AgencyDetails on ada.AgencyID equals adag.AgencyID
                    join aaa in db.AgencyAgents on adag.AgencyID equals aaa.AgencyID
                    join rlv in db.ResultLookups on ada.ResultCode equals rlv.ResultCode
                    // perform a left join on ApplicantInterviews so all fields are returned including NULLs
                    join aia in db.ApplicantInterviews on ada.ApplicantID equals aia.ApplicantID into appinterviews
                    from aia in appinterviews.DefaultIfEmpty()
                    //Remove the "[first name]" option from the grid
                    where ada.FirstName != "[first name]"
                    orderby ada.LastName
                    select new { ada.ApplicantID, ada.VacancyID, ada.AgencyID, ada.ResultCode, ApplicantName = ada.Salutation + ' ' + ada.FirstName + ',' + ' ' + ada.LastName, ada.Address, ada.Phone, ada.Email, ada.CVFilePath, vdv.Title, ClosingDate = vdv.ClosingDate.ToShortDateString(), adag.Company, rlv.ResultDescription, aaa.ContactFirstName, aaa.ContactLastName, aaa.AgentPhone, Successful = (aia.Successful == null) ? false : (aia.Successful) };