All amounts paid by the employer and received by the employee or the employee's dependents, by lump sum payments, shall be final, but the amount of any award payable periodically for more than six (6) months may be modified as follows:
(1) At any time by agreement of the parties and approval by the court; or
(2) If the parties cannot agree, then at any time after six (6) months from the date of the award an application may be made to the courts by either party, on the ground of increase or decrease of incapacity due solely to the injury. In those cases, the same procedure shall be followed as in § 50-6-225 in case of a disputed claim for compensation.