Alien Attack 25 years old

The 25th planet of the Cyrus Solar System, Vega is in danger, the 800yrs old Queen Mother is dying, afflicted by a disease we know as brain cancer. She has but a short time to live unless the part affected can be replaced. A select group of Aliens have been sent to earth to capture and bring back the part Affected-Medulla to be replaced and transplanted to the Queen Mother. It has taken them 4,5 light years to get here, now they have finally arrived.