Et Tumor, Brute?

Et Tumor, Brute? is a quest in Fallout: New Vegas.

Quick walkthrough
Caesar needs you to get the supplies to cure his headaches and remove his brain tumor. Your options are as follows: Note: If either of these two options are chosen, you can choose to cure him or rig the surgery to result in his death. If the latter is chosen, Speech 60 or Medicine 50 is needed to keep Lucius (and thus the Legion) friendly, so that you can still continue the Legion quest line.
 * Without a diagnostic scanning module, you'll need a doctor's bag and surgical tools, as well as Medicine 75 or Luck 9.
 * Otherwise, you'll need to find a functional diagnostic scanning module and a doctor's bag.
 * Finally, with Arcade Gannon as a follower, you also have the option of selling him into slavery as Caesar's personal doctor, but that will result in losing lots of Karma. In order to sell Arcade you have to leave him outside of Caesar's tent. Upon entering, talk to Lucius; he will ask you if you're sure you want to sell him.

Detailed walkthrough
If you choose to find the diagnostic scanning module, you must make your way towards the radiation and ghoul infested Vault 34. You can find the vault north-northwest of the NCR's Camp Golf or east of the NCR's Sharecropper Farms near New Vegas. It is recommended that you bring several Rad Away and RadX. You will notice the radiation right off the bat as the entrance is brimming with radiation. Due to the intense radiation, there will be several geckos on the way in and once entering the vault you'll find approximately 20-30 ghouls of various types inside. Once inside your objective will be to get to the armory, however the door is locked and has nothing to do with this quest(there is notable loot down there however). Your objective is to get to a room called Security Section A which is under a flooded hallway. First you must search the vault for two terminal passwords. The security terminal password is in the first flooded area, on a dead Glowing One/vault technician under a desk, and the utility terminal password is through the clinic and into the next flooded area, on the right, on another vault technician. After finding the passwords, go to the door just before the entrance to the armory (this is the Utility Room), and activate the pump system on the terminal. Next go to the once-flooded area where you found the utility password, which will now be a closed door. Go through and make your way to the door that reads Security Station-A. In the security terminal you will find a broken down Auto-Doc with the replacement diagnostic scanning module Note that you will be taking rads at a much higher rate in Security Station-A. Now return to Caesar, install the module in his Auto-Doc and perform the operation.

Behind the Scenes

 * The title of this quest is a play on Julius Caesar's famous last words, "Et tu, Brute?" from Shakespeare's play Julius Caesar which in English is "You too, Brutus?"
 * The quest is an elaborate allusion to Julius Caesar, who did indeed suffer from an ailment that caused severe headaches and was also a secret from the public.

Bugs

 * The auto-doc has a chance of spawning in the "Clinic." (Unknown what caused this)