Save outcome to CSV file, multiple datasets

For my research I want to extract the features of 40 different VOIs. Most ideally, I would like to save the outcome of the features automatically into a csv file. For 1 VOI this is no problem. But my question is, is it possible to save the new outcome to the same csv file everytime the code is runned?
So that I only have to change the name of the VOI, run the code 40 times and end up with 1 csv file with all the outcomes?

Thank you!