Since this forum has been so helpful for me, I thought I'd contribute in my own pathetic way:

As a warning to those who may not have a RadOnc program at there home school or would like to try another institution, getting a radonc away clerkship these days can be a challenge. Submitting 4-6 months in advance may not only help, but is some cases required. If you hold your breath on one they may only give you a month's notice to tell you "no", so it may even be a good idea to have a back up that you have applied for at the same time.

Thanks for the heads up!

I'm having a hard time too - there is a Rad Onc program at my school but, what if no externship is available? Is that a big, bad, black mark?

I'm having a hard time too - there is a Rad Onc program at my school but, what if no externship is available? Is that a big, bad, black mark?
it depends upon what youre asking. Must you do a radonc rotation? Lets put it this way: no program will look at you if you haven't: would you want a person who never rotated through the field? Must it be at your school? If there is a reasonable reason you didnt rotate at your school but did elsewhere, fair enough I would think.

I meant if you do a rotation at your own institution but can't get an externship at an outside program.

I meant if you do a rotation at your own institution but can't get an externship at an outside program.
no of course not. its useful to get letters and audition but it doesnt have tob e done and most people dont match at places they've ever rotated at by definition.