dont be aggressive, be assertive.
listen.
know when to keep your mouth shut...nothing worse than a know-it-all med student.
be attentive, ask questions, help out, stay late if needed.
Your job as a medical student is doing kick-ass jobs on H+P and then doing notes/dictations. Find out who you are going to see the next day and do your reading ahead of time. If you need to stay late to do this (e.g. no access from home), then do so. Not many residents will tell you to stay late to finish your work (it's just not cool). Don't start getting used to the 9 to 5 work hours you've been hearing about because that doesn't apply to medical students.
It would be nice if you can read a Perez or Leibel chapter, but realistically it's very hard and too long for one night. When I was rotating, I used the Red Book by Coia, which is more concise. However, now that I know a bit more, I am realizing that it is very out-dated. Therefore, I actually would NOT recommend Coia. Same thing with Baby Perez, (the blue book edited by Chao) it's full of pearls and bullet points, but, in my opinion, not very helpful for beginners. My recommendation is to read the NCCN clinical practice guideline (both algorithm and text), which can be found at
www.nccn.org. You can even log on and request a free CD to be sent home! It'll tell you how to stage a patient and how you would work-up, treat, and follow-up that patient; most practical questions you will be asked. It's concise enough for one night (at least the part that pertains to your patient). It is much more up-to-date than any textbook you will find. For natural history and epidemiology, though, you will have to go back to your favorite textbook. I found "Cancer Management: A multidisciplinary approach" to be a very manageable introductory oncology textbook. You can find a web copy at cancernetwork.com A pocket handbook by Hansen and Roach is good one to carry around for quick references. I wouldn't use it as the primary reading, though.
I see many medical students hung up on radiation oncology technique, prescription, etc. Frankly, you are not expected to know that kind of stuff. An attending who has a good perspective on things would not care if you know them. They would care, however, if you cannot tell them a coherent story about what happened to the patient. In other words, know oncology before tackling radiation oncology.
In addition to doing H+P and dictating, some attendings may invite you to do the contouring. If they don't, I would be proactive and ask if you can participate in planning even if it's just watching over their shoulder. I didn't do this because, frankly, I didn't know that treatment planning was such a large part of what rad oncs do. Not only will it show your enthusiasm, it will make your day much more interesting.
Unless you are paired with an attending one-on-one, do NOT kill yourself trying to see many patients. Instead, see one or two patients a day and do a good job. Attendings don't know you are working your butts off to see four patients a day, they just remember you didn't do such a good job on that one patient of his/hers.
Don't kill yourself trying to write the definitive history of the patient detailing every study ever ordered; this is a common medical student mistake. Write only what's pertinent. Remember: a good H+P has a concise history and more detailed discussion.
If you have some free time on your hand, DO NOT sit and read; reading is for afterhours. The last thing you want to do is to look bored. Instead, I recommend spending time with non-physicians such as physicists, rad biologists, dosimetrists and therapists to get more rounded exposure to the field. Advertise you are doing this ("I want to spend some time today with therapists to see how they set up patients."). It will reflect positively.
Do a good job on your end-of-rotation presentation. Ask the residents for guidance on these. Start preparing early.
MOST IMPORTANT: Residents ask themselves whether the rotating medical student is someone they can work with for four years. You should be asking yourself the same question. Radonc makes really good suggestions here. You have the best chance of matching at places you rotate, do not burn bridges.
Lastly, for the most part, you will be doing just H+P and dictation day-in-and-day-out. There is much more to rad onc than that! Don't be turned off by your rotation experience and think this is a boring field. Unless you really need adrenaline rush to get you going, this really is a fantastically interesting specialty.
Good luck.