(1) Get both opinions. We strongly urge you to consult with a physician who is good at both conventional micro-neurosurgery and stereotactic radiosurgery. It is not enough to speak only with someone who practices only SR. Be sure to talk with someone who is expert in the other method and get that view. In many cases, it is safer to approach a tumor with conventional surgery. You need a team of medical professionals who can help you to evaluate fairly the pros and cons of both procedures and decide which is better for you in this particular situation at this particular time.

(2) How big is the tumor? Recommendations are not to treat a hemangioblastoma larger than 2-3 centimeters at the very most (optimal size is 1.0-1.2 cm). Size is not the only issue, but it is a very important issue. The larger the tumor, the more energy it will absorb and the more it will swell.

(3) Is there cyst or other source of mass effect? "Mass effect" is the effect of having some additional mass in your skull. This could be from a cyst, swelling, or from the tumor itself. If there is already extra pressure inside your skull, SR is probably not a good idea, since the additional swelling caused by the procedure would compound the mass effect.

(4) Where is it? Once treated, there will be swelling (edema) of the tumor and surrounding tissues. What this means to you is that the treated tumor will get bigger before is gets smaller, and depending how much room there is for it to expand, your symptoms may increase before they get better. What position is the tumor in? When it swells, what symptoms may occur? How will the doctor propose to control the swelling? How can you work in partnership with the medical team to minimize the swelling and get through the swelling period? Note that this period of swelling is not measurable in days but in months. Ask your doctor how long you should expect this swelling period to last.

(5) What are the dangers to surrounding tissues? There is usually some margin of healthy tissue that will be irradiated with a therapeutic dosage. What tissue is within that margin? What would such damage do? If the tumor is in a position where there is fluid beside it, then there is some "margin for error," but if it is in a critical spot, then effects to the healthy tissue can be significant.

(6) How many tumors do they propose to treat? What is the sum of the radiation to which you would be subjected? If more than one tumor is to be treated, is it wise to treat them all at this same time? Will the combined swelling of the various tumors cause a dangerous situation? Is it better to treat them one at a time? Pacing the treatment can be critical to managing the post-treatment swelling.

(7) What medication(s) would the doctor propose to use to manage the post-treatment period? Have you taken this medication before? Can they test you for sensitivity to the medication before the treatment, to make sure that you are not likely to have an adverse reaction? The worst problems we have seen from stereotactic radiation involve sensitivities to the medication.

(8) What experience does this team have with treating hemangioblastoma, as opposed to other solid tumors? Hemangioblastomas react differently to radiation treatment. It is important to get someone with experience in treating hemangioblastoma to participate in reviewing the treatment plan prior to the beginning of treatment. If you cannot find someone in your area, we can suggest some sources of second opinions. This should be welcomed by your team, as it is for their protection as much as for your own.

For patient experiences, see Caution Urged on Stereotactic Radiosurgery

For the Handbook discussion, see VHL Handbook, Considering Stereotactic Radiosurgery

As printed in the VHL Family Forum 6:2, June 1998. For permission to reprint, please contact VHL Family Alliance, info@vhl.org.