Stereotactic Radiosurgery or Gamma Knife

In April 2005 the VHL Family Alliance opened a survey for people with VHL who have had Stereotactic Radiosurgery (SRS). SRS is the generic name for a treatment that is sometimes called by the name of the machine, like Gamma Knife or Cyberknife. Fifty-seven people responded to our survey, sharing their experiences. 46 (81%) of these respondents had a total of 63 planned treatments with SRS. 11 (19%) considered it, but chose not to have the procedure.

How did you first become aware of SRS? 35 people (61%) reported that the option was first raised by their neurosurgeon. Another five people learned about it through VHLFA.

Which of the advertised characteristics attracted you to this procedure? Here people could check more than one response, so the fractions add up to more than 100%. 46 (81%) wanted to avoid open brain surgery, and 35 (61%) wanted to avoid the complications of open surgery. About one-third were attracted by the claim that it was easy ("like a trip to the dentist") and that you could go right back to work. In five instances, the patient was told this was his or her only option, as the tumor was not approachable by open surgery.

What research did you do? People could check multiple answers. 47 (82%) spoke with a neurosurgeon, 28 (49%) spoke with a radiation oncologist, 23 (40%) read the VHL Handbook, and 11 (19%) read the articles on the VHL website. 18 (32%) got second opinions to confirm the plan. Only 10 (18%) spoke with another person with VHL who had had the procedure.

What helped the most in making the decision to proceed? 24 (57%) cited trust in their neurosurgeon. 17 (40%) said they just really did not want to go through surgery, and they felt there was "no apparent downside." Five considered it their only option.

Of the 11 people (19% of those responding) who chose not to go with SRS, one is still in the decision-making process. The other ten did thoughtful research with their surgical teams, and concluded that open surgery would be a better alternative in their particular circumstances. Their open surgeries were successful.

Half the treatments occurred before 2002. 16 people out of 46 (35%) have had only one planned treatment, which might have been delivered in more than one session. 7 (15%) have had two treatments, 8 (17%) have had three treatments, and 12 (26%) have had four or more treatments, for a total of 54 treatments reported.

Of these 54 treatments, in 24 cases (52%), the treatment was administered in one session. In 2 cases, the treatment was spread over three sessions, and in 7 (12%) cases it was spread over four or more sessions. 26 (46%) were done with a Gamma Knife machine, 13 (23%) with a Linear Accelerator. Two Cyberknife treatments were reported, one Proton beam, one Intensity-Modulated Radiation Therapy (IMRT), and the 13 remaining (23%) were unsure what machine was used.

21 treatments (37%) occurred before the year 2000; 12 (26%) between 2001 and 2002, and 21 (37%) occurred since 2003. We do see an rise in the number of times SRS is being used, and a significant rise in interest. This change is likely due to the larger number of machine manufacturers and instruments today. Prior to 2000, all treatments were either by the Gamma Knife or Lineac machines.

We asked people how well they felt before and after the procedure, and over the course of the following year. Nearly everyone complained about the attachment of the frame or helmet to the skull, and wished there were a way to avoid them. Several of the newer machines do not require a frame. Frame or not, there was usually some discomfort on the day after the procedure.

Of the 54 treatments reported, 27 (50%) of the patients felt pretty much the same throughout the course of the post-treatment year. Nearly all of these were treated with some medication for swelling and/or pain, which the medications were usually able to control.

Six people (11%) said they felt quite sick at three months post-procedure. The tumor was growing, or the swelling was hard to control. Two of these required open surgery. Four gradually got better after the first three months without additional intervention.

Nine (17%) did not feel their worst until six months after the procedure. Five of these went on to require surgical removal of the tumor. One woman died from uncontrolled swelling and complications. One person complained of memory problems for two years following the procedure, but reported that this has normalized after two years. Three began improving after the six months mark, but it was a very difficult 18 months.

Was the treatment successful? In only 20 cases (37%) the tumor(s) shrank. Three (6%) grew. Six (11%) required surgery, and in seven cases, it's a bit early to say but the patients are doing well.

In 17 (31%) cases the tumor stayed the same size. While it is good that the tumors did not grow, we do not yet have sufficient long-term data to know whether the tumor has been permanently disabled, or whether it is only in a quiet period.

Would you recommend this treatment to others? The answers aligned perfectly with the outcomes: 68% (with good outcomes) said yes, and (19%) said no.

I first went through the summarized data, and then went back and read each person's survey form to get a clearer picture of his or her own experience. As I read through them I began to realize that I could pretty much predict the outcome based on the amount of research a person had done. If someone reported having read everything available on the internet, talked with a neurosurgeon and a radiation oncologist, and one or more people who had had the procedure, and made a thoughtful evaluation of the situation with this broad medical team, then you could pretty much rest assured that they were going to have a good outcome, with or without SRS.

But if someone reported having listened only to one doctor's opinion, and having taken it on faith with no further evaluation, then you could sense danger ahead. This was especially true if the SRS option was first suggested by a trusted neurosurgeon. That neurosurgeon may not have done all the careful consideration, but may just be letting you know there are options besides surgery. As one respondent said, "I followed the recommendation without doing my own homework. If I had it to do over again, I would have read more about the procedure before embarking on it."

Because of the reports of bad outcomes, we asked ourselves if we should recommend against stereotactic radiosurgery for VHL. But in fairness, while there are some bad outcomes, there are lots of good outcomes as well. As with any new technology, it has its stunning successes, and its limitations. We have to understand where the limits are in order to use this new tool to its best advantage. It can be a very valuable tool. It can be exactly the right thing to do -- or not. There is no simple formula; each case has to be considered on its own.

We have seen good and poor outcomes from each of the machines. The machine is not the critical factor; the treatment plan and the experience of the operator are much more important. Be sure that somewhere in the planning you add the experience of a physician who has treated hemangioblastomas and understands how these soft tissue tumors will respond. The more experienced physicians qualify tumors carefully to avoid problems.

We were glad to see that the survey results confirm the current information in the VHL Handbook. If you have not yet read the newsletter articles describing patient experiences with SRS, make that an important part of your research. http://vhl.org/stereo Remember that 68% had good outcomes; 19% did not. Another ten people had good outcomes with open surgery, which is also success. Be sure you achieve a successful outcome, and help us shrink the 19%.

The lessons from this survey are summarized well by the respondents:

1. Do your homework. The people who had the best responses reported having spoken with both a neurosurgeon and a radiation oncologist, reading the Handbook, and reading the comments of other people with VHL who had had the procedure.

2. Tumors should be small. Larger tumors, or ones with an associated cyst, were more likely to respond badly. "I now think it was a mistake to treat five brain tumors in one day, especially when two of the tumors were large."

3. Take it easy for months after the procedure. This really is surgery. Give your body lots of time to heal. "I was feeling so good that I went tubing in the snow. After bouncing around I got light headed, passed out, and was air-lifted to a hospital. After a day I went home. My doctor said that after a surgery you are supposed to take it easy. It just didn't feel like a surgery."

4. Manage the swelling. One patient was told that "Edema is a rare occurrence." For people with VHL, this is not a rare occurrence, it is a very common experience. You and your doctor need to know before the treatment how you are going to treat the swelling that will occur after the procedure. Your team needs to calculate to what extent a tumor of this size is likely to swell, how the swelling will be managed, and anticipate the problem.

5. It's a treatment; it's not a "cure". "I misunderstood that this procedure would prevent future hemangioblastomas, so I stopped getting MRIs. My tumor grew back and needed to be removed surgically."

6. In sum: As one respondent put it, "Do your research. SRS won't work on every tumor. The tumor cannot be too large or have a cyst. If it works, it's a true blessing."

As printed in the VHL Family Forum 13:2, August/September 2005. For permission to reprint, please contact VHL Family Alliance, editor@vhl.org. Further information is available from the VHL Family Alliance, info@vhl.org.