Penn Gamma Knife Center at Pennsylvania Hospital
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Q&A Sessions: Most Recent Questions

John Y.K. Lee, MD has answered your questions about Gamma Knife radiosurgery.

Ehsan asks:
My son, who is 6 years old, has been suffering from a brain tumor craniophramgioma. We have operated from agha khan hospital karachi, after the surgery tumor size was 2.5 x 2.5 x 2.5 cm. The radiotherapist told us to come back after three months - if the tumor will grow, then we will start radiothrapy. After 3 months tumor size is 5 x 5 x 4 cm. Now, they are saying to operate again. That is a very difficult decision for me. Is this treatable from gamma knife.

Dr. Lee responds:
This size is too large for Gamma Knife Radiosurgery treatment to this kind of tumor.

Kay asks:
I was diagnosed with an acoustic neuroma that measures 2.6cm transversex3.0cm craniocaudalx2.7cm AP. Surgery was recommended by one surgeon but I was wondering, what is the difference between the gamma knife and Proton therapy? Would I be a candidate for both and if so, when does Penn plan to open its Proton Therapy facility.

Dr. Lee responds:
Yes. You could be a candidate for all three. I would be happy to discuss all three options with you. If you have any additional questions or would like to schedule an appointment, please call us at 800-789-PENN. You can also request an appointment online.

mt asks:
I had transphenoidal surgery to remove a pituitary adenoma a year ago with a pathology report of immunoreactivity for synaptophysin and ACTH. MY follow up MRI's in March showed that there is residual of the tumor, July and October MRI's show it measures slightly larger. I am diabetic and my sugar has been high since my surgery. I have been trying different meds and insulin and am concerned if the gamma knife will effect my sugar negatively. I had elevated blood levels in June of ACTH and Cortisol which indicated possible Cushing's Disease. I have since had two 24 hour urine test for cortisol and creatine levels which came out negative. So if it is not Cushings they want to do gamma knife. Is this my best option?

Dr. Lee responds:
Gamma Knife Radiosurgery can be an effective way to control pituitary adenomas.

Jo asks:
I had gamma knife procedure done in April of 2007 for atypical trigeminal -- the pain and electric shocks are back. Is there a follow procedure or what can I do next?

Dr. Lee responds:
Repeat Gamma Knife Radiosurgery or other surgical procedure such as Microvascular Decompression (MVD) or peripheral nerve stimulation may be an option. I would be happy to discuss options with you. If you have any additional questions or would like to schedule an appointment, please call us at 800-789-PENN. You can also request an appointment online.

Rick asks:
Would you please list any references you know of for long term safety of gamma knife (5-25 years) for benign tumors e.g AN, meningioma. e.g rates of secondary malignancy, cognitive decline, etc. Thanks !!

Dr. Lee responds:
Long term data from any neurosurgical procedure including conventional resection is not readily available because of the lack of uniform follow-up. Other countries with centralized health care systems may be able to provide more useful long term data.

Vit asks:
My mom is having a Meningoima of about 4mm. Should she proceed to Gamma Knife as recommended by the doctor or should she wait for further MRI after a few months to see whether there's any growth or changes before any treatment?

Dr. Lee responds:
I would recommend serial MRI scans to track growth pattern.

Kathy asks:
I read that the Gamma Knife can be used to help people with Epilepsy. What would this entail and what could the expected outcome be?

Dr. Lee responds:
Gamma Knife Radiosurgery is primarily used for patients with lesions such as tumors or vascular malformations in the brain that cause epilepsy.

Helen asks:
I had the Gamma Knife Surgery almost 2 years ago,but the pain is coming back. Can I have it done again ?

Dr. Lee responds:
Yes, repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia can be successful.

Heidi asks:
I have an acoustic neuroma and symptoms indicated it is putting pressure on my brain stem and causing breathing and tightness in my chest now. If the gamma knife is not advisable for the size, how many craniotomies have you done? We think that it must be taken care of soon. I am 37 with 5 young children. THANKS.

Dr. Lee responds:
Our center treats many patients with Acoustic Neuroma. I perform both surgery and radiosurgery and would be happy to see you in the office to discuss the relative merits of each approach. If you have any additional questions or would like to schedule an appointment, please call us at 800-789-PENN. You can also request an appointment online.

Candycane asks:
I have a paraganglioma. Is gamma knife an option?

Dr. Lee responds:
Yes, Gamma Knife Radiosurgery can be used to treat paragangiomas. If you have any additional questions or would like to schedule an appointment at 800-789-PENN. You can also request an appointment online.

Sara asks:
My mother was diagnosed with an AVM when she was 25 (she is now 50). Originally she was told that her AVM was unable to be operated on based on its location and size. Over the years, she has seen neurologist after neurologist and nobody seems to be able to manage her pain, migraines and psychological side effects. I know your specialty is in the Gamma Knife radiosurgery - but do you do have consultations on AVM's and potential treatments? If not, please refer me to someone at HUP who could. Thanks!

Dr. Lee responds:
I would be happy to see your mother in consultation regarding her AVM and potential treatment options. If you have any additional questions or would like to schedule an appointment, please call us at 800-789-PENN. You can also request an appointment online.

Mark asks:
I had Gamma Knife in Dec. '04 for AVM in the left occipital lobe. In May of '05, I had a Grand-Mal Seizure. With this, I dislocated my shoulder, tore my rotator cuff and broke the upper bone in my arm. I spent a week in the hospital to fix my arm/shoulder. Since this time, I have had a seizure every May for the past 3 years. I am now on and upto 600mg of Lamictal and 500mg of Dilantin a day. I have only had one issue since this last increase. Where now? We were not told about the possilbe seizures after the Gamma Knife procedure and did not get put on medicine till the first seizure. I am running out of time and energy. I am lost.

Dr. Lee responds:
Seizures are a side effect of any procedure in the brain, including Gamma Knife Radiosurgery. In addition, Arteriovenous Malformations in your brain make you more susceptible to seizures.

Darshit asks:
I have been diagnosed with Solid Hemangioblastoma in subcortical left cerebellar hemisphere. The size of lesion measures 13x12x10 mm. Please inform is it curable? What are the risk factors? Thanks in advance.

Dr. Lee responds:
Gamma Knife Radiosurgery can be used to treat hemangioblastomas of this size successfully.

Chris asks:
My son is 4 1/2 years old and was diagnosed with a cerebellar Pilocytic Astrocytoma in August 2008. It was the size of a golf ball, and surgically resected on 8/6/08. This was also complicated by a syringomyelia, which thankfully is now resolved with the tumor removal. His MRI in September showed residual bits of tumor around the brainstem. He already has right sided facial paralysis from his first surgery, so I would like to avoid a repeat resection if possible. Can the gamma knife procedure be performed on children.... and....which procedure is better for residual tumor, gamma knife, or proton beam radiation? Thank you!

Dr. Lee responds:
Gamma Knife Radiosurgery can be done in this situation and it has been safely performed by Dr. Lunsford at University of Pittsburgh Medical Center. Proton Beam Therapy may be another option.

SO asks:
My wife had a embolization for AVM the last three months (July 12, 2008. Did the follow up Angiogram on Oct. 31, 2008.) The result is 90% success. But the doctor advised that she needed to do the 10% for Gamma Knife. It is necessary to do? Also what are the side effects for this treatment?


Dr. Lee responds:
Embolization alone is usually not a permanent cure for AVM. Surgery or Gamma Knife Radiosurgery can provide cure.

Carol asks:
I have had Trigeminal Neuralgia for 4 years and pain pills do not work any longer. I was told that I have to have a procedure done. It is my 3rd nerve in my face that causes me constant pain. I don't know what procedure to have - gamma knife or microvascular decompression. Which one would be safer and have the least amount of side effects? I'm so confused.

Dr. Lee responds:
Microvascular Decompression provides the longest lasting relief of trigeminal neuralgia symptoms but is more invasive than Gamma Knife Radiosurgery. I would be happy to see you to discuss these options, since I perform a high volume of both procedures and can discuss the relative merits of each. If you have any additional questions or would like to schedule an appointment, please call us at 800-789-PENN. You can also request an appointment online.

Debbie asks:
I have a 21 year old son who has been diagnosed with astrocytoma glioma Grade II. As I understand it, surgery is not an option due to the extent of the tumor. A physician at NIH is recommending treatment with Temodar. Another physician at Johns Hopkins is recommending radiation or "wait and see". They have been monitoring this for about a year with very little, if any, growth. He appears normal in every way except for 20-30 second episodes of inability to speak with accompanying "tingling" sensations. Is he a candidate for the gamma knife procedure. Thank you.

Dr. Lee responds:
Gamma Knife Radiosurgery is occasionally performed for grade II astrocytomas, but most patients usually undergo a fractionated treatment such as what is being offered at JHU.

Noor asks:
My mom is 52 years old and was diagnosed with glioblastoma (grade 4 in the front part of her brain). She's gone through surgery, but of course they didn't remove all the tumor. She went through radiotherapy and is going through chemo. Can gamma knife be an option to make her quality of life and longer?

Dr. Lee responds:
Gamma Knife Radiosurgery can be used for gliomas, as it is another method to deliver high doses of radiation. However, glioblastoma is often refractory to conventional treatments.

Pat asks:
My husband is 72 years old with a history of COPD and has has a triple bypass in 2003. He has been diagnosed with a golf ball to lemon size meningioma in the right frontal area after a seizure. Because of his medical history and age I would prefer a noninvasive treatment if possible.

Do you think he could be a candidate for Gamma Knife radiosurgery? Please, I need a quick response if you could review his films. The neursurgeon in the local hospital where he is has suggested surgical removal, but I told him I would like a second opinion.

Dr. Lee responds:
It is difficult from the description to determine if your husband would be a candidate for Gamma Knife radiosurgery. I would be happy to review your husband's MRI images if you could send them to my office on CD along with a copy of the radiologist's report.

Please send the information to:

Department of Neurosurgery
Attn: Dr. John Lee
235 So. 8th St.
Philadelphia, PA 19107

Joyce asks:
Can a tumor that is 4cm large be treated successfully with this method?

Dr. Lee responds:
Gamma Knife radiosurgery side effects are determined by:

  1. Volume
  2. Location
  3. Individual Sensitivity

A single linear dimension of 3cm can represent a small volume if it is 3cm x 1cm x 1cm. I would be happy to review the films. Please send MRI films on cd and radiology reports to my attention:

Department of Neurosurgery
Attn: Dr. John Lee
235 So. 8th St.
Philadelphia, PA 19107

Evie asks:
What are the side effects of Gamma Knife surgery please?

Dr. Lee responds:
Side effects of Gamma Knife are specific to your diagnosis and the location of treatment and dose used. Most patients who undergo Gamma Knife radiosurgery, however, have minimal side effects. They may have a little headache after the procedure, but they can go home on the same day and return to full activities by the next day. I would be happy to discuss this in more detail, if you could provide more specifics.

Lynn asks:
How much does it cost for the Gamma Knife treatment for brain cancer?

Dr. Lee responds:
Gamma Knife radiosurgery is covered by most insurance providers as well as Medicaid and Medicare. The cost without insurance varies depending on the complexity of the treatment plan.

Daniel asks:
What are the advantages and disadvantages of the GammaKnife as compared to the Cyberknife? 

Dr. Lee responds:
The Gamma Knife is inarguably the gold standard by which all other intracranial radiosurgical delivery methods are judged. Not only was it the first, it still remains the only tool that is dedicated solely to intracranial lesions, such as your acoustic neuroma.

Since the introduction of Gamma Knife in the 1950's, there are now many competitors that have emerged. Some of the advantages of the competitors include the fact that that they can be used to treat brain tumors as well as lung, spine, and prostate tumors. Hence, the competitors are "all-purpose" knives.

Gamma Knife stereotactic radiosurgery is extremely accurate, but it does require a frame. This stereotactic frame is light weight and is affixed to your outer skull with four pins. The frame provides exact MR correlation from planning to treatment delivery in 3D. It is with the use of this frame that Gamma Knife provides pinpoint accuracy at less than 0.5mm. Without a frame, Cyberknife may not be as accurate.

To minimize discomfort during the frame placement, we provide intravenous sedation and analgesia as well as local anesthetic to the pin sites. The large majority of our patients tolerate the frame placement very well with little discomfort. In conclusion, perhaps more important than choice of instrument is the choice of radiosurgeon and team. You should be comfortable with their level of experience and expertise.

Go asks:
In March, my mother was diagnosed with adenocarcinoma lung cancer, with one brain metastasis. She had a successful brain surgery to resect this tumor and has been on Tarceva for the past five months. She just had a scan with no trace of tumors in her brain, and the lung tumor is now inactive.

Now a radiation oncologist wants her to undergo whole brain radiation as well as lung radiation. I am not sure that her quality of life will be extremely compromised after whole brain radiation. Is this a clear benefit to her? Should we consider not having whole brain radiation? What would your opinion be in her situation?

She did see Tracey Evans back in March — Dr. Evans recommended you for the neurosurgery. My mom lives in Dallas and we decided to have the surgery done near her. She has been under the care of a lung oncologist since then. But we would be willing to have her radiation done here with you if you felt that it would be better.

Dr. Lee responds:
The role of WBXRT in the management of brain metastasis used to be quite straightforward. Everybody would get their entire brain radiated. Today with the widespread availability of good MRI scans and stereotactic radiosurgery, the role of WBXRT has changed.

I would be happy to see you and your mother in consultation to discuss treatment options further. If you have any additional questions or would like to schedule an appointment, please call us at 800-789-PENN. You can also request an appointment online.

Homi asks:
My mother has ovarian cancer that spreads to her brain while on Toxel; there are many small pockets in brain. Doctors are suggesting full head radiation. Should she use Gamma Knife? Does it work with Gamma Knife? Since she has still cancer in stomach, I worry if they take her off Toxel and work on head, the cancer would spread to other organs which are still clean. What is the solution here?

Dr. Lee responds:
In general, Gamma Knife radiosurgery is used for patients with less than five brain metastases.

Wanda asks:
What is the success rate for the Gamma Knife surgery as it relates to trigeminal neuralgia? Will I still have to take medication once the surgery is done? Currently, I am taking 1600 mg of Neurontin twice a day and 200 mg of Lamictal.

This has stopped working for me the pain in my face has increased. It seems to have affected my nasal cavity. Also, every since I started taking the Lamictal, I have aged. At the age of 50, I look as though I am 60 years old. That should not be. Last year, everyone thought I was at least 38.

Dr. Lee responds:
80-90 percent of patients treated with Gamma Knife radiosurgery for trigeminal neuralgia have good pain relief such that they would repeat the procedure again. The durability of benefit is variable.

Clarissa asks:
Just diagnosed with meningioma via CT Scan. Now have to decide on treatment and would obviously prefer Gamma Knife non invasive. However, I also have a pacemaker and MRI cannot be used. Can Gamma Knife procedures be done with CT as well or is MRI essential?

Dr. Lee responds:

Kirk asks:
Dr Lee, I have glossopharyngeal neuralgia and trigeminal neuralgia. I have had failed MVD. Is there any work being done using Gamma Knife for glossopharyngeal neuralgia?

Dr. Lee responds:
There is one case report of this having been performed at Wake Forest. See Stieber VW et al. 2005.

JR asks:
A 65 year-old relative has been diagnosed with a 1 cm mass in the vermis. There is no hydrocephalus. He has no support system near him, and he is refusing open surgery at this time. Is the gamma knife appropriate?

Dr. Lee responds:
Gamma Knife radiosurgery can be done without pathologic confirmation only if the MRI findings are pathognomonic (a pathognomonic sign is a particular sign whose presence means, beyond any doubt, that a particular disease is present). In your relative's case, the MRI findings may be more difficult to interpret.

Martha asks:
I have been diagnosed with an auditory neuroma size .5 Very small. I do have a small amount of hearing loss in the ear that has the tumor. I have been told to wait and see how fast it grows by a top surgeon in New York City.

Do you think it would be useful for me to have a consultation? I would like very much to preserve my hearing and have been told there is a good chance I will lose it in my right ear. I welcome your opinion and would be happy to set up a consultation if you think it would be useful.

Dr. Lee responds:
Absolutely. Small to medium sized acoustic neuromas are best treated with either observation or Gamma Knife Radiosurgery. See Pollock et al, 2006, "Patient outcomes after vestibular schwannoma management: a prospective comparison of microsurgical resection and stereotactic radiosurgery" which provides the best prospective study and evidence to support this strategy.

Barbara asks:
I had a Gamma Knife procedure for an acoustic neuroma about six months ago. If my follow-up MRI shows no change or slight enlargement-is this common? I heard the tumor can swell before it shrinks. How long can it take to see results?

Dr. Lee responds:
Yes, it is common at the six month MRI to see swelling. At the 12 month MRI, you should see a decrease in the size of the tumor or stability.

Kim asks:
I had a stage II oligodendroglioma fully resected about eight years ago. It came back as a stage II again and small (the tip of your finger). This tumor was also removed. They want me to do radiation. Is Gamma Knife used in situations where the tumor was fully resected?

Dr. Lee responds:
Conventional radiation with IMRT is a more common treatment strategy for your tumor.

CarolJane asks:
I am a fifteen year breast cancer survivor, dealing with metastasis to the bones since late 2001. Along with that, we've been monitoring two meningiomas. One in the left temple area is stable. The other, may need some attention. It's in the right frontal lobe, and has grown slightly, about two mm. in each direction, in the past six months. It's about the size of a grape. The radiology report states that it could be an atypical, aggressive meningioma, a metastasis, or a "collision tumor" - combination of the two.

I'm scheduled for another consult with a neurosurgeon. I'm assuming he'll send me to a radiation oncologist. Would you advise a second opinion outside of our locality? Also, my local hospital has a Gamma Knife department. Any idea of how they compare to Penn?

Dr. Lee responds:
Absolutely, I would recommend a second opinion. I would be happy to review your films and/or see you for consultation. If you would like, please send your MRI images on cd along with reports to me:

Department of Neurosurgery
Attn: Dr. John Lee
235 So. 8th St.
Philadelphia, PA 19107

Patrick asks:
My wife was just diagnosed with frontal meningioma (3cm+) golf ball size. Is Gamma Knife possible with this size of meningioma. Our neuro advised us that because of its size gamma is unlikely.

Dr. Lee responds:
Gamma Knife radiosurgery side effects are determined by:

  1. Volume
  2. Location
  3. Individual sensitivity

A single linear dimension of 3cm can represent a small volume if it is 3cm x 1cm x 1cm. I would be happy to review your wife's films. Please send MRI films on cd and radiology reports to me:

Department of Neurosurgery
Attn: Dr. John Lee
235 So. 8th St.
Philadelphia, PA 19107

Joe asks:
I was diagnosed with trigeminal neuralgia more than two years ago, and suffer unbelievable headaches every day and am interested in the Gamma Knife procedure. Mine is on the right side and accompany cheek and eye spasms and sensitivity to sound and light. But due to a back injury years ago I am on disability.

Since I do get medicare as well as medical assistance from the state of PA (Medicaid) I was wondering if either of those two insurance options would help to pay for the procedure.

Ultimately, I would like to get back to working but I currently cannot due to the headaches and high doses of meds. to keep them at bay. Currently I take prescription pain medications including oxycodone and would like to get away from them. If the insurance I have does not pay for it, approximately how much does the procedure cost if I had to pay for it myself?

Dr. Lee responds:
Gamma Knife radiosurgery is covered by both Medicare and Medicaid. I would be happy to see you for consultation regarding your trigeminal neuralgia. To schedule an appointment, please call us at 800-789-PENN. You can also request an appointment online.

Dan asks:
My mother is 78 years old and was just diagnosed yesterday with meningiomas. She is going to get another MRI of her spine to see if there are meningiomas there, too. Is she a proper candidate for Gamma Knife radiosurgery? I am very concerned about having my mother cut open with brain surgery due to her age and if there is a nonsurgical alternative for her, I would like to explore it.

Dr. Lee responds:
Absolutely, your mother would be an excellent candidate for Gamma Knife radiosurgery. It is less invasive than traditional cranial surgery, and is therefore often a better alternative for elderly patients.


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