Gamma Knife Radiosurgery Archive Questions

Below are Dr. Kwok’s answers to Gamma Knife Radiosurgery questions
received through the Ask the Expert feature.

This content is provided for informational purposes only, and is not intended
to be a substitute for individual medical advice in diagnosing or treating a
health problem. Please consult with your physician about your specific health
care concerns.



Now displaying records 1 to 15 of 39.

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Q : 1 05/10/2010	My son is epileptic and has a Vegas Stimulator. Could gamma knife treatment offer a surgical cure/improvement for him? He is 51-years-old. There is limited but growing literature on use of gamma knife in the treatment of epilepsy. This is still a very rare indication for gamma knife and must be considered only after a thorough consultation.
Q : 2 04/19/2010	My father was diagnosed with a brain tumor (glioma) last July and was treated with standard surgery, wafer implant, and radiation. An MRI recently showed a recurrence. Is the gamma knife procedure a potential treatment? What questions should we ask his doctors to determine if the gamma knife is a good or best option? This depends on how big the recurrence is and where it has recurred. Small recurrences can be treated with Gamma Knife. For large recurrences, repeat surgery is often valuable. Finally, chemotherapy is often necessary for recurrences. He has to be evaluated by an experienced team. Good luck!
Q : 3 04/16/2010	Is Gamma Knife appropriate for the treatment of an anaplastic astrocytoma approximately 4 x 4.7cm? If so, when would its effect start to show in MRI? A 4x4.7cm tumor is too large for Gamma Knife. Typically for anaplastic astrocytoma, daily fractionated radiation with temozolomide chemotherapy is performed after an aggressive surgical resection.
Q : 4 03/22/2010	I am 53 and was diagnosed with a meningioma of the brain, found on an MRI test. It's the size of a pea. The doctors say it is nothing to worry about because of the size. Should I have it removed? Small meningiomas can safely be observed if you are not having symptoms or problems from it. If you are having symptoms from it or it starts to grow, then the location of the tumor has a significant impact on the decision-making process. The established options for small meningiomas include watchful waiting or radiosurgery (gamma knife). It's difficult to justify a craniotomy/surgery in small meningiomas unless it is pressed against the optic apparatus or other sensitive parts of the brain where a gamma knife could not be done. You need to be evaluated by an experienced physician. Good luck.
Q : 5 03/13/2010	I underwent transsphenoidal removal of pituitary macroadenoma three months ago. I am now scheduled to have Gamma Knife radiosurgery. Can I get pregnant safely after this treatment? Gamma Knife is very effective in pituitary tumors. The radiation does not pose a threat to the pregnancy at all, since you would not be radioactive as soon as you get off of the treatment table. However, you could become hormone deficient and require hormonal management. So, it is always safe to have a close relationship with your endocrinologist and obstetrician and communicate with them as you contemplate getting pregnant. Good luck.
Q : 6 02/03/2010	My daughter has been diagnosed with a anaplastic ependymoma. She had a partial resection and 6 weeks of radiation. If her tumor starts growing, can she have the Gamma Knife surgery, even though she has already had radiation for six weeks? If her tumor starts to grow again, yes, she can get Gamma Knife stereotactic radiosurgery even after 6 weeks of radiation, provided that certain conditions are met. The two most important conditions are size and location. The regrown tumor cannot be too large (e.g., larger than 3 to 4 cm) as gamma knife would be not as effective and would be more toxic. Then, a repeat surgery would be advised before considering gamma knife. Second, the regrown tumor should not be close to critical structures such as the brain stem or optic nerve/apparatus, in which case more surgery would be advised first before considering gamma knife. Good luck.
Q : 7 01/04/2010	I was diagnosed with a pineal cyst 1.5 years ago, fairly small in size, found on a CT scan when I went into the ER for face numbness, headache and no taste. It is partially calcified. Also found to have multi-nodular goiter during tests. Back in 2005, I had a CT scan for severe headaches but nothing was found at that time. A doctor looking at my old films says the tumor was there back then, but would not be the cause of my headaches. I am extremely lethargic all the time, a lot of weight gain, headaches, ringing in the ear, and recently have a very hard time concentrating. I am confused and need help finding someone who can explain things to me. Pineal cysts are quite common, perhaps as many of 25% of the population. Calcifications typically mean a very slow process. I doubt your goiter and thyroid issues are related to the pineal cyst. They almost certainly are not related. Concentration issues and weight gain can be from hypothyroidism or clinical depression. What you need is periodic scans of your brain for a couple of years to demonstrate stability and a good physician (e.g., endocrinologist) to follow your thyroid functions and explain the test results with you. Certainly there are good physicians everywhere and you may need to ask around locally to find one that suites your needs. Good luck!
Q : 8 01/04/2010	My wife has been diagnosed with hypothalmic tumor. What is the best option to deal with it? This depends of the appearance of the tumor. This question is very difficult to answer without looking at the CT or MRI images. Typically, a biopsy is performed if it is deemed safe. However, this is not necessarily a universal recommendation since the appearance of the tumor can suggest a diagnosis. It is difficult to operate on these tumors since it is in a dangerous area. Radiation can be employed to treat this in many cases. This needs to be evaluated by an experienced surgeon and/or radiation oncologist. Good luck.
Q : 9 11/23/2009	Has the Gamma Knife surgery been helpful for someone with Parkinson's Disease manifested mainly in a hand tremor? Yes, there are published studies of Gamma Knife for Parkinson's and other movement disorders. However, this is a very complex subject and a thorough evaluation by a neurosurgeon, radiation oncologist and neurologist before proceeding with possible Gamma Knife is essential.
Q : 10 11/08/2009	My 38-yo sister-in-law has metastatic breast cancer with 5 lesions in the brain. Total of 7 years since onset of original diagnosis, with this being the second metastatic occurrence. MRI shows 2x1cm in left frontal lobe, 2.7x3cm in parietal lobe, 1.7cm in the posterior fossa, and small lesion in cerebellum. She is receiving oral chemo and completed multiple radiation treatments. Doctors said inoperable. Would she benefit from the Gamma Knife procedure, especially in the posterior fossa? Possibly. Typically when there are 5 lesions, we do not operate (craniotomy). However, if she is in good shape, she may potentially benefit from Gamma Knife stereotactic radiosurgery. The decision can only be made after a thorough consultation and examination and a review of the the MRI scans before and after whole brain radiation.
Q : 11 10/09/2009	I have an benign ependymoma. I had surgery in 1998 and localized radiation in 2006. It has now been recommended that I have surgery again. Do you have any recommendations for post-op experimentatal ways to deal with it? Gamma Knife has been discussed. This is a very complicated case and all depends on the location of your ependymoma and the amount of radiation you received. Whenever safe and possible, a maximal safe surgery should be performed before a decision is made regarding repeat radiation in the form of Gamma Knife radiosurgery or fractionated repeat radiation. So much of this depends on the location of the tumor in relation to critical structures like the brain stem and the optic apparatus. I strongly recommend a second opinion from an experienced hospital with a strong foundation in multi-disciplinary (Radiation Oncology and Neurosurgery) teamwork. It is critical you do so before a decision is made. Good luck.
Q : 12 09/27/2009	How do you feel about treatment using CyberKnife when the Gamma Knife is not an option for a brain tumor? It is extremely rare for a patient to have Gamma Knife ruled out as a possible treatment and then be considered as a candidate for CyberKnife. Typically, when a patient is not an ideal for Gamma Knife, they are not candidates for other ways of delivering stereotactic radiosurgery, including CyberKnife, Trilogy, TomoTherapy, etc. When patients have very large tumors, tumors on the optic nerve/chiasm, or innumerable lesions (for example, more than 7), then these patients are not great stereotactic radiosurgery candidates. The recommendation for whether someone is a good candidate for radiosurgery or not should really be made by a person who specializes in brain tumors and radiosurgery.
Q : 13 06/27/2009	I am scheduled to have radiotherapy after having surgery to remove a craniopharyngioma which is located close to the optic nerve. Is it safe to have radiotherapy? Could it cause me to lose my vision? Blindness, pituitary problems and brain damage are all problems associated with receiving radiation to these tumors. However, the tumor can also cause these problems (and is more likely to do so if untreated). In the balance, I would not expect fractionated radiotherapy to cause you to lose your vision. The Gamma Knife is usually not an option, as it is more likely to cause blindness.
Q : 14 06/17/2009	My mother recently finished treatment for lung cancer. Her doctors are now telling her that she will need radiation to decrease the chance of the cancer spreading to the brain. However, they have said that there are no tumors and no cancer present in the brain at this point. Is this a common practice? Yes, it is what is called prophylactic craniospinal radiation and it is a common practice for lung cancer. A radiation oncologist could give you a more informed opinion.
Q : 15 06/08/2009	I was diagnosed with a large left lateral ventricular tumor (5.3cm x 5.4ml x 9.3cm AP diameter). I presented with symptoms of a lasting mild headache and some numbness of the right arm and right leg prior to performing the MRI, and NO dysphasia, hearing or vision problems, or any other neuro deficits. My doctor thinks this is most probably a benign tumor (possibly Epindymoma) and suggested the use of Gamma Knife as a possible treatment option. Others suggested that the size of the tumor was too big to use Gamma Knife. We would appreciate it if you could comment on whether or not it is applicable and the possible benefits of its use. The size, if the dimensions you give are indeed correct, is too large to even consider gamma knife. A definitive diagnosis needs to be made requiring at least a biopsy. Finally, I would not consider an ependymoma to be a benign diagnosis. These situations often require radiation, chemotherapy and have a worrisome recurrence risk.

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