GammaKnife Statistics

[Vivian B.]

Hello Everybody,

I was wondering if anyone has any new statistics on success for gammaknife treatment? I have been doing my own search and  can't seem to find anything concrete.

Your comments are welcome.

Thanks.

Vivian

[russcape]

Hello;

   I haven't seen a large study set of statistics produced for GK since UPMCs. GK's been in use for so long now for AN ( 1969 ).

   There was produced on another group, however, a link showing it's effiacy for nerve preservation as being about the same as hyperfractionated radiation.

   Some may claim the 10 - 15% advantage to hearing preservation with hyperfractions as CK or FSR, but probably this is highly individualized and not well predictable. GK is of itself, hearing and nerve sparing by nature.

[mk]

Vivian,

what kind of stats are you looking for? i.e. control rates, hearing preservation, probability of nerve disfunction?

Kate B posted recently an article on statistics for hearing preservation

http://anausa.org/forum/index.php?topic=9486.0

Here is an abstract from a publication in 2005, that reviewed comprehensively a large number of cases over 15 years.
Radiosurgery of vestibular schwannomas: summary of
experience in 829 cases
L. DADE LUNSFORD, M.D., AJAY NIRANJAN, M.B.B.S, M.S., JOHN C. FLICKINGER, M.D.,
ANN MAITZ, M.SC., AND DOUGLAS KONDZIOLKA, M.D., F.R.C.S., 2005.
Departments of Neurological Surgery and Radiation Oncology, The University of Pittsburgh School of
Medicine; and The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
Object. Management options for vestibular schwannomas (VSs) have greatly expanded since the introduction of stereotactic radiosurgery. Optimal outcomes reflect long-term tumor control, preservation of cranial nerve function, and retention of quality of life. The authors review their 15-year experience. Methods. Between 1987 and 2002, some 829 patients with VSs underwent gamma knife surgery (GKS). Dose selection,
imaging, and dose planning techniques evolved between 1987 and 1992 but thereafter remained stable for 10 years. The average tumor volume was 2.5 cm3. The median margin dose to the tumor was 13 Gy (range 10–20 Gy). No patient sustained significant perioperative morbidity. The average duration of hospital stay was less than 1 day.
Unchanged hearing preservation was possible in 50 to 77% of patients (up to 90% in those with intracanalicular tumors). Facial neuropathy risks were reduced to less than 1%. Trigeminal symptoms were detected in less than 3% of patients whose tumors reached the level of the trigeminal nerve. Tumor control rates at 10 years were 97% (no additional
treatment needed). Conclusions. Superior imaging, multiple isocenter volumetric conformal dose planning, and optimal precision and dose delivery contributed to the long-term success of GKS, including in those patients in whom initial microsurgery
had failed. Gamma knife surgery provides a low risk, minimally invasive treatment option for patients with newly diagnosed or residual VS. Cranial nerve preservation and quality of life maintenance are possible in long-term follow up.


Marianna

[Vivian B.]

Thanks for replying guys,

Marianna, I should have been more specific. I am looking for success of tumour control statistics.

Thanks.

Vivian

[russcape]

Marianna;

   That is the large UPMC study I was referencing. Thank you for providing a URL!

   

[mk]

There are many other recent studies, from Japanese, Chinese, and European groups. They all agree on the high success rates (above 95%). Some recent studies have focused on the possibility of lower control rates if very low doses (below 11 Gy) are used. These studies however do not cover such an extensive span of time as the UPMC study - they usually cover up to 5 years.

Marianna

[Vivian B.]

Hi Marianna,

Thanks for the information you provided. The treatment seems quite promissing. It's very encouraging.

Vivian