| Proton
Beam Radiosurgery Comparison of Charged Particles
History
of Stereotactic Radiosurgery
Gamma
Knife® Radiosurgery
by
Stephen B. Tatter, M.D., Ph.D.
Proton
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Comparison
of Charged ParticlesComparison of Charged Particles (e. g.
Protons) and Photons (Gamma particles)
Photons
produced in Gamma Knife® and linear accelerator radiosurgery
units do not produce a peak of interaction of a single beam with
tissue as do charged particles such as protons. There is also no
rapid fall off after the target is reached. Thus, with Gamma Knife
and LINAC radiosurgical doses must be achieved by superimposing
a large number of beams on the target while only a small number
of beams reach other areas. The large number of different target
paths required makes milling of individual collimators impractical,
a limitation that will not be overcome until variably-gated (or
dynamically-collimated) linear accelerators are widely available.
The circular collimators currently in use in photon radiosurgery
units result in roughly spherical or elliptical target volumes.
Most lesions can still be satisfactorily covered using multiple
superimposed ellipsoids. However, this may significantly increase
the dose inhomgeneity leading to the potential for side effects
in regions recieving particularly high doses. This also suggetsts
that proton radiosurgery will be particularly appealing in applications
where dose fractionation is of benefit, since no portion of target
in a proton field is expected to receive a complication producing
dose because of superimposition of high dose areas. Fractionated
particle beam radiosurgery is, therefore, an area of active current
research.
The Proton Beam Unit was founded in 1962 and has the largest experience
with stereotactic radiosurgery of any center in the United States.
Proton beam offers certain theoretical advantages over other modalities
of stereotactic radiosurgery (i.e. Gamma Knife® and linear
accelerators) because it makes use of the quantum wave properites
of protons to reduces doses to surrounding tissue beyond the target
to a theoretical minimum of zero. In practice, the proton facility
offers advantages for the treatment of unusually shaped brain
tumors and arteriovenous malformations. The homogeneous doses
delivered also makes fractionated therapy possible. Proton beam
radiosurgery also has the ability to treat tumors outside of the
cranial cavity. These properties make it the ideal post-resection
therapy for many chordomas and certain chondrosarchomas of the
spine and skull base as well as an excellent mode of therapy for
many other types of tumors.
References
- Rand
R: The stereotactic Cobalt 60 Gamma Unit in the treatment of acoustic
neuromas. in Brackmann DE (ed): Neurological Surgery of the Ear
and Skull base. 1982, pp 379-389
-
Thomsen J, Tos M, Borgesen SE: Gamma Knife: Hydrocephalus as a
complication of stereotactic radiosurgical treatment of an acoustic
neuroma. Am J Otol 11:330-333, 1990
-
Ganz JC, Backlund EO, Thorsen FA: The results of Gamma Knife surgery
of meningiomas, related to size of tumor and dose. Stereotactic
and Func Neurosurg 61:23-29, 1993
-
Kondziolka D, Lunsford LD, Coffey RJ, Flickinger JC: Gamma Knife
radiosurgery of meningiomas. Stereotactic and Func Neurosurg 57:11-21,
1991
-
Steiner L, Lindquist C, Steiner M: Meningiomas and Gamma Knife
radiosurgery, in Al Mefty O (ed): Meningiomas. Raven Press, New
York, 1991, pp 263-272
-
Coffey, R.J., D.A. Nichols, and E.G. Shaw, Stereotactic radiosurgical
treatment ofcerebral arteriovenous malformations. Gamma Unit Radiosurgery
Study Group[see comments]. Mayo Clin Proc, 1995. 70(3): p. 214-22.
-
Coffey RJ, Lunsford LD: Stereotactic gamma radiosurgery for brainstem
AVM. Neurosurgeon 10:238-246, 1991
-
Fukuoka S; Suematsu K; Nakamura J [Gamma knife radiosurgery for
arteriovenous malformation Nippon Rinsho 1993 Dec;51 Suppl: 353-8.
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Guo WY, Lindquist C, Karlsson B, Kihlstrom L, Steiner L: Gamma
Knife surgery of cerebral arteriovenous malformations: Serial
MR imaging studies after radiosurgery. Int J Radiat Oncol Biol
Phys 25:315-323, 1993
-
Guo WY, Wikholm G, Karlsson B, Lindquist C, Svendsen P, Ericson
K: Combined embolization and Gamma Knife radiosurgery for cerebral
arteriovenous malformations. Acta Radiologica 34:600-606, 1993
-
Guo W, Lindquist M, Lindquist C, Ericson K, Nordell B, Karlsson
B, Kihlstrom L: Stereotaxic angiography in Gamma Knife radiosurgery
of intracranial arteriovenous malformations. Am Journal Neuroradiol
13:1107-1114, 1992
-
Guo W: Radiological aspects of Gamma Knife radiosurgery for arteriovenous
malformations and other non-tumoural disorders of the brain. Acta
Radiologica Supplementum 34:388, 1993
-
Lunsford LD, Coffey RJ, Bissonette D, Flickinger JC: Stereotactic
radiosurgery for arteriovenous malformations. Case selection and
initial results from the first North American Gamma Unit. Proc
Harvard Radiosurgery Update. Boston, 1990
-
Lunsford LD, Kondziolka D, Pollock BE, Maitz A, Flickinger JC:
Gamma knife stereotactic radiosurgery for brain arteriovenous
malformations: What we have learned. Neurosurgeons (in press):
1994
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Flickinger JC, Lunsford LD, Linskey ME, Duma CM, Kondziolka D:
Gamma Knife radiosurgery for acoustic tumors: Multivariate analysis
of four year results. Radiotherapy & Oncol 27:91-98, 1993
-
Kamerer DB, Lunsford LD, Moller M: Gamma Knife. An alternative
treatment for acoustic neurinomas. Ann Otol Rhinol Laryngol 97:631-635,
1988
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Kobayashi T, Tanaka T, Kida Y: The early effects of Gamma Knife
on 40 cases of acoustic neuroma. Proc ISRS. Stockholm, 1993
-
Noren G, Greitz A, Lax I: Gamma Knife surgery in acoustic tumors.
Acta Neurochir (Wien) 58:104-107, 1993
-
Noren G, Greitz D, Hirsch A, Lax I: Gamma Knife radiosurgery in
acoustic neurinoma, in L. Steiner (ed): Radiosurgery: Baseline
and Trends. Raven Press, New York, 1992, pp 141-148
-
Noren G: Gamma Knife radiosurgery in acoustic neurinomas, in Haid
CT (ed): Vestibular Diagnosis and Neuro-Otosurgical Management
of the Skull Base. Demeter Verlag, Grfelfing, 1991, pp 43-47
-
Ogunrinde OK, Lunsford LD, Flickinger JC, Maitz AH, Kondziolka
D: Facial nerve preservation and tumor control after Gamma Knife
radiosurgery of unilateral acoustic tumors. Skull Base Surg 4(2):87-92,
1994
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