Treatment planning and dosimetry for the Harvard-MIT Phase I clinical trial of cranial neutron capture therapy.
OBJECTIVE
A Phase I trial of cranial neutron capture therapy (NCT) was conducted at Harvard-MIT. The trial was designed to determine maximum tolerated NCT radiation dose to normal brain.


METHODS
Twenty-two patients with brain tumors were treated by infusion of boronophenylalanine-fructose (BPA-f) followed by exposure to epithermal neutrons. The study began with a prescribed biologically weighted dose of 8.8 RBE (relative biologic effectiveness) Gy, escalated in compounding 10% increments, and ended at 14.2 RBE Gy. BPA-f was infused at a dose 250-350 mg/kg body weight. Treatments were planned using MacNCTPlan and MCNP 4B. Irradiations were delivered as one, two, or three fields in one or two fractions.


RESULTS
Peak biologically weighted normal tissue dose ranged from 8.7 to 16.4 RBE Gy. The average dose to brain ranged from 2.7 to 7.4 RBE Gy. Average tumor dose was estimated to range from 14.5 to 43.9 RBE Gy, with a mean of 25.7 RBE Gy.


CONCLUSIONS
We have demonstrated that BPA-f-mediated NCT can be precisely planned and delivered in a carefully controlled manner. Subsequent clinical trials of boron neutron capture therapy at Harvard and MIT will be initiated with a new high-intensity, high-quality epithermal neutron beam.
Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA. mpalmer@caregroup.harvard.edu
Matthew R
MR
Palmer
J Timothy
JT
Goorley
W S
WS
Kiger
Paul M
PM
Busse
Kent J
KJ
Riley
Otto K
OK
Harling
Robert G
RG
Zamenhof
D000328:Adult; D000368:Aged; D001895:Boron / Q000097:blood; D001921:Brain / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000532:radiotherapy*; D005260:Female; D005909:Glioblastoma / Q000532:radiotherapy; D006801:Humans; D008297:Male; D008545:Melanoma / Q000532:radiotherapy; D008875:Middle Aged; D017247:Neutron Capture Therapy / Q000379:methods*; D009502:Neutrons; D019047:Phantoms, Imaging; D011874:Radiometry / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed
D001895:Boron