
There will be two applications of Neutron bombardment discussed here.  One is Fast Neutrons, the other is Boron Neutron Capture Therapy.


<b>Fast Neutrons</b>
Treatment with Fast Neutrons is done at the Midwest Institute for Neutron Therapy at Fermilab.  High energy neutron therapy [also called fast neutron therapy] is appropriate for patients with localized brain metastasis from primary sarcoma.

For more information &&url


<b>Boron Neutron Capture Therapy [BNCT] for Brain Tumors</b> 
Treatment of some primary brain cancers by surgery, chemotherapy, and conventional radiation has had only limited success.  These tumors recur, usually close to the original margins.  Effective therapy must cover a larger volume that has been defined.  The problem is how to achieve eradication of all tumor cells without damaging or destroying normal brain cells. 

Boron neutron capture therapy [BNCT] is based on a nuclear reaction that occurs when the stable isotope boron-10 is irradiated with neutrons to produce boron-11.  Boron-11 is not stable, and it undergoes immediate nuclear fission to produce high energy alpha particles and lithium-7 nuclei.  These heavy charged particles have path lengths of approximately the diameter of a cell, so deposit most of their energy, and do most of their damage, within the cells that contain boron. 

If enough low energy neutrons reach the boron-10, and the boron-10 is selectively delivered to the tumor in higher amounts than to the normal tissues, then the tumor cells can be destroyed selectively because of the Boron capture reaction. 

Results of clinical trials in the 1950's and '60's required more tumor selective boron-containing drugs, and higher energy neutron beams with greater tissue penetrating properties. The development of reactor based epithermal beams is available in the US, Japan, Argentina, and several European countries.  Molecular targeting of tumor cell's overexpressed receptors [like EGFR and PDGF] is being actively researched. 

BNCT is an experimental technique.

Journal of Neuro-Oncology 62: 1-5, 2003. <b>A critical assessment of boron neutron capture therapy: an overview</b> Rolf F. Barth Dept of Pathology, Ohio State University, Columbus OH USA 
&&url

<b>For More Information

Search Pubmed for &&url


Annotated Medical Journal Citations"</b>

Neurooncol. 2003 Mar-Apr;62(1-2):101-9. 
<b>Assessment of the results from the phase I/II boron neutron capture therapy trials at the Brookhaven National Laboratory from a clinician's point of view. </b>
Diaz AZ. 
Roswell Park Cancer Institute, Buffalo, NY 14263, USA. aidnag.diaz@roswellpark.org 

Boron neutron capture therapy (BNCT) represents a promising modality for a relatively selective radiation dose delivery to the tumor tissue. The key to effective BNCT of tumors such as glioblastoma multiforme (GBM) is the homogeneous preferential accumulation of 10B in the tumor, including the infiltrating GBM cells, as compared to that in the vital structures of the normal brain. ...<b> it is the ratio of the 10B concentration in tumor cells to that in the normal brain cells and the blood that will largely determine the therapeutic gain of BNCT. </b> Clinical Trial, Phase II 
&&url PMID: 12749706  


2: J Neurooncol. 2003 Mar-Apr;62(1-2):111-21. 
<b>A critical examination of the results from the Harvard-MIT NCT program phase I clinical trial of neutron capture therapy for intracranial disease. </b>
Busse PM, Harling OK, Palmer MR, Kiger WS 3rd, Kaplan J, Kaplan I, Chuang CF, Goorley JT, Riley KJ, Newton TH, Santa Cruz GA, Lu XQ, Zamenhof RG. 
Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA. pbusse@caregroup.harvard.edu 

A phase I trial was designed to evaluate normal tissue tolerance to neutron capture therapy (NCT); tumor response was also followed as a secondary endpoint. ...Cranial NCT can be delivered at doses high enough to exhibit a clinical response with an acceptable level of toxicity. Acute toxicity was primarily associated with increased intracranial pressure; late pulmonary effects were seen in two subjects. Factors such as average brain dose, tumor volume, and skin, mucosa, and lung dose may have a greater impact on tolerance than peak dose alone. Two subjects exhibited a complete radiographic response and 13 of 17 evaluable subjects had a measurable reduction in enhanced tumor volume following NCT. Clinical Trial, Phase I 
&&url PMID: 12749707  


compiled by doctordee
November 2003
