Neutron Therapy
Cryogenics is at the heart of nuclear accelerators. Accelerators such as Fermilab’s Tevatron make neutron therapy for cancer possible.
From Fermilab Today 4/20/09:
Fermilab currently offers neutron therapy. But staff at Fermilab designed and built the proton accelerator used by the nation’s first hospital-based treatment center to use protons against cancer cells, Loma Linda Proton Treatment Center in California, which opened in the early 1990s. Fermilab helped pioneer the use of particle beams from a compact proton accelerator to treat cancer.
The differences between the two types of cancer therapy are described below.
Neutron therapy works best on large, slow growing tumors. In large tumors, a lack of blood flow to the center of the tumor can cause it to go dormant, which then resists traditional gamma or X-ray radiation but not neutron radiation. Neutron therapy is favored for melanoma, locally advanced prostate cancer, and tumors in the nasal, head, sinus, neck and salivary area.
Proton therapy works best on 1 to 1.5 cm in diameter tumors or those next to sensitive areas because the protons can stop precisely in the tumor, eliminating exit doses of radiation. Proton therapy is favored for many tumors at the base of the skull, near blood vessels in the brain and behind the eye.
Neutron therapy deposits energy more densely to destroy the nucleus of the DNA of the dormant portion of the tumor cell where as proton therapy causes a chemical break in the tumor DNA, which can repair itself overtime.
Neutron radiation is three times as powerful as proton radiation so patients get one-third the dose. Typically, neutron therapy requires three doses a week for four weeks while proton therapy requires five doses a week for six to eight weeks.
