A tumor treatment apparatus may include an array of collimated CZT detectors configured to intersect a known coordinate and measure gamma radiation activity, for example at 511 keV. A radiation delivery system may be configured to direct radiation through the known coordinate on the basis of the gamma radiation activity. A translatable and rotatable table may be configured to support a tumor host, wherein the tumor is positionable relative to the known coordinate on the basis of the gamma radiation activity emitted by the tumor and measured by the array of collimated CZT detectors. Radiation from the radiation delivery system may be delivered to the tumor at the known coordinate, and may be delivered in an intra-operative surgical environment.
