Intensity and dose modulated radiosurgical needle system and method

A radiotherapy system, comprising:

• I. a treatment head comprising:
• an electron source for generating an initial electron beam;
• a first beam corrector for focusing the initial electron beam into a focused electron beam;
• a Bremsstrahlung target comprising target material that when impacted by the focused electron beam, generates Bremsstrahlung x-ray photons;
• a radiosurgical needle with an elongated radiopaque needle body portion having an interior lumen, a proximal end and a distal end, the distal end comprising a pointed tissue-piercing tip, wherein the elongated radiopaque needle body portion of the radiosurgical needle has an outside diameter and the pointed tissue-piercing tip has a smallest tip diameter, and the smallest tip diameter is less than the outside diameter of the elongated radiopaque needle body portion, the Bremsstrahlung target being positioned within the lumen and closer to the distal end than the proximal end, the distal end of the radiosurgical needle comprising a radiolucent portion for transmitting x-ray photons generated at the Bremsstrahlung target to surrounding tissues, the radiosurgical needle further comprising a pointed tip portion for piercing a tissue of a patient, wherein the Bremsstrahlung target, the radiolucent portion, and the pointed tip are provided at the distal end of the radiosurgical needle, and the Bremsstrahlung target and radiolucent portion are geometrically positionable for beam forming and targeting towards tissues being treated;
• a first beam steering device for steering the focused electron beam to the target;
• and,
• an elongated radiopaque micro drift tube with an open interior extending from the electron source to the radiosurgical needle, the micro drift tube having a proximal end nearest the electron source, and a distal end nearest the radiosurgical needle, the proximal end of the radiosurgical needle being affixed to the distal end of the micro drift tube, the open interior of the micro drift tube communicating with the lumen of the radiosurgical needle so as to define an electron flow path from the electron source to the Bremsstrahlung target;
• II. a robotic arm for manipulating the treatment head;
• and,
• III. a base unit for supporting the robotic arm.

A method for conducting radiotherapy, comprising the steps of:

• providing a radiosurgical needle with an elongated radiopaque needle body portion having an interior lumen, a proximal end and a distal end, the distal end comprising a pointed tissue-piercing tip for piercing the tissue of a patient, wherein the elongated radiopaque needle body portion of the radiosurgical needle has an outside diameter and the pointed tip has a tip diameter, and the tip diameter is less than the outside diameter of the elongated radiopaque needle body portion, the radiosurgical needle further comprising a Bremsstrahlung target comprising target material that when impacted by the focused electron beam generates Bremsstrahlung x-ray photons, the Bremsstrahlung target being positioned within the lumen, the radiosurgical needle comprising a radiolucent portion for transmitting x-ray photons generated at the target to surrounding tissues, wherein the target, the radiolucent portion, and the pointed tip are provided at the distal end of the radiosurgical needle, and the Bremsstrahlung target and radiolucent portion are geometrically positionable for beam forming and targeting towards tissues being treated;
• inserting the radiosurgical needle into the body of a patient by piercing a tissue of the patient with the tissue-piercing tip and advancing the radiosurgical needle to a patient therapy location;
• directing a focused and steered electron beam at the target, wherein Bremsstrahlung x-ray photons will be generated at the target and will be transmitted through the radiolucent portion to the patient therapy location.