Systems and methods for patient monitoring for radiotherapy

Abstract

Disclosed herein are systems and methods for real-time monitoring of patient position and/or location during a radiation treatment session. Images acquired of a patient during a treatment session can be used to calculate the patient's position and/or location with respect to the components of the radiation therapy system. One variation of a radiation therapy system includes a circular gantry with a rotatable ring coupled to a stationary frame, a therapeutic radiation source mounted on the rotatable ring, and a patient-monitoring imaging system mounted on the rotatable ring. The patient-monitoring system may have one or more image sensors or cameras disposed on the rotatable ring within a bore region of the radiation therapy system, and may be configured to acquire image data as the ring rotates.

1 . A method for generating a 3-D patient model comprising:
 positioning a patient on a patient platform of a radiation therapy system, the radiation therapy system further comprising a circular gantry having a rotatable ring about a bore, a therapeutic radiation source coupled to the rotatable ring, an optical imaging coupled to the rotatable ring inside the bore, wherein the patient platform is movable within a patient area that is at least partly located within the bore;   acquiring images of the patient and the patient platform using the optical imaging system while rotating the optical imaging system;   generating a 3-D model of the patient and the patient platform using the acquired images; and   generating a 3-D model of the patient by subtracting a pre-calculated 3-D model of the patient platform from the generated 3-D model of the patient and the patient platform.   
     
     
         2 . The method of  claim 1 , wherein acquiring images comprises acquiring 2-D images during at least one rotation of the ring about the patient area. 
     
     
         3 . The method of  claim 2 , wherein acquiring 2-D images comprising acquiring 2-D images at four or more pre-defined locations about the patient area. 
     
     
         4 . The method of  claim 1 , wherein the 3-D model of the patient platform is calculated based on position sensor data and patient platform geometry. 
     
     
         5 . The method of  claim 1 , wherein generating a 3-D model of the patient and the patient platform comprises depth-sensing methods. 
     
     
         6 . The method of  claim 5 , wherein depth-sensing methods comprise stereovision methods. 
     
     
         7 . The method of  claim 5 , wherein depth-sensing methods comprise laser scanning methods. 
     
     
         8 . The method of  claim 5 , wherein depth-sensing methods comprise time-of-flight methods. 
     
     
         9 . The method of  claim 5 , wherein depth-sensing methods comprise projected light methods. 
     
     
         10 . A method for generating a collision notification for a radiation therapy system comprising:
 deriving a 3-D model of a rotatable ring of a radiation therapy system based on positional sensor data;   generating a 3-D patient model using the method of  claim 1 ;   comparing the generated 3-D patient model with the 3-D model of the rotatable ring to determine a location of the patient relative to the rotatable ring; and   if the generated 3-D patient model is located within a pre-determined safety margin of the 3-D model of the rotatable ring, generating a notification to alert an operator of the radiation therapy system.   
     
     
         11 . The method of  claim 10 , wherein if the generated 3-D patient model is located within a pre-determined collision margin of the 3-D model of the rotatable ring, the method further comprises generating a notification to stop motion of the patient platform. 
     
     
         12 . The method of  claim 10 , wherein the generated 3-D patient model is a partial 3-D patient model that includes patient position data acquired from a subset of circumferential locations about the patient area.