Prompt gamma radiation monitors proton dose
Researchers at Hampton University (Hampton, VA) have developed a system for range and dose verification of hadron therapy (WO/2011/143367). The apparatus works by measuring beam-induced radiation emitted during, or directly following, treatment. This includes, for example, secondary prompt gamma radiation emitted during proton and carbon-ion irradiation. Measuring this gamma radiation, or other beam-induced radiation, enables optimization of radiation dose deposition to the target tissue and improved sparing of surrounding critical structures and normal tissue. Adjustments to the treatment can be performed as required, based on actual and measured applied dosages.
IGRT system tracks target with reduced dose
Radiation oncology company Accuray (Sunnyvale, CA) has described systems, methods and computer programs for performing image-guided radiation therapy (IGRT) with streamlined intrafraction computation, reduced patient X-ray dose, and/or reduced delivery margins (WO/2011/156526). The IGRT system tracks target motion by comparing intrafraction X-ray tomosynthesis image data with initial tomosynthesis data acquired with the patient in the treatment position. The initial image is inherently registered with co-acquired image data from a set-up imaging system integrated with (or with known geometry relative to) the tomosynthesis imaging system. The filing notes that repeated registration of the intrafraction image data with pre-acquired reference image data from a different frame of reference is not required during radiation delivery.
Dual-mode transducer takes control of ultrasound therapy
A team at the University of Minnesota (Saint Paul, MN) has invented a dual-mode ultrasound system that provides real-time imaging and therapy using the same elements of an ultrasound transducer array (WO/2011/156624). The array of transducer elements delivers sequential bursts of therapeutic ultrasonic energy and transmit/receive imaging ultrasound to/from the target. A control apparatus controls the imaging signals, generates treatment region images to identify target points, generates signals to drive one or more transducer elements to deliver sequential bursts of therapeutic ultrasonic energy to the target points, and generates control image data during and/or after each therapy burst. The control image data are used as feedback to drive the ultrasound transducer elements to deliver a subsequent therapy burst.
Nanoparticles guide radiation therapy
A method for nanoparticle-guided radiotherapy is detailed in international patent application WO/2012/007567. The nanoparticles comprise CT contrast agents in a solid form, with the ability to block or attenuate the X-ray radiation. After administration to the patient, the particles remain in circulation long enough to localize to the target malignant cells. X-ray-based images, such as CT images, are then used to define the precise location of the target tumour cells, and this information is used to direct external-beam radiotherapy to the tumour cells and spare normal tissue. According to the Technical University of Denmark inventors, the method – which enables simultaneous external-beam radiotherapy and imaging – provides safer and less costly imaging and radiation treatment.
Optimizer eases multimodal radiotherapy planning
Philips Electronics of the Netherlands has published details of an optimizer for treatment planning of multimodal radiotherapy (WO/2011/154853). The system concurrently optimizes a combined plan that employs both intensity-modulated radiotherapy (IMRT) and intensity-modulated proton therapy (IMPT) to treat a volume-of-interest in a patient. A simulator generates multiple variations of a simulation model, by iteratively adjusting a number of optimization parameters for each treatment device, until the model satisfies user-defined treatment objective criteria, such as maximum dose or dose placement, for example.
Raster scanning delivers tissue surface irradiation
Xoft (Sunnyvale, CA) has come up with a system for administering radiation therapy to a tissue surface, utilizing computer-driven mechanical translation of a miniature X-ray source (WO/2011/156009). A servo-controlled manipulator can effect a raster scan of the desired area, such as an area of the skin, in any desired pattern, including serpentine, spiral, parallel but unidirectional, and irregular patterns. Preferably, a third direction of control, i.e. depth, is included. The signal from an appropriate depth sensor can be used to adjust the radiation source for consistent irradiation of the tissue surface over varied contours.