Beam current optimization minimizes treatment time

Varian Medical Systems Particle Therapy has developed a time optimized radiation treatment scheme (WO/2017/174189). In one approach, the system receives information relating to a proton- or ion-beam treatment plan, plus information regarding the limitations of one or more machines involved in the therapy, and determines a time-optimized beam current for the proton or ion beam based on the plan and the machine-limitation information. The time-optimized beam current minimizes the time required to deliver a required quantity of monitor units to one of a number of beam spots, where each spot is a particular area of the target tissue. Minimizing treatment time is beneficial, not only for the convenience of the patient and treating doctor, but also for efficacy and safety in breath-hold techniques or treatment of moving targets.

Liquid-based brachytherapy treats skin cancers

Inventors at Seoul National University Hospital have described a remote afterloading brachytherapy apparatus that uses liquid radioactive isotopes (WO/2017/200298). In particular, the system is designed for treating skin cancer that develops on an irregular skin surface. The brachytherapy apparatus places the therapeutic liquid radioactive isotope at regular intervals from a lesion using 3D scanning and/or through a patient-specific applicator made with a 3D printer. It places the liquid at a constant thickness to deliver a uniform prescription dose. To minimize radiation exposure of normal tissues, a liquid beta-ray or a low-energy gamma ray source can be used. In addition, radiation exposure of medical staff and operators who treat patients using radioactive isotopes may be prevented through the remote afterloading.

Radiotherapy planning tool optimizes fractionation

Scientists at Philips and Massachusetts General Hospital have created a fractionation optimization tool for radiotherapy planning (WO/2017/182300). The tool receives inputs including the radiation dose distribution to be delivered, maximum and minimum number of fractions, and biologically effective dose (BED) constraints for one or more organs-at-risk. The system generates a 2D graph displaying total dose (sum over N fractions of the fractional dose) versus total squared dose. Lines are also displayed on the 2D graph depicting each BED constraint. The system displays a marker at a location on the graph defined by a current fractionation and current total dose. When a new value for the current fractionation and/or the current total dose is input, the marker is updated accordingly. Alternatively, a second marker can be displayed showing the new fractionation scheme along with its advantages and disadvantages with respect to the current fractionation scheme.

Nuclear targeting enables Cerenkov-activated PDT

Photodynamic therapy (PDT) uses visible or near-infrared light to activate photosensitizers localized within tumours. To reach deep-seated tumours, the use of external X-rays to generate Cerenkov radiation within the target volume, creating an in situ PDT light source, is proposed. However, it's not clear whether the intensity of linac-generated Cerenkov light is high enough to give an effective PDT response at an X-ray dose that will not damage normal tissues. Researchers from the University Health Network and the University of Toronto have described methods to circumvent the limitation of the low intensity of X-ray-generated Cherenkov light (WO/2017/197531). They do this by exploiting the large increase in photodynamic cell kill that can be achieved by targeting the photosensitizer to the cell nucleus, rather than cytoplasmic organelles such as mitochondria, which are the primary targets in conventional PDT.

Nanoparticle conjugates target brain tumours

US researchers have detailed nanoparticle conjugates with enhanced penetration of tumour tissue (for example, brain tumour tissue) and diffusion within the tumour interstitium, for treatment of cancer including primary and metastatic brain tumours (WO/2017/189961). The team, from Memorial Sloan Kettering Cancer Center and Cornell University, also describe methods of targeting tumour-associated macrophages, microglia and/or other cells in a tumour microenvironment using these nanoparticle conjugates. The filing also includes details of diagnostic, therapeutic and theranostic platforms featuring the nanoparticle conjugates for treating targets in the tumour and surrounding microenvironment, thereby enhancing efficacy of cancer treatment. The researchers envisage that the nanoparticle conjugates will also be used with other conventional therapies, including chemotherapy, radiotherapy and immunotherapy.

Monitoring system keeps an eye on patient motion

Vision RT has invented a monitoring system for patients undergoing radiotherapy, such as stereotactic surgery, for example, where an immobilization mask may be used (WO/2017/178804). The system comprises a projector that projects a pattern of light onto the patient, a restraint for immobilizing the patient relative to the treatment apparatus during treatment, and a detector to obtain images of the patient. A model generation module then processes the images to create a model of the surface of a portion of the patient. At least a portion of the patient restraint is coloured and the module is inhibited from generating a model of the coloured portion of the patient restraint.