Periodic Reporting for period 2 - ORIGIN (Optical Fibre Dose Imaging for Adaptive Brachytherapy)
Berichtszeitraum: 2021-07-01 bis 2023-12-31
Radiotherapy is the use of radiation for the treatment of cancer and 50 – 60 % of patients require radiotherapy at some point during their treatment. It is delivered in the form of external beam radiotherapy, using X-rays to kill cancer cells, or internally, using radioactive sources, in what is known as brachytherapy. Brachytherapy is further divided into Low Dose Rate (LDR), where the radioactive sources, known as seeds, remain implanted permanently, releasing radiation slowly over a number of months to destroy the cancer cells and High Dose Rate (HDR), where higher activity radiation sources are temporarily inserted into the target area for a few minutes at a time. Correct placement of the radiation source is vital to ensure adequate radiation to the target area (tumour), while ensuring minimum exposure to nearby critical organs, such as, in the case of prostate and gynaecological cancers, the bladder, urethra and rectal wall. Current positioning techniques rely on pre- and post-treatment CT and ultrasound imaging and the dose is calculated via a computerised treatment planning system. Without direct in person and real time monitoring of the dose being delivered to the patient, there is no independent dose verification, with many errors going undetected at the time of treatment.
ORIGIN aims to deliver more precise and effective brachytherapy for gynaecological and prostate cancer treatment through advanced real-time imaging and mapping of the radiation dose and exact location of the radiation source. This will be achieved by the development of a new 16-point optical fibre based sensor system for Low Dose Rate (LDR) and High Dose Rate (HDR) Brachytherapy. The ORIGIN system will lead to a 50% improvement in uncertainty over existing systems. In addition, the technology being developed will provide real-time monitoring of the radiation source location during treatment, which is currently not available. ORIGIN will be integrated into existing clinical brachytherapy treatment planning and delivery systems to confirm that the dose prescribed to the tumour is achieved, whilst ensuring the dose to organs at risk (OARs) is within acceptable limits.
ORIGIN aims to deliver more precise and effective brachytherapy for gynaecological and prostate cancer treatment through advanced real-time imaging and mapping of the radiation dose and exact location of the radiation source. This will be achieved by the development of a new 16-point optical fibre based sensor system for Low Dose Rate (LDR) and High Dose Rate (HDR) Brachytherapy. The ORIGIN system will lead to a 50% improvement in uncertainty over existing systems. In addition, the technology being developed will provide real-time monitoring of the radiation source location during treatment, which is currently not available. ORIGIN will be integrated into existing clinical brachytherapy treatment planning and delivery systems to confirm that the dose prescribed to the tumour is achieved, whilst ensuring the dose to organs at risk (OARs) is within acceptable limits.
The work within ORIGIN was centred on two main areas, System Development and Manufacturability, and Clinical Integration, each with specific challenges associated with them:
SYSTEM DEVELOPMENT AND MANUFACTURABILITY
To measure the radiation, optical fibre sensors have been designed with a special radiation-sensitive material, known as a scintillator, which converts the radiation into visible light. Although the scintillating material differs for LDR and HDR brachytherapy, the design of the probes are identical. Therefore, the same fabrication process and equipment can be used, increasing the manufacturing efficiency and decreasing costs.
The detector system, which measures the light emitted by the optical fibres, has been developed to meet the needs of the differing radiation profiles of LDR and HDR brachytherapy. Both detector systems are based on a 16-channel array which allows the radiation dose to be measured at multiple points simultaneously. The multi-channel detector systems employs specialist technology known as silicon photomultiplier (SiPM), which enables the detection or “counting” of single photons. This provides both the sensitivity and range required for different brachytherapy treatments. When exposed to ionising radiation the scintillating tip of the sensor emits photons of light which travel along the optical fibre to the detector system.
Accurate placement and measurement of the radioactive source during brachytherapy is crucial to guarantee the dose prescribed to the target area, whilst also ensuring minimum exposure to nearby organs. Using artificial intelligence, the dose readings from the optical fibre sensors, combined with the sensors’ position, provided by an electromagnetic tracking system, enables the determination of the location of the radiation source(s). A heat map can then be generated, which, when overlaid with the patient’s CT or ultrasound image, confirms the position and dose of the radiation being received.
CLINICAL INTEGRATION
A careful consideration of the ORIGIN system development has been to ensure it is compatible with existing clinical practice and equipment. Several custom made devices have been designed to enable the ORIGIN sensors to be secured within existing brachytherapy applicators. Models known as phantoms, constructed using 3D printing technology, were developed to mimic the human pelvic area and enable the examination of dose measurements in anatomically correct models. The ORIGIN system prototypes were clinically evaluated by the project’s three clinical partners, Blackrock Health Galway Clinic, Northern Ireland Cancer Centre, and University Hospital of Asturias. A protocol for the integration of the ORIGIN system with existing treatment planning systems was developed for prostate and gynaecological HDR and LDR brachytherapy.
SYSTEM DEVELOPMENT AND MANUFACTURABILITY
To measure the radiation, optical fibre sensors have been designed with a special radiation-sensitive material, known as a scintillator, which converts the radiation into visible light. Although the scintillating material differs for LDR and HDR brachytherapy, the design of the probes are identical. Therefore, the same fabrication process and equipment can be used, increasing the manufacturing efficiency and decreasing costs.
The detector system, which measures the light emitted by the optical fibres, has been developed to meet the needs of the differing radiation profiles of LDR and HDR brachytherapy. Both detector systems are based on a 16-channel array which allows the radiation dose to be measured at multiple points simultaneously. The multi-channel detector systems employs specialist technology known as silicon photomultiplier (SiPM), which enables the detection or “counting” of single photons. This provides both the sensitivity and range required for different brachytherapy treatments. When exposed to ionising radiation the scintillating tip of the sensor emits photons of light which travel along the optical fibre to the detector system.
Accurate placement and measurement of the radioactive source during brachytherapy is crucial to guarantee the dose prescribed to the target area, whilst also ensuring minimum exposure to nearby organs. Using artificial intelligence, the dose readings from the optical fibre sensors, combined with the sensors’ position, provided by an electromagnetic tracking system, enables the determination of the location of the radiation source(s). A heat map can then be generated, which, when overlaid with the patient’s CT or ultrasound image, confirms the position and dose of the radiation being received.
CLINICAL INTEGRATION
A careful consideration of the ORIGIN system development has been to ensure it is compatible with existing clinical practice and equipment. Several custom made devices have been designed to enable the ORIGIN sensors to be secured within existing brachytherapy applicators. Models known as phantoms, constructed using 3D printing technology, were developed to mimic the human pelvic area and enable the examination of dose measurements in anatomically correct models. The ORIGIN system prototypes were clinically evaluated by the project’s three clinical partners, Blackrock Health Galway Clinic, Northern Ireland Cancer Centre, and University Hospital of Asturias. A protocol for the integration of the ORIGIN system with existing treatment planning systems was developed for prostate and gynaecological HDR and LDR brachytherapy.
In addressing the need for more effective medical interventions and treatments for cancer, ORIGIN’s societal impact is three-fold:
1. Improving Health Related Quality of Life Outcomes
Monitoring the precise radiation dose delivered to critical organs near the tumour, such as the urethra and rectal wall, is crucial to reduce adverse side-effects and further improve the quality of life of cancer survivors. ORIGIN has developed a multi-point radiation monitoring system that provides real-time dose information allowing for comparison with treatment plans to ensure that the dose prescribed to the tumour is achieved, whilst ensuring dose to organs at risk (OARs) is within acceptable limits. Currently, there are no commercially available systems for real-time radiation monitoring in brachytherapy.
2. Improved dose-led treatment plans
The ability to accurately monitor the radiation dose provides for the possibility of safely employing dose escalation. This affords the clinicians the opportunity to offer hypofractionated HDR-BT treatment plans (higher doses over fewer fractions).
3. Preventing treatment errors
It is widely acknowledged that there is serious under-reporting of incidents in radiotherapy, especially in brachytherapy. In vivo, or “within the living”, measurements are a vital safeguard against major setup errors and calculation or transcription errors that were missed during the pre-treatment chart check. By monitoring the radiation doses and source location in real-time, the ORIGIN system will be able to identify and interrupt the treatment if there are significant discrepancies with the treatment plan and/or dose limits for organs at risk (OARs) have been reached. This will reduce the number of errors in brachytherapy due to human error or equipment malfunction.
ORIGIN has also demonstrated, for the first time to the best of our knowledge, a fabrication methodology compatible with series production and assembly of optical fibre sensor tips. The clear advancement beyond the state-of-the-art, the novelty and the inventiveness is supported by a patent application on "Sensor Tip and Method of Manufacturing the Same" and ensures Europe's competitiveness in photonics manufacturing.
1. Improving Health Related Quality of Life Outcomes
Monitoring the precise radiation dose delivered to critical organs near the tumour, such as the urethra and rectal wall, is crucial to reduce adverse side-effects and further improve the quality of life of cancer survivors. ORIGIN has developed a multi-point radiation monitoring system that provides real-time dose information allowing for comparison with treatment plans to ensure that the dose prescribed to the tumour is achieved, whilst ensuring dose to organs at risk (OARs) is within acceptable limits. Currently, there are no commercially available systems for real-time radiation monitoring in brachytherapy.
2. Improved dose-led treatment plans
The ability to accurately monitor the radiation dose provides for the possibility of safely employing dose escalation. This affords the clinicians the opportunity to offer hypofractionated HDR-BT treatment plans (higher doses over fewer fractions).
3. Preventing treatment errors
It is widely acknowledged that there is serious under-reporting of incidents in radiotherapy, especially in brachytherapy. In vivo, or “within the living”, measurements are a vital safeguard against major setup errors and calculation or transcription errors that were missed during the pre-treatment chart check. By monitoring the radiation doses and source location in real-time, the ORIGIN system will be able to identify and interrupt the treatment if there are significant discrepancies with the treatment plan and/or dose limits for organs at risk (OARs) have been reached. This will reduce the number of errors in brachytherapy due to human error or equipment malfunction.
ORIGIN has also demonstrated, for the first time to the best of our knowledge, a fabrication methodology compatible with series production and assembly of optical fibre sensor tips. The clear advancement beyond the state-of-the-art, the novelty and the inventiveness is supported by a patent application on "Sensor Tip and Method of Manufacturing the Same" and ensures Europe's competitiveness in photonics manufacturing.