Periodic Reporting for period 2 - SOLUS (Smart optical and ultrasound diagnostics of breast cancer)
Reporting period: 2018-05-01 to 2019-10-31
Mammographic screening has been an effective way of reducing breast-cancer mortality. At the same time, screening programs result in detection of a significant number of false positive cases, leading to needless additional imaging and invasive procedures like biopsies, with a negative impact on the patient’s quality of life and high burden on healthcare systems: On average about 50% of positive breast screening outcomes turn out to be false positives and further invasive examination should have been avoided.
Thus, there is a clear need for an affordable and highly specific point-of-care system for substantially improved in-depth diagnosis of breast lesions.
Several techniques are being investigated or used as an adjunct to mammography, including ultrasound and optical tomography.
Ultrasonography is the first choice to further assess and characterise lesions visible at mammography and to guide breast biopsy. Advanced ultrasound techniques are also able to measure tissue stiffness, a good indicator for malignancy. However, the current diagnostic results of ultrasound techniques are not satisfactory.
Optical tomography methods can provide further information about the tissue complementary to ultrasound. With diffuse optics, it is possible to measure the tissue composition (e.g. collagen, water and fat content) and functional blood parameters, such as oxygen saturation. These all provide information about the nature of the lesion.
Contrary to other imaging methods like MRI and PET, ultrasound and optical tomography do not involve the use of ionizing radiation or contrast agents, and are cheaper and easier to use.
The SOLUS project is developing an innovative tomographic system combining diffuse optics and ultrasound to support the diagnosis of breast cancer. Our system aims at the classification of breast lesions after a positive screening, and specifically at improving the discrimination of lesions that are borderline between benign and malignant and presently undergo screening evaluation with high false positive rate.
Combining diffuse optics with ultrasound favours the development of a portable, cost-effective, non-invasive, point-of-care diagnostic tool.
We are exploiting new concepts in the field of photonics and developing new components to reach our overall objective and enable the SOLUS system to achieve unprecedented sensitivity, resolution, and depth penetration and provide effective, diagnostic information.
In particular, we’ve already developed an innovative module, called a smart optode to perform diffuse optical tomography to a depth of a few centimeters. The smart optode is being integrated into a probe capable of performing diffuse optical tomography as well as conventional and advanced ultrasound measurements at the same time.
The SOLUS system and breast examination procedure will be very similar to current standard ultrasound practices, but will provide information on tissue morphology, stiffness and composition for high-specificity breast imaging and diagnosis of breast cancer.
So far, we’ve completed the development of a fast, compact laser driver and a new wide area time-gated single-photon detector for the diffuse optics, and the subsequent smart optode.
We’re also working on the integration of the optode into the multimodal probe. The ergonomics of the probe are highly important, and special attention is being paid to feedback from clinicians.
Automated image processing and reconstruction algorithms have been developed, where anatomical information from US is being used as priors for the reconstruction of the diffuse optics measurements.
Next to the development of the multimodal probe, the full system software and integration is being worked on. The protocol for the clinical pilot study has been developed and, following the integration of all new components, clinical validation can start.
The improvement in the characterisation of breast lesions leads to higher specificity in non-invasive breast cancer diagnosis. Women receiving a negative report after their examination will be spared unnecessary additional examinations, including unnecessary biopsies.
The system will also allow more effective treatment and therapy management. Effective therapy response prediction and monitoring is currently not available, while it will enable personalised decision-making, therapy planning and optimisation for each patient. This also contributes to a significant decrease of the total cost of breast cancer management.
The project will advance the current state-of-the-art for ultrasound and diffuse optical tomography in biomedicine and the characterisation of cancer. It will also improve the monitoring of chemotherapy of breast cancer and the prediction of treatment outcome through better capabilities of characterising tumours.
The multimodal SOLUS system will have application in other segments of medical imaging as well, such as musculoskeletal imaging, thyroid imaging etc.
The smart optode itself is a groundbreaking small size stand-alone device for diffuse optical tomography with potential use in several fields, from wearable devices (e.g. to monitor athletic training) to the non-destructive assessment of fruit quality.
The single photonics components (both laser driver and detector) also represent an advancement beyond the current state-of-the-art.
Furthermore, the project brings together key industrial players in the field and contribute to a secured and reinforced industrial leadership for Europe in the biophotonics market.
Finally, at present, there are no relevant standards for diffuse optical tomography instruments. SOLUS is laying the foundation of future standards. More specifically, SOLUS has already developed a protocol for the performance assessment of such instruments and built a set of tissue phantoms to effectively carry out the performance assessment.