Hybrid photoacoustic and ultrasound mammography

Breast cancer is the most common type of female cancer worldwide. Conventionally used imaging techniques (x-ray mammography, ultrasonography, MRI) have their limitations and drawbacks.

In this observational diagnostic clinical study with our third generation photoacoustic mammoscope (PAMMOTH), we want to test the feasibility of the PAMMOTH device in imaging breast cancer. Feasibility measurements will be performed with healthy volunteers. Using patient measurements, the performance of the PAMMOTH system will be measured, by comparing the obtained images of benign and malignant lesions to those of conventional imaging techniques and pathology results. The aim is to find photoacoustic image descriptors characteristic of malignant and benign breast lesions as well as of the healthy breast.

A maximum of 60 subjects (45 patients and 15 healthy volunteers) are measured at the Medisch Spectrum Twente hospital in Oldenzaal (Netherlands) after being informed about the study and signing an informed consent form. The study population consists of adult women who come to the hospital with a lesion suspect for malignancy, which, after clinical investigation and diagnostic imaging is classified as BI-RADS 2, 3, 4 or 5. There is also a sub-population of adult healthy women. For each subject, the maximum total measurement time is 10 minutes (two times 5 minutes per breast), during which the subject lies prone on a bed with one of her breasts hanging in an imaging tank, supported by a cup, filled with warm water.

Breast cancer is the most common type of female cancer worldwide. Early detection has proven to have a positive influence on the prognosis and survival rate. An important aid in the detection and diagnosis of breast cancer is the use of medical imaging techniques. Conventionally used imaging techniques (x-ray mammography, ultrasonography, MRI) have their limitations and drawbacks. In the past years, a new method of imaging called photoacoustics (PA) has been developed and applied for breast cancer imaging at the University of Twente. PA combines high optical contrast with high ultrasound resolution. The contrast is based on light absorption by an increased amount of hemoglobin in and around malignancies. The method is non-invasive and harmless. The first and second generation Twente photoacoustic mammoscope (PAM 1 and PAM2) were tested in the clinic. PAM1 was able to visualize known malginancies, while with the PAM2, significant improvements have been made in improving the image quality. We are now working on the even better, third version photoacoustic mammoscope (PAMMOTH). This is a hybrid system, combining PA with ultrasound computed tomography (USCT). The PAMMOTH device has so far not been tested in the clinical setting. With our clinical study, we want to test the feasibility of the PAMMOTH device in imaging breast cancer. Feasibility measurements will be performed with healthy volunteers. Using patient measurements, the performance of the PAMMOTH system will be measured, by comparing the obtained images of benign and malignant lesions to those of conventional imaging techniques and pathology results.

The photoacoustic measurements are performed when a patient is already at the centre for mammacare (Medisch Spectrum Twente hospital in Oldenzaal, Netherlands) for conventional imaging / diagnosis. After informing her about the study and obtaining informed consent, the photoacoustic measurements are performed. When the measurements are completed, the subject is asked to fill out a questionnaire. Photoacoustic image reconstruction and analysis are conducted afterwards.

For healthy volunteer measurements:
As described, after a healthy adult woman decides to participate, an appointment is made to perform measurements at the Medisch Spectrum Twente hospital in Oldenzaal, Netherlands. When the measurements are completed, the subject is asked to fill out a questionnaire. Photoacoustic image reconstruction and analysis are conducted afterwards.