Oncology Dust - An Implantable Sensor for Cancer Surveillance

Michel Maharbiz and Stefanie Garcia

Berkeley Sensor and Actuator Center

We aim to develop a micro surveillance device for early identification of recurrent cancerous cell growth in collaboration with radiation oncology research from UCSF. UCSF has developed a molecular probe that specifically targets prostate specific membrane antigen (PSMA), which is over-expressed on prostate cancer cells. By radiolabelling these probes with P-32 (beta emitter), previously treated tumor sites may be monitored for recurrence with many micro implantable “dust” arrays. After the probe is administered, P-32 radiolabelled probes will bind to the cancer site. The “dust” sensors can detect the frequency of beta events and communicate this information back to the surgeon using ultrasound. We will design a 100x100 um semiconductor based, implantable radiation sensor that can feasibly detect and localize cancer recurrence from 10^4 – 10^5 cells when placed near a cancer site. (This is 4 orders of magnitude lower than current MRI and PET imaging techniques) The sensors will use ultrasonic methods for power and signal transmission, as demonstrated in Dongjin et al, arXiv preprint arXiV:1307.2196 (2013). Initial sensor design will enhance CMOS device sensitivity to time dependent signal variation and will also explore signal recovery in the limited window where the radiolabelled probe is detectable.