In vivo test-driven upgrade of a time domain multi-wavelength optical mammograph

Abstract

A recent upgrade of the time domain multi-wavelength optical mammograph developed by Politecnico di Milano achieved good performance in laboratory tests [Biomed. Opt. Express 9, 755 (2018).10.1364/BOE.9.000755]. However, it proved unsatisfactory when in vivo measurements were finally performed. That led to a further upgrade, including the replacement of the time-to-digital converter with a new model, and the related set-up changes. The new instrument version offers improved laboratory performance (as assessed through established protocols: BIP and MEDPHOT) and good in vivo performance (extension of the scanned breast area, repeatability, consistency of estimated tissue composition with physiology). Besides introducing the new set-up and detailing its laboratory and in vivo performance, we highlight the importance of systematic in vivo testing before entering clinical trials.

High-throughput multi-wavelength time-resolved optical mammograph: importance of in vivo performance assessment

“…In fact, the replacement of the TDC with another model, become available recently on the market and optimized for highthroughput applications (the 8-channel MultiHarp 150 8N, PicoQuant, Germany [12]), has been resolutive [10]. The validation process has then been repeated from step 1.…”

Optical mammography in the time domain up to 1060 nm: from tests on healthy women to initial data for monitoring neoadjuvant chemotherapy

“…Clinical trials should be preceded by propaedeutic in vivo tests. In light of this good practice, we recently performed laboratory measurements on 3 healthy women, that highlighted the importance of preparatory in vivo tests to comply with a clinical environment [5]. The results obtained for the 3 sessions dedicated to healthy volunteer #1 are depicted in Table 1 We can observe that CV values over the three sessions never exceed 6% for any constituents of interest, implying an adequate level of reproducibility for our purposes.…”

“…Light is collected on the opposite surface by an 8-SiPM (Silicon PhotoMultipliers) detector and, after amplification, the signal is processed by a Time-to-Digital Converter (MultiHarp 150 8N, PicoQuant, Germany). Finally, data are acquired by a PC [5].…”

“…Before going to clinics, in vivo rehearsals have been performed in laboratory as the last step of a thorough validation protocol [5]. They are essential to verify whether the optical mammograph is ready to begin the clinical trial, paying particular attention to the breast intrinsic heterogeneity and inter-subject variability.…”

Anthropomorphic Polydimethylsiloxane silicone-based phantom for Diffuse Optical Imaging

“… [5] , [6] and tissue oxygenation [7] , [8] . Moreover, research has advanced to the point of designing and testing clinical prototypes [9] , [10] , [11] , [12] , [13] , [14] . In this way, the development of devices intended for clinical applications, such as early detection, diagnosis, or measurements of response to therapy, is one of the main research goals in Biomedical Optics.…”