Sense-checking the approach to quantitative sensory testing to detect chemotherapy-induced peripheral neuropathy

People with chemotherapy-induced peripheral neuropathy (CIPN) have abnormalities in Quantitative Sensory Test (QST) findings. However, the predictive utility of QST for the early detection of CIPN in individuals has not been demonstrated. This will require longitudinal QST during chemotherapy treatments. However, QST is time-consuming, requires expertise and complex, costly equipment which has largely prevented its adoption in routine clinical practice. We aimed to assess approaches to develop a reliable, straightforward, time efficient and sensitive sensory testing method. Guided by patient partner input and previous literature, we selected thermal and vibration detection thresholds as target QST parameters. A series of iterative experiments was conducted to determine the optimal body test site and to develop a novel vibration testing protocol. The thenar eminence emerged as the best candidate due to higher sensitivity to all stimulus modalities, lower variance and less age-related change compared to the feet. We demonstrated significant differences in thermal thresholds between healthy participants and people with CIPN measured at the thenar but not the feet. The vibration testing protocol, employing a linear resonant actuator, performed better than a calibrated tuning fork being sufficiently sensitive to identify age-related and body site differences in sensory function well as tracking sensory loss induced by local anaesthetic nerve block. These findings establish a testing framework to deliver QST at a single convenient body site with a reduced set of modalities to efficiently track multifibre sensory function for patients at risk of developing neuropathy.