Intraoperative Tissue Identification Using Rapid Evaporative Ionization

Mass SpectrometryTyler Daly

Biomedical Engineering11/10/2015

Introduction What is REIMS? Case Study & Results Discussion

Overview

More than 300,000 new cancer cases diagnosed in the UK yearly

1.8 million diagnostic, curative, or palliative surgical procedures performed as means of treatment Problem: using “margin with clearances”- surgeons cut

away excess healthy tissue Cosmetic success of surgery depends on how much excess

healthy tissue is removed Ex: 20% of breast cancer patients who receive lumpectomies

require further surgery to clear positive margins.

Introduction

Problem: re-excision not always possible in soft tissue areas of the body

Accurate tumor invasion assessed accurately through multiple histological analyses in postoperative phases

In uncertain surgical cases, removed tissue gets sent to pathology labs and analyzed, while patient is under general anesthesia Expensive and time consuming (20-30 minutes

minimum)

Introduction

Almost no technologies is current clinical practice to assist surgeons on accurate cancer tissue clearance in real-time

Rapid evaporative ionization mass spectrometry (REIMS)- real-time characterization of human tissue in vivo Analysis of the “smoke” released during

electrosurgical dissection Pairing REIMS technology with electrosurgery for tissue

diagnostics known as the intelligent knife (iKnife)

Solution: REIMS (and the iKnife)

***REIMS converts tissue components into gas-phase ionic species that are then sent through mass spectrometric analysis***

Before the case study took place, iKnife data was collected ex vivo (tissue dissected and tested outside of the body) to create a reference library of data for the in vivo (tissue analyzed within the body) testing

Data ranged from benign to malignant tumors of gastric, colonic, hepatic, breast, lung, and brain tissue sample

Case Study

Multicenter observational study at three hospitals in Hungary (May 1, 2010 – February 29, 2012)

393 patients recruited Cancers ranging from gastric, colorectal, liver,

breast, lung, and brain

Case Study

Mass spectrometric tissue identification matched postoperative histopathology in 96.2% of the cases 15 cases conflicted pre/postoperative tissue

identification

The REIMS-iKnife technique was able to correctly identify 11 tissue types and correctly identify 9 of the cases to be malignant or benign (81.8% accuracy) For the two cases that were incorrect, it was later

revealed through further exploration that the disease present was actually a case of Chrohn’s disease

The final case was inconclusive

Results

Data collected from the case study provides concrete evidence that REIMS-iKnife technology is a viable option for real-time tissue analysis This would solve many problems such as:

The need to go in for secondary surgery The removal of excess healthy tissue The need to hold patients under general

anesthetics for extended periods of time

Discussion

Many factors limit the potential of growth of other means of accurate tissue characterization (potential toxicity and pharmacokinetics, limitations of information provided from infrared dyes and Raman spectroscopy, etc)

REIMS- iKnife technology has room to grow, as it already can distinguish between types of cancer and their dangers

Cost effective/Time saving

Discussion

Questions?