[Organ preserving strategies for rectal cancer treatment]

Handheld macroscopic Raman spectroscopy imaging instrument for machine-learning-based molecular tissue margins characterization

SIGNIFICANCE

Raman spectroscopy has been developed for surgical guidance applications interrogating live tissue during tumor resection procedures to detect molecular contrast consistent with cancer pathophysiological changes. To date, the vibrational spectroscopy systems developed for medical applications include single-point measurement probes and intraoperative microscopes. There is a need to develop systems with larger fields of view (FOVs) for rapid intraoperative cancer margin detection during surgery.

AIM

We design a handheld macroscopic Raman imaging system for in vivo tissue margin characterization and test its performance in a model system.

APPROACH

The system is made of a sterilizable line scanner employing a coherent fiber bundle for relaying excitation light from a 785-nm laser to the tissue. A second coherent fiber bundle is used for hyperspectral detection of the fingerprint Raman signal over an area of 1  cm2. Machine learning classifiers were trained and validated on porcine adipose and muscle tissue.

RESULTS

Porcine adipose versus muscle margin detection was validated ex vivo with an accuracy of 99% over the FOV of 95  mm2 in ∼3  min using a support vector machine.

CONCLUSIONS

This system is the first large FOV Raman imaging system designed to be integrated in the workflow of surgical cancer resection. It will be further improved with the aim of discriminating brain cancer in a clinically acceptable timeframe during glioma surgery.

[Clinical research for rectal carcinoma: State of the art and objectives]

The treatment of rectal carcinoma is based on multidisciplinary strategy and multimodal approaches including gastrointestinal tract specialists, medical oncologists, radiation oncologists and surgery. The different objectives should be declined according to the characteristics of the tumours. The aim of the therapist would be to select the best strategy offering to the patient to be cured with as less as possible late adverse toxicity. The challenge of the treatment of small tumours is to maintain a functional anal sphincter while minimizing the risk of local recurrence. The standard treatment of locally advanced disease is aiming firstly to cure the patient and secondly to prevent late complications. Each of these clinical presentations of the disease has to be considered as a whole taking into account the new surgical techniques and a personalized approach adapted to the tumour. Nowadays they should be studied with dedicated clinical trials.