Koert Kuhlmann

Second St. Gallen European Organisation for Research and Treatment of Cancer Gastrointestinal Cancer Conference: consensus recommendations on controversial issues in the primary treatment of rectal cancer

Primary treatment of rectal cancer was the focus of the second St. Gallen European Organisation for Research and Treatment of Cancer (EORTC) Gastrointestinal Cancer Conference. In the context of the conference, a multidisciplinary international expert panel discussed and voted on controversial issues which could not be easily answered using published evidence. Main topics included optimal pretherapeutic imaging, indication and type of neoadjuvant treatment, and the treatment strategies in advanced tumours. Here we report the key recommendations and summarise the related evidence. The treatment strategy for localised rectal cancer varies from local excision in early tumours to neoadjuvant radiochemotherapy (RCT) in combination with extended surgery in locally advanced disease. Optimal pretherapeutic staging is a key to any treatment decision. The panel recommended magnetic resonance imaging (MRI) or MRI + endoscopic ultrasonography (EUS) as mandatory staging modalities, except for early T1 cancers with an option for local excision, where EUS in addition to MRI was considered to be most important because of its superior near-field resolution. Primary surgery with total mesorectal excision was recommended by most panellists for some early tumours with limited risk of recurrence (i.e. cT1-2 or cT3a N0 with clear mesorectal fascia on MRI and clearly above the levator muscles), whereas all other stages were considered for multimodal treatment. The consensus panel recommended long-course RCT over short-course radiotherapy for most clinical situations where neoadjuvant treatment is indicated, with the exception of T3a/b N0 tumours where short-course radiotherapy or even no neoadjuvant therapy were regarded to be an option. In patients with potentially resectable tumours and synchronous liver metastases, most panel members did not see an indication to start with classical fluoropyrimidine-based RCT but rather favoured preoperative short-course radiotherapy with systemic combination chemotherapy or alternatively a liver-first resection approach in resectable metastases, which both allow optimal systemic therapy for the metastatic disease. In general, proper patient selection and discussion in an experienced multidisciplinary team was considered as crucial component of care.

Differentiation of healthy and malignant tissue in colon cancer patients using optical spectroscopy: A tool for image-guided surgery

Surgery for colorectal cancer aims for complete tumor resection. Optical‐based techniques can identify tumor and surrounding tissue through the tissue specific optical properties, absorption and scattering, which are both influenced by the biochemical and morphological composition of the tissue.

Comparing position and orientation accuracy of different electromagnetic sensors for tracking during interventions

PurposeTo compare the position and orientation accuracy between using one 6-degree of freedom (DOF) electromagnetic (EM) sensor, or the position information of three 5DOF sensors within the scope of tumor tracking.MethodsThe position accuracy of Northern Digital Inc Aurora 5DOF and 6DOF sensors was determined for a table-top field generator (TTFG) up to a distance of 52xa0cm. For each sensor 716 positions were measured for 10xa0s at 15xa0Hz. Orientation accuracy was determined for each of the orthogonal axis at the TTFG distances of 17, 27, 37 and 47xa0cm. For the 6DOF sensors, orientation was determined for sensors in-line with the orientation axis, and perpendicular. 5DOF orientation accuracy was determined for a theoretical 4xa0cm tumor. An optical tracking system was used as reference.ResultsPosition RMSE and jitter were comparable between the sensors and increasing with distance. Jitter was within 0.1xa0cm SD within 45xa0cm distance to the TTFG. Position RMSE was approximately 0.1xa0cm up to 32xa0cm distance, increasing to 0.4xa0cm at 52xa0cm distance. Orientation accuracy of the 6DOF sensor was within 1

In vivo tumor identification of colorectal liver metastases with diffuse reflectance and fluorescence spectroscopy

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Nerve detection during surgery: optical spectroscopy for peripheral nerve localization

∘, except when the sensor was in-line with the rotation axis perpendicular to the TTFG plane (4

In vivo nerve identification in head and neck surgery using diffuse reflectance spectroscopy: Optical intra-operative nerve identification

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