Long-Term Anorectal and Urogenital Dysfunction After Rectal Cancer Treatment

Diffuse reflection spectroscopy at the fingertip: design and performance of a compact side-firing probe for tissue discrimination during colorectal cancer surgery

Optical technologies are widely used for tissue sensing purposes. However, maneuvering conventional probe designs with flat-tipped fibers in narrow spaces can be challenging, for instance during pelvic colorectal cancer surgery. In this study, a compact side-firing fiber probe was developed for tissue discrimination during colorectal cancer surgery using diffuse reflectance spectroscopy. The optical behavior was compared to flat-tipped fibers using both Monte Carlo simulations and experimental phantom measurements. The tissue classification performance was examined using freshly excised colorectal cancer specimens. Using the developed probe and classification algorithm, an accuracy of 0.92 was achieved for discriminating tumor tissue from healthy tissue.

State of Recovery 6 Months After Rectal Cancer Surgery: Postoperative Symptoms and Differences With Regard to Surgical Procedure

Rectal cancer surgery has developed to be highly technological and precise. Nevertheless, postoperative symptoms can affect patients for a long time after surgery and might also be persistent. The purpose of this study was to describe the level of postoperative symptoms 6 months after rectal cancer surgery as well as differences in symptoms with regard to surgical procedure. Data from 117 patients recovering from rectal cancer surgery were collected 6 months after surgery using the Postoperative Recovery Profile (PRP) questionnaire measuring self-reported postoperative symptoms. Results showed that the majority of patients had no or mild problems with the 19 symptoms recorded in the questionnaire. There was a significant difference between surgical procedures: patients after anterior resection experienced mild problems in gastrointestinal function (physical domain) and interest in their surroundings (social domain), whereas most patients after abdominoperineal resection and abdominoperineal resection with myocutaneous flap showed no problems. In all groups, a considerably high proportion of patients reported severe problems in sexual activity (physical domain). Findings in this study emphasize that healthcare professionals should pay attention to patients recovering from anterior resection especially regarding problems in the gastrointestinal function. Moreover, there is a need to acknowledge eventual sexual dysfunctions in all rectal cancer patients.

Tissue diagnosis during colorectal cancer surgery using optical sensing: an in vivo study

Background

In colorectal cancer surgery there is a delicate balance between complete removal of the tumor and sparing as much healthy tissue as possible. Especially in rectal cancer, intraoperative tissue recognition could be of great benefit in preventing positive resection margins and sparing as much healthy tissue as possible. To better guide the surgeon, we evaluated the accuracy of diffuse reflectance spectroscopy (DRS) for tissue characterization during colorectal cancer surgery and determined the added value of DRS when compared to clinical judgement.

Methods

DRS spectra were obtained from fat, healthy colorectal wall and tumor tissue during colorectal cancer surgery and results were compared to histopathology examination of the measurement locations. All spectra were first normalized at 800 nm, thereafter two support vector machines (SVM) were trained using a tenfold cross-validation. With the first SVM fat was separated from healthy colorectal wall and tumor tissue, the second SVM distinguished healthy colorectal wall from tumor tissue.

Results

Patients were included based on preoperative imaging, indicating advanced local stage colorectal cancer. Based on the measurement results of 32 patients, the classification resulted in a mean accuracy for fat, healthy colorectal wall and tumor of 0.92, 0.89 and 0.95 respectively. If the classification threshold was adjusted such that no false negatives were allowed, the percentage of false positive measurement locations by DRS was 25% compared to 69% by clinical judgement.

Conclusion

This study shows the potential of DRS for the use of tissue classification during colorectal cancer surgery. Especially the low false positive rate obtained for a false negative rate of zero shows the added value for the surgeons.

Trail registration This trail was performed under approval from the internal review board committee (Dutch Trail Register NTR5315), registered on 04/13/2015, https://www.trialregister.nl/trial/5175.

Diffuse reflectance spectroscopy as a tool for real-time tissue assessment during colorectal cancer surgery

Colorectal surgery is the standard treatment for patients with colorectal cancer. To overcome two of the main challenges, the circumferential resection margin and postoperative complications, real-time tissue assessment could be of great benefit during surgery. In this ex vivo study, diffuse reflectance spectroscopy (DRS) was used to differentiate tumor tissue from healthy surrounding tissues in patients with colorectal neoplasia. DRS spectra were obtained from tumor tissue, healthy colon, or rectal wall and fat tissue, for every patient. Data were randomly divided into training (80%) and test (20%) sets. After spectral band selection, the spectra were classified using a quadratic classifier and a linear support vector machine. Of the 38 included patients, 36 had colorectal cancer and 2 had an adenoma. When the classifiers were applied to the test set, colorectal cancer could be discriminated from healthy tissue with an overall accuracy of 0.95 (±0.03). This study demonstrates the possibility to separate colorectal cancer from healthy surrounding tissue by applying DRS. High classification accuracies were obtained both in homogeneous and inhomogeneous tissues. This is a fundamental step toward the development of a tool for real-time in vivo tissue assessment during colorectal surgery.

The Australian Pelvic Floor Questionnaire is a valid measure of pelvic floor symptoms in patients following surgery for colorectal cancer

AIMS

This study evaluated the construct validity of the Australian Pelvic Floor Questionnaire against two alternative measures of the severity of bladder and bowel symptoms.

METHODS

This was an exploratory analysis of data from two prospective studies. Patients who had undergone surgery for colorectal cancer were analysed. Bladder and bowel symptoms were measured using three validated questionnaires: the Australian Pelvic Floor Questionnaire, the International Consultation on Incontinence Questionnaire Short Form Questionnaire for urinary incontinence and the International Consultation on Incontinence Questionnaire-Bowel Module post-cancer treatment.

RESULTS

The study sample consisted of 44 participants, including 25 men and 19 women. The Australian Pelvic Floor Questionnaire bladder and bowel domain scores demonstrated moderate positive correlations with the International Consultation on Incontinence Questionnaire Short Form Questionnaire for urinary incontinence (r = 0.74, P < 0.01) and the International Consultation on Incontinence Questionnaire-Bowel Module (r = 0.69-0.78, P < 0.01). Similar results were obtained in each gender subgroup.

CONCLUSIONS

This study suggested that the Australian Pelvic Floor Questionnaire may be a valid measurement tool for use in colorectal cancer populations in clinical trials and practice. Future research using larger cohorts is warranted.