Integrated slice-specific dynamic shimming diffusion weighted imaging (DWI) for rectal Cancer detection and characterization

Purpose To compare integrated slice-specific dynamic shimming (iShim) diffusion weighted imaging (DWI) and single-shot echo-planar imaging (SS-EPI) DWI in image quality and pathological characterization of rectal cancer. Materials and methods A total of 193 consecutive rectal tumor patients were enrolled for retrospective analysis. Among them, 101 patients underwent iShim-DWI (b = 0, 800, and 1600 s/mm2) and 92 patients underwent SS-EPI-DWI (b = 0, and 1000 s/mm2). Qualitative analyses of both DWI techniques was performed by two independent readers; including adequate fat suppression, the presence of artifacts and image quality. Quantitative analysis was performed by calculating standard deviation (SD) of the gluteus maximus, signal intensity (SI) of lesion and residual normal rectal wall, apparent diffusion coefficient (ADC) values (generated by b values of 0, 800 and 1600 s/mm2 for iShim-DWI, and by b values of 0 and 1000 s/mm2 for SS-EPI-DWI) and image quality parameters, such as signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of primary rectal tumor. For the primary rectal cancer, two pathological groups were divided according to pathological results: Group 1 (well-differentiated) and Group 2 (poorly differentiated). Statistical analyses were performed with p < 0.05 as significant difference. Results Compared with SS-EPI-DWI, significantly higher scores of image quality were obtained in iShim-DWI cases (P < 0.001). The SDbackground was significantly reduced on b = 1600 s/mm2 images and ADC maps of iShim-DWI. Both SNR and CNR of b = 800 s/mm2 and b = 1600 s/mm2 images in iShim-DWI were higher than those of b = 1000 s/mm2 images in SS-EPI-DWI. In primary rectal cancer of iShim-DWI cohort, SIlesion was significantly higher than SIrectum in both b = 800 and 1600 s/mm2 images. ADC values were significantly lower in Group 2 (0.732 ± 0.08) × 10− 3 mm2/s) than those in Group 1 ((0.912 ± 0.21) × 10− 3 mm2/s). ROC analyses showed significance of ADC values and SIlesion between the two groups. Conclusion iShim-DWI with b values of 0, 800 and 1600 s/mm2 is a promising technique of high image quality in rectal tumor imaging, and has potential ability to differentiate rectal cancer from normal wall and predicting pathological characterization.

Determinants of choice in offering drug holidays during first-line therapy for metastatic colorectal cancer

Background: ‘Drug holidays’ (DH) for metastatic colorectal cancer (mCRC) were introduced to preserve quality of life. We studied factors associated to a DH offer in first line. Materials & methods: We retrospectively analyzed 754 consecutive patients treated with chemotherapy for mCRC in two Italian institutions between 2005 and 2017. Associations between baseline clinical-pathological factors and DH (56 or more days of treatment interruption) were investigated. Results: In 754 patients, previous metastasectomy, previous thermoablation and previous surgery of primary tumor were independently associated with DH. Excluding procedures or clinical trials: primary rectal cancer and resection of primary tumor were significantly associated to DH. Conclusions: DH was offered to patients with lower burden of disease, but further investigations are needed to safely guide a holiday strategy.

Non-operative Management of Benign Colorectal Anastomotic Stenosis in Patients Undergoing Elective Surgery for Non-Metastatic Primary Rectal Cancer

Introduction: Benign anastomosis stenosis may develop in postoperative or long term period due to many reasons such as anastomosis leakage and anastomosis ischemia after colorectal surgery. While surgical treatment was commonly used in benign anastomosis stenosis in the past, surgery has left its place to more minimally invasive methods such as endoscopic treatments. There is no gold standard treatment method in the management of benign anastomosis strictures in the literature. In this study, we aimed to present our clinical experience in the treatment of benign anastomosis strictures in patients undergoing elective surgery for nonmetastatic primary rectal cancer. Material and Methods: One hundred fifty-six (156) patients who underwent resection and colorectal anastomosis between January 2013 and January 2018 were included in the study. 22 patients developed benign anastomotic stenosis has been determined and etiological factors and treatment modalities applied has been compared retrospectively. Results: In 22 patients, 9 patients were treated with digital or balloon dilatation, at least 2 sessions and up to 5 sessions. Four patients were treated with dilatation followed by stenting. The remaining 9 patients were taken to surgical treatment. Among whole patients with stenosis, it has been determined that 15 of them had neoadjuvant therapy history, 5 had anastomosis leakage and in 16 of them 28 mm circular stapler have been used. Discussion and Conclusion: Neoadjuvant treatment history, the presence of anastomosis leakage and the usage of 28 mm circular stapler have been detected to be the most important etiological factors in development of benign anastomotic stenosis. Endoscopic treatments should be tried primarily to treat benign anastomotic stenosis. High success rates can be achieved with endoscopic methods and patient quality of life can be improved. With this approach, the need for surgery will be reduced and possible postoperative complications can be prevented. Keywords: Rectal Neoplasms, Stenosis, Laparoscopy, Anastomostic stenosis