Diagnostic value of FDG-PET/CT for lateral pelvic lymph node metastasis in rectal cancer treated with preoperative chemoradiotherapy.

BACKGROUND: The aim of this study was to elucidate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography (PET)-computed tomography (CT) for lateral pelvic lymph node (LPN) metastasis in rectal cancer treated with preoperative chemoradiotherapy (CRT). METHODS: Eighteen rectal cancer patients with enlarged (≥ 8 mm) LPNs were treated with CRT followed by total mesorectal excision with LPN dissection during 2012-2015. After CRT, LPN maximum standard uptake values (SUVmax) were measured using PET/CT and long diameters of LPNs were measured using CT or magnetic resonance imaging (MRI). LPN size and SUVmax were compared with pathological status in the resected specimen. Radiologically identified nodes were matched with surgically resected nodes by separate examination of 4 lymph nodal regions: internal iliac, obturator, external iliac and common iliac lymph nodes. RESULTS: In total, 34 LPNs were located by CT or MRI. Metastatic LPNs were significantly larger than non-metastatic LPNs (size, mean ± standard deviation: 13.0 ± 8.3 vs. 4.9 ± 3.5 mm, p < 0.01). SUVmax was determinable for 28 of the LPNs, among which metastatic LPNs were found to have significantly higher SUVmax than non-metastatic LPNs (mean ± standard deviation: 2.2 ± 1.3 vs. 1.2 ± 0.3, p < 0.01). Receiver operating characteristic analysis suggested optimal cutoff values of size = 12 mm which had an accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 82.1, 70.6, 100, 100, and 68.8%, respectively. An SUVmax = 1.6 had an accuracy, sensitivity, specificity, PPV, and NPV of 85.7, 76.5, 100, 100, and 73.3%, respectively. When LPNs that were ≥ 12 mm in size and/or had an SUV ≥ 1.6, the accuracy, sensitivity, specificity, PPV, and NPV were 92.9, 88.2, 100, 100, and 84.6%, respectively. CONCLUSIONS: After CRT, PET/CT alone or in combination with CT and MRI can predict the presence of metastatic LPN with a high degree of accuracy. PET/CT may be useful in selecting patients with rectal cancer who would benefit from LPN dissection in addition to TME. These results need to be confirmed by larger studies.

Appendiceal orifice inflammation is associated with proximal extension of disease in patients with ulcerative colitis.

AIM: Ulcerative colitis (UC) is considered to be a disease of continuous mucosal inflammation extending proximally from the rectum. However, appendiceal orifice inflammation (AOI) is a skip lesion with segments of continuous involvement from the rectum. The aim of this study was to examine the clinical characteristics and clinical course, particularly focused on proximal extension, of UC in patients with AOI. METHOD: A retrospective evaluation of patients with UC who underwent total colonoscopy at the Department of Surgical Oncology, The University of Tokyo, from 2004 to 2014. The degree of AOI was graded endoscopically as follows: 0 (no inflammation); 1 (slight oedema); 2 (moderate inflammation); and 3 (marked inflammation). A total of 189 patient records were reviewed retrospectively. The presence of AOI was analysed with regard to the clinical information of each patient, and its association with proximal extension of proctitis or left-sided colitis was evaluated. RESULTS: Of 189 patients with UC who underwent total colonoscopy at our institution, 92 were diagnosed with pancolitis, 50 with left-sided colitis and 47 with proctitis. Endoscopic findings of AOI were observed in 26 patients, including 11 (12.0%) with pancolitis, six (12.0%) with left-sided colitis and nine (19.1%) with proctitis. During follow up, proximal extension of the disease occurred in all nine patients with proctitis AOI. CONCLUSION: AOI is more frequently observed in patients with proctitis. Our results showed correlations between AOI and subsequent proximal extension of mucosal inflammation in patients with proctitis.

Clinical pattern and progression of ulcerative proctitis in the Japanese population: a retrospective study of incidence and risk factors influencing progression.

AIM: The rate of extension of proctitis in Western countries has been reported, but no data regarding long-term follow-up have been described for the Japanese population. Additionally, patients with long-standing or extensive ulcerative colitis have an increased risk for developing colorectal cancer. This study evaluated both the rate of extension of the disease and the development of neoplasia among patients with an initial diagnosis of ulcerative proctitis. METHOD: We retrospectively investigated the medical charts of patients with proctitis from 1979 to 2014. The primary focus of this research was the extension of the inflammatory area. The secondary focus included risk factors for disease extension and the development of neoplasia. RESULTS: Sixty-six patients satisfied the inclusion criteria. Proximal extension of the disease occurred in 34 patients: 19 patients had left-sided colitis and 15 had pancolitis. According to a multivariate analysis, disease extension was significantly higher in patients with disease onset before 25 years of age (P-value = 0.043). The cumulative rates of disease extension at 10 and 20 years were 33.8% and 52.2%, respectively. Three patients were diagnosed with dysplasia during follow-up, all of whom experienced disease extension before the development of dysplasia. CONCLUSION: The rate of extension of ulcerative colitis in the Japanese population was comparable to that in Western countries. A younger age of disease onset was associated with disease extension. Extension of proctitis may be associated with an increased risk of colorectal cancer.