[Preliminary establishment of an unsupervised quantification model of Ki-67 proliferation index based on local variable threshold method].

PURPOSE: To develop an effective machine learning method for estimation of Ki-67 cell proliferation index. METHODS: Oral squamous cell carcinoma(OSCC) slices were selected for Ki-67 immunohistochemical staining. The digital pathology images were obtained through whole-slide imaging technology. Variable threshold method based on local statistics was applied to preprocess the images, aiming at reducing the noise in the images. Adaptive threshold method was used to remove the irrelevant light-colored background area in the image, retaining the nucleus part. A threshold method in space was applied to differentiate brown from blue content. Finally, the proliferation index was estimated and compared with manual and the color deconvolution method by paired sample t test and spearman correlation coefficients with SPSS 24.0 software package. RESULTS: A new nucleus detection and classification method was established, which can process pathologic images of different sizes, and effectively detect immunohistochemical brown positive cells and blue negative cells. There was no significant difference between this algorithm and manual counting（P＞0.05）, but the speed was faster. The calculation efficiency advantage was more obvious when processing a large image, and the detection result of Ki-67 proliferation index was better than the commonly used color deconvolution method（P＜0.05）. CONCLUSIONS: The automatic nucleus quantitative analysis method developed in this study can analyze Ki-67 staining of the nucleus in OSCC cells efficiently and calculate the proliferation index, which can be used for auxiliary diagnosis in pathology.

Clinicopathologic Analysis of Oral Squamous Cell Carcinoma After 125I Interstitial Brachytherapy.

Oral squamous cell carcinoma is a common malignancy in the head and neck region. Brachytherapy after radical surgery has achieved much progress as a cancer adjuvant treatment. This study focused on the pathologic characteristics of the patients with oral squamous cell carcinoma who underwent seed implantation after radical surgery, and the relationship of these characteristics with prognosis. Thus, 76 patients with oral squamous cell carcinoma, who were treated with surgery and subsequently with iodine 125 (125I) radioactive seed implantation, were recruited in this study. We summarized the demographic information, tumor size, location, clinical stage, prognosis, and pathologic characteristics, and discussed the correlations between prognosis and histologic features of oral squamous cell carcinoma after seed implantation. The data showed that the median age was 64 years old, the male/female ratio was 47/29, and the frequent location of the carcinoma was the tongue (35.5%). The median follow-up time was 126 months, and of the patients, 52 (68.4%) exhibited recurrent tumors. The 5-year survival rate was 81.5%, and the local control rate in 6 months was 95.3%. Microscopically, 25 cases demonstrated lymph node metastasis, there was obvious necrosis in 13 cases, and 55 cases exhibited confirmed adjacent tissue invasion including muscle, gland, vessel, nerve, and bone infiltration. Among those, vascular infiltration (13 cases) was significantly correlated with tumor recurrence ( P < .05). This study suggests that detailed pathologic diagnosis and microscopic description, especially of vascular infiltration, was valuable in the prognosis prediction of brachytherapy.