Complete Pathologic Response Prediction by Radiomics Wavelets Features of Unenhanced CT Simulation Images in Locally Advanced Rectal Cancer Patients after Neoadjuvant Chemoradiation.

BACKGROUND: For locally advanced rectal cancer patients a watch-and-wait strategy is an acceptable treatment option in cases of complete tumor response. Clinicians need robust methods of patient selection after neoadjuvant chemoradiation. OBJECTIVES: To predict pathologic complete response (pCR) using computer vision. To analyze radiomic wavelet transform to predict pCR. METHODS: Neoadjuvant chemoradiation for patients with locally advanced rectal adenocarcinoma who passed computed tomography (CT)-based simulation procedures were examined. Gross tumor volume was examind on the set of CT simulation images. The volume has been analyzed using radiomics software package with wavelets feature extraction module. Statistical analysis using descriptive statistics and logistic regression was performed was used. For prediction evaluation a multilayer perceptron algorithm and Random Forest model were used. RESULTS: In the study 140 patients with II-III stage cancer were included. After a long course of chemoradiation and further surgery the pathology examination showed pCR in 38 (27.1%) of the patients. CT-simulation images of tumor volume were extracted with 850 parameters (119,000 total features). Logistic regression showed high value of wavelet contribution to model. A multilayer perceptron model showed high predictive importance of wavelet. We applied random forest analysis for classifying the texture and predominant features of wavelet parameters. Importance was assigned to wavelets. CONCLUSIONS: We evaluated the feasibility of using non-diagnostic CT images as a data source for texture analysis combined with wavelets feature analysis for predicting pCR in locally advanced rectal cancer patients. The model performance showed the importance of including wavelets features in radiomics analysis.

Tumor Volume as Predictor of Pathologic Complete Response Following Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer.

PURPOSE: Neoadjuvant chemoradiation followed by surgery is the current standard of care in the treatment of locally advanced rectal cancer. Those who achieved pathologic complete response, following this standard of care, complete pathologic response (pCR) had better outcome. Until now there are no reliable clinical parameters to predict this response. The purpose of the study was to evaluate whether tumor volume may serve as a predictive factor in patients treated with neoadjuvant chemoradiotherapy. MATERIALS AND METHODS: Between September 2015 and September 2019, patients diagnosed with stage IIA to IIIC rectal adenocarcinoma, who were treated with neoadjuvant chemoradiation, were enrolled to this study. All patients underwent rectal ultrasound, pelvic magnetic resonance imaging, fluorodeoxyglucose-positron emission tomography-computed tomography and the diagnosis was confirmed by pathology report. Radiation therapy was consisted of 50 Gy delivered to the tumor site, 2 Gy a day, 5 times a week and to the pelvic lymph nodes for a total of 45 Gy in 1.8 Gy a day, 5 times a week. The gross tumor volume (GTV) was contoured by radiation oncology expert, reviewed by radiology and nuclear medicine expert and approved by radiation therapy tumor board. Chemotherapy was consisted of either capecitabine 875 mg/m2 twice a day or continuous. IV infusion of 5 fluorouracil 375 mg/m2 for 4 consecutive days in a 3 weeks apart. Operation, either low anterior or abdominoperineal resection was carried out 6 to 8 weeks following completion of treatment. Patients were assigned to either complete pathologic response (pCR) or non-pCR groups. GTV, among other clinical and treatment parameters, were evaluated for prediction of pCR. Statistical methods included independent t test, logistic regression, area under the curve-receiver operating characteristic, Bayesian independent statistics and multilayer perceptron model. RESULTS: One hundred ninety-three patients were enrolled to this study, 6 were excluded due to metastatic disease detected at the time of operation. Seventy had stage II and 117 had stage III. Forty-four of 187 (23.5%) patients achieved pCR and 143 patients had either partial or no response/progressive disease. Among the 44 pCR group, 21 had stage II and 23 had stage III disease. Treatment interruption, defined as either a delay of up to 1 week in radiation, and a dose reduction to 75%, was occurred in 42 patients. Sex, ethnicity, distance from anal verge to tumor, height, weight, age, delivered radiation dose, radiotherapy techniques, clinical T and N stage and GTV were evaluated for prediction of pCR. GTV at the volume of <39.5 cm3 was the only significant predictive factor to detect pCR by logistic regression model (P<0.01) and by Bayesian independent test (P=0.026). Area under the receiver operating characteristic curve of GTV <39.5 cm3 showed area under the curve of 0.715 (P=0.009) for stage II and area under the curve of 0.62 (P>0.05) for stage III. CONCLUSION: GTV may serve as a predictive factor for achieving pCR in locally advanced rectal cancer after neoadjuvant chemoradiotherapy.

Non-primary salivary malignancies: A 22-year retrospective study.

PURPOSE: Most salivary gland malignancies are primary tumors, but in our medical center one of six is non-primary. The relative scarcity of such reports justifies studying them. SUBJECTS & METHODS: We studied patients' demographic and clinical parameters, salivary tumors/metastasis, diagnosis and treatment, and survival rates. RESULTS: Of all our salivary malignancy patients over the last 22 years, 15% (18/119) had non-primary malignant tumors, all located in the parotid glands. Of these, nine had skin cancer (SCC), 3 malignant solid tumors and 6 hematological systemic malignancies. Four had concomitant second malignancy. Mean age was 70.2 ± 13.8 years, 66.7% of the patients were males, 27.8% were smokers, none reported alcohol use. The most prevalent diagnostic tools used were CT (16 patients), FNA (13) and PET-CT (12). Eleven of 18 patients died from the disease despite receiving therapy: 6 SCC patients, 2 CLL patients and all 3 with solid tumors. All four lymphoma patients survived as did another three SCC patients. CONCLUSIONS: Chemotherapy and radiotherapy for systemic disease prolonged life rather than surgery. Patients with poor prognosis non-primary salivary tumors should be treated conservatively; surgery should be for those without widespread metastases or systemic disease. Sometimes a palliative patient may benefit from tumor debulking.

Mortality rates and prognostic factors in patients with malignant salivary tumors.

Malignancies of the salivary glands represent a multifarious disease. Evaluating the prognostic factors of these malignancies may help predict patient outcome and aid decision-making in choosing the most suitable therapy. We examined the role of various salivary tumorigenic, clinical and therapeutic features in a cohort of 101 patients diagnosed and treated for primary malignant salivary tumors. These include histo-pathological diagnosis, stage, grade and T, N, M values as well as the existence of perineural invasion and extra-parenchymal spread. We also identified the salivary gland involved, the sub-compartment specific location of the tumor and the therapy administered. All these were related to mortality. Of the 101 patients examined, 79 survived and 22 died due to the disease. Tumor staging, distant metastasis and perineural invasion were highly significant predictors of increased lethality. Histo-pathological grading was also a predictor but to a lesser degree. Neither neck metastasis nor tumor size or type had a significant impact on lethality. Performing neck dissections did not decrease lethality rate. Location of the tumor in the parotid gland and more so in its deep lobe adversely affected lethality; extra-parenchymal spread also had an adverse effect. Our results seem to indicate hematogenous rather than lymphogenous spread of metastasis from malignant salivary tumors. The highest therapeutic priority should be achieving full local control of the disease by safe removal of the primary salivary tumor, accompanied by regional control of perineural invasion and extra-parenchymal spread and appropriate systemic treatment aimed at eradicating distant metastasis.

Kaplan-Meier analysis of salivary gland tumors: prognosis and long-term survival.

PURPOSE: We evaluated the impact of various tumor related parameters on survival probability in a cohort of patients with malignant salivary tumors, using the Kaplan-Meier analysis. METHODS: We measured patients up to 15 years following therapy, looking at T N M stage, grade perineural invasion and extra-parenchymal spread. RESULTS: Of 101 patients diagnosed with various salivary malignant tumors in our medical center, 79 patients survived while 22 died with disease (DWD). The impact of distant metastasis (M+) was devastating (survival probability at 60 months and at 180 months dropped from 0.93 (M-) to 0.40 (M+) and from 0.67 to 0.40, respectively, p = 0.0001), the impact of perineural invasion was severe (at 180 months the probability of survival dropped from 0.75 to 0.21, p = 0.002). Higher stage tumor also decreased survival (from 0.82 to 0.53 at 180 months, p = 0.002) as did poor histological grade (from 0.85 to 0.48 at 180 months, p = 0.019). Neck metastasis (N+) impact was quite moderate (at 180 months the probability of survival dropped from 0.69 to 0.58, p = 0.044) while neither tumor size (T) nor extra-parenchymal spread significantly affected survival. CONCLUSIONS: Salivary tumor location and its potential to infiltrate nerves and blood vessels and to metastasize is the most telling parameter. Systemic therapy aimed at halting distant metastatic spread is the most effective therapeutic goal. Dissection of N0 neck metastasis is not necessarily a valuable treatment.

Survival Probabilities Related to Histology, Grade and Stage in Patients With Salivary Gland Tumors.

BACKGROUND: The diversity of malignant salivary gland tumors challenges the study of survival rates. The current study evaluated patient survival rates using Kaplan-Meier analysis and examined the relative effects of histology, grade and stage on survival. MATERIALS AND METHODS: Using the Kaplan-Meier model, cancer-specific (CSS) and disease-free (DFS) survival probabilities were calculated as a function of time. RESULTS: Of 101 patients, 79 survived and 22 died of their disease. The probability of CSS was 0.83, 0.73 and 0.61 at 5, 10 and 15 years, respectively; corresponding probability of DFS was 0.69, 0.59 and 0.54, respectively. CONCLUSION: CSS and the DFS probabilities in patients with salivary malignancies were quite high at 5 years, although these rates dropped over the long-term; the lethal effect of the malignancy is often delayed and prolonged. Tumor histology, grade and stage are well established factors in predicting prognosis. Although the subgroups of patients with MECA and SCC were too small to allow adequate statistical analysis, clear tendencies for devastating effects of poor differentiation in SCC and higher grade in MECA were shown. That is, 2/4 patients with high-grade MECA died from their disease, while only 1/15 with low-intermediate grade MECA died from their disease. Similarly, 2/4 patients with poorly differentiated SCC died from their disease, while only 1/5 with well-to-moderately-differentiated SCC died from their disease. Factors such as molecular markers should be further studied in an effort to improve prognosis prediction.

Salivary malignancies- medical, demographic and diagnostic analysis.

We examined systemic medical and demographic characteristics of patients diagnosed with salivary malignant tumors in order to better understand the pathogenesis of the disease. Of 101 patients who received definitive treatment for malignant salivary gland tumors in our medical center, 22 died with disease (DwD) and were compared with the remaining 79 patients (Other). Mean ages were 66.7 years (median 68.0) in DwD group and 58.7 years (median 59.0) in the Others. The difference is significant (p = 0.037). Mucoepidermoid carcinoma was the diagnosis in 27.3% of DwDs and 27.8% of the others, Adenoidcystic carcinoma in 36.4% vs 21.5%, SCC and Acinic cell carcinoma were diagnosed in 18.3% vs 7.6% and 4.6% vs 7.6%, respectively. Alcohol consumption, concomitant malignancies, and chronic illnesses other than hypertension, were similar in the two groups, but hypertension (63.6%) in the DwD group was significantly higher than in the Other group (26.6%), (p = 0.0010). Smoking was also significantly different between the two groups: 50% of the DwD vs. 27.9% of the Others group smoked cigarettes. Similar distribution of the various malignant tumors in both groups emphasizes the relative importance of systemic factors such as smoking, aging and hypertension, in the salivary carcinogenesis process.

Role of 18F-FDG PET/CT in the staging of pediatric peritoneal mesothelioma.

A 7-year-old girl with a 1-month history of diffuse abdominal pain underwent an ultrasound which showed a pelvic mass with multiple peritoneal implants and ascites. An US-guided core biopsy of one of the implants as well as a transrectal biopsy of the pelvic tumor showed pathological findings consistent with epithelioid mesothelioma. We describe the findings on (18)F-FDG PET/CT in pediatric peritoneal mesothelioma.

Unexpected foci of 18F-FDG uptake in the breast detected by PET/CT: incidence and clinical significance.

PURPOSE: The aim of this study was to evaluate the frequency and clinical significance of unexpected focal (18)F-fluorodeoxyglucose (FDG) uptake localized by PET/CT within the breast. METHODS: The files of 4,038 consecutive female cancer patients referred for FDG PET/CT over a period of 74 months were retrospectively reviewed. Patients with breast cancer were excluded from the study. The incidence of focal sites of increased FDG uptake localized by PET/CT to the breast was determined. The intensity of uptake was measured using the lean body mass maximum standard uptake value (LBM SUV(max)), and the presence and patterns of morphologic changes on CT were assessed. The etiology and clinical significance of findings were confirmed histologically or with imaging and clinical follow-up. RESULTS: Unexpected FDG foci in the breast were identified in 33 of 4,038 patients (0.82%). Follow-up data were available for 30 patients. Malignancy was diagnosed in 17 patients (histology 12, clinical 5) and excluded in 13 patients (histology 9, clinical 4). There was a borderline statistically significant difference in FDG uptake (LBM SUV(max)) between malignant (3.13 +/- 2.25) and benign (1.85 +/- 1.18) lesions (p = 0.05). Focal lesions were seen on CT in 23 patients (malignant 11, benign 12), and CT was negative in 7 patients (malignant 6, benign 1). CONCLUSION: Although rare, incidental focal abnormal FDG uptake in the breast may represent malignant lesions in up to 57% of patients. Breast incidentalomas on PET/CT warrant further assessment including tissue sampling to define the etiology of these unexpected FDG-avid foci.