Prediction of Response to Neoadjuvant Chemoradiotherapy by MRI-Based Machine Learning Texture Analysis in Rectal Cancer Patients

Introduction Neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection is the standard treatment for locally advanced rectal cancer (LARC). Radiomics can be used as noninvasive biomarker for prediction of response to therapy. The main aim of this study was to evaluate the association of MRI texture features of LARC with nCRT response and the effect of Laplacian of Gaussian (LoG) filter and feature selection algorithm in prediction process improvement. Methods All patients underwent MRI with a 3T clinical scanner, 1 week before nCRT. For each patient, intensity, shape, and texture-based features were derived from MRI images with LoG filter using the IBEX software and without preprocessing. We identified responder from a non-responder group using 9 machine learning classifiers. Then, the effect of preprocessing LoG filters with 0.5, 1 and 1.5 value on these classification algorithms' performance was investigated. Eventually, classification algorithm's results were compared in different feature selection methods. Result Sixty-seven patients with LARC were included in the study. Patients' nCRT responses included 11 patients with Grade 0, 19 with Grade 1, 26 with Grade 2, and 11 with Grade 3 according to AJCC/CAP pathologic grading. In MR Images which were not preprocessed, the best performance was for Ada boost classifier (AUC = 74.8) with T2W MR Images. In T1W MR Images, the best performance was for aba boost classifier (AUC = 78.1) with a sigma = 1 preprocessing LoG filter. In T2W MR Images, the best performance was for naive Bayesian network classifier (AUC = 85.1) with a sigma = 0.5 preprocessing LoG filter. Also, performance of machine learning models with CfsSubsetEval (CF SUB E) feature selection algorithm was better than others. Conclusion Machine learning can be used as a response predictor model in LARC patients, but its performance should be improved. A preprocessing LoG filter can improve the machine learning methods performance and at the end, the effect of feature selection algorithm on model's performance is clear. Keywords:MRI; Rectal cancer; Radiomics; Machine learnin

Prediction of Response to Neoadjuvant Chemoradiotherapy by MRI-Based Machine Learning Texture Analysis in Rectal Cancer Patients

Introduction: Neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection is the standard treatment for locally advanced rectal cancer (LARC). Radiomics can be used as noninvasive biomarker for prediction of response to therapy. The main aim of this study was to evaluate the association of MRI texture features of LARC with nCRT response and the effect of Laplacian of Gaussian (LoG) filter and feature selection algorithm in prediction process improvement. Methods: All patients underwent MRI with a 3T clinical scanner, 1 week before nCRT. For each patient, intensity, shape, and texture-based features were derived from MRI images with LoG filter using the IBEX software and without preprocessing. We identified responder from a non-responder group using 9 machine learning classifiers. Then, the effect of preprocessing LoG filters with 0.5, 1 and 1.5 value on these classification algorithms’ performance was investigated. Eventually, classification algorithm’s results were compared in different feature selection methods. Result: Sixty-seven patients with LARC were included in the study. Patients’ nCRT responses included 11 patients with Grade 0, 19 with Grade 1, 26 with Grade 2, and 11 with Grade 3 according to AJCC/CAP pathologic grading. In MR Images which were not preprocessed, the best performance was for Ada boost classifier (AUC = 74.8) with T2W MR Images. In T1W MR Images, the best performance was for aba boost classifier (AUC = 78.1) with a σ = 1 preprocessing LoG filter. In T2W MR Images, the best performance was for naive Bayesian network classifier (AUC = 85.1) with a σ = 0.5 preprocessing LoG filter. Also, performance of machine learning models with CfsSubsetEval (CF SUB E) feature selection algorithm was better than others. Conclusion: Machine learning can be used as a response predictor model in LARC patients, but its performance should be improved. A preprocessing LoG filter can improve the machine learning methods performance and at the end, the effect of feature selection algorithm on model’s performance is clear. KEYWORDS: MRI; Machine learning; Radiomics; Rectal cance

Participation in International ABC and ATLAS Trials of Adjuvant Treatment for Breast Cancer: An Inspiring Clinical Research Experience

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Local recurrence after breast conserving surgery in breast cancer: a study in Cancer Institute, Tehran

"n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Breast conservative therapy is associated with similar outcomes in comparison with mastectomy. The aim of this study is assessment of local recurrence rate and related risk factors in patients who have been treated with radiotherapy after conservative surgery for breast cancer."n"nMethods: This is a cohort study which data of all breast cancer patients who have visited in follow up clinic in radiation oncology department of cancer institute of Imam Khomeini Hospital complex in Tehran, Iran, during years 2007-2009 were collected. All of the patients were investigated for local recurrence and the possible risk factors."n"nResults: Two hundred and seventy seven patients have entered the study and all have followed for at least one year since data entry. Median follow-up time from the start of radiotherapy were 35 months (12-148 mo). We had seven cases (2.5%) with local recurrences (2.5%) which most of them occurred in first year after treatment. Because of low rate of recurrence none of the variables such as margin and nodal status has significant correlation with local recurrence which this should be due to small number of patient and short time of follow up."n"nConclusions: At median follow up of 35 months from the beginning of radiation therapy, local recurrence rate was 2.5% which is similar to the literature. We recommend to follow a larger group of patients for longer times to estimate recurrence risk after breast conservative therapy

Concomitant boost chemoradiotherapy in locally advanced head and neck cancer: Treatment tolerance and acute side effects

Aim: In the present study, we evaluated treatment tolerance and side effects of 6 days a week accelerated radiation therapy using concomitant boost methods with chemotherapy in locally advanced head and neck cancer. Materials and Methods: Thirty patients suffered locally advanced head and neck malignancies were included into this clinical trial. The patients were scheduled for accelerated radiotherapy with total dose of 70 Gy 6 days a week (5 days radiotherapy and 1-day concomitant boost radiotherapy) for 5 weeks and also concurrently for chemotherapy with cisplatin and also celecoxib. Results: The average age of the patients was 51.47 ΁ 11.49 years. The incidence of acute mucositis at the end of the 1st week was 33.3% that was gradually increased until the end of the 5th week (93.3%) and then had a ecreasing trend within the 6th week (70.0%). The incidence of acute dysphagia was estimated 23.3% at the end of the 1st week and reached 60% at completion of treatment. Conclusion: Scheduling a treatment approach with 6 days a week, accelerated radiation therapy using concomitant boost methods with chemotherapy, and celecoxib leads to significant reducing the incidence of complications in the final weeks of therapy in patients with locally advanced head and neck cance

Delivered dose to scrotum in rectal cancer radiotherapy by thermoluminescence dosimetry comparing to dose calculated by planning software

Background: Colorectal carcinoma is a common malignancy, in treatment of which pelvic radiotherapy plays an important role. But this may lead to azospermia. We designed a study to determine the delivered dose to the testis with thermoluminescence dosimetry (TLD) and compare it to the dose calculated by the Three-dimensional planning software. Methods: We measured the testicular doses by TLD; the TLDs were fixed to the scrotum in six points anteriorly and posteriorly in two random fractions of the radiation course. All patients received a 50-50.4 Gy radiation dose to the pelvis in a prone position with standard fractionation and 3-dimensional planning, through three or four fields. The average dose of the TLD measurements was compared to the average of 6 relevant point doses calculated by the planning software. Results: In 33 patients with a mean age of 56 years, the mean testis dose of radiation measured by TLD was 3.77 Gy, equal to 7.5% of the total prescribed dose. The mean of point doses calculated by the 3-dimensional planning software was 4.11 Gy, equal to 8.1% of the total prescribed dose. A significant relationship was seen between the position of the inferior edge of the fields and the mean testis dose (P= 0.04). Also body mass index (BMI) was inversely related with the testicular dose (P= 0.049). Conclusion: In this study, the mean testis dose of radiation was 3.77 Gy, similar to the dose calculated by the planning software (4.11 Gy). This dose could be significantly harmful for spermatogenesis, though low doses of scattered radiation to the testis in fractionated radiotherapy might be followed with better recovery. Based on above findings, careful attention to testicular dose in radiotherapy of rectal cancer for the males desiring continued fertility seems to be required

Chemoradiation in Nasopharyngeal Carcinoma: A 6-Year Experience in Tehran Cancer Institute

To determine the addition of value of neoadjuvant, concurrent and adjuvant chemotherapy to radiation in the treatment of nasopharyngeal carcinoma with regard to the overall survival (OS) and disease free survival (DFS) within a six year period in Tehran cancer institute. Files of all patients with nasopharyngeal carcinoma treated by radiotherapy with or without concurrent chemotherapy in a curative setting in Tehran cancer institute during the period of 1999-2005 were retrospectively reviewed.. A total of 103 patients with nasopharyngeal carcinoma had been treated during the study period with radiotherapy or chemoradiotherapy in our institute. There were 29 (28.2%) females and 74 (71.8%) males. The median age at the time of radiotherapy was 47 years old (range 9-75 years). The patients were followed 2 to 76 months with a median follow-up of 14 months. Time of first recurrence after treatment was 3-44 months with a median of 10 months.. Survival in 2 groups of patients treated with radiotherapy alone or chemoradiation did not have a significant difference (P>0.1). Two-year survival in patients treated with or without adjuvant chemotherapy and had local recurrence after treatment did not have significant difference (P>0.1). Two-year survival in patients with or without local recurrence after treatment did not have significant difference (P>0.1). A beneficial affect or a survival benefit of adjuvant/neoadjuvant chemotherapy and concurrent chemoradiation was not observed in Iranian patients

Complications of stent placement in patients with esophageal cancer: A systematic review and network meta-analysis.

Palliative treatments and stents are necessary for relieving dysphagia in patients with esophageal cancer. The aim of this study was to simultaneously compare available treatments in terms of complications.Web of Science, Medline, Scopus, Cochrane Library and Embase were searched. Statistical heterogeneity was assessed using the Chi2 test and was quantified by I2. The results of this study were summarized in terms of Risk Ratio (RR). The random effects model was used to report the results. The rank probability for each treatment was calculated using the p-score.Out of 17855 references, 24 RCTs reported complications including treatment related death (TRD), bleeding, stent migration, aspiration, severe pain and fistula formation. In the ranking of treatments, thermal ablative therapy (p-score = 0.82), covered Evolution® stent (p-score = 0.70), brachytherapy (p-score = 0.72) and antireflux stent (p-score = 0.74) were better treatments in the network of TRD. Thermal ablative therapy (p-score = 0.86), the conventional stent (p-score = 0.62), covered Evolution® stent (p-score = 0.96) and brachytherapy (p-score = 0.82) were better treatments in the network of bleeding complications. Covered Evolution® (p-score = 0.78), uncovered (p-score = 0.88) and irradiation stents (p-score = 0.65) were better treatments in network of stent migration complications. In the network of severe pain, Conventional self-expandable nitinol alloy covered stent (p-score = 0.73), polyflex (p-score = 0.79), latex prosthesis (p-score = 0.96) and brachytherapy (p-score = 0.65) were better treatments.According to our results, thermal ablative therapy, covered Evolution® stents, brachytherapy, and antireflux stents are associated with a lower risk of TRD. Moreover, thermal ablative therapy, conventional, covered Evolution® and brachytherapy had lower risks of bleeding. Overall, fewer complications were associated with covered Evolution® stent and brachytherapy

Morbidity and Mortality Following Short Course Preoperative Radiotherapy in Rectal Carcinoma

The aim of this study was to evaluate the morbidity and mortality in patients with operable stage II and III rectal cancers within one or two months after surgery, who has been treated pre-operatively with short course radiotherapy. Twenty-eight patients with rectal adenocarcinoma, consecutively referred to the Cancer Institute of Imam Khomeini Hospital from March 2009 to March 2010, were selected for the study after staging by endorectal ultrasound and CT of abdomen, pelvis, and chest; and if they had inclusion criteria for short course schedule, they were treated with radiotherapy alone at 2500 cGy for 5 sessions, and then they were referred to the surgical service for operation one week later. They were visited there by a surgeon unaware of the research who completed a questionnaire about pre-operative, operative, and post-operative complications. Of 28 patients, 25 patients underwent either APR or LAR surgery with TME. One patient developed transient anal pain grade I and one patient had dysuria grade I; they were improved in subsequent follow-up. Short course schedule can be performed carefully in patients with staged rectal cancer without concerning about serious complications. This shorter treatment schedule is cost-effective and would be more convenient for patients due to fewer trips to the hospital and the main treatment, i.e. operating the patient, will be done with the shortest time the following diagnosis