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1.
Article in English | WPRIM | ID: wpr-918241

ABSTRACT

Objective@#Computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are considered substitutes for each other for evaluating Crohn’s disease (CD). However, the adequacy of mixing them for routine periodic follow-up for CD has not been established. This study aimed to compare MRE alone with the mixed use of CTE and MRE for the periodic follow-up of small bowel inflammation in patients with CD. @*Materials and Methods@#We retrospectively compared two non-randomized groups, each comprising 96 patients with CD. One group underwent CTE and MRE (MRE followed by CTE or vice versa) for the follow-up of CD (interval, 13–27 months [median, 22 months]), and the other group underwent MRE alone (interval, 15–26 months [median, 21 months]). However, these two groups were similar in clinical characteristics. Three independent readers from three different institutions determined whether inflammation had decreased, remained unchanged, or increased within the entire small bowel and the terminal ileum based on sequential enterography of the patients after appropriate blinding. We compared the two groups for inter-reader agreement and accuracy (terminal ileum only) using endoscopy as the reference standard for enterographic interpretation. @*Results@#The inter-reader agreement was greater in the MRE alone group for the entire small bowel (intraclass correlation coefficient [ICC]: 0.683 vs. 0.473; p = 0.005) and the terminal ileum (ICC: 0.656 vs. 0.490; p = 0.030). The interpretation accuracy was higher in the MRE alone group without statistical significance (70.9%–74.5% vs. 57.9%–64.9% in individual readers; adjusted odds ratio = 3.21; p = 0.077). @*Conclusion@#The mixed use of CTE and MRE was inferior to MRE alone in terms of inter-reader reliability and could probably be less accurate than MRE alone for routine monitoring of small bowel inflammation in patients with CD. Therefore, the consistent use of MRE is favored for this purpose.

2.
Article in Korean | WPRIM | ID: wpr-916281

ABSTRACT

Interest in health insurance coverage for artificial intelligence (AI)–based medical technologies is growing. This article provides a review of the current developments in the sphere and provides future perspectives, focusing on AI application in radiology.Current Concepts: In December 2019, the Health Insurance Review and Assessment Service under the Korean Ministry of Health and Welfare released its first guidelines for determining the National Health Insurance coverage for AI–based medical technologies. Additionally, in 2020, the largest US health insurance provider, the Centers for Medicare and Medicaid Services, approved payment for AI technologies using two different systems. First, in September 2020, it granted New Technology Add-on Payments for AI algorithms that facilitate the diagnosis and treatment of large vessel occlusion strokes. Second, in December 2020, the Centers for Medicare and Medicaid Services finalized the provision of reimbursements for IDx-DR through a Current Procedural Terminology code. The AI system screens for more than mild diabetic retinopathy, which requires further evaluation by an ophthalmologist.Discussion and Conclusion: An in-depth look at the three events suggests the importance of demonstrating the added clinical value of AI technologies through improved patient outcomes in enabling insurance coverage. Therefore, it is critical to create clinically meaningful collaboration between healthcare professionals and AI by understanding and combining their unique strengths, thus actualizing new forms of patient care instead of having AI merely copy the professionals. Furthermore, if National Health Insurance coverage is granted for AI technologies in radiology, add-on payments would be the most appropriate method.

3.
Korean Journal of Radiology ; : 1451-1461, 2021.
Article in English | WPRIM | ID: wpr-902510

ABSTRACT

Objective@#Adequate methods of combining T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) to assess complete response (CR) to chemoradiotherapy (CRT) for rectal cancer are obscure. We aimed to determine an algorithm for combining T2WI and DWI to optimally suggest CR on MRI using visual assessment. @*Materials and Methods@#We included 376 patients (male:female, 256:120; mean age ± standard deviation, 59.7 ± 11.1 years) who had undergone long-course CRT for rectal cancer and both pre- and post-CRT high-resolution rectal MRI during 2017– 2018. Two experienced radiologists independently evaluated whether a tumor signal was absent, representing CR, on both post-CRT T2WI and DWI, and whether the pre-treatment DWI showed homogeneous hyperintensity throughout the lesion. Algorithms for combining T2WI and DWI were as follows: ‘AND,’ if both showed CR; ‘OR,’ if any one showed CR; and ‘conditional OR,’ if T2WI showed CR or DWI showed CR after the pre-treatment DWI showed homogeneous hyperintensity. Their efficacies for diagnosing pathologic CR (pCR) were determined in comparison with T2WI alone. @*Results@#Sixty-nine patients (18.4%) had pCR. AND had a lower sensitivity without statistical significance (vs. 62.3% [43/69]; 59.4% [41/69], p = 0.500) and a significantly higher specificity (vs. 87.0% [267/307]; 90.2% [277/307], p = 0.002) than those of T2WI. Both OR and conditional OR combinations resulted in a large increase in sensitivity (vs. 62.3% [43/69]; 81.2% [56/69], p < 0.001; and 73.9% [51/69], p = 0.008, respectively) and a large decrease in specificity (vs. 87.0% [267/307]; 57.0% [175/307], p < 0.001; and 69.1% [212/307], p < 0.001, respectively) as compared with T2WI, ultimately creating additional false interpretations of CR more frequently than additional identification of patients with pCR. @*Conclusion@#AND combination of T2WI and DWI is an appropriate strategy for suggesting CR using visual assessment of MRI after CRT for rectal cancer.

4.
Korean Journal of Radiology ; : 1697-1707, 2021.
Article in English | WPRIM | ID: wpr-902493

ABSTRACT

The recent introduction of various high-dimensional modeling methods, such as radiomics and deep learning, has created a much greater diversity in modeling approaches for survival prediction (or, more generally, time-to-event prediction). The newness of the recent modeling approaches and unfamiliarity with the model outputs may confuse some researchers and practitioners about the evaluation of the performance of such models. Methodological literacy to critically appraise the performance evaluation of the models and, ideally, the ability to conduct such an evaluation would be needed for those who want to develop models or apply them in practice. This article intends to provide intuitive, conceptual, and practical explanations of the statistical methods for evaluating the performance of survival prediction models with minimal usage of mathematical descriptions. It covers from conventional to deep learning methods, and emphasis has been placed on recent modeling approaches. This review article includes straightforward explanations of C indices (Harrell’s C index, etc.), timedependent receiver operating characteristic curve analysis, calibration plot, other methods for evaluating the calibration performance, and Brier score.

5.
Korean Journal of Radiology ; : 1640-1649, 2021.
Article in English | WPRIM | ID: wpr-902490

ABSTRACT

Objective@#Flattening in the anteroposterior direction (AP flattening) of the terminal ileum (TI) or sigmoid colon (SC) lying across the psoas muscle, on magnetic resonance enterography (MRE), might mimic bowel inflammation in the coronal view.This study investigated the prevalence of AP flattening and the factors associated with its development. @*Materials and Methods@#A total of 364 surgery-naïve patients with Crohn’s disease (CD) who had undergone MRE were retrospectively reviewed. AP flattening was defined as a luminal collapse in the anteroposterior direction, with a bowel width in the axial plane < 1/4 of the normal diameter without reduction of bowel width in coronal images. The prevalence of AP flattening of the TI and SC on MRE in patients with bowel segments lying across the psoas muscle was determined. We further compared the rate of AP flattening between MRE and computed tomography enterography (CTE) in a subcohort of patients with prior CTE. The factors associated with AP flattening were analyzed using multivariable logistic regression in a subcohort of patients with endoscopic findings of TI. @*Results@#Three hundred and twenty-two and 363 patients, respectively, had TI and SC lying across the psoas muscle. The prevalence of AP flattening on MRE was 7.5% (24/322) in TI and 5.2% (19/363) in SC. The prevalences were significantly higher on MRE than on CTE in both the TI (7.3% [12/164] vs. 0.6% [1/164]; p = 0.003) and SC (5.8% [11/190] vs. 1.6% [3/ 190]; p = 0.039). AP flattening of the TI was independently and strongly associated with the absence of CD inflammation on endoscopy, with an adjusted odds ratio of 0.066 (p = 0.003) for the presence versus the absence (reference) of inflammation. @*Conclusion@#AP flattening of the TI or SC lying across the psoas muscle was uncommon and predominantly observed on MRE of the bowel without CD inflammation.

6.
Annals of Coloproctology ; : S51-S54, 2021.
Article in English | WPRIM | ID: wpr-896756

ABSTRACT

Few radiation-induced bowel perforations have been reported to date. Furthermore, perforation after ileal restoration in asymptomatic patients is rare. We report the case of a 61-year-old man who was administered preoperative chemoradiotherapy for advanced rectal cancer. The patient underwent ultra-low anterior resection with ileal diversion, followed by ileal restoration. Perforation was detected 9 days after restoration, and he underwent a right hemicolectomy. The histologic evaluation indicated ileal perforation caused by acute radiation enteritis.

7.
Korean Journal of Radiology ; : 1451-1461, 2021.
Article in English | WPRIM | ID: wpr-894806

ABSTRACT

Objective@#Adequate methods of combining T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) to assess complete response (CR) to chemoradiotherapy (CRT) for rectal cancer are obscure. We aimed to determine an algorithm for combining T2WI and DWI to optimally suggest CR on MRI using visual assessment. @*Materials and Methods@#We included 376 patients (male:female, 256:120; mean age ± standard deviation, 59.7 ± 11.1 years) who had undergone long-course CRT for rectal cancer and both pre- and post-CRT high-resolution rectal MRI during 2017– 2018. Two experienced radiologists independently evaluated whether a tumor signal was absent, representing CR, on both post-CRT T2WI and DWI, and whether the pre-treatment DWI showed homogeneous hyperintensity throughout the lesion. Algorithms for combining T2WI and DWI were as follows: ‘AND,’ if both showed CR; ‘OR,’ if any one showed CR; and ‘conditional OR,’ if T2WI showed CR or DWI showed CR after the pre-treatment DWI showed homogeneous hyperintensity. Their efficacies for diagnosing pathologic CR (pCR) were determined in comparison with T2WI alone. @*Results@#Sixty-nine patients (18.4%) had pCR. AND had a lower sensitivity without statistical significance (vs. 62.3% [43/69]; 59.4% [41/69], p = 0.500) and a significantly higher specificity (vs. 87.0% [267/307]; 90.2% [277/307], p = 0.002) than those of T2WI. Both OR and conditional OR combinations resulted in a large increase in sensitivity (vs. 62.3% [43/69]; 81.2% [56/69], p < 0.001; and 73.9% [51/69], p = 0.008, respectively) and a large decrease in specificity (vs. 87.0% [267/307]; 57.0% [175/307], p < 0.001; and 69.1% [212/307], p < 0.001, respectively) as compared with T2WI, ultimately creating additional false interpretations of CR more frequently than additional identification of patients with pCR. @*Conclusion@#AND combination of T2WI and DWI is an appropriate strategy for suggesting CR using visual assessment of MRI after CRT for rectal cancer.

8.
Korean Journal of Radiology ; : 1697-1707, 2021.
Article in English | WPRIM | ID: wpr-894789

ABSTRACT

The recent introduction of various high-dimensional modeling methods, such as radiomics and deep learning, has created a much greater diversity in modeling approaches for survival prediction (or, more generally, time-to-event prediction). The newness of the recent modeling approaches and unfamiliarity with the model outputs may confuse some researchers and practitioners about the evaluation of the performance of such models. Methodological literacy to critically appraise the performance evaluation of the models and, ideally, the ability to conduct such an evaluation would be needed for those who want to develop models or apply them in practice. This article intends to provide intuitive, conceptual, and practical explanations of the statistical methods for evaluating the performance of survival prediction models with minimal usage of mathematical descriptions. It covers from conventional to deep learning methods, and emphasis has been placed on recent modeling approaches. This review article includes straightforward explanations of C indices (Harrell’s C index, etc.), timedependent receiver operating characteristic curve analysis, calibration plot, other methods for evaluating the calibration performance, and Brier score.

9.
Korean Journal of Radiology ; : 1640-1649, 2021.
Article in English | WPRIM | ID: wpr-894786

ABSTRACT

Objective@#Flattening in the anteroposterior direction (AP flattening) of the terminal ileum (TI) or sigmoid colon (SC) lying across the psoas muscle, on magnetic resonance enterography (MRE), might mimic bowel inflammation in the coronal view.This study investigated the prevalence of AP flattening and the factors associated with its development. @*Materials and Methods@#A total of 364 surgery-naïve patients with Crohn’s disease (CD) who had undergone MRE were retrospectively reviewed. AP flattening was defined as a luminal collapse in the anteroposterior direction, with a bowel width in the axial plane < 1/4 of the normal diameter without reduction of bowel width in coronal images. The prevalence of AP flattening of the TI and SC on MRE in patients with bowel segments lying across the psoas muscle was determined. We further compared the rate of AP flattening between MRE and computed tomography enterography (CTE) in a subcohort of patients with prior CTE. The factors associated with AP flattening were analyzed using multivariable logistic regression in a subcohort of patients with endoscopic findings of TI. @*Results@#Three hundred and twenty-two and 363 patients, respectively, had TI and SC lying across the psoas muscle. The prevalence of AP flattening on MRE was 7.5% (24/322) in TI and 5.2% (19/363) in SC. The prevalences were significantly higher on MRE than on CTE in both the TI (7.3% [12/164] vs. 0.6% [1/164]; p = 0.003) and SC (5.8% [11/190] vs. 1.6% [3/ 190]; p = 0.039). AP flattening of the TI was independently and strongly associated with the absence of CD inflammation on endoscopy, with an adjusted odds ratio of 0.066 (p = 0.003) for the presence versus the absence (reference) of inflammation. @*Conclusion@#AP flattening of the TI or SC lying across the psoas muscle was uncommon and predominantly observed on MRE of the bowel without CD inflammation.

10.
Annals of Coloproctology ; : S51-S54, 2021.
Article in English | WPRIM | ID: wpr-889052

ABSTRACT

Few radiation-induced bowel perforations have been reported to date. Furthermore, perforation after ileal restoration in asymptomatic patients is rare. We report the case of a 61-year-old man who was administered preoperative chemoradiotherapy for advanced rectal cancer. The patient underwent ultra-low anterior resection with ileal diversion, followed by ileal restoration. Perforation was detected 9 days after restoration, and he underwent a right hemicolectomy. The histologic evaluation indicated ileal perforation caused by acute radiation enteritis.

11.
Article in English | WPRIM | ID: wpr-875280

ABSTRACT

Artificial intelligence (AI) will likely affect various fields of medicine. This article aims to explain the fundamental principles of clinical validation, device approval, and insurance coverage decisions of AI algorithms for medical diagnosis and prediction.Discrimination accuracy of AI algorithms is often evaluated with the Dice similarity coefficient, sensitivity, specificity, and traditional or free-response receiver operating characteristic curves. Calibration accuracy should also be assessed, especially for algorithms that provide probabilities to users. As current AI algorithms have limited generalizability to realworld practice, clinical validation of AI should put it to proper external testing and assisting roles. External testing could adopt diagnostic case-control or diagnostic cohort designs. A diagnostic case-control study evaluates the technical validity/ accuracy of AI while the latter tests the clinical validity/accuracy of AI in samples representing target patients in realworld clinical scenarios. Ultimate clinical validation of AI requires evaluations of its impact on patient outcomes, referred to as clinical utility, and for which randomized clinical trials are ideal. Device approval of AI is typically granted with proof of technical validity/accuracy and thus does not intend to directly indicate if AI is beneficial for patient care or if it improves patient outcomes. Neither can it categorically address the issue of limited generalizability of AI. After achieving device approval, it is up to medical professionals to determine if the approved AI algorithms are beneficial for real-world patient care. Insurance coverage decisions generally require a demonstration of clinical utility that the use of AI has improved patient outcomes.

12.
Article | WPRIM | ID: wpr-833546

ABSTRACT

Objective@#To provide an evidence-based guide for the MRI interpretation of complete tumor response after neoadjuvant chemoradiation therapy (CRT) for rectal cancer using visual assessment on T2-weighted imaging (T2) and diffusion-weighted imaging (DWI). @*Materials and Methods@#PubMed MEDLINE, EMBASE, and Cochrane Library were searched on November 28, 2019 to identify articles on the following issues: 1) sensitivity and specificity of T2 or DWI for diagnosing pathologic complete response (pCR) and the criteria for MRI diagnosis; 2) MRI alone vs. MRI combined with other test(s) in sensitivity and specificity for pCR; and 3) tests to select patients for the watch-and-wait management. Eligible articles were selected according to meticulous criteria and were synthesized. @*Results@#Of 1615 article candidates, 55 eligible articles (for all three issues combined) were identified. Combined T2 and DWI performed better than T2 alone, with a meta-analytic summary sensitivity of 0.62 (95% confidence interval [CI], 0.43– 0.77; I2 = 80.60) and summary specificity of 0.89 (95% CI, 0.80–0.94; I2 = 92.61) for diagnosing pCR. The criteria for the complete response on T2 in most studies had the commonality of remarkable tumor decrease to the absence of mass-like or nodular intermediate signal, although somewhat varied, as follows: (near) normalization of the wall; regular, thin, hypointense scar in the luminal side with (near) normal-appearance or homogeneous intermediate signal in the underlying wall; and hypointense thickening of the wall. The criteria on DWI were the absence of a hyperintense signal at high b-value (≥ 800 sec/mm2) in most studies. The specific algorithm to combine T2 and DWI was obscure in half of the studies. MRI combined with endoscopy was the most utilized means to select patients for the watch-and-wait management despite a lack of strong evidence to guide and support a multi-test approach. @*Conclusion@#This systematic review and meta-analysis provide an evidence-based practical guide for MRI assessment of complete tumor response after CRT for rectal cancer.

13.
Article in English | WPRIM | ID: wpr-832912

ABSTRACT

Purpose@#To survey the perception, knowledge, wishes, and expectations of Korean radiology residents regarding artificial intelligence (AI) in radiology. @*Materials and Methods@#From June 4th to 7th, 2019, questionnaires comprising 19 questions related to AI were distributed to 113 radiology residents. Results were analyzed based on factors such as the year of residency and location and number of beds of the hospital. @*Results@#A total of 101 (89.4%) residents filled out the questionnaire. Fifty (49.5%) respondents had studied AI harder than the average while 68 (67.3%) had a similar or higher understanding of AI than the average. In addition, the self-evaluation and knowledge level of AI were significantly higher for radiology residents at hospitals located in Seoul and Gyeonggi-do compared to radiology residents at hospitals located in other regions. Furthermore, the self-evaluation and knowledge level of AI were significantly lower in junior residents than in residents in the 4th year of training. Of the 101 respondents, only 16 (15.8%) had experiences in AI-related study while 91 (90%) were willing to participate in AI-related study in the future. @*Conclusion@#Organizational efforts through a radiology society would be needed to meet the need of radiology trainees for AI education and to promote the role of radiologists more adequately in the era of medical AI.

14.
Article | WPRIM | ID: wpr-832006

ABSTRACT

Background@#The goal of this study was to evaluate the clinical and radiological outcomes of arthroscopic partial repair with medialization of the attachment site of the rotator cuff tendon and to identify prognostic factors affecting rotator cuff healing in patients with irreparable large to massive posterosuperior rotator cuff tears. @*Methods@#Between July 2012 and March 2016, 42 patients with irreparable large to massive posterosuperior rotator cuff tears underwent an arthroscopic partial repair with medialization of the attachment site of the rotator cuff tendon. All patients had a minimum of 2-year follow-up (mean, 35.4 ± 7.3 months). Clinical evaluation was performed using the visual analog scale, the University of California, Los Angeles shoulder rating scale, Constant score, and active range of motion. Radiological evaluation was performed using magnetic resonance imaging and simple radiography. @*Results@#Clinical outcomes at the final follow-up improved significantly compared with the preoperative values (all p < 0.001). The failure rate was 23.8% (10/42); however, clinical outcomes significantly improved regardless of cuff healing (all p < 0.001). The mean acromiohumeral distance was 6.5 ± 1.7 mm (range, 3.2–9.7 mm) before surgery and 6.3 ± 1.6 mm (range, 2.8–9.5 mm) at the final follow-up. Preoperative acromiohumeral distance was associated with failure of cuff healing in the univariate analysis (p = 0.043) and multivariate analysis (p = 0.048). A receiver operating characteristic curve was used to determine the predictive cutoff value for the smallest preoperative acromiohumeral distance for successful healing, which was calculated as 5.3 mm. @*Conclusions@#Despite healing failure, arthroscopic partial repair with medialization can be a possible treatment option for irreparable large to massive posterosuperior rotator cuff tears because of the improvement in clinical outcome. The shorter preoperative acromiohumeral distance was the single most important factor negatively affecting cuff healing, and the likelihood of success of healing might be improved if a repair is performed when the preoperative acromiohumeral distance is < 5.3 mm.

15.
Article | WPRIM | ID: wpr-837190

ABSTRACT

The following report describes the occurrence of severe hypotension and bradycardia in a healthy 50-year-old man following placement from supine to the beach chair position during general anesthesia for injured rotator cuff tendon repair, as well as the occurrence of micturition syncope in a 71-year-old man following postobstructive diuresis after combined spinal–epidural anesthesia for total knee replacement. Rapid decompression of the urinary bladder is associated with severe hypotension, bradycardia, and syncope. Neurally mediated syncope includes true vasovagal and situational syncope that can occur in association with various situations such as cough, micturition, postprandial state, and interscalene block. We report two cases of neurally mediated syncope (true vasovagal and situational) that occurred in different conditions and were controlled well with prompt and proper management without serious complications.

16.
Article | WPRIM | ID: wpr-837189

ABSTRACT

If you have conventional general anesthesia using muscle relaxants for video-assisted thoracic surgery, one lung ventilation with double lumen tube could be dangerous when residual lung volume of non-operated lung could be lacking, and positive pressure ventilation for maintenance of proper minute ventilation could be impossible when there could be too much air leakage. Also, if the abnormal bleeding tendency is, thoracic epidural anesthesia for maintenance of spontaneous breathing could be difficult to perform. A 66-year-old male with a consolidative lesion in involving right middle and lower lobe, and left pneumothorax and pleural effusion successfully underwent video-assisted thoracic bullectomy using ketamine with remifentanil for maintenance of spontaneous breathing and intermittent positive pressure support ventilation within 10 cmH2O for protection of excessive air leakage.

17.
Article in Korean | WPRIM | ID: wpr-834771

ABSTRACT

Artificial intelligence (AI) will likely affect various fields of medicine. This article aims to explain the fundamental principles of clinical validation, device approval, and insurance coverage decisions of AI algorithms for medical diagnosis and prediction. Discrimination accuracy of AI algorithms is often evaluated with the Dice similarity coefficient, sensitivity, specificity, and traditional or free-response receiver operating characteristic curves. Calibration accuracy should also be assessed, especially for algorithms that provide probabilities to users. As current AI algorithms have limited generalizability to real-world practice, clinical validation of AI should put it to proper external testing and assisting roles. External testing could adopt diagnostic case-control or diagnostic cohort designs. A diagnostic case-control study evaluates the technical validity/accuracy of AI while the latter tests the clinical validity/accuracy of AI in samples representing target patients in real-world clinical scenarios. Ultimate clinical validation of AI requires evaluations of its impact on patient outcomes, referred to as clinical utility, and for which randomized clinical trials are ideal. Device approval of AI is typically granted with proof of technical validity/accuracy and thus does not intend to directly indicate if AI is beneficial for patient care or if it improves patient outcomes. Neither can it categorically address the issue of limited generalizability of AI. After achieving device approval, it is up to medical professionals to determine if the approved AI algorithms are beneficial for real-world patient care. Insurance coverage decisions generally require a demonstration of clinical utility that the use of AI has improved patient outcomes.

18.
Journal of Gastric Cancer ; : 421-430, 2020.
Article in English | WPRIM | ID: wpr-899310

ABSTRACT

Purpose@#Currently, there is no clear evidence to support any specific treatment as a principal therapy for stage IV gastric cancer outlet obstruction (GCOO) patients. This study evaluated the outcomes of palliative gastrectomies and survival prognostic factors in patients with stage IV resectable GCOO. @*Materials and Methods@#We retrospectively reviewed the medical records of 48 stage IV GCOO patients who underwent palliative gastrectomies between June 2010 and December 2019.Palliative gastrectomies were performed only in patients with resectable disease. Early surgical outcomes and prognostic factors were analyzed using univariate and multivariate analyses. @*Results@#There were no specific risk factors for postoperative complications, except for being underweight. Severe postoperative complications developed in five patients, and most of the patients underwent interventional procedures and received broad-spectrum antibiotics for intra-abdominal abscesses. The multivariate survival analysis showed that palliative chemotherapy is a positive prognostic factor, while the specific type of hematogenous and lymphatic metastasis is a negative prognostic factor. @*Conclusions@#We recommend that the treatment method for stage IV GCOO should be selected according to each patient's physical condition and tumor characteristics. In addition, we suggest that palliative gastrectomies can be performed in stage IV resectable GCOO patients without unfavorable prognostic factors (types of hematogenous and lymphatic metastases).

19.
Journal of Gastric Cancer ; : 421-430, 2020.
Article in English | WPRIM | ID: wpr-891606

ABSTRACT

Purpose@#Currently, there is no clear evidence to support any specific treatment as a principal therapy for stage IV gastric cancer outlet obstruction (GCOO) patients. This study evaluated the outcomes of palliative gastrectomies and survival prognostic factors in patients with stage IV resectable GCOO. @*Materials and Methods@#We retrospectively reviewed the medical records of 48 stage IV GCOO patients who underwent palliative gastrectomies between June 2010 and December 2019.Palliative gastrectomies were performed only in patients with resectable disease. Early surgical outcomes and prognostic factors were analyzed using univariate and multivariate analyses. @*Results@#There were no specific risk factors for postoperative complications, except for being underweight. Severe postoperative complications developed in five patients, and most of the patients underwent interventional procedures and received broad-spectrum antibiotics for intra-abdominal abscesses. The multivariate survival analysis showed that palliative chemotherapy is a positive prognostic factor, while the specific type of hematogenous and lymphatic metastasis is a negative prognostic factor. @*Conclusions@#We recommend that the treatment method for stage IV GCOO should be selected according to each patient's physical condition and tumor characteristics. In addition, we suggest that palliative gastrectomies can be performed in stage IV resectable GCOO patients without unfavorable prognostic factors (types of hematogenous and lymphatic metastases).

20.
Annals of Coloproctology ; : 275-281, 2019.
Article in English | WPRIM | ID: wpr-762327

ABSTRACT

PURPOSE: We investigated the sensitivity of various evaluating modalities in predicting a pathologic complete response (pCR) after preoperative chemoradiation therapy (PCRT) for locally advanced rectal cancer (LARC). METHODS: From a population of 2,247 LARC patients who underwent PCRT followed by surgery at Asan Medical Center, Seoul, Korea from January 2007 to June 2016, we retrospectively analyzed 313 patients (14.1%) who showed a pCR after surgery. Transrectal ultrasound (TRUS), high-resolution magnetic resonance imaging (MRI), abdominopelvic computed tomography (AP-CT), and endoscopy were performed within 2 weeks prior to surgery. RESULTS: Of the 313 patients analyzed, 256 (81.8%) had a pCR after radical surgery and 57 (18.2%) showed total regression after local excision. Preoperative TRUS, MRI, and AP-CT were performed in 283, 305, and 139 patients, respectively. Among these 3 groups, a prediction of a pCR of the primary tumor was made in 41 (14.5%), 51 (16.7%), and 27 patients (19.4%), respectively, before surgery. A prediction of a clinical N0 stage was made in 204 patients (88.3%) using TRUS, 130 (52.2%) using MRI, and 78 (65.5%) using AP-CT. Of the 211 patients who underwent endoscopy, 87 (41.2%) had a mention of clinical CR in their records. A prediction of a pathologic CR was made for 124 patients (39.6%) through at least one diagnostic modality. CONCLUSION: The various evaluation methods for predicting a pCR after PCRT show a predictive sensitivity of 0.15–0.41 for primary tumors and 0.52–0.88 for lymph nodes. Endoscopy is a relatively superior modality for predicting the pCR of the primary tumor of LARC patients.


Subject(s)
Endoscopy , Humans , Korea , Lymph Nodes , Magnetic Resonance Imaging , Polymerase Chain Reaction , Rectal Neoplasms , Retrospective Studies , Seoul , Ultrasonography
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