Prognostic Significance of Bulky Nodal Disease in Anal Cancer Management: A Multi Institutional Study.

Purpose: This study aimed to assess the prognostic significance of bulky nodal involvement in patients with anal squamous cell carcinoma treated with definitive chemoradiotherapy. Materials and Methods: We retrospectively analyzed medical records of patients diagnosed with anal squamous cell carcinoma who underwent definitive chemoradiotherapy at three medical centers between 2004 and 2021. Exclusion criteria included distant metastasis at diagnosis, 2D radiotherapy, and salvage treatment for local relapse. Bulky N+ was defined as nodes with a long diameter of 2 cm or greater. Results: A total of 104 patients were included, comprising 51 with N0, 46 with non-bulky N+, and 7 with bulky N+. The median follow-up duration was 54.0 months (range, 6.4-162.2 months). Estimated 5-year progression-free survival (PFS), loco-regional recurrence-free survival (LRRFS), and overall survival (OS) rates for patients with bulky N+ were 42.9%, 42.9%, and 47.6%, respectively. Bulky N+ was significantly associated with inferior PFS, LRRFS and OS compared to patients without or with non-bulky N+, even after multivariate analysis. We proposed a new staging system incorporating bulky N+ as N2 stage, with estimated 5-year LRRFS, PFS, and OS rates of 81.1%, 80.6%, and 86.2% for stage I, 67.7%, 60.9%, and 93.3% for stage II, and 42.9%, 42.9%, and 47.6% for stage III disease, enhancing the predictability of prognosis. Conclusion: Patients with bulky nodal disease treated with standard chemoradiotherapy experienced poor survival outcomes, indicating the potential necessity for further treatment intensification.

Assessment of lymph node area coverage with total marrow irradiation and implementation of total marrow and lymphoid irradiation using automated deep learning-based segmentation.

BACKGROUND: Total marrow irradiation (TMI) and total marrow and lymphoid irradiation (TMLI) have the advantages. However, delineating target lesions according to TMI and TMLI plans is labor-intensive and time-consuming. In addition, although the delineation of target lesions between TMI and TMLI differs, the clinical distinction is not clear, and the lymph node (LN) area coverage during TMI remains uncertain. Accordingly, this study calculates the LN area coverage according to the TMI plan. Further, a deep learning-based model for delineating LN areas is trained and evaluated. METHODS: Whole-body regional LN areas were manually contoured in patients treated according to a TMI plan. The dose coverage of the delineated LN areas in the TMI plan was estimated. To train the deep learning model for automatic segmentation, additional whole-body computed tomography data were obtained from other patients. The patients and data were divided into training/validation and test groups and models were developed using the "nnU-NET" framework. The trained models were evaluated using Dice similarity coefficient (DSC), precision, recall, and Hausdorff distance 95 (HD95). The time required to contour and trim predicted results manually using the deep learning model was measured and compared. RESULTS: The dose coverage for LN areas by TMI plan had V100% (the percentage of volume receiving 100% of the prescribed dose), V95%, and V90% median values of 46.0%, 62.1%, and 73.5%, respectively. The lowest V100% values were identified in the inguinal (14.7%), external iliac (21.8%), and para-aortic (42.8%) LNs. The median values of DSC, precision, recall, and HD95 of the trained model were 0.79, 0.83, 0.76, and 2.63, respectively. The time for manual contouring and simply modified predicted contouring were statistically significantly different. CONCLUSIONS: The dose coverage in the inguinal, external iliac, and para-aortic LN areas was suboptimal when treatment is administered according to the TMI plan. This research demonstrates that the automatic delineation of LN areas using deep learning can facilitate the implementation of TMLI.

Safety and Efficacy of Neoadjuvant SABR in Pancreatic Cancer: Effect of Magnetic Resonance Imaging-Guided Respiratory-Gated Adaptive Radiation Therapy.

Purpose: We aimed to evaluate the safety and efficacy of neoadjuvant SABR using magnetic resonance imaging-guided respiratory-gated adaptive radiation therapy (MRgRg-ART) in pancreatic cancer. Methods and Materials: We performed a single-institution retrospective review in patients with pancreatic cancer who underwent neoadjuvant SABR followed by surgical resection. After neoadjuvant chemotherapy, those considered resectable by the multidisciplinary team received SABR over 5 consecutive days using MRgRg-ART. Factors associated with severe postoperative complications (Clavien-Dindo grade ≥III) and prognostic factors for overall survival were analyzed. Results: Sixty-two patients were included in the analysis, with a median follow-up of 10.3 months. The median prescribed dose to the planning target volume was 50 Gy. Fifty-two (85.3%) patients underwent R0 resection, and 11 (18.0%) experienced severe postoperative complications. No factors were associated with the incidence of severe postoperative complications. There were 3 cases of locoregional recurrence, resulting in a 12-month local control rate of 93.1%. Elevated postoperative carbohydrate antigen 19-9 was significantly associated with poor overall survival in the multivariate analysis (P = .037). Conclusions: Neoadjuvant SABR with 50 Gy using MRgRg-ART delivered to pancreatic cancer resulted in a notable survival outcome with acceptable toxicities. Further studies are warranted to investigate the long-term effects of this method.

Validity and reliability of positive attitudes toward and perceived importance of wearable display technology as an effective learning tool among nursing students.

AIM: This study aims to verify the validity and reliability of two separate instruments used for measuring nursing students' positive attitudes toward and perceived importance of wearable display technology as an effective learning tool. BACKGROUND: Healthcare professionals and undergraduates, including nursing students, use wearable display technologies, such as smart glasses and head-mounted displays, as learning tools. However, the validation of the instruments used to evaluate the perception of such use is insufficient. DESIGN: This methodological study assessed an instrument used to measure nursing students' positive attitudes toward and perceived importance of wearable display technology. METHODS: In total, 284 students from eight universities in six regions across South Korea participated in this study. The collected data were analyzed using SPSS/WIN 25.0 and Amos 22.0. The construct validity (exploratory factor analysis, confirmatory factor analysis and group comparison) and reliability (internal consistency) were analyzed. RESULTS: Three factors and thirteen items related to positive attitudes toward wearable displays were extracted through exploratory factor analysis, with a cumulative explanatory power of 66.22%. One factor and six items were extracted, with an explanatory power of 74.61% for the perceived importance of the wearable display subscale. In the group comparison, differences in the positive attitudes toward and perceived importance of wearable display technology were observed according to the level of satisfaction with college life, level of satisfaction with the nursing major, whether the participants owned a wearable display and whether they would consider purchasing a wearable display. Each factor loading was adequate, according to the confirmatory factor analysis results. Cronbach's α for positive attitudes toward wearable displays was.79, while that for perceived importance of wearable displays was.93. CONCLUSION: The developed instrument can be used to evaluate nursing students' positive attitudes toward and perceived importance of wearable display technology as an effective learning tool in the future. This study can serve as a basis for developing and applying wearable display technologies in nursing education.

Plasma Circulating Cell-free DNA in Advanced Hepatocellular Carcinoma Patients Treated With Radiation Therapy.

BACKGROUND/AIM: Although radiation therapy (RT) is an effective and safe treatment when administered locally for various stages of hepatocellular carcinoma (HCC), adequate biomarkers that are predictive of therapeutic efficacy have not been identified. We evaluated the clinical utility of circulating cell-free DNA (cfDNA) to predict treatment response of patients with HCC treated with RT. PATIENTS AND METHODS: We prospectively recruited 37 patients diagnosed with HCC between March 2019 and May 2020. All patients were treated with RT as salvage therapy. Whole peripheral blood was collected twice, one before RT (baseline; V1) and another aliquot one week after the end of RT (V2). We determined whether cfDNA genomic copy number variations (CNVs) could predict treatment outcome. An I-score was calculated from the plasma cfDNA that reflected CNVs of cfDNA, which is evidence of genomic instability. RESULTS: The I-score at V1 exhibited a strong correlation with the planning target volume (PTV) (coefficient=0.65) and was a predictive marker for progression-free survival (PFS). In particular, a mean I-score value at V1 of ≥6.3 had a significant positive correlation with PFS (p=0.017). Compared with patients who had a complete response (CR) following RT, non-CR patients had a higher mean I-score value at V2 ≥6.2 (p=0.034). Furthermore, I-score values at V1 and V2 and the delta I-score ratio were significantly associated with a pre-RT alpha-fetoprotein level ≥200 among non-CR patients. CONCLUSION: I-score values calculated from plasma cfDNA represent a potential biomarker for predicting treatment outcomes in patients with advanced HCC receiving RT.

Total neoadjuvant therapy with short-course radiotherapy Versus long-course neoadjuvant chemoradiotherapy in Locally Advanced Rectal cancer, Korean trial (TV-LARK trial): study protocol of a multicentre randomized controlled trial.

BACKGROUND: For locally advanced rectal cancer (LARC), total neoadjuvant therapy (TNT) may enhance tumour response, reduce recurrence, and improve patient compliance compared to upfront surgery. Recent studies have shown that chemoradiotherapy (CRT) followed by consolidation chemotherapy leads to higher rate of pathologic complete response (pCR) than induction chemotherapy followed by CRT. However, an optimal TNT regimen that maximise the pCR rate and minimise toxicity has not been established. Therefore, the aim of this trial was to investigate whether preoperative short-course radiotherapy followed by chemotherapy with four cycles of CAPOX can double the pCR rate compared to a standard schedule of long-course preoperative CRT in patients with LARC. METHODS: This is a multi-centre, prospective, open label, randomised controlled trial. Patients with clinical primary tumour stage 3 and higher or regional node-involved rectal cancer located within 10 cm from the anal verge were randomly assigned equally to short-course radiotherapy (25 Gy in 5 fractions over 1 week) followed by four cycles of CAPOX (intravenous oxaliplatin [130 mg/m2, once a day] on day 1 and capecitabine [1,000 mg/m2, twice a day] from days 1 to 14) (TNT) or CRT (50.4 Gy in 28 fractions over 5 weeks, concurrently with concomitant oral capecitabine 825 mg/m2 twice a day). After preoperative treatment, total mesorectal excision was performed 2-4 weeks in the TNT group and 6-10 weeks in the CRT group, followed by optional additional adjuvant chemotherapy. The primary endpoint is the pCR rate, and secondary endpoints include disease-related treatment failure, quality of life, and cost-effectiveness. Assuming a pCR rate of 28% and 15% in the TNT and CRT groups, respectively, and one-side alpha error rate of 0.025 and power of 80%, 348 patients will be enrolled considering 10% dropout rate. DISCUSSION: The TV-LARK trial will evaluate the superiority of employed TNT regimen against the standard CRT regimen for patients with LARC. We aimed to identify a TNT regimen that will improve the pCR rate and decrease systemic recurrence in these patients. TRIAL REGISTRATION: Cris.nih.go.kr ID: KCT0007169 (April 08, 2022). The posted information will be updated as needed to reflect the protocol amendments and study progress.

Integrative modeling of tumor genomes and epigenomes for enhanced cancer diagnosis by cell-free DNA.

Multi-cancer early detection remains a key challenge in cell-free DNA (cfDNA)-based liquid biopsy. Here, we perform cfDNA whole-genome sequencing to generate two test datasets covering 2125 patient samples of 9 cancer types and 1241 normal control samples, and also a reference dataset for background variant filtering based on 20,529 low-depth healthy samples. An external cfDNA dataset consisting of 208 cancer and 214 normal control samples is used for additional evaluation. Accuracy for cancer detection and tissue-of-origin localization is achieved using our algorithm, which incorporates cancer type-specific profiles of mutation distribution and chromatin organization in tumor tissues as model references. Our integrative model detects early-stage cancers, including those of pancreatic origin, with high sensitivity that is comparable to that of late-stage detection. Model interpretation reveals the contribution of cancer type-specific genomic and epigenomic features. Our methodologies may lay the groundwork for accurate cfDNA-based cancer diagnosis, especially at early stages.

Association between COVID-19-related stress and self-directed learning ability among Korean nursing students.

PURPOSE: Traditional face-to-face classes for nursing students due to the COVID (Coronavirus Disease)-19 pandemic around the world made it inevitable to operate education delivery method using remote/hybrid fashion. This study was aimed to validate the Korean version of the Student Stress Inventory-Stress Manifestations (SSI-SM) and assess the association between COVID-19 pandemic related stress level and self-directed learning ability competence in nursing students. DESIGN: This research was a cross-sectional study design. METHODS: The study was conducted from December 2020 to January 2021, with a convenience sample of 172 nursing students in the 3rd and 4th grades in South Korea. The Korean version of SSI-SM(K-SSI-SM) was translated and adapted according to standard guideline, and tested construct validity and reliability. In addition, a multiple linear regression analysis was used to examine the associations between the COVID-19 related stress level and the self-directed learning ability. RESULTS: An exploratory analysis showed that K-SSI-SM composed of 13-item in three factors (uncertainty, non-sociability, and somatization) accounted for 68.73% of the total variance after it was modified. The internal consistency was good with 0.91. Multiple linear regression analysis revealed that higher self-directed learning ability was associated with lower stress levels (ß = -0.19, p = 0.008), positive toward online learning (ß = 0.41, p = 0.003) and scored higher in theory (ß = 0.30, p < 0.001) in nursing students. CONCLUSION: The K-SSI-SM is an acceptable instrument for assessing stress levels in Korean nursing students. And nursing faculties need to pay attention to related factors of self-directed learning ability, in order to achieve the course's self-directed learning goal in students attending online classes.

Standard versus longer interval of radical resection after neoadjuvant chemoradiotherapy in locally advanced rectal cancer: A 20-year single-center experience & propensity-score matching.

BACKGROUND AND OBJECTIVES: Despite the standard interval of 6-8 weeks between neoadjuvant chemoradiotherapy (nCRT) and surgery, it is debated whether an interval of >8 weeks increases the pathologic complete response (pCR) rate. We investigated the interval between nCRT and surgery, and its impact on oncological outcomes and postoperative complications in patients with locally advanced rectal cancer. METHODS: We retrospectively reviewed patients with rectal cancer who underwent total mesorectal excision after long-course nCRT between 2000 and 2020. They were divided into two groups-those who underwent surgery at 6-8 and >8 weeks after nCRT. Surgical outcomes (stoma rate and postoperative complications), pCR, tumor regression grade (TRG), recurrence-free survival (RFS), and overall survival (OS) were compared. RESULTS: We selected 770/1153 patients with rectal cancer, including 502 and 268 patients surgically treated at 6-8 and >8 weeks after nCRT, respectively. The pCR rates were similar between the two groups (14.7% vs. 15.3%, p = 0.836), while the TRG was significantly better in the >8 weeks group (p = 0.267). Additionally, the postoperative complications, recurrence, 5-year RFS, and OS rates were not significantly different between the two groups. CONCLUSIONS: Although tumor regression increased in the >8 weeks group, the oncological benefits of surgery >8 weeks after nCRT remain uncertain.

Plasma Cell-Free DNA in Uterine Cervical Cancer: Therapeutic Monitoring and Prognostic Values after Radical Radiotherapy.

PURPOSE: In the present study, we aimed to establish a liquid biopsy-based monitoring method using peripheral blood cell-free DNA (cfDNA) for patients with cervical cancer who underwent radical radiotherapy (RT). Materials and Methods: Twenty-five patients with cervical cancer were prospectively recruited and treated with external beam RT and brachytherapy. In all patients, except one, chemotherapy was administered concurrently during RT. Whole peripheral blood samples were obtained at least twice from each patient. We performed next-generation sequencing (NGS) for the target-captured libraries (67 oncogenes and human papillomavirus [HPV] type 16/18) using 64 plasma cfDNA samples from the 25 participants. The ratio of HPV cfDNA and the variant allele frequency (VAF) in cfDNA was calculated, and their dynamic changes were monitored. The median follow-up duration was 25.4 months. RESULTS: In total, we identified 21,866 cfDNA variants. ARID1A and frameshift variants occupied the largest portion of altered genes and HIGH-grade variant types, respectively. In most cases, tumor shrinkage was followed by a decrease in the HPV ratio; however, an increase in HPV ratio indicated distant metastasis, despite the reduced tumor size. The initial HPV ratio reflecting the tumor burden was likely associated with treatment outcomes (p = 0.16). We did not determine a role for serial changes in the VAF in cfDNA. CONCLUSION: Our findings suggest that the HPV cfDNA ratio, calculated after targeted NGS, may be valuable for monitoring and predicting treatment responses. Accordingly, further validation of these findings is warranted.

Image-Guided Versus Conventional Brachytherapy for Locally Advanced Cervical Cancer: Experience of Single Institution with the Same Practitioner and Time Period.

PURPOSE: This study aimed to compare treatment outcomes and toxicity profile between imaged-guided brachytherapy (IGBT) versus conventional brachytherapy (CBT) performed by the same practitioner during the same time period. MATERIALS AND METHODS: Medical records of 104 eligible patients who underwent brachytherapy for locally advanced cervical cancer were retrospectively reviewed. Fifty patients (48.1%) underwent IGBT, and 54 (51.9%) patients underwent CBT. All patients underwent concurrent chemoradiation with cisplatin. High-dose-rate intracavitary brachytherapy with dose prescription of 25-30 Gy in 4-6 fractions was performed for all patients. Late lower gastrointestinal (GI) and urinary toxicities occurred more than 3 months after the end of brachytherapy were included for comparative and dosimetric analyses. RESULTS: The median follow-up period was 18.33 months (range, 3.25 to 38.43 months). There were no differences in oncologic outcomes between the two groups. The IGBT group had lower rate of actuarial grade ≥ 3 toxicity than the CBT group (2-year, 4.5% vs. 25.7%; p=0.030). Cumulative equieffective D2cc of sigmoid colon was significantly correlated with grade ≥ 2 lower GI toxicity (p=0.033), while equieffective D2cc of rectum (p=0.055) and bladder (p=0.069) showed marginal significance with corresponding grade ≥ 2 toxicities in the IGBT group. Half of grade ≥ 3 lower GI toxicities impacted GI tract above the rectum. Optimal thresholds of cumulative D2cc of sigmoid colon and rectum were 69.7 Gy and 70.8 Gy, respectively, for grade ≥ 2 lower GI toxicity. CONCLUSION: IGBT showed superior toxicity profile to CBT. Evaluating the dose to the GI tract above rectum by IGBT might prevent some toxicities.

Consolidatory ablative stereotactic body radiation therapy after induction chemotherapy for unresectable pancreatic cancer: A single center experience.

Background and purpose: Consolidatory radiotherapy in form of stereotactic body radiation therapy (SBRT) with an ablative dose following induction chemotherapy is emerging as a promising treatment scheme for unresectable pancreatic cancer. Outcomes of given treatment at a single center for contiguous patients with unresectable pancreatic cancer were evaluated to build the optimal treatment strategy. Materials and methods: In this retrospective study, a total of 50 patients with unresectable pancreatic cancer who underwent induction chemotherapy and ablative dose SBRT were included. SBRT dose was 40-50 Gy in five fractions. Two strategies were adopted to adhere to the organs at risk (OAR) dose constraints: simultaneous integrated protection (SIP) technique and magnetic resonance (MR)-guided adaptive technique. Overall survival (OS) and local progression-free survival (LPFS) were calculated from the start date of SBRT. Results: The median follow-up period for survivors was 21.1 months (range, 6.2-61.0 months). Eleven (22.0%) patients underwent resection after SBRT, which were all R0 resection. In patients with non-metastatic disease, the median OS was 26.5 months (range, 4.1-61.0 months), and the 1- and 3-year LPFS were 90.0% (95% confidence interval [CI], 72.0-96.7%) and 57.4% (95% CI, 31.7-76.4%), respectively. Patients with oligometastatic disease had inferior survival outcomes, but there was no survival difference among responders to induction chemotherapy. In the multivariable analysis, tumor size ≤4 cm, non-metastatic status, and good response to induction chemotherapy were associated with improved LPFS. In dosimetric analysis, GTV Dmin ≥50.5 Gy was the strongest prognosticator against local progression. Grade ≥3 adverse events occurred in two (4.0%) patients with non-adaptive RT, but none in patients with MR-guided adaptive RT. Conclusion: Ablative dose SBRT following induction chemotherapy is an effective strategy for selected patients with unresectable pancreatic cancer. The SIP technique and MR-guided adaptive RT were attributed to minimizing the risk of adverse events. Further studies are needed to identify the best candidates for consolidatory SBRT in unresectable pancreatic cancer.

Prediction and clinical impact of delayed lymphopenia after chemoradiotherapy in locally advanced non-small cell lung cancer.

Introduction: The dosimetric factors of radiotherapy have an acute impact on the host immune system during chemoradiotherapy (CRT) in locally advanced non-small cell lung cancer (NSCLC). However, even after CRT, a substantial number of patients remain immunosuppressed with delayed lymphopenia. Therefore, we aimed to evaluate clinical and dose-volumetric predictors of delayed lymphopenia after CRT in locally advanced NSCLC. Materials and methods: We retrospectively reviewed 272 patients with locally advanced NSCLC who received definitive CRT from January 2012 to August 2020. Differential blood count data, including serum albumin values, were obtained at baseline, during and at first follow up after CRT. Acute and delayed lymphopenia events were defined as grade III/IV lymphopenia developed during or 4-12 weeks after CRT completion, which accounted for 84% and 10% of cases, respectively. Dose-volume histogram parameters for planned target volume, whole body, heart, lung, great vessels, spleen, esophagus and thoracic vertebral bodies were evaluated. Results: Multivariate analysis revealed that patients with delayed lymphopenia were associated with inferior overall survival (HR 2.53, P = 0.001) and progression-free survival (HR 1.98, P = 0.006). However, there was no significant survival difference between groups stratified by acute lymphopenia. On multivariable logistic regression models, lung V5, baseline ALC, during-CRT ALC, and albumin nadir were significant predictors for delayed lymphopenia. Furthermore, the nomogram for delayed lymphopenia based on these variables had good discrimination (area under the curve, 0.905). Conclusions: In this study, we investigated the prognostic significance of delayed lymphopenia and identified clinico-dosimetric parameters to predict delayed lymphopenia.

Sex-Based Differences in Outcomes of Coronavirus Disease 2019 (COVID-19) in Korea.

PURPOSE: This study examined the factors affecting mortality and clinical severity score (CSS) of male and female patients with Coronavirus Disease 2019 (COVID-19) using clinical epidemiological information provided by the Korea Disease Control and Prevention Agency. METHODS: This is a retrospective observational cohort study. From January 21 to April 30, 2020, 5624 subjects who were released from quarantine or died were analyzed. RESULTS: The factors influencing relsease or death that differed by sex were high heart rate and malignancy in males and chronic kidney disease in females. In addition, the factors influencing progression to severe CSS were high BMI (severe obesity) and rheumatic disease in males and high temperature, sputum production, absence of sore throat and headache, chronic kidney disease, malignancy, and chronic liver disease in females. Older age, low lymphocyte count and platelets, dyspnea, diabetes mellitus, dementia, and intensive care unit (ICU) admission affected mortality in all the patients, and older age, low lymphocyte count and platelets, fever, dyspnea, diabetes mellitus, dementia, and ICU admission affected progression to severe stage of CSS. CONCLUSIONS: This study is expected to contribute to the general results by analyzing nationally representative data. The results of this study present an important basis for development of differentiated nursing and medical management strategies in consideration of factors that influence treatment effects and outcomes according to sex of COVID-19 patients.

Role of Dedicated Subspecialized Radiologists in Multidisciplinary Team Discussions on Lower Gastrointestinal Tract Cancers.

OBJECTIVE: To determine the impact of dedicated subspecialized radiologists in multidisciplinary team (MDT) discussions on the management of lower gastrointestinal (GI) tract malignancies. MATERIALS AND METHODS: We retrospectively analyzed the data of 244 patients (mean age ± standard deviation, 61.7 ± 11.9 years) referred to MDT discussions 249 times (i.e., 249 cases, as five patients were discussed twice for different issues) for lower GI tract malignancy including colorectal cancer, small bowel cancer, GI stromal tumor, and GI neuroendocrine tumor between April 2018 and June 2021 in a prospective database. Before the MDT discussions, dedicated GI radiologists reviewed all imaging studies again besides routine clinical reading. The referring clinician's initial diagnosis, initial treatment plan, change in radiologic interpretation compared with the initial radiology report, and the MDT's consensus recommendations for treatment were collected and compared. Factors associated with changes in treatment plans and the implementation of MDT decisions were analyzed. RESULTS: Of the 249 cases, radiologic interpretation was changed in 73 cases (29.3%) after a review by dedicated GI radiologists, with 78.1% (57/73) resulting in changes in the treatment plan. The treatment plan was changed in 92 cases (36.9%), and the rate of change in the treatment plan was significantly higher in cases with changes in radiologic interpretation than in those without (78.1% [57/73] vs. 19.9% [35/176], p < 0.001). Follow-up records of patients showed that 91.2% (227/249) of MDT recommendations for treatment were implemented. Multiple logistic regression analysis revealed that the nonsurgical approach (vs. surgical approach) decided through MDT discussion was a significant factor for patients being managed differently than the MDT recommendations (Odds ratio, 4.48; p = 0.017). CONCLUSION: MDT discussion involving additional review of radiology examinations by dedicated GI radiologists resulted in a change in the treatment plan in 36.9% of cases. Changes in treatment plans were significantly associated with changes in radiologic interpretation.

Dosimetric evaluation of magnetic resonance imaging-guided adaptive radiation therapy in pancreatic cancer by extent of re-contouring of organs-at-risk.

PURPOSE: The safety of online contouring and planning for adaptive radiotherapy is unknown. This study aimed to evaluate the dosimetric difference of the organ-at-risk (OAR) according to the extent of contouring in stereotactic magnetic resonance image-guided adaptive RT (SMART) for pancreatic cancer. MATERIALS AND METHODS: We reviewed the treatment plan data used for SMART in patients with pancreatic cancer. For the online contouring and planning, OARs within 2 cm from the planning target volume (PTV) in the craniocaudal direction were re-controlled daily at the attending physician's discretion. The entire OARs were re-contoured retrospectively for data analysis. We termed the two contouring methods the Rough OAR and the Full OAR, respectively. The proportion of dose constraint violation and other dosimetric parameters was analyzed. RESULTS: Nineteen patients with 94 fractions of SMART were included in the analysis. The dose constraint was violated in 10.6% and 43.6% of the fractions in Rough OAR and Full OAR methods, respectively (p = 0.075). Patients with a large tumor, a short distance from gross tumor volume (GTV) to OAR, and a tumor in the body or tail were associated with more occult dose constraint violations-large tumor (p = 0.027), short distance from GTV to OAR (p = 0.061), tumor in body or tail (p = 0.054). No dose constraint violation occurred outside 2 cm from the PTV. CONCLUSION: More occult dose constraint violations can be found by the Full OAR method in patients with pancreatic cancer with some clinical factors in the online re-planning for SMART. Re-contouring all the OARs would be helpful to detect occult dose constraint violations in SMART planning. Since the dosimetric profile of SMART cannot be represented by a single fraction, patient selection for the Full OAR method should be weighted between the clinical usefulness and the time and workforce required.

A Novel Scoring System for Response of Preoperative Chemoradiotherapy in Locally Advanced Rectal Cancer Using Early-Treatment Blood Features Derived From Machine Learning.

BACKGROUND: Preoperative chemoradiotherapy (CRT) is a standard treatment for locally advanced rectal cancer (LARC). However, individual responses to preoperative CRT vary from patient to patient. The aim of this study is to develop a scoring system for the response of preoperative CRT in LARC using blood features derived from machine learning. METHODS: Patients who underwent total mesorectal excision after preoperative CRT were included in this study. The performance of machine learning models using blood features before CRT (pre-CRT) and from 1 to 2 weeks after CRT (early-CRT) was evaluated. Based on the best model, important features were selected. The scoring system was developed from the selected model and features. The performance of the new scoring system was compared with those of systemic inflammatory indicators: neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and the prognostic nutritional index. RESULTS: The models using early-CRT blood features had better performances than those using pre-CRT blood features. Based on the ridge regression model, which showed the best performance among the machine learning models (AUROC 0.6322 and AUPRC 0.5965), a novel scoring system for the response of preoperative CRT, named Response Prediction Score (RPS), was developed. The RPS system showed higher predictive power (AUROC 0.6747) than single blood features and systemic inflammatory indicators and stratified the tumor regression grade and overall downstaging clearly. CONCLUSION: We discovered that we can more accurately predict CRT response by using early-treatment blood data. With larger data, we can develop a more accurate and reliable indicator that can be used in real daily practices. In the future, we urge the collection of early-treatment blood data and pre-treatment blood data.

Impact of Computed Tomography-Based, Artificial Intelligence-Driven Volumetric Sarcopenia on Survival Outcomes in Early Cervical Cancer.

The purpose of this study was to investigate the impact of sarcopenia and body composition change during primary treatment on survival outcomes in patients with early cervical cancer. We retrospectively identified patients diagnosed with 2009 International Federation of Gynecology and Obstetrics stage IB1-IIA2 cervical cancer who underwent primary radical hysterectomy between 2007 and 2019. From pre-treatment CT scans (n = 306), the skeletal muscle area at the third lumbar vertebra (L3) and the waist skeletal muscle volume were measured using an artificial intelligence-based tool. These values were converted to the L3 and volumetric skeletal muscle indices by normalization. We defined L3 and volumetric sarcopenia using 39.0 cm2/m2 and the first quartile (Q1) value, respectively. From pre- and post-treatment CT scan images (n = 192), changes (%) in waist skeletal muscle and fat volumes were assessed. With the use of Cox regression models, factors associated with progression-free survival (PFS) and overall survival (OS) were analyzed. Between the L3 sarcopenia and non-sarcopenia groups, no differences in PFS and OS were observed. In contrast, volumetric sarcopenia was identified as a poor prognostic factor for PFS (adjusted hazard ratio [aHR], 1.874; 95% confidence interval [CI], 1.028-3.416; p = 0.040) and OS (aHR, 3.001; 95% CI, 1.016-8.869; p = 0.047). During primary treatment, significant decreases in waist skeletal muscle (median, -3.9%; p < 0.001) and total fat (median, -5.3%; p < 0.001) were observed. Of the two components, multivariate analysis revealed that the waist fat gain was associated with worse PFS (aHR, 2.007; 95% CI, 1.009-3.993; p = 0.047). The coexistence of baseline volumetric sarcopenia and waist fat gain further deteriorated PFS (aHR, 2.853; 95% CI, 1.257-6.474; p = 0.012). In conclusion, baseline volumetric sarcopenia might be associated with poor survival outcomes in patients with early cervical cancer undergoing primary RH. Furthermore, sarcopenia patients who gained waist fat during primary treatment were at a high risk of disease recurrence.

Current usage of stereotactic body radiotherapy for oligometastatic prostate cancer in Korea: patterns of care survey (KROG 19-08).

BACKGROUND: Growing evidence suggests that metastasis-directed therapy and/or prostate-directed therapy may benefit patients with oligometastatic prostate cancer (OMPC). Stereotactic body radiotherapy (SBRT) is increasingly used to treat oligometastases in various cancers. The purpose of this study was to investigate the current patterns of curative-intent SBRT for OMPC in Korea. METHODS: A 20-item questionnaire was sent to 326 radiation oncologists in 93 institutions in Korea. Only 1 physician per institution was required to complete the survey. Subsequently, the second survey consisting of 3 clinical scenarios was sent to 64 physicians with clinical experience in SBRT: case 1, cT4N0M1 (direct invasion to two pelvic bones); case 2, cT2N0M1 (three bone metastases); and case 3, solitary spine metastasis after radical prostatectomy. RESULTS: Seventy-six physicians from 93 institutions (82%) answered the first survey. The multidisciplinary team approach was practiced in 16 institutions (21%). Most physicians (75%) agreed on the definition of oligometastases as limited lesions and/or organs ≤5: 25% agreed with low-volume disease according to CHAARTED trial. During the last year, 49 physicians (64%) treated OMPC patients with curative intent. Sixty four physicians (84%) had a clinical experience with SBRT: 48 (75%) stated that both dose and fraction number should be considered when defining SBRT, whereas others (25%) stated that only fraction size should be considered. Fifty-five faculties (86%) answered the second survey. Physicians agreed with oligometastases in 89% for case 1, in 80% for case 2, and in 100% for case 3. The rate of SBRT application was the highest in case 3 (70%). CONCLUSIONS: There was diversity in the patterns of SBRT for OMPC in Korea. Additional prospective studies are necessary to strengthen evidence regarding role of SBRT in OMPC.

Model Setting and Interpretation of Results in Research Using Structural Equation Modeling: A Checklist with Guiding Questions for Reporting.

PURPOSE: This study develops a checklist with guidelines for the methods and important factors to consider in research using structural equation modeling (SEM). METHOD: The paper discusses the factors to consider in the process across the three stages of 1) model setting, 2) model evaluation and modification, and 3) interpretation and reporting of SEM-based studies. RESULTS: The authors present a checklist for researchers during the stages of model setting, model evaluation and modification, result analysis, and reporting, along with examples of figures and tables with explanations. CONCLUSION: A checklist will help to improve the reporting quality of SEM-based studies.