Assessment of deep learning-based auto-contouring on interobserver consistency in target volume and organs-at-risk delineation for breast cancer: Implications for RTQA program in a multi-institutional study.

Purpose: To quantify interobserver variation (IOV) in target volume and organs-at-risk (OAR) contouring across 31 institutions in breast cancer cases and to explore the clinical utility of deep learning (DL)-based auto-contouring in reducing potential IOV.

Methods And Materials: In phase 1, two breast cancer cases were randomly selected and distributed to multiple institutions for contouring six clinical target volumes (CTVs) and eight OAR. In Phase 2, auto-contour sets were generated using a previously published DL Breast segmentation model and were made available for all participants.

Association Between Thyroid Radiation Dose and Hypothyroidism in Breast Cancer Patients Undergoing Volumetric Modulated Arc Therapy for Regional Nodal Irradiation.

Background/aim: To investigate the association between the thyroid dysfunction and thyroid radiation dose in regional nodal irradiation (RNI) using volumetric modulated arc therapy (VMAT) for breast cancer.

Patients And Methods: We reviewed medical data of 67 patients with breast cancer who underwent curative surgery followed by adjuvant radiotherapy, including RNI using VMAT, between 2018 and 2021. All patients had normal thyroid functional test results, including thyroid stimulating hormone (TSH), T3, and free-T4.

Mask dependency of the lacrimal gland dose under whole brain radiotherapy when the six-degrees of freedom couch is not available.

Background: Dry eye syndrome has been recently reported in patients who underwent whole brain radiotherapy (WBRT). WBRT based on a couch with three-degrees of freedom (3D) can occasionally be performed in which the rotational head motion is not corrected. This study assessed the dependency of the rotational errors on the mask and the dose variation of the lens and lacrimal gland in WBRT patients.

Assessment of the Mutation Profile of Tonsillar Squamous Cell Carcinomas Using Targeted Next-Generation Sequencing.

Data regarding driver mutation profiles in tonsillar squamous cell carcinomas (TSCCs) remain scarce, limiting the understanding of its pathogenesis and unexpected behavior in the updated staging system. We investigated the incidence of clinically relevant mutations and their contribution in the prognosis of the condition, and their association with human papillomavirus (HPV) infection and adjuvant therapy. We subjected 43 surgically resected TSCC samples to targeted next-generation sequencing, determined their HPV status using polymerase chain reaction, and performed The Cancer Genomic Atlas and Gene Set Enrichment analyses.

Variation in clinical target volume delineation in postoperative radiotherapy for biliary tract cancer.

We aimed to evaluate the inter-clinician variability in the clinical target volume (CTV) for postoperative radiotherapy (PORT) for biliary tract cancer (BTC) including extrahepatic bile duct cancer (EBDC) and gallbladder cancer (GBC). Nine experienced radiation oncologists delineated PORT CTVs for distal EBDC (pT2N1), proximal EBDC (pT2bN1) and GBC (pT2bN1) patients. The expectation maximization algorithm for Simultaneous Truth and Performance Level Estimation (STAPLE) was used to quantify expert agreements.

Effects of Radiation Dose on Liver After Free-breathing Volumetric Modulated Arc Therapy for Breast Cancer.

Background/aim: To evaluate the early effect of radiation dose on liver function in breast cancer patients undergoing free-breathing volumetric modulated arc therapy (FB-VMAT).

Patients And Methods: Medical records of 125 patients with breast cancer who underwent curative surgery followed by postoperative radiotherapy using FB-VMAT during 2018-2021 were reviewed. Results of the liver function test (LFT), performed within 1-week before and 6-months after radiotherapy, were collected and compared.

Postmastectomy Radiation Therapy for Node-Negative Breast Cancer of 5 cm or Larger Tumors: A Multicenter Retrospective Analysis (KROG 20-03).

Purpose: To evaluate the role of postmastectomy radiation therapy (PMRT) in patients with node-negative breast cancer of 5cm or larger tumors undergoing mastectomy.

Materials And Methods: Medical records of 274 patients from 18 institutions treated with mastectomy between January 2000 and December 2016 were retrospectively reviewed. Among these, 202 patients underwent PMRT, while 72 did not.

Inter-institutional Variation in Intensity-modulated Radiotherapy for Breast Cancer in Korea (KROG 19-01).

Background/aim: To present the variations in the target delineation and the planning results of intensity-modulated radiation therapy (IMRT) for breast cancers.

Patients And Methods: We requested the target volumes and organs at risk delineation for two cases of left breast cancers, and evaluated the IMRT plans including the supraclavicular and internal mammary node irradiation.

Results: Twenty-one institutions participated in this study.

Negative Prognostic Implication of Promoter Mutations in Human Papillomavirus-Negative Tonsillar Squamous Cell Carcinoma Under the New 8th AJCC Staging System.

Telomerase reverse transcriptase gene promoter () mutation is a potential candidate for pathogenesis and therapeutic target of tonsillar squamous cell carcinomas (TSCCs) in association with human papillomavirus (HPV). Their clinical relevance has not been validated under the new 8th American Joint Committee on Cancer (AJCC) staging system. We analyzed real-time peptide nucleic acid-mediated PCR and sequencing methods ( mutation) and real-time PCR-based assay (HPV) in 80 surgically resected TSCCs.

Neutrophil-to-Lymphocyte Ratio After Definitive Concurrent Chemoradiotherapy Predicts Survival in Patients With Esophageal Squamous Cell Carcinoma.

Background/aim: Lymphocyte-to-monocyte ratio, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio represent systemic immune-inflammatory responses. We evaluated the association between immune-inflammatory cell ratios and prognosis in esophageal squamous cell carcinoma (ESCC) patients who underwent definitive concurrent chemoradiotherapy (dCCRT).

Patients And Methods: Medical records of 68 ESCC patients in three institutions who underwent dCCRT between 2006 and 2017 were reviewed.

Interobserver variability in clinical target volume delineation in anal squamous cell carcinoma.

We evaluated the inter-physician variability in the target contouring of the radiotherapy for anal squamous cell carcinoma (ASCC). Clinical target volume (CTV) of three patients diagnosed with ASCC was delineated by seven experienced radiation oncologists from multi-institution. These patients were staged as pT1N1a, cT2N0, and cT4N1a, respectively, according to 8 edition of the American Joint Committee on Cancer staging system.

Comparison of Dose Distribution in Regional Lymph Nodes in Whole-Breast Radiotherapy vs. Whole-Breast Plus Regional Lymph Node Irradiation: An In Silico Planning Study in Participating Institutions of the Phase III Randomized Trial (KROG 1701).

The purpose of the current in silico planning study is to compare radiation doses of whole-breast irradiation (WBI) and whole-breast plus regional lymph node irradiation (WBI+RNI) administered to the regional lymph nodes (RLN) in pN1 breast cancer. Twenty-four participating institutions were asked to create plans of WBI and WBI+RNI for two dummy cases. To compare target coverage between the participants, an isodose line equal to 90% of the prescribed dose was converted to an isodose contour (contour) The relative nodal dose (RND) was obtained using the ratio of RLN dose to the target dose.

Prognostic factors for survival in colorectal cancer patients with brain metastases undergoing whole brain radiotherapy: multicenter retrospective study.

Whole brain radiotherapy (WBRT) is a mainstay of the treatment for brain metastases (BM). We evaluated prognostic factors in colorectal cancer (CRC) patients undergoing WBRT for BM. The medical records of 106 CRC patients undergoing WBRT for BM between 2000 and 2014 at three institutions were reviewed.

Adjuvant Chemotherapy and Dose Escalation in Definitive Concurrent Chemoradiotherapy for Esophageal Squamous Cell Carcinoma.

Background/aim: To validate the effect of treatment intensification on survival in esophageal squamous cell carcinoma (ESCC) patients undergoing definitive concurrent chemoradiotherapy (dCCRT).

Patients And Methods: We reviewed the medical records of 73 ESCC patients who underwent dCCRT between 2006 and 2017 in 3 institutions.

Results: The median follow-up time was 13.

Radiation therapy for extrahepatic bile duct cancer: Current evidences and future perspectives.

Extrahepatic bile duct cancer (EBDC) is a rare malignancy that involves neoplastic changes extending from both hepatic ducts to the common bile duct. The treatment of choice is surgical resection, but the predominant pattern of initial treatment failure is locoregional recurrence. Accordingly, adjuvant radiotherapy has been administered after surgical resection based on these rationales.

Impact of adjuvant treatments on survival in Korean patients with WHO grade II gliomas: KNOG 15-02 and KROG 16-04 intergroup study.

Introduction: Optimal treatment strategies for low-grade glioma (LGG) remain controversial. We analyzed treatment outcomes and evaluated prognostic factors of adult LGG patients in Korea.

Methods: We reviewed the medical records of 555 patients diagnosed with WHO grade II LGG (astrocytoma 37.

Enhancement of megavoltage electronic portal images for markerless tumor tracking.

Purpose: The poor quality of megavoltage (MV) images from electronic portal imaging device (EPID) hinders visual verification of tumor targeting accuracy particularly during markerless tumor tracking. The aim of this study was to investigate the effect of a few representative image processing treatments on visual verification and detection capability of tumors under auto tracking.

Methods: Images of QC-3 quality phantom, a single patient's setup image, and cine images of two-lung cancer patients were acquired.

Multi-institutional study of treatment patterns in Korean patients with WHO grade II gliomas: KNOG 15-02 and KROG 16-04 intergroup study.

Introduction: We performed this study to identify the treatment patterns of patients with low-grade gliomas (LGG) in Korea.

Methods: A total of 555 patients diagnosed as WHO grade II gliomas between 2000 and 2010 at 14 Korean institutions were included. The patients were divided into four adjuvant treatment groups: adjuvant fractionated radiotherapy (RT, N = 204), adjuvant chemotherapy (N = 20), adjuvant fractionated RT and chemotherapy (N = 65), and non-adjuvant treatment (N = 266) groups.

MicroRNA-200c increases radiosensitivity of human cancer cells with activated EGFR-associated signaling.

MicroRNA-200c (miR-200c) recently was found to have tumor-suppressive properties by inhibiting the epithelial-mesenchymal transition (EMT) in several cancers. miR-200c also interacts with various cellular signaling molecules and regulates many important signaling pathways. In this study, we investigated the radiosensitizing effect of miR-200c and its mechanism in a panel of human cancer cell lines.

Radiotherapy and immune checkpoint blockades: a snapshot in 2016.

Immune checkpoint blockades including monoclonal antibodies (mAbs) of cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1) have been emerged as a promising anticancer therapy. Several immune checkpoint blockades have been approved by US Food and Drug Administration (FDA), and have shown notable success in clinical trials for patients with advanced melanoma and non-small cell lung cancer. Radiotherapy is a promising combination partner of immune checkpoint blockades due to its potent pro-immune effect.

Brain metastasis in human epidermal growth factor receptor 2-positive breast cancer: from biology to treatment.

Overexpression of human epidermal growth factor receptor 2 (HER2) is found in about 20% of breast cancer patients. With treatment using trastuzumab, an anti-HER2 monoclonal antibody, systemic control is improved. Nonetheless, the incidence of brain metastasis does not be improved, rather seems to be increased in HER2-positive breast cancer.

Impact of Lymph Node Ratio on Oncologic Outcomes in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy followed by Total Mesorectal Excision, and Postoperative Adjuvant Chemotherapy.

Purpose: To evaluate the prognostic impact of the lymph node ratio (LNR) in ypStage III rectal cancer patients who were treated with neoadjuvant chemoradiotherapy (NCRT).

Materials And Methods: We retrospectively reviewed the data of 638 consecutive patients who underwent NCRT followed by total mesorectal excision, and postoperative adjuvant chemotherapy for rectal cancer from 2004 to 2011. Of these, 125 patients were positive for lymph node (LN) metastasis and were analyzed in this study.

Dosimetric effects of the acuros XB and anisotropic analytical algorithm on volumetric modulated arc therapy planning for prostate cancer using an endorectal balloon.

Background: To compare the dosimetric effects of Acuros XB (AXB) and Anisotropic Analytical Algorithm (AAA) on volumetric modulated arc therapy (VMAT) planning for postoperative prostate cancer patients irradiated using an endorectal balloon (ERB).

Methods: We measured central axis doses with film in a phantom containing an air cavity, and compared measurements with calculations of the AAA and AXB. For clinical study, 10 patients who had undergone whole pelvic radiotherapy (WPRT) followed by prostatic bed-only radiotherapy (PBRT) using VMAT were enrolled.