Quantitative analysis of hemodynamic changes induced by the discrepancy between the sizes of the flow diverter and parent artery.

The efficacy of flow diverters is influenced by the strut configuration changes resulting from size discrepancies between the stent and the parent artery. This study aimed to quantitatively analyze the impact of size discrepancies between flow diverters and parent arteries on the flow diversion effects, using computational fluid dynamics. Four silicone models with varying parent artery sizes were developed. Real flow diverters were deployed in these models to assess stent configurations at the aneurysm neck. Virtual stents were generated based on these configurations for computational fluid dynamics analysis. The changes in the reduction rate of the hemodynamic parameters were quantified to evaluate the flow diversion effect. Implanting 4.0 mm flow diverters in aneurysm models with parent artery diameters of 3.0-4.5 mm, in 0.5 mm increments, revealed that a shift from oversized to undersized flow diverters led to an increase in the reduction rates of hemodynamic parameter, accompanied by enhanced metal coverage rate and pore density. However, the flow diversion effect observed transitioning from oversizing to matching was less pronounced when moving from matching to undersizing. This emphasizes the importance of proper sizing of flow diverters, considering the benefits of undersizing and not to exceed the threshold of advantages.

Influence of circle of Willis modeling on hemodynamic parameters in anterior communicating artery aneurysms and recommendations for model selection.

Computational fluid dynamics (CFD) has been utilized to calculate hemodynamic parameters in anterior communicating artery aneurysm (AComA), which is located at a junction between left and right A1 and A2 segments. However, complete or half circle of Willis (CoW) models are used indiscriminately. This study aims to suggest recommendations for determining suitable CoW model. Five patient-specific CoW models with AComA were used, and each model was divided into complete, left-half, and right-half models. After validating the CFD using a flow experiment, the hemodynamic parameters and flow patterns in five AComAs were compared. In four out of five cases, inflow from one A1 side had a dominant influence on the AComA, while both left and right A1 sides affected the AComA in the remaining case. Also, the average difference in time-averaged wall shear stress between the complete and half models for four cases was 4.6%, but it was 62% in the other case. The differences in the vascular resistances of left and right A1 and A2 segments greatly influenced the flow patterns in the AComA. These results may help to enhance clinicians' understanding of blood flow in the brain, leading to improvements in diagnosis and treatment of cerebral aneurysms.

Clinical feasibility of deep learning-based synthetic CT images from T2-weighted MR images for cervical cancer patients compared to MRCAT.

This work aims to investigate the clinical feasibility of deep learning-based synthetic CT images for cervix cancer, comparing them to MR for calculating attenuation (MRCAT). Patient cohort with 50 pairs of T2-weighted MR and CT images from cervical cancer patients was split into 40 for training and 10 for testing phases. We conducted deformable image registration and Nyul intensity normalization for MR images to maximize the similarity between MR and CT images as a preprocessing step. The processed images were plugged into a deep learning model, generative adversarial network. To prove clinical feasibility, we assessed the accuracy of synthetic CT images in image similarity using structural similarity (SSIM) and mean-absolute-error (MAE) and dosimetry similarity using gamma passing rate (GPR). Dose calculation was performed on the true and synthetic CT images with a commercial Monte Carlo algorithm. Synthetic CT images generated by deep learning outperformed MRCAT images in image similarity by 1.5% in SSIM, and 18.5 HU in MAE. In dosimetry, the DL-based synthetic CT images achieved 98.71% and 96.39% in the GPR at 1% and 1 mm criterion with 10% and 60% cut-off values of the prescription dose, which were 0.9% and 5.1% greater GPRs over MRCAT images.

Experience of Implementing Deep Learning-Based Automatic Contouring in Breast Radiation Therapy Planning: Insights From Over 2000 Cases.

PURPOSE: This study evaluated the impact and clinical utility of an auto-contouring system for radiation therapy treatments. METHODS AND MATERIALS: The auto-contouring system was implemented in 2019. We evaluated data from 2428 patients who underwent adjuvant breast radiation therapy before and after the system's introduction. We collected the treatment's finalized contours, which were reviewed and revised by a multidisciplinary team. After implementation, the treatment contours underwent a finalization process that involved manual review and adjustment of the initial auto-contours. For the preimplementation group (n = 369), auto-contours were generated retrospectively. We compared the auto-contours and final contours using the Dice similarity coefficient (DSC) and the 95% Hausdorff distance (HD95). RESULTS: We analyzed 22,215 structures from final and corresponding auto-contours. The final contours were generally larger, encompassing more slices in the superior or inferior directions. Among organs at risk (OAR), the heart, esophagus, spinal cord, and contralateral breast demonstrated significantly increased DSC and decreased HD95 postimplementation (all P < .05), except for the lungs, which presented inaccurate segmentation. Among target volumes, CTVn_L2, L3, L4, and the internal mammary node showed increased DSC and decreased HD95 postimplementation (all P < .05), although the increase was less pronounced than the OAR outcomes. The analysis also covered factors contributing to significant differences, pattern identification, and outlier detection. CONCLUSIONS: In our study, the adoption of an auto-contouring system was associated with an increased reliance on automated settings, underscoring its utility and the potential risk of automation bias. Given these findings, we underscore the importance of considering the integration of stringent risk assessments and quality management strategies as a precautionary measure for the optimal use of such systems.

Therapeutic effects of surgical debulking of metastatic lymph nodes in cervical cancer IIICr: a trial protocol for a phase III, multicenter, randomized controlled study (KGOG1047/DEBULK trial).

BACKGROUND: Bulky or multiple lymph node (LN) metastases are associated with poor prognosis in cervical cancer, and the size or number of LN metastases is not yet reflected in the staging system and therapeutic strategy. Although the therapeutic effects of surgical resection of bulky LNs before standard treatment have been reported in several retrospective studies, well-planned randomized clinical studies are lacking. Therefore, the aim of the Korean Gynecologic Oncology Group (KGOG) 1047/DEBULK trial is to investigate whether the debulking surgery of bulky or multiple LNs prior to concurrent chemoradiation therapy (CCRT) improves the survival rate of patients with cervical cancer IIICr diagnosed by imaging tests. METHODS: The KGOG 1047/DEBULK trial is a phase III, multicenter, randomized clinical trial involving patients with bulky or multiple LN metastases in cervical cancer IIICr. This study will include patients with a short-axis diameter of a pelvic or para-aortic LN ≥2 cm or ≥3 LNs with a short-axis diameter ≥1 cm and for whom CCRT is planned. The treatment arms will be randomly allocated in a 1:1 ratio to either receive CCRT (control arm) or undergo surgical debulking of bulky or multiple LNs before CCRT (experimental arm). CCRT consists of extended-field external beam radiotherapy/pelvic radiotherapy, brachytherapy and LN boost, and weekly chemotherapy with cisplatin (40 mg/m²), 4-6 times administered intravenously. The primary endpoint will be 3-year progression-free survival rate. The secondary endpoints will be 3-year overall survival rate, treatment-related complications, and accuracy of radiological diagnosis of bulky or multiple LNs. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05421650; Clinical Research Information Service Identifier: KCT0007137.

Normal tissue complication probability models of hypothyroidism after radiotherapy for breast cancer.

Purpose: We aimed to develop Lyman-Kutcher-Burman (LKB) and multivariable normal tissue complication probability (NTCP) models to predict the risk of radiation-induced hypothyroidism (RIHT) in breast cancer patients. Materials and methods: A total of 1,063 breast cancer patients who underwent whole breast irradiation between 2009 and 2016 were analyzed. Individual dose-volume histograms were used to generate LKB and multivariable logistic regression models. LKB model was fit using the thyroid radiation dose-volume parameters. A multivariable model was constructed to identify potential dosimetric and clinical parameters associated with RIHT. Internal validation was conducted using bootstrapping techniques, and model performance was evaluated using the area under the curve (AUC) and Hosmer-Lemeshow (HL) goodness-of-fit test. Results: RIHT developed in 4 % of patients with a median follow-up of 77.7 months. LKB and multivariable NTCP models exhibited significant agreement between the predicted and observed results (HL P values > 0.05). The multivariable NTCP model outperformed the LKB model in predicting RIHT (AUC 0.62 vs. 0.54). In the multivariable model, systemic therapy, age, and percentage of thyroid volume receiving ≥ 10 Gy (V10) were significant prognostic factors for RIHT. The cumulative incidence of RIHT was significantly higher in patients who exceeded the cut-off values for all three risk predictors (systemic therapy, age ≥ 40 years, and thyroid V10 ≥ 26 %, P < 0.005). Conclusions: Systemic therapy, age, and V10 of the thyroid were identified as strong risk factors for the development of RIHT. Our NTCP models provide valuable insights to clinicians for predicting and preventing hypothyroidism by identifying high-risk patients.

Choosing the right adjuvant therapy for stage III-IVA endometrial cancer: A comparative analysis of chemoradiotherapy and chemotherapy.

OBJECTIVE: The optimal adjuvant treatment for patients with locally advanced endometrial cancer (EC) remains debatable. We comparatively analyzed recurrence patterns and survival outcomes in patients with stage III-IVA EC treated with adjuvant chemotherapy (CT) exclusively or combined with radiotherapy (CRT). METHODS: We retrospectively analyzed 184 patients treated for stage III-IVA EC at 2 tertiary institutions between 2010 and 2021. All patients underwent standard primary surgery and received either CT alone (n = 89) or CRT (n = 95) as an adjuvant treatment. We compared the failure patterns, recurrence-free survival (RFS), and overall survival (OS) between the CT and CRT groups. RESULTS: The median follow-up period was 54.8 months. Most patients underwent pelvic (94.6%) or para-aortic (75.5%) lymphadenectomies. The 5-year RFS was 69.2% with CRT versus 56.3% with CT (P = 0.038), and 5-year OS was 86.1% versus 78.9% (P = 0.357). Pelvic and para-aortic recurrence rates were significantly higher in the CT group (pelvic: 29.2%; para-aortic: 20.2%) than in the CRT group (pelvic: 10.5%; para-aortic: 6.3%). The CRT group showed a higher rate of distant recurrence (CRT, 23.2% vs. CT, 14.6%) however, the 5-year cumulative incidence of distant recurrence was not significantly different between the two groups (CRT, 28% vs. CT, 35%). CONCLUSIONS: This study highlights the potential benefits of adjuvant CRT in patients with stage III-IVA EC. The incorporation of molecular classification is necessary to derive optimal personalized adjuvant treatment strategies for this patient population.

Diagnostic assessments and treatment results of well-differentiated gastric-type adenocarcinoma of the uterine cervix (Adenoma malignum): A multicenter retrospective analysis of KROG 22-03 study.

OBJECTIVE: Among cervical adenocarcinomas, well-differentiated gastric adenocarcinoma of the uterine cervix (WD-GAS), previously termed adenoma malignum (minimal deviation adenocarcinoma) is not well understood. Because of its rarity and difficulty in diagnosis, there is no standard care for WD-GAS. Thus, we conducted the first multicenter retrospective study on WD-GAS to clarify prognostic factors for long-term survival and recurrence. METHODS: Patients diagnosed with WD-GAS at eight hospitals participated in this multi-center study. Overall survival (OS) and recurrence-free survival (RFS) were calculated with the Kaplan-Meier method. Additionally, OS between the early and advanced FIGO stage groups were compared with the log-rank test. Cox regression analysis was conducted to identify significant factors associated with recurrence-free survival (RFS). RESULTS: A total of 73 patients from eight hospitals in South Korea were included in the analysis. The median follow-up period was 44.8 months, and all patients underwent curative surgical intervention as the primary treatment. Recurrence was observed in 17 patients (23.3%). Ten patients had locoregional recurrence, four patients had distant metastasis, and three patients presented with both locoregional recurrence and distant metastasis. The Cox regression analysis identified several statistically significant factors associated with RFS, including vaginal invasion (VI), parametrial invasion (PMI), resection margin (RM), and nodal and lymphovascular invasion (LVI). When considering these five factors together, patients without any of the factors exhibited recurrence-free survival (RFS) of 97.0% at three years and those with more than one of these factors had a 3-year RFS of 65.4% (P < 0.001). CONCLUSION: WD-GAS showed relatively high locoregional recurrence rate. Positive PMI, VI, RM, nodal involvement, and LVI were associated with a significant increase in recurrence or distant metastasis rates.

Assessment of Eligibility and Utilization of Accelerated Partial Breast Irradiation in Korean Breast Cancer Patients (KROG 22-15).

PURPOSE: We investigated the proportions of patients eligible for accelerated partial breast irradiation (APBI) among those with pT1-2N0 breast cancer, based on the criteria set by the American Society for Radiation Oncology (ASTRO), the Groupe Européen de Curiethérapie and the European Society for Radiotherapy and Oncology (GEC-ESTRO), the American Brachytherapy Society (ABS), and the American Society of Breast Surgeons (ASBS). Additionally, we analyzed the rate of APBI utilization among eligible patients. MATERIALS AND METHODS: Patients diagnosed with pT1-2N0 breast cancer in 2019 were accrued in four tertiary medical centers in Korea. All patients had undergone breast conserving surgery followed by radiotherapy, either whole breast irradiation or APBI. To determine which guideline best predicts the use of APBI in Korea, the F1 score and Matthews Correlation Coefficient (MCC) were determined for each guideline. RESULTS: A total of 1,251 patients were analyzed, of whom 196 (15.7%) underwent APBI. The percentages of eligible patients identified by the ASTRO, GEC-ESTRO, ABS, and ASBS criteria were 13.7%, 21.0%, 50.5%, and 63.5%, respectively. APBI was used to treat 54.4%, 37.2%, 27.1%, and 23.7% of patients eligible by the ASTRO, GEC-ESTRO, ABS, and ASBS criteria, respectively. The ASTRO guideline exhibited the highest F1 score (0.76) and MCC (0.67), thus showing the best prediction of APBI utilization in Korea. CONCLUSION: The proportion of Korean breast cancer patients who are candidates for APBI is substantial. The actual rate of APBI utilization among eligible patients may suggest there is a room for risk-stratified optimization in offering radiation therapy.

Concurrent Lapatinib With Brain Radiation Therapy in Patients With HER2+ Breast Cancer With Brain Metastases: NRG Oncology-KROG/RTOG 1119 Phase 2 Randomized Trial.

PURPOSE: Lapatinib plus whole brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS) was hypothesized to improve the 12-week intracranial complete response (CR) rate compared with either option of radiation therapy (RT) alone for patients with brain metastases (BM) from human epidermal growth factor receptor 2-positive (HER2+) breast cancer. METHODS AND MATERIALS: This study included patients with HER2+ breast cancer with ≥1 measurable, unirradiated BM. Patients were randomized to WBRT (37.5 Gy/3 wk)/SRS (size-based dosing) ± concurrent lapatinib (1000 mg daily for 6 weeks). Secondary endpoints included objective response rate (ORR), lesion-specific response, central nervous system progression-free survival, and overall survival. RESULTS: From July 2012 to September 2019, 143 patients were randomized, with 116 analyzable for the primary endpoint. RT + lapatinib did not improve 12-week CR (0% vs 6% for RT alone, 1-sided P = .97), or ORR at 12 weeks. At 4 weeks, RT + lapatinib showed higher ORR (55% vs 42%). Higher graded prognostic assessment and ≤10 lesions were associated with higher 12-week ORR. Grade 3 and 4 adverse event rates were 8% and 0% for RT and 28% and 6% for RT + lapatinib. CONCLUSIONS: The addition of 6 weeks of concomitant lapatinib to WBRT/SRS did not improve the primary endpoint of 12-week CR rate or 12-week ORR. Adding lapatinib to WBRT/SRS showed improvement of 4-week ORR, suggesting a short-term benefit from concomitant therapy.

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. The difference in IOV of submitted contours in phases 1 and 2 was investigated quantitatively using the Dice similarity coefficient (DSC) and Hausdorff distance (HD). The qualitative analysis involved using contour heat maps to visualize the extent and location of these variations and the required modification. RESULTS: Over 800 pairwise comparisons were analysed for each structure in each case. Quantitative phase 2 metrics showed significant improvement in the mean DSC (from 0.69 to 0.77) and HD (from 34.9 to 17.9 mm). Quantitative analysis showed increased interobserver agreement in phase 2, specifically for CTV structures (5-19 %), leading to fewer manual adjustments. Underlying IOV differences causes were reported using a questionnaire and hierarchical clustering analysis based on the volume of CTVs. CONCLUSION: DL-based auto-contours improved the contour agreement for OARs and CTVs significantly, both qualitatively and quantitatively, suggesting its potential role in minimizing radiation therapy protocol deviation.

Perioperative Low-Dose Aspirin Management for Planned Clipping Surgery: When, How Long, and With What Precautions?

BACKGROUND AND OBJECTIVE: Perioperative low-dose aspirin (ASA) management for open craniotomy surgery lacked information. We analyze to establish the perioperative ASA strategy to minimize both hemorrhagic and thromboembolic complications. METHODS: The investigators designed a multicenter retrospective study, which included patients scheduled to have clipping surgery for unruptured intracranial aneurysm. The incidence and risk factors were analyzed for postoperative hemorrhagic complications and major cardio- and cerebrovascular events (MACCEs) within 1 month postoperation. RESULTS: This study included 503 long-term ASA users of 3654 patients at three tertiary centers. The incidence of hemorrhagic complications and MACCEs was 7.4% (37/503) and 8.8% (44/503), respectively. Older age (>70 years, odds ratio [OR]: 2.928, 95% CI [1.337-6.416]), multiple aneurysms operation (OR: 2.201, 95% CI [1.017-4.765]), large aneurysm (>10 mm, OR: 4.483, 95% CI [1.485-13.533]), and ASA continuation (OR: 2.604, 95% CI [1.222-5.545]) were independent risk factors for postoperative hemorrhagic complications. Intracranial hemorrhage was the only type of hemorrhagic complication that increased in the ASA continuation group (10.6% vs 2.9%, P = .001). Between the ASA continuation and discontinuation groups, the overall incidence of MACCEs was not significantly different (log-rank P = .8). In the subgroup analysis, ASA discontinuation significantly increased the risk of MACCEs in the secondary prevention group (adjusted hazard ratio: 2.580, 95% CI [1.015-6.580]). CONCLUSION: ASA continuation increased the risk of postoperative intracranial hemorrhage. Simultaneously, ASA discontinuation was the major risk factor for postoperative MACCEs in the high-risk group. Without evidence of intracranial hemorrhage, early ASA resumption was indicated (a total cessation duration <7-10 days) in the secondary prevention group.

Large institutional experience of early outcomes and dosimetric findings with postoperative stereotactic partial breast irradiation in breast cancer.

PURPOSE: To analyze the dosimetric and toxicity outcomes of patients treated with postoperative stereotactic partial breast irradiation (S-PBI). METHODS: We identified 799 women who underwent S-PBI at our institution between January 2016 and December 2022. The most commonly used dose-fraction and technique were 30 Gy in 5 fractions (91.7 %) and a robotic stereotactic radiation system with real-time tracking (83.7 %). The primary endpoints were dosimetric parameters and radiation-related toxicities. For comparison, a control group undergoing ultra-hypofractionated whole breast irradiation (UF-WBI, n = 468) at the same institution was selected. RESULTS: A total of 815 breasts from 799 patients, with a median planning target volume (PTV) volume of 89.6 cm3, were treated with S-PBI. Treatment plans showed that the mean and maximum doses received by the PTV were 96.2 % and 104.8 % of the prescription dose, respectively. The volume of the ipsilateral breast that received 50 % of the prescription dose was 32.3 ± 8.9 %. The mean doses for the ipsilateral lung and heart were 2.5 ± 0.9 Gy and 0.65 ± 0.39 Gy, respectively. Acute toxicity occurred in 175 patients (21.5 %), predominantly of grade 1. Overall rate of late toxicity was 4 % with a median follow-up of 31.6 months. Compared to the UF-WBI group, the S-PBI group had comparably low acute toxicity (21.5 % vs. 25.2 %, p = 0.12) but significantly lower dosimetric parameters for all organs-at-risks (all p < 0.05). CONCLUSION: In this large cohort, S-PBI demonstrated favorable dosimetric and toxicity profiles. Considering the reduced radiation exposure to surrounding tissues, external beam PBI with advanced techniques should at least be considered over traditional WBI-based approaches for PBI candidates.

Investigation of paraclinoid aneurysm formation by comparing the combined influence of hemodynamic parameters between aneurysmal and non-aneurysmal arteries.

Numerous studies have evaluated the effects of hemodynamic parameters on aneurysm formation. However, the reasons why aneurysms do not initiate in intracranial arteries are still unclear. This study aimed to investigate the influence of hemodynamic parameters, wall shear stress (WSS) and strain, on aneurysm formation by comparing between aneurysmal and non-aneurysmal arteries. Fifty-eight patients with paraclinoid aneurysms on one side were enrolled. Based on magnetic resonance angiography, each patient's left and right internal carotid arteries (ICAs) were reconstructed. For a patient having an aneurysm on one side, the ICA with the paraclinoid aneurysm was defined as the aneurysmal artery after eliminating the aneurysm, whereas the opposite ICA without aneurysm was defined as the non-aneurysmal artery. Computational fluid dynamics and fluid-structure interaction analyses were then performed for both aneurysmal and non-aneurysmal arteries. Finally, the relationship between high hemodynamic parameters and aneurysm location was investigated. For aneurysmal arteries, high WSS and strain locations were well-matched with the aneurysm formation site. Also, considerable correlations between high WSS and strain locations were observed. However, there was no significant relationship between high hemodynamic parameters and aneurysm formation for non-aneurysmal arteries. The findings are helpful for understanding aneurysm formation mechanism and encouraging further relevant research.

Stereotactic radiosurgery for noncavernous sinus dural arteriovenous fistulas: treatment outcomes and their predictors.

OBJECTIVE: Stereotactic radiosurgery (SRS) has emerged as a safe and effective treatment modality for dural arteriovenous fistulas (dAVFs), particularly cavernous sinus (CS) dAVFs. However, the long-term outcomes of non-CS dAVFs are not well known. This study aimed to evaluate the efficacy and safety of SRS for non-CS dAVFs and to investigate the risk factors for incomplete obliteration. METHODS: Between 2007 and 2020, 65 non-CS dAVFs in 63 patients were treated using SRS at a single institution. Demographic characteristics, initial clinical presentations, clinical outcomes, and radiological findings were retrospectively reviewed. The procedure-related complications were assessed. Radiological outcomes were evaluated as complete obliteration, incomplete obliteration, and angiographic worsening, whereas clinical outcomes were evaluated for symptom recovery. RESULTS: At a median follow-up of 17 months, the overall complete obliteration rate was 63.1%, and the cumulative obliteration rates were 24.6%, 60.0%, 70.0%, and 74.3% at 12, 24, 36, and 48 months, respectively. Six patients underwent retreatment due to angiographic worsening; in 5 of these patients, recruitment of arterial feeders was newly observed in the adjacent sinus, which was not treated in the initial SRS. In the multivariate analysis, high-flow shunt and venous ectasia were associated with incomplete obliteration. No adverse events occurred after SRS. CONCLUSIONS: SRS for non-CS dAVFs is safe, and its efficacy is highly variable according to location. High-flow shunts may indicate greater radioresistance. In the retreated cases, new fistulas tended to be accompanied by sinus steno-occlusion and formed in the adjacent sinus segments.

Study protocol for prospective multi-institutional phase III trial of standard of care therapy with or without stereotactic ablative radiation therapy for recurrent ovarian cancer (SABR-ROC).

BACKGROUND: Efforts have been made to investigate the role of salvage radiotherapy (RT) in treating recurrent ovarian cancer (ROC). Stereotactic ablative radiation therapy (SABR) is a state-of-the-art therapy that uses intensity modulation to increase the fractional dose, decrease the number of fractions, and target tumors with high precision. METHODS: The SABR-ROC trial is a phase 3, multicenter, randomized, prospective study to evaluate whether the addition of SABR to the standard of care significantly improves the 3-year overall survival (OS) of patients with ROC. Patients who have completed the standard treatment for primary epithelial ovarian cancer are eligible. In addition, patients with number of metastases ≤ 10 and maximum diameter of each metastatic site of gross tumor ≤ 5 cm are allowed. Randomization will be stratified by (1) No. of the following clinical factors met, platinum sensitivity, absence of ascites, normal level of CA125, and ECOG performance status of 0-1; 0-3 vs. 4; (2) site of recurrence; with vs. without lymph nodes; and (3) PARP inhibitor; use vs. non-use. The target number of patients to be enrolled in this study is 270. Participants will be randomized in a 1:2 ratio. Participants in Arm 2 will receive SABR for recurrent lesions clearly identified in imaging tests as well as the standard of care (Arm 1) based on treatment guidelines and decisions made in multidisciplinary discussions. The RT fraction number can range from 1 to 10, and the accepted dose range is 16-45 Gy. The RT Quality Assurance (QA) program consists of a three-tiered system: general credentialing, trial-specific credentialing, and individual case reviews. DISCUSSION: SABR appears to be preferable as it does not interfere with the schedule of systemic treatment by minimizing the elapsed days of RT. The synergistic effect between systemic treatment and SABR is expected to reduce the tumor burden by eradicating gross tumors identified through imaging with SABR and controlling microscopic cancer with systemic treatment. It might also be beneficial for quality-of-life preservation in older adults or heavily treated patients. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov (NCT05444270) on June 29th, 2022.

Retinal artery/arteriole occlusion risks after endovascular treatment for unruptured intracranial aneurysm.

BACKGROUND: To evaluate the association between retinal artery/arteriole occlusion (RAO) and unruptured intracranial aneurysm (UIA). METHODS: Incident UIA patients from a nationwide cohort (n=253 240) were categorised into three groups based on subsequent treatment: observation (n=208 993), microsurgical clipping (n=14 168) and endovascular treatment (EVT) groups (n=30 079). The incidence and the incident time of RAO were analysed. HRs of RAO and associated risk factors were evaluated. Additionally, a hospital cohort comprising 2569 consecutive UIA patients treated at a tertiary hospital was analysed with detailed clinical information of UIAs. RESULTS: In the nationwide cohort analysis, the incidence of RAO was significantly higher in EVT group than in observation and clipping groups, especially within 60 days (early RAO (within 60 days): HR=4.00, 95% CI: 2.44 to 6.56); delayed RAO (after 60 days): HR=1.74, 95% CI: 1.13 to 2.68). Multivariable analysis showed that the presence of chronic kidney disease (p=0.009) and use of a balloon microcatheter during the procedure (p=0.013) were associated with a higher risk of RAO. In hospital cohort analysis, 11 (0.8%) cases of RAO occurred after EVT, whereas none occurred after microsurgical clipping (p<0.001). Patients with RAO were younger and received balloon microcatheters more frequently than their counterparts. Ten cases of RAO (90.9%) occurred in paraclinoid aneurysms, where EVT was preferred over microsurgical clipping. CONCLUSIONS: Performing EVT for UIA may increase the risk of subsequent RAO. Care should be taken when treating paraclinoid aneurysms with balloon microcatheters.

Machine learning­based radiomics models for prediction of locoregional recurrence in patients with breast cancer.

Locoregional recurrence (LRR) is the predominant pattern of relapse after definitive breast cancer treatment. The present study aimed to develop machine learning (ML)-based radiomics models to predict LRR in patients with breast cancer by using preoperative magnetic resonance imaging (MRI) data. Data from patients with localized breast cancer that underwent preoperative MRI between January 2013 and December 2017 were collected. Propensity score matching (PSM) was performed to adjust for clinical factors between patients with and without LRR. Radiomics features were obtained from T2-weighted with and without fat-suppressed MRI and contrast-enhanced T1-weighted with fat-suppressed MRI. In the present study five ML models were designed, three base models (support vector machine, random forest, and logistic regression) and two ensemble models (voting model and stacking model) composed of the three base models, and the performance of each base model was compared with the stacking model. After PSM, 28 patients with LRR and 86 patients without LRR were included. Of these 114 patients, 80 patients were randomly selected to train the models, and the remaining 34 patients were used to evaluate the performance of the trained models. In total, 5,064 features were obtained from each patient, and 47-51 features were selected by applying variance threshold and least absolute shrinkage and selection operator. The stacking model demonstrated superior performance in area under the receiver operating characteristic curve (AUC), with an AUC of 0.78 compared to a range of 0.61 to 0.70 for the other models. An external validation study to investigate the efficacy of the stacking model of the present study was initiated and is still ongoing (Korean Radiation Oncology Group 2206).

Quality-adjusted survival in women with gynecologic malignancies receiving IMRT after surgery: A Ppatient Rreported Ooutcome study of NRG oncology's RTOG 1203.

INTRODUCTION: NRG/RTOG 1203 compared 3-D conformal radiotherapy (3D CRT) to intensity-modulated radiotherapy (IMRT) in patients with endometrial or cervical cancer requiring post-operative radiotherapy after hysterectomy. The purpose of this study was to report the first quality-adjusted survival analysis comparing the two treatments. METHODS: NRG/RTOG 1203 randomized patients having undergone hysterectomy to either 3DCRT or IMRT. Stratification factors included RT dose, chemotherapy, and disease site. The EQ-5D, both index and visual analog scale (VAS), were obtained at baseline, 5 weeks after the start of RT, 4-6 weeks post RT and 1 and 3-years post RT. EQ-5D index and VAS scores along with quality-adjusted survival (QAS) were compared between treatment arms using the t-test at a two-sided significance level of 0.05. RESULTS: NRG/RTOG 1203 enrolled 289 patients of which 236 consented to participate in the patient reported outcome (PRO) assessments. QAS was higher in women treated with IMRT, 1374 vs 1333 days (p = 0.5) compared to patients treated with 3DCRT, but this difference was not statistically different. Patients treated with IMRT had less of a decline in VAS score 5 weeks post RT, -5.04, compared to patients treated with 3DCRT, -7.48, although not statistically significant (p = 0.38). CONCLUSION: This is the first report of the use of the EQ-5D comparing two radiotherapy techniques in the treatment of gynecologic malignancies after surgery. While there were no significant differences in QAS and VAS scores between patients who received IMRT vs. 3DCRT, RTOG 1203 was not powered to show statistical differences in these secondary endpoints.