Upfront Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy in Elderly Patients with Brain Metastases from Non-small cell lung cancer: A Retrospective Analysis of a 10-Year Bi-Institutional Experience.

Purpose: Stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) are increasingly used as initial therapies for brain metastases (BM). We aimed to assess the outcomes of SRS/FSRT in patients aged ≥65 years who had 1-10 BM from non-small cell lung cancer (NSCLC). Materials and Methods: We retrospectively reviewed 91 elderly NSCLC patients with 222 BM who were treated with SRS/FSRT at two institutions between 2010 and 2020. The primary endpoint was overall survival (OS) after SRS/FSRT. In addition, in-field local control (IFLC) within the treated field was evaluated. Statistical analysis was performed to identify the prognostic factors affecting OS and IFLC. Results: During a median follow-up of 18 months, the median OS was 32 months. The 1- and 2-year survival rates were 69.8 and 56.1%, respectively. In multivariate analysis, the NSCLC-specific graded prognostic assessment (GPA) score (p=0.007) and administration of systemic therapy (p=0.039) were defined as prognosticators affecting OS. The median IFLC period was 31 months, and the 1- and 2-year IFLC rates were 75.9 and 57.6%, respectively. The total BM volume (p=0.042) significantly affected IFLC. No severe adverse events were reported after SRS/FSRT. Conclusion: SRS/FSRT is an effective upfront treatment option for BM arising from NSCLC in elderly patients, with a good OS without severe side effects. Higher GPA score and active systemic treatment were associated with improved OS, indicating that elderly patients are significant candidates for SRS/FSRT.

Correction: Sung et al. Linear Tumor Regression of Rectal Cancer in Daily MRI during Preoperative Chemoradiotherapy: An Insight of Tumor Regression Velocity for Personalized Cancer Therapy. Cancers 2022, 14, 3749.

In the original publication [...].

Ceramic Aneurysm Clip with Titanium Spring.

OBJECTIVE: To design and evaluate ceramic aneurysm clips with integrated titanium springs, focusing on ergonomic application and precision in neurosurgical procedures. METHODS: The clip design was executed with precision using Creo Parametric 3D CAD software. It comprises a zirconia body and a titanium spring for durability and consistent tension and features a four-coil hairpin titanium spring for enhanced closing force and a ball-type head for versatile maneuverability during surgery. To assess durability, closing forces were rigorously measured using a force gauge system, comparing the ceramic clip with the standard Mizuho permanent clip over 30 open-close cycles. For MR artifact assessment, both ceramic and Yasargil clips were evaluated using a 3 Tesla magnetic resonance imaging (MRI) scanner with specific imaging sequences. RESULTS: The straight type ceramic clip's initial closing force was 1.70 N, dropping to 1.22 N after 30 cycles, indicating a retention of 72% of its initial force. In MRI, the ceramic clip displayed significantly lower measurement discrepancies compared to the titanium alloy Yasargil clip, particularly in high resolution T1 weighted images. The lowest variance was at measurement point L2, where the ceramic clip showed 3% discrepancy. Further, the ceramic clip yielded clearer images than the titanium alloy clip, particularly at the clip's end. CONCLUSIONS: Ceramic clips with titanium springs demonstrated satisfactory closing force and superior MRI compatibility, promising enhancements in surgical application and postoperative assessment.

Preservation of the middle meningeal artery during unruptured aneurysm surgery: an independent risk factor for postoperative chronic subdural hematoma.

Background: Although microsurgical clipping for unruptured aneurysms has become safer and more efficient with modern neurosurgical advances, postoperative chronic subdural hematoma (CSDH) persists as an underrecognized complication. This study investigated the association between preservation of the anterior branch of the middle meningeal artery (MMA) during surgery and CSDH development. Methods: We retrospectively reviewed 120 patients who underwent clipping for unruptured aneurysms at Kyungpook National University Chilgok Hospital between May 2020 and July 2023. We evaluated the patients on the basis of surgical approach-lateral supraorbital (LSO) or standard pterional craniotomy-and the status of the MMA postoperatively. We employed pre-and post-operative MR angiography to assess MMA preservation and used follow-up computed tomography scans to monitor CSDH development. Results: Of the 120 patients, 22 (18.3%) developed CSDH. Univariate analysis revealed that male sex, advanced age, and MMA preservation are risk factors for postoperative CSDH. Multivariate analysis supported these findings, indicating a significant association with the development of CSDH. MMA preservation was reported in 65 patients, of whom 60 and 5 underwent LSO and pterional craniotomy, respectively. Conclusion: Preservation of the anterior branch of the MMA during unruptured aneurysm surgery is a risk factor for postoperative CSDH development. Advanced age and male sex also contribute to the increased risk. These findings highlight the need for further investigation into surgical techniques that could mitigate postoperative CSDH development.

Alterations in Plasma Lipid Profile before and after Surgical Removal of Soft Tissue Sarcoma.

Soft tissue sarcoma (STS) is a relatively rare malignancy, accounting for about 1% of all adult cancers. It is known to have more than 70 subtypes. Its rarity, coupled with its various subtypes, makes early diagnosis challenging. The current standard treatment for STS is surgical removal. To identify the prognosis and pathophysiology of STS, we conducted untargeted metabolic profiling on pre-operative and post-operative plasma samples from 24 STS patients who underwent surgical tumor removal. Profiling was conducted using ultra-high-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry. Thirty-nine putative metabolites, including phospholipids and acyl-carnitines were identified, indicating changes in lipid metabolism. Phospholipids exhibited an increase in the post-operative samples, while acyl-carnitines showed a decrease. Notably, the levels of pre-operative lysophosphatidylcholine (LPC) O-18:0 and LPC O-16:2 were significantly lower in patients who experienced recurrence after surgery compared to those who did not. Metabolic profiling may identify aggressive tumors that are susceptible to lipid synthase inhibitors. We believe that these findings could contribute to the elucidation of the pathophysiology of STS and the development of further metabolic studies in this rare malignancy.

Successive Development and Rupture of Blister-Like Anterior Communicating Artery Aneurysms at Mirror Locations.

This is the first report of the successive development and rupture of blister-like anterior communicating artery (ACoA) aneurysms at mirror locations with a short interval. A 49-year-old man presented with an angiogram-negative subarachnoid hemorrhage with significant basal frontal interhemispheric blood. Surgical exploration revealed a blister-like aneurysm on the left side of the superior wall of the ACoA, which was treated using a microsuturing technique. On the 18th day after the initial subarachnoid hemorrhage, the second operation due to another angiogram-negative hemorrhage revealed a de novo blister-like aneurysm with a small blood clot on the posterosuperior wall of the ACoA close to the right A1/A2 junction. The rupture point and ACoA on the right side were occluded using an aneurysm clip. Follow-up digital subtraction angiogram (DSA) at 4 years and computed tomography angiogram (CTA) at 14 years after the surgery showed no recurrence or associated abnormality.

The impact of boost radiation therapy after hysterectomy on cervical cancer patients with close or positive resection margins.

PURPOSE: We investigated the effect of boost radiation therapy (RT) in addition to whole pelvis RT (WPRT) on treatment outcome and safety of cervical cancer patients following hysterectomy with close/positive resection margins (RM). METHODS: We retrospectively analyzed 51 patients with cervical cancer who received WPRT with or without boost-RT as adjuvant treatment between July 2006 and June 2022. Twenty patients (39.2%) were treated with WPRT-alone, and 31 (60.8%) received boost-RT after WPRT using brachytherapy or intensity-modulated RT. RESULTS: The median follow-up period was 41 months. According to RT modality, the 4-year local control (LC) and locoregional control (LRC) rates of patients treated with WPRT-alone were 61% and 61%, respectively, whereas those in LC and LRC rates in patients who underwent WPRT with boost-RT were 93.2% and 75.3%, with p-values equal to 0.005 and 0.090, respectively. Seven patients (35.0%) had local recurrence in the WPRT-treated group compared to only two out of the 31 patients (6.5%) in the WPRT with boost-RT-treated counterparts (p = 0.025). Boost-RT was a significantly good prognostic factor for LC (p = 0.013) and LRC (p = 0.013). Boost-RT did not result in statistically-significant improvements in progression-free survival or overall survival. The acute and late toxicity rates were not significantly different between groups. CONCLUSION: Boost RT following WPRT is a safe and effective treatment strategy to improve LC without increasing toxicity in patients with cervical cancer with close/positive RM after hysterectomy.

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.

A Real-World Comparative Analysis of Atezolizumab Plus Bevacizumab and Transarterial Chemoembolization Plus Radiotherapy in Hepatocellular Carcinoma Patients with Portal Vein Tumor Thrombosis.

This study aimed to compare the treatment outcomes of atezolizumab-plus-bevacizumab (Ate/Bev) therapy with those of transarterial chemoembolization plus radiotherapy (TACE + RT) in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombosis (PVTT) and without metastasis. Between June 2016 and October 2022, we consecutively enrolled 855 HCC patients with PVTT. After excluding 758 patients, 97 patients (n = 37 in the Ate/Bev group; n = 60 in the TACE + RT group) were analyzed. The two groups showed no significant differences in baseline characteristics and had similar objective response and disease control rates. However, the Ate/Bev group showed a significantly higher one-year survival rate (p = 0.041) compared to the TACE + RT group, which was constantly displayed in patients with extensive HCC burden. Meanwhile, the clinical outcomes were comparable between the two groups in patients with unilobar intrahepatic HCC. In Cox-regression analysis, Ate/Bev treatment emerged as a significant factor for better one-year survival (p = 0.049). Finally, in propensity-score matching, the Ate/Bev group demonstrated a better one-year survival (p = 0.02) and PFS (p = 0.01) than the TACE + RT group. In conclusion, Ate/Bev treatment demonstrated superior clinical outcomes compared to TACE + RT treatment in HCC patients with PVTT. Meanwhile, in patients with unilobar intrahepatic HCC, TACE + RT could also be considered as an alternative treatment option alongside Ate/Bev therapy.

Unexpected shunt-dependent hydrocephalus after unruptured aneurysm surgery-a case report.

A chronic hydrocephalus after unruptured aneurysm surgery is an extremely rare condition. Its etiology and pathophysiology are also unclear. We report a case of chronic hydrocephalus in a patient who underwent permanent shunt placement after unruptured aneurysm clipping surgery. A 65-year-old man developed chronic hydrocephalus requiring shunt placement after clipping surgery of left anterior cerebral artery aneurysm and right middle cerebral artery aneurysm. This case shows that chronic hydrocephalus is a possible complication of unruptured aneurysm surgery, which can be resolved with an appropriate shunt operation.

Reduced volume intensity-modulated radiotherapy with simultaneous integrated boost for patients with high-grade glioma: A retrospective observational study.

Radiotherapy (RT) is an essential treatment for patients with high-grade gliomas. however, a consensus on the target area of RT has not yet been achieved. In this study, we aimed to analyze progression-free survival (PFS), recurrence patterns, and toxicity in patients who received reduced volume intensity-modulated radiotherapy with simultaneous integrated boost (rvSIB-IMRT). In addition, we attempted to identify prognostic factors for recurrence. Twenty patients with high-grade gliomas who received rvSIB-IMRT between July 2011 and December 2021 were retrospectively analyzed. For rvSIB-IMRT, clinical target volume 1/2 was set at a 5 to 10 mm margin on each gross tumor volume (GTV) 1 (resection cavity and enhanced lesion) and GTV2 (high-signal lesion of T2/fluid-attenuated inversion recovery). RT doses were prescribed to 60 Gy/30 fractions (fxs) for planning target volume (PTV)1 and 51 to 54 Gy/30 fxs for PTV2. The median PFS and overall survival of the total cohorts were 10.6 and 13.6 months, respectively. Among the 12 relapsed patients, central, in-field, and marginal recurrences were identified in 8 (66.7%), 2 (16.7%), and 1 patient (8.3%), respectively. Distant recurrence was identified in 3 patients. Gross total resection (GTR) and high Ki-67 index (>27.4%), and subventricular involvement (SVI) were identified as significant factors for PFS in the multivariate analysis. During the follow up, 4 patients showed pseudoprogression and 1 patient showed radiation necrosis. The rvSIB-IMRT for high-grade gliomas resulted in comparable PFS and tolerable toxicity. Most recurrences were central/in-field (10 cases of 12, 83.4%). GTR, high Ki-67 index (>27.4%), and SVI were significant factors for recurrence.

Efficacy of Liver-Directed Combined Radiotherapy in Locally Advanced Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis.

PURPOSE: Although systemic treatment is the mainstay for advanced hepatocellular carcinoma (HCC), numerous studies have highlighted the added value of local treatment. This study aimed to investigate the clinical efficacy of liver-directed combined radiotherapy (LD combined RT) compared with that of sorafenib, a recommended treatment until recently for locally advanced HCC presenting portal vein tumor thrombosis (PVTT), using a multinational patient cohort. MATERIALS AND METHODS: We identified patients with HCC presenting PVTT treated with either sorafenib or LD combined RT in 10 tertiary hospitals in Asia from 2005 to 2014. Propensity score matching (PSM) was performed to minimize the imbalance between the two groups. The primary endpoint was overall survival (OS), and the secondary endpoints were progression-free survival (PFS) and treatment-related toxicity. RESULTS: A total of 1035 patients (675 in the LD combined RT group and 360 in the sorafenib group) were included in this study. After PSM, 305 patients from each group were included in the analysis. At a median follow-up of 22.5 months, the median OS was 10.6 and 4.2 months for the LD combined RT and sorafenib groups, respectively (p < 0.001). The conversion rate to curative surgery was significantly higher (8.5% vs. 1.0%, p < 0.001), while grade ≥ 3 toxicity was fewer (9.2% vs. 16.1%, p < 0.001) in the LD combined RT group. CONCLUSIONS: LD combined RT improved survival outcomes with a higher conversion rate to curative surgery in patients with locally advanced HCC presenting PVTT. Although further prospective studies are warranted, active multimodal local treatment involving radiotherapy is suggested for locally advanced HCC presenting PVTT.

Re-Irradiation with Intensity-Modulated Radiation Therapy for the Treatment of Recurrent Cervical Cancer in the Pelvis: An Analysis of Outcomes and Toxicity.

Background and Objectives: Treatment options for most patients with recurrent cervical cancer within the previously irradiated field are limited. This study aimed to investigate the feasibility and safety of re-irradiation using intensity-modulated radiation therapy (IMRT) for patients with cervical cancer who experienced intrapelvic recurrence. Materials and Methods: We retrospectively analyzed 22 patients with recurrent cervical cancer who were treated with re-irradiation for intrapelvic recurrence using IMRT between July 2006 and July 2020. The irradiation dose and volume were determined based on the range considered safe for the tumor size, location, and previous irradiation dose. Results: The median follow-up period was 15 months (range: 3-120) and the overall response rate was 63.6%. Of the symptomatic patients, 90% experienced symptom relief after treatment. The 1- and 2-year local progression-free survival (LPFS) rates were 36.8% and 30.7%, respectively, whereas the 1- and 2-year overall survival (OS) rates were 68.2% and 25.0%, respectively. Multivariate analysis revealed that the interval between irradiations and gross tumor volume (GTV) were significant prognostic factors for LPFS. The response to re-irradiation showed borderline statistical significance for LPFS. The GTV and response to re-irradiation were also independent prognostic factors for OS. Grade 3 late toxicities were observed in 4 (18.2%) of the 22 patients. Recto- or vesico-vaginal fistula occurred in four patients. The irradiation dose was associated with fistula formation with borderline significance. Conclusions: Re-irradiation using IMRT is a safe and effective treatment strategy for patients with recurrent cervical cancer who previously received RT. Interval between irradiations, tumor size, response to re-irradiation, and radiation dose were the main factors affecting efficacy and safety.

Non-endometrioid endometrial cancer: analysis of recurrence pattern and identification of prognostic and treatment factors affecting recurrence and survival.

PURPOSE: We investigated the characteristics of recurrence pattern and survival of patients with non-endometrioid endometrial cancer (NEEC) and attempted to identify prognostic and treatment factors affecting disease-free survival (DFS) and overall survival (OS) of these patients. METHODS: Fifty-seven patients with histologically confirmed International Federation of Gynecology and Obstetrics (FIGO) stage IA-IVA NEEC from February 2003 to December 2021 were retrospectively analyzed. RESULTS: The 5­year DFS and OS rates of the total cohort were 50.6% and 56.1%, respectively. Recurrence occurred in 28 patients (49.1%) during follow-up, and the most common recurrence pattern was distant metastasis (DM; 78.6% of total recurrences). The occurrence of relapse significantly reduced 5­year OS (recurrence group vs. non-recurrence group: 12.5% vs. 100%; p < 0.001). In univariate analysis, adjuvant radiotherapy (RT) group showed significantly higher 5­year DFS (56.7% vs. 37.9%; p = 0.04), local recurrence-free survival (91.6% vs. 50.5%; p = 0.01), and regional recurrence-free survival (88.2% vs. 56.5%; p < 0.01) than the non-RT group. In multivariate analysis, advanced FIGO stage was identified as a negative prognostic factor for DFS and OS. Lymphovascular space invasion (LVSI) and adjuvant RT were independent prognostic factors for DFS. CONCLUSION: The most common recurrence pattern observed in patients with NEEC was DM. FIGO stage and LVSI were identified as prognostic factors for survival, and RT was identified as a therapeutic modality that could increase DFS. To improve the OS of patients with NEEC, the addition of effective chemotherapy that can reduce DM may be important.

Omission of axillary lymph node dissection in patients with ypN+ breast cancer after neoadjuvant chemotherapy: A retrospective multicenter study (KROG 21-06).

BACKGROUND: We evaluated the impact of omitting axillary lymph node dissection (ALND) on oncological outcomes in breast cancer patients with residual nodal disease after neoadjuvant chemotherapy (NAC). METHODS: The medical records of patients who underwent NAC followed by surgical resection and had residual nodal disease were retrospectively reviewed. In total, 1273 patients from 12 institutions were included; all underwent postoperative radiotherapy. Axillary surgery consisted of ALND in 1103 patients (86.6%) and sentinel lymph node biopsy (SLNBx) alone in 170 (13.4%). Univariate and multivariate analyses of disease-free survival (DFS) and overall survival (OS) were performed before and after propensity score matching (PSM). RESULTS: The median follow-up was 75.3 months (range, 2.5-182.7). Axillary recurrence rates were 4.8% in the ALND group (n = 53) and 4.7% in the SLNBx group (n = 8). Before PSM, univariate analysis indicated that the 5-year OS rate was inferior in the ALND group compared to the SLNBx group (86.6% vs. 93.3%, respectively; P = 0.002); multivariate analysis did not show a difference between groups (P = 0.325). After PSM, 258 and 136 patients were included in the ALND and SLNBx groups, respectively. There were no significant differences between the ALND and SLNBx groups in DFS (5-year rate, 75.8% vs. 76.9%, respectively; P = 0.406) or OS (5-year rate, 88.7% vs. 93.1%, respectively; P = 0.083). CONCLUSIONS: SLNBx alone did not compromise oncological outcomes in patients with residual nodal disease after NAC. The omission of ALND might be a possible option for axillary management in patients treated with NAC and postoperative radiotherapy.

Clinical adoption patterns of 0.35 Tesla MR-guided radiation therapy in Europe and Asia.

BACKGROUND: Magnetic resonance-guided radiotherapy (MRgRT) utilization is rapidly expanding, driven by advanced capabilities including better soft tissue imaging, continuous intrafraction target visualization, automatic triggered beam delivery, and the availability of on-table adaptive replanning. Our objective was to describe patterns of 0.35 Tesla (T)-MRgRT utilization in Europe and Asia among early adopters of this novel technology. METHODS: Anonymized administrative data from all 0.35T-MRgRT treatment systems in Europe and Asia were extracted for patients who completed treatment from 2015 to 2020. Detailed treatment information was analyzed for all MR-linear accelerators (linac) and -cobalt systems. RESULTS: From 2015 through the end of 2020, there were 5796 completed treatment courses delivered in 46,389 individual fractions. 23.5% of fractions were adapted. Ultra-hypofractionated (UHfx) dose schedules (1-5 fractions) were delivered for 63.5% of courses, with 57.8% of UHfx fractions adapted on-table. The most commonly treated tumor types were prostate (23.5%), liver (14.5%), lung (12.3%), pancreas (11.2%), and breast (8.0%), with increasing compound annual growth rates (CAGRs) in numbers of courses from 2015 through 2020 (pancreas: 157.1%; prostate: 120.9%; lung: 136.0%; liver: 134.2%). CONCLUSIONS: This is the first comprehensive study reporting patterns of utilization among early adopters of a 0.35T-MRgRT system in Europe and Asia. Intrafraction MR image-guidance, advanced motion management, and increasing adoption of on-table adaptive RT have accelerated a transition to UHfx regimens. MRgRT has been predominantly used to treat tumors in the upper abdomen, pelvis and lungs, and increasingly with adaptive replanning, which is a radical departure from legacy radiotherapy practices.

Linear Tumor Regression of Rectal Cancer in Daily MRI during Preoperative Chemoradiotherapy: An Insight of Tumor Regression Velocity for Personalized Cancer Therapy.

Objective: Neoadjuvant chemoradiotherapy (CCRT) is current standards of care for locally advanced rectal cancer. The precise and thorough investigation of a tumor during the full course of CCRT by means of daily MRI can provide an idea on real-time treatment sensitivity in addition to tumor biology. Tumor volumetry from daily MRI during CCRT may allow patient-driven treatment decisions. Material and Methods: Patients diagnosed with cT3-4 and/or cN+ rectal adenocarcinoma undergoing preoperative CCRT with capecitabine on the pelvis up to 50 Gy in 25 daily fractions from November 2018 to June 2019 were consecutively included. Rectal tumor volume was uniformly measured by a single physician (YKK) in daily 0.35T MRI obtained with MR-guided linear accelerator. Primary endpoint was to assess the pattern of tumor volume regression throughout the full course of CCRT using daily registration MRI. Secondary endpoint was to assess the effect of tumor regression velocity on disease-free survival (DFS). Tumor regression velocity (cc) per fraction of each patient was calculated using the simple regression analysis of tumor volumes from fraction 1 to fraction 25. Results: Twenty patients were included. Daily tumor volumetry demonstrated linear tumor regression during CCRT. The tumor regression velocity of all 20 patients was 2.40 cc per fraction (R2 = 0.93; p < 0.001). The median tumor regression velocity was 1.52 cc per fraction. Patients with tumor regression velocity ≥ 1.52 cc per fraction were grouped as rapid regressors (N = 9), and those with tumor regression velocity < 1.52 cc per fraction were grouped as slow regressors (N = 11). Rapid regressors had greater tumor regression velocity (4.58 cc per fraction) compared to that of slow regressors (0.78 cc per fraction) with statistical significance (p < 0.001). The mean DFS of rapid regressors was 36.8 months, numerically longer than the 31.9 months of slow regressors (p = 0.400) without statistical significance. Rapid regressors had numerically superior DFS rate compared to slow regressors without statistical significance. The 2-year DFS was 88.9% for rapid regressors and 72.7% for slow regressors, respectively (p = 0.400). Conclusion: This study is the first observation of linear tumor regression in daily MRI during the preoperative CCRT of locally advanced rectal cancer. Daily tumor regression velocity discriminated DFS, although without statistical significance. This study with a phenomenal approach is hypothesis-generating. Nevertheless, the potential of CCRT from therapeutics to a newer level, the "theranostics", has been inceptively suggested. Further validation studies for the value of daily tumor volumetry on treatment decisions are warranted.

Application of real-time MRI-guided linear accelerator in stereotactic ablative body radiotherapy for non-small cell lung cancer: one step forward to precise targeting.

PURPOSE: Tumor motion is a major challenge in stereotactic ablative body radiotherapy (SABR) for non-small cell lung cancer (NSCLC), causing excessive irradiation to compensate for this motion. Real-time tumor tracking with a magnetic resonance imaging-guided linear accelerator (MR-Linac) could address this problem. This study aimed to assess the effects and advantages of MR-Linac in SABR for the treatment of lung tumors. METHODS: Overall, 41 patients with NSCLC treated with SABR using MR-Linac between March 2019 and December 2021 were included. For comparison, 40 patients treated with SABR using computed tomography-based modalities were also enrolled. The SABR dose ranged from 48 to 60 Gy in 3-5 fractions. The primary endpoint was a lower radiation volume compared to CT-based SABR. The secondary endpoint was the local control rate of SABR using the MR-Linac. RESULTS: The median follow-up time was 19 months (range: 3-105 months). There was no significant difference in the gross tumor volume between the MR and CT groups (7.1 ± 9.3 cm3 vs 8.0 ± 6.8 cm3, p = 0.643), but the planning target volume was significantly smaller in the MR group (20.8 ± 18.8 cm3 vs 34.1 ± 22.9 cm3, p = 0.005). The 1-year local control rates for the MR and CT groups were 92.1 and 75.4%, respectively (p = 0.07), and the 1-year overall survival rates were 87.4 and 87.0%, respectively (p = 0.30). CONCLUSION: Lung SABR with MR-Linac can reduce the radiation field without compromising the local control rate. Further follow-up is needed to assess the long-term effects.

Comparison of Heart and Lung Doses According to Tumor Bed Boost Techniques in Early-Stage Left-Sided Breast Cancer: Simultaneous Integrated Boost versus Sequential Boost.

Background and Objectives: The boost dose to the tumor bed after whole breast irradiation (WBI) can be divided into sequential boost (SEQ) and simultaneous integrated boost (SIB). SIB using modern radiation therapy (RT) techniques, such as volumetric modulated arc therapy, allow the delivery of a highly conformal dose to the target volume and has a salient ability to spare at-risk organs. This study aimed to compare the radiation dose delivered to the heart and lungs according to boost technique and tumor bed location. Materials and Methods: RT planning data of 20 patients with early-stage left-sided breast cancer were used in this study. All patients were treated with volumetric modulated arc therapy after breast-conserving surgery with a sentinel lymph node biopsy. For each patient, two different plans, whole breast irradiation with simultaneous integrated boost (WBI-SIB) and sequential boost after WBI (WBI-SEQ), were generated. To compare the dose received by each organ at risk (OAR), dose-volume histogram data were analyzed. The mean dose (Dmean) and volume of each organ that received x Gy (Vx) were calculated and compared. Results: For the heart, the V10 was lower for the WBI-SIB plan than for the WBI-SEQ plan (5.223 ± 1.947% vs. 6.409 ± 2.545%, p = 0.008). For the left lung, the V5 was lower in the WBI-SIB plan than for the WBI-SEQ plan (27.385 ± 3.871% vs. 32.092 ± 3.545%, p < 0.001). The Dmean for the heart and left lung was lower for the WBI-SIB plan than for the WBI-SEQ plan (heart: 339.745 ± 46.889 cGy vs. 413.030 ± 52.456 cGy, p < 0.001; left lung: 550.445 ± 65.094 cGy vs. 602.270 ± 55.775 cGy, p < 0.001). Conclusions: The WBI-SIB plan delivered lower radiation doses to the heart and left lung than the WBI-SEQ plan in terms of Dmean and low-dose volume in hypofractionated RT of early-stage left-sided breast cancer patients. Furthermore, a large radiation dose per day may be advantageous, considering the radiobiologic aspects of breast cancer. Long-term follow-up data are needed to determine whether the dosimetric advantages of the WBI-SIB plan can lead to clinically improved patient outcomes and reduced late side effects.