Dosimetric Correlation of Acute Radiation Dermatitis in Patients With Breast Cancer Undergoing Hypofractionated Proton Beam Therapy Using Pencil Beam Scanning.

PURPOSE: Pencil-beam scanning (PBS) is a modern delivery technique used in proton beam therapy (PBT) to reduce normal tissue reactions. No dosimetric correlation between dermatitis and PBS has been reported for breast cancer. The current study aimed to investigate the factors associated with grade 2 or higher dermatitis in patients with breast cancer undergoing PBT using PBS. METHODS: The medical data of 42 patients with breast cancer who underwent adjuvant radiotherapy between December 2019 and September 2023 were reviewed. All patients received hypofractionated radiotherapy (HFRT), either 26 Gy (relative biological effectiveness [RBE])/five fractions or 40.05 or 43.5 Gy (RBE)/15 fractions, for the whole breast/chest wall with or without nodal irradiation. The duration of acute radiation dermatitis was defined as within 90 days from the start of radiotherapy. The Kaplan-Meier method and Cox proportional hazards model were used for univariate and multivariate analyses of the actuarial rates of grade 2-3 dermatitis. RESULTS: Twenty-two (52.4%) and 20 (47.6%) patients were diagnosed with grade 1 and 2 dermatitis, respectively. Multivariate analysis revealed a clinical target volume (CTV) ≥ of 320 cc (p = 0.035) and a skin dose of D10cc ≥ 38.3 Gy (RBE) (p = 0.009) as independent factors of grade 2 dermatitis. The 10-week cumulative grade 2 dermatitis rates were 88.2%, 39.4%, and 8.3% (p < 0.001) for patients with both high, either high, and neither high CTV and D10cc, respectively. CONCLUSION: To the best of our knowledge, this is the first study on dosimetric correlations for dermatitis in patients with breast cancer who underwent hypofractionated PBT using PBS. In the era of HFRT, skin dose modulation using PBS may reduce the incidence of dermatitis.

Comparative Analysis of Oncologic Outcomes in Patients with Squamous Cell Carcinoma of the Uterine Cervix with High-Risk Features for Para-Aortic Recurrence: Prophylactic Extended-Field versus Pelvic Chemoradiotherapy.

Purpose: To compare the oncologic outcomes of prophylactic extended-field radiation therapy (EFRT) and whole pelvic radiation therapy (WPRT) in cervical patients at high risk of para-aortic lymph node (PALN) recurrence. Patients and Methods: From July 1999 to May 2022, a total of 115 patients with cervical cancer and high-risk features of PALN recurrence based on tumor markers, positive LNs and extensive parametrial invasion were retrospectively analyzed. All patients had received EFRT or WPRT at a dose of 39.6-45 Gy and concurrent chemotherapy. In EFRT, coverage was extended to include the para-aortic region below the level of the left renal vein or T12. Results: Twenty-eight and 87 patients underwent EFRT and WPRT, respectively. For patients who survived, the median follow-up time was 60.8 months (range 9.2-131.6 months) in the EFRT group and 115.9 months (range 16.9-212.1 months) in the WPRT group. The 5-year overall survival (OS) and pelvic, extrapelvic and PALN recurrence rates were 87.7% vs 60.8% (p=0.019), 10.9% vs 25.3% (p=0.119), 18.1% vs 45.8% (p=0.011), and 0% vs 30.4% (p=0.005), respectively, between the EFRT and WPRT groups. Multivariate analysis revealed that EFRT and 2018 FIGO stage IV disease status were significant predictors of OS and extrapelvic recurrence. Conclusion: Compared to WPRT, EFRT significantly improved OS and reduced extrapelvic and PALN recurrence in patients with cervical cancer with high-risk recurrence features.

Role of microbiota in radiation-induced small-bowel damage.

Radiation-induced gastrointestinal damage is a common acute radiation syndrome. Previous studies have highlighted that Galectin-1 and Interleukin-6 (IL-6) are associated with flaking of small intestinal villi and intestinal radioresistance. Therefore, our goal is to study whether gut bacteria regulated by galectin-1 or IL-6 can mitigate radiation-induced small intestine damage. In this study, differences between galectin-1, sgp130-regulated and wild-type (WT) mice were analyzed by microbiome array. The effects of the Firmicutes/Bacteroidetes (F/B) ratio and the proportion of bacterial distribution at the phylum level were observed after 18 Gy whole abdomen radiation. Fecal microbiota transplantation was used to implant radioresistant gut flora into WT mice, and the number of viable small intestinal crypt foci was observed by immunohistochemistry. Fecal transplantation from galectin-1 knockout and sgp130 transgenic mice, with higher radiation resistance, into WT mice significantly increased the number of surviving small intestinal crypts. This radiation resistance, generated through gene regulation, was not affected by the F/B ratio. We initially found that the small intestinal villi of WT mice receiving radioresistant mouse fecal bacteria demonstrated better repair outcomes after radiation exposure. These results indicate the need for a focus on the identification and application of superior radioresistant bacterial strains. In our laboratory, we will further investigate specific radioresistant bacterial strains to alleviate acute side effects of radiation therapy to improve the patients' immune ability and postoperative quality of life.

Impact of Genomic Alterations on the Clinical Outcome of Patients With Hepatitis B-related Hepatocellular Carcinoma Receiving Curative Surgery: A Retrospective Cohort Study.

BACKGROUND/AIM: The aim of the current study was to obtain comprehensive genomic information on viral hepatitis B (HBV)-related hepatocellular carcinoma (HCC) and identify potential biomarkers of early recurrence in patients receiving curative surgery. PATIENTS AND METHODS: A total of 104 patients with HBV-related HCC receiving curative surgery at Kaohsiung Chang Gung Memorial Hospital between January 2017 and December 2020 were identified, including 52 patients each with and without recurrence. Next-generation sequencing was performed to investigate genomic alterations caused by surgical resection of specimens. The Kaplan-Meier method was used to estimate disease-free survival and overall survival. RESULTS: The landscape of gene mutations in HCC patients of our cohort showed a median number of single nucleotide variants of 250, a median number of insertions and deletions of 22, and a median number of protein-coding mutations of 185. The 10 most frequently mutated genes were TP53 (43%), TTN (39%), MUC16 (28%), PCLO (25%), OBSCN (22%), ADGRV1 (19%), ALB (18%), SYNE1 (18%), DNAH17 (17%), and RYR1 (17%). The tumour mutation burden was 4.8 mutations per megabase, and high microsatellite instability was reported in only three patients. In addition, the mutational signatures showed that aristolochic acid exposure was highly implicated in our HCC cohort. Five mutant genes, TBC1D4, ITGA4, RPS6KA3, VWA8, and FMN2, were more frequent in the recurrence group than that in the non-recurrence group. CONCLUSION: Our results present an in-depth genomic analysis of HBV-related HCC. The study findings provide an improved understanding of the related molecular mechanisms and identify potential biomarkers associated with early tumour recurrence after curative resection.

Feasibility evaluation of N-Isopropyl Acrylamide 3D gel dosimeters for proton therapy.

This study aimed to investigate the feasibility of applying 3D gel dosimeters for proton therapy. Two different formulations (5-5-3-5, 5-3-3-10) for the N-Isopropyl Acrylamide (NIPAM) polymer gel were used to find the best composition for the application of NIPAM polymer gels for proton therapy. The reaction of the gel under different physical conditions, including dependence on energy and dependence on the dose rate of the NIPAM gel under proton irradiation, was also explored. A NIPAM gel dosimeter was used to record the 3D dose distribution, and a self-developed parallel beam optical computed tomography scanner was used to obtain non-irradiated and post-irradiated gel phantom images. The NIPAM gel was filled into a cylindrical acrylic phantom. The results showed that the optical density of the irradiated NIPAM dosimeter was linear in the dose range of 0 to 6 Gy, and the linearity of the two NIPAM gel formulations at the depth of the dose point (2 cm) was 0.98 to 0.89. The dose depth curves showed different patterns with different gel sensitivities. This study demonstrated that the NIPAM gel dosimeter with the 5-3-3-10 formulation is suitable for verifying the dosimetry dose of proton beams.

Prediction of extranodal extension in head and neck squamous cell carcinoma by CT images using an evolutionary learning model.

BACKGROUND: Extranodal extension (ENE) in head and neck squamous cell carcinoma (HNSCC) correlates to poor prognoses and influences treatment strategies. Deep learning may yield promising performance of predicting ENE in HNSCC but lack of transparency and interpretability. This work proposes an evolutionary learning method, called EL-ENE, to establish a more interpretable ENE prediction model for aiding clinical diagnosis. METHODS: There were 364 HNSCC patients who underwent neck lymph node (LN) dissection with pre-operative contrast-enhanced computerized tomography images. All the 778 LNs were divided into training and test sets with the ratio 8:2. EL-ENE uses an inheritable bi-objective combinatorial genetic algorithm for optimal feature selection and parameter setting of support vector machine. The diagnostic performances of the ENE prediction model and radiologists were compared using independent test datasets. RESULTS: The EL-ENE model achieved the test accuracy of 80.00%, sensitivity of 81.13%, and specificity of 79.44% for ENE detection. The three radiologists achieved the mean diagnostic accuracy of 70.4%, sensitivity of 75.6%, and specificity of 67.9%. The features of gray-level texture and 3D morphology of LNs played essential roles in predicting ENE. CONCLUSIONS: The EL-ENE method provided an accurate, comprehensible, and robust model to predict ENE in HNSCC with interpretable radiomic features for expanding clinical knowledge. The proposed transparent prediction models are more trustworthy and may increase their acceptance in daily clinical practice.

Comparison of Oncologic Outcomes between Radical Hysterectomy and Primary Concurrent Chemoradiotherapy in Women with Bulky IB and IIA Cervical Cancer under Risk Stratification.

PURPOSE: To stratify patients according to tumor marker and histology and compare the survival outcome between radical hysterectomy (RH) and primary concurrent chemoradiotherapy (CCRT) in bulky IB and IIA cervical cancer. METHODS: A total of 442 patients with cervical cancer were enrolled in the Chang Gung Research Database from January 2002 to December 2017. Patients with squamous cell carcinoma (SCC) and carcinoembryonic antigen (CEA) ≥10 ng/mL, adenocarcinoma (AC), or adenosquamous carcinoma (ASC) were stratified into the high-risk (HR) group. The others were classified into the low-risk (LR) group. We compared oncology outcomes between RH and CCRT in each group. RESULTS: In the LR group, 5-year overall survival (OS) and recurrence-free survival (RFS) were 85.9% vs. 85.4% (p = 0.315) and 83.6% vs. 82.5% (p = 0.558) in women treated with RH (n = 99) vs. CCRT (n = 179), respectively. In the HR group, the 5-year OS and RFS were 83.2% vs. 73.3% (p = 0.164) and 75.2% vs. 59.6% (p < 0.036) in patients treated with RH (n = 128) vs. CCRT (n = 36), respectively. Regarding recurrence, locoregional recurrence (LRR) (8.1% vs. 8.6%, p = 0.812) and distant metastases (DM) (17.8% vs. 21%, p = 0.609) were similar between RH and CCRT in the LR group. However, lower LRR (11.6% vs. 26.3%, p = 0.023) but equivalent DM (17.8% vs. 21%, p = 0.609) were found for women undergoing RH compared with CCRT in the HR group. CONCLUSIONS: There were similar survival and recurrence rates between both treatment modalities in low-risk patients. Meanwhile, primary surgery with or without adjuvant radiation provides better RFS and local control in women with high-risk features. Further prospective studies are needed to confirm these findings.

Heart rate variability as an indicator of the beneficial effects of Qigong and mindfulness training on the mind-body well-being of cancer survivors.

BACKGROUND: Cancer-related fatigue (CRF) and fear of recurrence (FOR) are frequently experienced by cancer patients. This study aimed to improve cancer survivors' CRF, FOR, quality of life (QOL), and heart rate variability (HRV) through Qigong and mindfulness interventions. METHODS: A quasi-experimental design was adopted, and 125 cancer survivors were recruited using snowball sampling. The participants were assigned to 1 of 3 groups (Qigong, mindfulness, and control) based on their needs and preferences. All groups received 4 h of nutrition education at the pretest (T0). CRF, FOR, and QOL questionnaires and HRV parameters were used as the measurement tools. Data were collected at the pretest (T0), posttest (T1), and follow-up (T2). RESULTS: Qigong had a better effect on improving CRF (ΔT1-T0 = - 0.108, ΔT2-T1 = - 0.008) and FOR (ΔT1-T0 = - 0.069, ΔT2-T1 = - 0.150) in the long term, while mindfulness improved QOL (ΔT1-T0 = 0.096, ΔT2-T1 = 0.013) better in the long term. Both Qigong and mindfulness had a short-term effect in improving SDNN (Q: ΔT1-T0 = 1.584; M: ΔT1-T0 = 6.979) and TP (Q: ΔT1-T0 = 41.601; M: ΔT1-T0 = 205.407), but the improvement in LF (Q: ΔT2-T1 = - 20.110; M: ΔT2-T1 = - 47.800) was better in the long term. CONCLUSION: HRV evaluation showed that Qigong and the mindfulness interventions had short-term effects in significantly improving overall physical and mental health, self-emotional regulation, and QOL and relieving fatigue and autonomic dysfunction. HRV may serve as an observational indicator of interventions to improve physical and mental health. The consistent practice of mind-body interventions is the primary means of optimizing overall health and well-being.

Safe magnetic resonance imaging on biocompatible nanoformulations.

Magnetic resonance imaging (MRI) holds promise for the early clinical diagnosis of various diseases, but most clinical MR techniques require the use of a contrast medium. Several nanomaterial (NM) mediated contrast agents (CAs) are widely used as T1- and T2-based MR contrast agents for clinical and non-clinical applications. Unfortunately, most NM-based CAs are toxic or non-biocompatible, restricting their practical/clinical applications. Therefore, the development of nontoxic and biocompatible CAs for clinical MRI diagnosis is highly desired. To this end, several biocompatible and biomimetic strategies have been developed to offer long blood circulation time, significant biocompatibility, in vivo biodistribution and high contrast ability for efficient imaging. However, detailed review reports on biocompatible NMs, specifically for MR imaging have not yet been summarized. Thus, in the present review we summarize  various surface coating strategies (such as polymers, proteins, cell membranes, etc.) to achieve biocompatible NPs, providing a detailed discussion of advances and future prospects for safe MRI imaging.

MicroRNA-29a Manifests Multifaceted Features to Intensify Radiosensitivity, Escalate Apoptosis, and Revoke Cell Migration for Palliating Radioresistance-Enhanced Cervical Cancer Progression.

Radioresistance remains a major clinical challenge in cervical cancer therapy and results in tumor relapse and metastasis. Nevertheless, the detailed mechanisms are still largely enigmatic. This study was conducted to elucidate the prospective impacts of microRNA-29a (miR-29a) on the modulation of radioresistance-associated cervical cancer progression. Herein, we established two pairs of parental wild-type (WT) and radioresistant (RR) cervical cancer cells (CaSki and C33A), and we found that constant suppressed miR-29a, but not miR-29b/c, was exhibited in RR-clones that underwent a dose of 6-Gy radiation treatment. Remarkably, radioresistant clones displayed low radiosensitivity, and the reduced apoptosis rate resulted in augmented surviving fractions, measured by the clonogenic survival curve assay and the Annexin V/Propidium Iodide apoptosis assay, respectively. Overexpression of miR-29a effectively intensified the radiosensitivity and triggered the cell apoptosis in RR-clones. In contrast, suppressed miR-29a modestly abridged the radiosensitivity and abolished the cell apoptosis in WT-clones. Hence, ectopically introduced miR-29a into RR-clones notably attenuated the wound-healing rate and cell migration, whereas reduced miR-29a aggravated cell mobilities of WT-clones estimated via the in vitro wound-healing assay and time-lapse recording assay. Notably, we further established the in vivo short-term lung locomotion metastasis model in BALB/c nude mice, and we found that increased lung localization was shown after tail-vein injection of RR-CaSki cells compared to those of WT-CaSki cells. Amplified miR-29a significantly eliminated the radioresistance-enhanced lung locomotion. Our data provide evidence suggesting that miR-29a is a promising microRNA signature in radioresistance of cervical cancer cells and displays multifaceted innovative roles involved in anti-radioresistance, escalated apoptosis, and anti-cell migration/metastasis. Amalgamation of a nucleoid-based strategy (miR-29a) together with conventional radiotherapy may be an innovative and eminent strategy to intensify the radiosensitivity and further protect against the subsequent radioresistance and the potential metastasis in cervical cancer treatment.

Prognostic Significance of Galectin-1 but Not Galectin-3 in Patients With Lung Adenocarcinoma After Radiation Therapy.

Introduction: To investigate the role of tumor galectin-1 and galectin-3 in patients with lung adenocarcinoma after definitive radiation therapy. Methods: A total of 41 patients with localized lung adenocarcinoma undergoing thoracic radiation therapy without concurrent chemotherapy were enrolled. Their paraffin-embedded lung tissues were sent for immunohistochemical staining for galectin-1 and galectin-3. The clinical treatment outcomes, including overall (OS), locoregional progression-free (LRPFS), and distant metastasis-free (DMFS) survivals, were evaluated. Univariable and multivariable Cox regression analyses were applied. Results: Overexpression of tumor galectin-1 and galectin-3 were found in 26.8% and 19.5% of patients, respectively. Overexpression of tumor galectin-1 was the most significant prognosticator to predict worse LRPFS in both univariable (p = 0.007) and multivariable analyses (p = 0.022). Besides, patients with overexpression of tumor galectin-1 had a trend of worse OS (p = 0.066) than those with low expression in multivariable analysis, and worse DMFS (p = 0.035) in univariable analysis. The overexpression of tumor galectin-3 had no significant effect on survival outcomes. Conclusions: The overexpression of tumor galectin-1, but not galectin-3, is associated with poor LRPFS of patients with lung adenocarcinoma after thoracic radiation therapy. Future research on the mechanism of galectin-1 affecting radiation response in lung adenocarcinoma may be worth exploring.

Electrospun Polyacrylonitrile Silver(I,III) Oxide Nanoparticle Nanocomposites as Alternative Antimicrobial Materials.

Infectious microbial diseases can easily be transferred from person to person in the air or via high contact surfaces. As a result, researchers must aspire to create materials that can be implemented in surface contact applications to disrupt pathogen growth and transmission. This study examines the antimicrobial properties of polyacrylonitrile (PAN) nanofibers coated with silver nanoparticles (AgNPs) and silver(I,III) oxide. PAN was homogenized with varied weight concentrations of silver nitrate (AgNO3) in N,N-dimethylformamide solution, a common organic solvent that serves as both an electrospinning solvent and as a reducing agent that forms AgNPs. The subsequent colloids were electrospun into nanofibers, which were then characterized via various analysis techniques, including scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray analysis, dynamic light scattering, and X-ray photoelectron spectroscopy. A total of 10 microbes, including 7 strains of Gram-positive bacteria, 2 strains of Gram-negative bacteria, and Candida albicans, were incubated with cutouts of various PAN-AgNP nanocomposites using disk diffusion methods to test for the nanocomposites' antimicrobial efficiency. We report that our electrospun PAN-AgNP nanocomposites contain 100% AgO, a rare, mixed oxidation state of silver(I,III) oxide that is a better sterilizing agent than conventional nanosilver. PAN-AgNP nanocomposites also retain a certain degree of antimicrobial longevity; samples stored for approximately 90 days demonstrate a similar antimicrobial activity against Escherichia coli (E. coli) and Lactobacillus crispatus (L. crispatus) when compared to their newly electrospun counterparts. Moreover, our results indicate that PAN-AgNP nanocomposites successfully display antimicrobial activity against various bacteria and fungi strains regardless of their resistance to conventional antibiotics. Our study demonstrates that PAN-AgNP nanocomposites, a novel polymer material with long-term universal antimicrobial stability, can potentially be applied as a universal antimicrobial on surfaces at risk of contracting microbial infections and alleviate issues related to antibiotic overuse and microbial mutability.

Outcomes and Prognosis of Non-Elderly Patients with Brain Metastases-A Prospective Cohort Incorporating Individualized Assessment of Heart Rate Variability.

Outcomes and prognostic factors among patients with brain metastases (BM) have been widely studied, but seldom for the non-elderly. Heart rate variability (HRV) is a physiological phenomenon and has been shown as a survival prognostic factor in cancer patients. This study aimed to evaluate the outcomes and prognosis among non-elderly BM patients with the incorporation of HRV analysis. Forty non-elderly BM patients treated using whole brain radiotherapy (WBRT) were studied from January 2010 prospectively with 5-min electrocardiography (ECG) recordings. Individualized HRV was generated by the ECG, and the time domain HRV index SDNN was chosen for survival analysis. The median overall survival (OS) for the entire group was 6.21 months. Univariate analysis revealed that a KPS < 80 (p = 0.019) and an SDNN < 10 ms (p = 0.007) demonstrated statistical significance for OS; multivariate analysis confirmed that a KPS < 80 (p = 0.004; HR = 3.060, CI = 1.437-6.517) and an SDNN < 10 ms (p = 0.010; HR = 2.664, CI = 1.262-5.624) were independent prognostic factors. Prospective studies for risk stratification among non-elderly BM patients based on our results are warranted to validate our findings.

Radiation-Induced Emesis (RIE) in Extended-Field Radiotherapy for Gynecological Malignancies: Dosimetric and Non-Dosimetric Factors.

Radiation-induced emesis (RIE) is usually noted during abdominal-pelvic radiotherapy. In gynecological malignancies, it is usually noted in para-aortic but not whole-pelvic irradiation. Irradiated small bowel (SB) may be associated with RIE. The significance of SB dosimetry remains unclear. Dosimetric and non-dosimetric factors were evaluated and correlated with RIE in 45 patients with gynecological malignancies undergoing extended-field radiotherapy (EFRT) (median 45 Gy) from 2006 to 2021. Early-onset RIE (within 72 h after the first fraction of EFRT) was noted in 10 of 12 RIE patients. RIE was significantly associated with the SB mean dose. The RIE rates were 58.3% and 15.2% (p = 0.007) in patients with a low (<63%) and high (≥63%) SB mean dose. Logistic regression revealed that the SB mean dose remained the independent factor of overall RIE (p = 0.049) and early-onset RIE (p = 0.014). Therefore, constraint of the SB mean dose limited to less than 63% of the prescribed dose is suggested to decrease RIE.

Concurrent Sorafenib and Radiotherapy versus Radiotherapy Alone for Locally Advanced Hepatocellular Carcinoma: A Propensity-Matched Analysis.

PURPOSE: Evidence is lacking concerning the benefit of the combination of sorafenib and radiotherapy to treat advanced hepatocellular carcinoma (HCC). To date, no publication has reported the outcomes of radiotherapy alone versus concurrent therapy. We aimed to compare the effectiveness of radiotherapy alone versus concurrent radiotherapy and sorafenib for locally advanced hepatocellular carcinoma. MATERIALS AND METHODS: We conducted a propensity score matching (PSM) cohort study comparing the effectiveness of the concurrent use of sorafenib and external beam radiotherapy versus radiotherapy alone in Barcelona Clinic Liver Cancer (BCLC) stage B or C, nonsurgically managed, nonmetastatic patients with HCC. Two subpopulations were matched based on baseline characteristics. Stratified analysis was also performed to assess the heterogeneous effects of the two arms. Overall survival (OS) was compared. Radiation-induced liver disease (RILD) and overt gastrointestinal (GI) bleeding events were also recorded. RESULTS: Seven hundred thirty-one BCLC stage B or C nonmetastatic HCC patients were identified from 2007 to 2017. Of these, 347 patients met the inclusion criteria (Radiotherapy alone: 269 patients; concurrent therapy: 78 patients). Propensity score matching yielded 73 patients each in the radiotherapy and concurrent groups. The median OS was 9.6 months in the radiotherapy-alone group and 9.9 months in the concurrent group (hazard ratio (HR): 1.12; 95% CI=0.78-1.62; p=0.544). Posttreatment toxicities, including radiation-induced liver disease and overt gastrointestinal bleeding, showed no significant differences between the groups. CONCLUSION: In our study, the concurrent use of sorafenib and conventional external beam radiotherapy shows no survival benefit over radiotherapy alone for locally advanced hepatocellular carcinoma.

Significant Reduction in Vertebral Artery Dose by Intensity Modulated Proton Therapy: A Pilot Study for Nasopharyngeal Carcinoma.

Intensity modulated proton therapy (IMPT) with the vertebral artery (VA)-sparing technique has been initially proposed in our institution. This pilot study was conducted to compare the dose to VAs between IMPT and volumetric-modulated arc therapy (VMAT) for patients with nasopharyngeal carcinoma (NPC). A total of six patients with NPC treated by IMPT were enrolled in the study. Target volumes and organs at risk (OARs) were delineated, including 12 samples of right and left VAs, respectively, for each patient. Treatment planning by IMPT and dual-arc VMAT was carried out for comparison. The IMPT plan significantly reduced VA mean dose, V10, V20, V30, V40, and V50, compared to the VMAT plan in all 12 samples (p < 0.001). The average mean dose to VAs for IMPT was 35.2% (23.4-46.9%), which was less compared to VMAT (p < 0.001). Adequate dose coverage was achieved with both IMPT and VMAT plans for three different dose levels of target volumes for all patients. IMPT significantly reduces VA dose while maintaining adequate dose coverage of all target volumes. For patients with head and neck cancer who seek to preserve their blood flow to the brain in order to decrease late vascular and neurologic sequelae, IMPT should be considered. A prospective study with longer follow-up is ongoing to confirm our preliminary results.

Galectin-1 Expression Is Associated with the Response and Survival Following Preoperative Chemoradiotherapy in Locally Advanced Esophageal Squamous Cell Carcinoma.

The galectin-1 has been found to be involved in poor outcomes after treatment of a variety of cancers. To the best of our knowledge, however, the significance of galectin-1 expression in the sensitivity to chemoradiotherapy (CCRT) of patients with locally advanced esophageal squamous cell carcinoma (ESCC) remains unclear. Expression levels of galectin-1 were evaluated by immunohistochemistry and correlated with the treatment outcome in 93 patients with locally advanced ESCC who received preoperative CCRT between 1999 and 2012. Galectin-1 expression was significantly associated with the pathological complete response (pCR). The pCR rates were 36.1% and 13.0% (p = 0.01) in patients with low and high galectin-1 expression, respectively. Univariate analyses revealed that galectin-1 overexpression, clinical 7th American Joint Committee on Cancer (AJCC) stage III and a positive surgical margin were significant factors of worse overall survival and disease-free survival. In multivariate analyses, galectin-1 overexpression and a positive surgical margin represented the independent adverse prognosticators. Therefore, galectin-1 expression both affects the pCR and survival in patients with locally advanced ESCC receiving preoperative CCRT. Our results suggest that galectin-1 may be a potentially therapeutic target for patients with ESCC treated with preoperative CCRT.

Involvement of Galectin-1 Tumor Microenvironment in Radiosensitivity.

BACKGROUND/AIM: The mechanisms of galectin-1 in radioresistance may not only involve intracellular but also extracellular effects because galectin-1 can be secreted into the extracellular matrix. We, therefore, aimed to investigate the role of the galectin-1 tumor microenvironment on radiosensitivity in a murine tumor model. MATERIALS AND METHODS: Wild-type or stable galectin-1-down-regulated cancer cells (melanoma (B16F10) and lung cancer (LLC1)) were injected (subcutaneous injection) into wild-type or knockout (galectin-1, B cells, and T cells) mice that were subject to 0 or 8 Gy irradiation. RESULTS: Galectin-1-down-regulated B16F10 cells showed increased radiosensitivity when injected into galectin-1 knockout mice. Interestingly, radioresistance of wild-type LCC1 tumors was noted when injected into galectin-1 and B cell knockout mice. However, radiosensitization was observed in T cell knockout mice with wild-type LCC1 cells. CONCLUSION: The role of endogenous galectin-1 in radioresistance exists in cases without extracellular galectin-1. Extracellular galectin-1 requires endogenous galectin-1 to radiosensitize tumors in mice.

Medical Mask Wearing During Treatment for Patients Undergoing Radiotherapy in COVID-19 Pandemic - An Experience of Protocol Setup and Dosimetric Evaluation for Particle/Proton Beam Therapy.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has caused extreme challenges for the healthcare system. Medical masks have been proven to effectively block disease transmission. Radiotherapeutic departments are at unique risk for disease exposure with the repeated daily treatment schedule. A protocol of mask wearing during daily treatment was established, and the effect of wearing medical masks on dosimetry during proton beam therapy (PBT) was validated. METHODS: A department protocol of medical mask wearing was initiated after the COVID-19 pandemic. Medical masks that were made under standardized specification and regulation were obtained for analyses. The physical and dosimetric characteristics of these medical masks were measured by different proton energies using commercialized measurement tools. RESULTS: Patients and staff were able to adopt the protocol on a weekly basis, and no adverse events were reported. The average physical thickness of a single piece of medical mask was 0.5 mm with a water equivalent thickness (WET) of 0.1 mm. CONCLUSION: Our study revealed that mask wearing for patients undergoing daily radiotherapy is feasible and can provide basic protection for patients and staff. The impact of mask wearing on dosimetry was only 0.1 mm in WET, which has no impact on clinical PBT treatment. A medical mask-wearing policy can be applied safely without dosimetric concerns and should be considered as a standard practice for PBT centers during the COVID-19 pandemic.

Rectal Dose Is the Other Dosimetric Factor in Addition to Small Bowel for Prediction of Acute Diarrhea during Postoperative Whole-Pelvic Intensity-Modulated Radiotherapy in Gynecologic Patients.

We studied the association of rectal dose with acute diarrhea in patients with gynecologic malignancies undergoing whole-pelvic (WP) intensity-modulated radiotherapy (IMRT). From June 2006 to April 2019, 108 patients with previous hysterectomy who underwent WP IMRT were enrolled in this cohort study. WP irradiation of 39.6-45 Gy/22-25 fractions was initially delivered to the patients. Common Terminology Criteria for Adverse Events (CTCAE) version 3 was used to evaluate acute diarrhea during radiotherapy. Small bowel volume at different levels of isodose curves (Vn%) and mean rectal dose (MRD) were measured for statistical analysis. The multivariate analysis showed that the MRD ≥ 32.75 Gy (p = 0.005) and small bowel volume of 100% prescribed (V100%) ≥ 60 mL (p = 0.008) were independent factors of Grade 2 or higher diarrhea. The cumulative incidence of Grade 2 or higher diarrhea at 39.6 Gy were 70.5%, 42.2%, and 15.0% (p < 0.001) in patients with both high (V100% ≥ 60 mL and MRD ≥ 32.75 Gy), either high, and both low volume-dose factors, respectively. Strict constraints for the rectum/small bowel or image-guided radiotherapy to reduce these doses are suggested.