Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10  TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60  TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

[Impact of COVID-19 pandemic on the management of imported malaria in China]

OBJECTIVE

To examine the impact of COVID-19 pandemic on the epidemic status of imported malaria and national malaria control program in China, so as to provide insights into post-elimination malaria surveillance.

METHODS

All data pertaining to imported malaria cases were collected from Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 through December 31, 2021. The number of malaria cases, species of malaria parasites, country where malaria parasite were infected, diagnosis and treatment after returning to China, and response were compared before (from January 1, 2018 to January 22, 2020) and after the COVID-19 pandemic (from January 23, 2020 to December 31, 2021).

RESULTS

A total of 2 054 imported malaria cases were reported in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 to December 31, 2021, and there were 1 722 cases and 332 cases reported before and after the COVID-19 pandemic, respectively. All cases were reported within one day after definitive diagnosis. The annual mean number of reported malaria cases reduced by 79.30% in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region after the COVID-19 pandemic (171 cases) than before the pandemic (826 cases), and the number of monthly reported malaria cases significantly reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region since February 2020. There was a significant difference in the constituent ratio of species of malaria parasites among the imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic (χ2 = 146.70, P < 0.05), and P. falciparum malaria was predominant before the COVID-19 pandemic (72.30%), while P. ovale malaria (44.28%) was predominant after the COVID-19 pandemic, followed by P. falciparum malaria (37.65%). There was a significant difference in the constituent ratio of country where malaria parasites were infected among imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic (χ2 = 13.83, P < 0.05), and the proportion of malaria cases that acquired Plasmodium infections in western Africa reduced after the COVID-19 pandemic that before the pandemic (44.13% vs. 37.95%; χ2 = 4.34, P < 0.05), while the proportion of malaria cases that acquired Plasmodium infections in eastern Africa increased after the COVID-19 pandemic that before the pandemic (9.58% vs. 15.36%; χ2 = 9.88, P = 0.02). The proportion of completing case investigation within 3 days was significantly lower after the COVID-19 pandemic than before the pandemic (96.69% vs. 98.32%; χ2= 3.87, P < 0.05), while the proportion of finishing foci investigation and response within 7 days was significantly higher after the COVID-19 pandemic than before the pandemic (100.00% vs. 98.43%; χ2 = 3.95, P < 0.05).

CONCLUSIONS

The number of imported malaria cases remarkably reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region of China during the COVID-19 pandemic, with a decreased proportion of completing case investigations within 3 days. The sensitivity of the malaria surveillance-response system requires to be improved to prevent the risk of secondary transmission of malaria due to the sharp increase in the number of imported malaria cases following the change of the COVID-19 containment policy.

Targeting XPO1 Combined with Radiotherapy to Enhance Systemic Anti-tumor Effects in Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

The combination of radiation and radiosensitizing chemotherapeutic agents have shown promising anti-tumor effects in NSCLC. Acting as an oncogenic driver, XPO1 is frequently overexpressed and/or mutated in lung cancer. Thus, suppression of XPO1-mediated nuclear export presents a unique therapeutic strategy. We hypothesize that XPO1 inhibition combined with radiotherapy (XRT) may remodel the tumor immune microenvironment (TIME) and reduce radioresistance, thus enhance systemic anti-tumor effects.

MATERIALS/METHODS

Herein, we optimized a small molecule inhibitor, WJ01024, which can bind to XPO1 and antagonize its activity to inhibit nuclear export. In the C57BL/6 mouse subcutaneous tumor model, we evaluated the ability of different treatment regimens containing oral WJ01014 single or combined with XRT (one fractions of 15 Gy) in tumor control and tumor recurrence inhibition. The effects of each treatment regimen on the alterations of immunophenotypes, including the quantification, activation, proliferative capacity, exhaustion marker expression, and memory status, were evaluated by flow cytometry.

RESULTS

In our study, we found that the overexpression of XPO1 was associated with poor prognosis and survival in radioresistant patients with NSCLC. The combination therapy of WJ01024 and XRT resulted in an increase of apoptosis and a decrease of proliferation compared to monotherapy, which was closely correlated with tumor regression and improved survival in the C57BL/6 mouse subcutaneous tumor model. Notably, we found that WJ01024 were shown to enhance the therapeutic effect of XRT by remodeling TIME. Compared with XRT, the addition of WJ01024 increased the infiltration and proliferation of radiation-stimulated CD8+ T cells, which especially promoted the production of interferon-γ and granzyme B. Moreover, the combination therapy also reversed the immunosuppressive effect of radiation on the percentage of Tregs and exhausted T cells in mouse xenografts. Thus, the TIME was significantly improved in combination therapy. Strikingly, mechanistic studies suggested that the activation of cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) signaling pathway is required to reshape TIME and produce synergistic anti-tumor effect with the combination of WJ01024 and XRT.

CONCLUSION

Our findings suggest that WJ01024 might be a potential synergistic treatment for radiotherapy to control the proliferation of NSCLC cells, promote tumor regression and prolong survival in mouse model of NSCLC by activating cGAS/STING signaling, and this in turn potentiate the immune microenvironment.

Development and Assessment of a Multi-Purpose Knowledge-Based Planning Model (RapidPlan) for Prostate Radiation

PURPOSE/OBJECTIVE(S)

RapidPlan (RP) is a knowledge-based planning (KBP) tool to improve plan quality, planning speed, and reduce inter-patient plan variability. For small to medium institutions, it is difficult to find sufficient patient numbers to configure a reliable KBP-RP model. This study aimed to build a multi-purpose KBP-RP model for prostate cancers.

MATERIALS/METHODS

A total of 124 prostate plans from 2018-2022 at our institution were selected to configure the initial RP model. After model training, outliers were removed. 77 patients were used for the final RP model. Three fine-tuned RP sub-models with different optimized constraints corresponding to prostate bed, prostate + seminal vesicles (SV), and prostate boost plans were generated. RP models were validated by comparing plan quality with the original manually optimized plans (MP). 54 independent plans were selected to validate the RP models. Validation included: dose to 99% and 2% of PTV (D99%, D2%), PTV conformity index (CI); for organs at risk (OARs), volume receiving >70Gy and >60Gy (V70Gy, V60Gy) to bladder and rectum, maximum dose (Dmax) to femur heads (FHs) and small bowel. Statistical t-test analysis was performed with a significance of p<0.05.

RESULTS

A total of 48/54 model-based plans were clinically approved after single RP optimization. 6/54 failed plans were prostate bed plans and were deemed acceptable after additional minor constraint adjustments. For PTV, D99%, D2%, and CI were comparable (p>0.05) to MP. Bladder and rectum V70Gy were comparable (p>0.05), and V60Gy were significantly lower to MP (p<0.05), with an average Dmean of 23.21±14.58Gy and 16.41±10.63Gy vs 26.36±16.89Gy and 18.24±12.81Gy for RP and MP. RP significantly reduced Dmax to FHs and small bowel (p<0.05), with average Dmax of 34.95±6.06Gy and 35.62±18.99Gy vs 36.81±7.05Gy and 38.14±17.81Gy, respectively.

CONCLUSION

Multi-purpose prostate RP model was configured and approved plans were generated after single optimization. Prostate RP plans had equivalent PTV coverage with better or comparable OAR constraints.

The Effect of PARP Inhibitor Radiosensitization on the mRNA Translational Regulation of T Cell Chemokines

PURPOSE/OBJECTIVE(S)

Immunotherapy has modestly improved survival for small cell lung cancer (SCLC) patients. Low response rate and rapid disease progression remain an intractable challenge. One of the factors that contribute to immunotherapy resistance is the lack of cytotoxic T cell infiltration. The expression of chemoattractant cytokines, like CCL5 and CXCL10, are essential for T cell infiltration. The control of chemokine expression is not fully understood, but both transcriptional and translational control pathways could play a major role. Previous studies have shown a correlation between DNA damage and chemokine expression and that PARP inhibitors (PARPi) are radiosensitizers for SCLC that increases DNA damage. The objectives of this study were to define this potential PARPi immunogenic radiosensitizing relationship.

MATERIALS/METHODS

We identified doses of olaparib+ radiation treatment (RT) that conferred radiosensitization in SCLC cell-lines by cell viability and/or clonogenic assays. Olaparib+RT induced CCL5 and CXCL10 mRNA expression was measured by qPCR across SCLC cell-lines. Protein level of chemokines was assessed by immunoblotting. SBC5 cells were treated with olaparib+RT and submitted for RNA sequencing analysis. Genes with adjusted p value<0.05 were considered significant. Protein level changes and target gene knock-out (KO) were confirmed by immunoblotting. Chemokine CXCL10 mRNA and protein level in wildtype (WT) and KO cells were measured by qPCR and western blot, respectively. A mRNA decay assay and dual-luciferase reporter assay was used to identify the region of CXCL10 mRNA that confers mRNA stability control. In vivo anti-tumor efficacy and tumor T cell infiltration studies were done in B6129F mice bearing KP1 tumors. And the T cell infiltration was measured by immune profiling.

RESULTS

In vitro, olaparib+RT significantly increased CXCL10 mRNA in all four SCLC subtype cell-lines in comparison to vehicle control. Consistently, the increase of CXCL10 protein levels (3-fold) was observed in SBC5 cells. By RNA-Seq, a top-ranking translational repressor was EIF4E2 (4EHP) mRNA. The downregulation of EIF4E2 protein by olaparib+RT was validated in four SCLC subtypes by western blot. EIF4E2 KO in HEK293 and SBC5 cells increased CXCL10 mRNA and protein level. By mRNA decay assay and western blot, the absence of EIF4E2 stabilized CXCL10 mRNA and increased CXCL10 protein levels. The dual-luciferase assay demonstrated EIF4E2 destabilizes CXCL10 mRNA via the 3'UTR of CXCL10. In vivo, immune profiling showed olaparib+RT significantly increased the total T cell and CD8+ T cell infiltration. Finally, anti-PD-L1 inhibition potentiated olaparib + IR to improve tumor control in KP1 allograft.

CONCLUSION

Our study demonstrated olaparib + RT increases CXCL10 protein levels through downregulating EIF4E2 to subsequently increase T cell infiltration. Olaparib + RT enhanced anti-PD-L1 immunotherapy efficacy and has therapeutic potential as an immunogenic radiosensitizer.

The Predictive Value of Circulating Exosomal PD-L1 in Cervical Cancer Immunotherapy

PURPOSE/OBJECTIVE(S)

Programmed death ligand 1 (PD-L1) expression was wildly used as a predictor of immune Check-Point Inhibitors (ICIs) efficiency. However, emerging results showed that PD-L1 was of great heterogeneity in sampling time and site. Recently, some studies found that exosomal PD-L1(ExoPD-L1) was related to ICIs response. In this study, we aimed to explore the predictive value of ExoPD-L1 in ICIs treatment of cervical cancer (CC) for the first time.

MATERIALS/METHODS

A total of 40 primarily diagnosed CC patients who accepted radical radiotherapy (RT) from March 2021 to October 2022 were included. The consecutive tumor sample were collected before and during RT. Another 37 advanced CC patients who accepted ICIs combination therapy from June 2020 to October 2022 were enrolled in this study. Blood samples were collected from each participant before and during treatment. Exosomes were derived by differential centrifugation, which was further identified by Western blot (WB) (CD9/TSG101/Calnexin), transmission electron microscope analysis and nanoparticle tracking analysis. ExoPD-L1 detection was conducted by enzyme-linked immuno-sorbent assay (ELISA). The knockout of PD-L1 was conducted via CRISPR/Cas9 assay and the overexpress of PD-L1 was conducted by lentiviral transfection. CD8+ T cells were extracted from murine spleen by CD8+ T Cell Isolation Kit. Immune cells and cytokines markers were detected by multicolor flow cytometry.

RESULTS

The consecutive detection of PD-L1 showed a dynamic change during RT. Compared with the level before RT, PD-L1 expression elevated in most patients (87.5%, 35/40) after RT. And the responders (n = 18) had elevated ExoPD-L1 level at the first two circles in the ICIs combination therapy (P<0.001). Whereas the level of pre-treatment ExoPD-L1 couldn't stratified clinical responders and non-responders (P = 0.181). The median follow-up time was 14.13 months. The mPFS in increased group vs. decreased group: not reach vs.11.02 months (P = 0.025, HR: 0.218, 0.052-0.913). Continuous blood sampling of mice models also found that effective therapeutic intervention could increase ExoPD-L1 in the early stage. The combination of exosome inhibitor GW4869 and anti-PD-1 further inhibited tumor growth. Mice were injected with external ExoPD-L1OE and ExoPD-L1KO. The results showed that ExoPD-L1OE suppressed body immunity and promoted tumor growth. The results of flow cytometry showed that ExoPD-L1OE inhibited CD8+ T cells from releasing interferon-and granzyme B. And ExoPD-L1OE also suppressed the CD8+ T cells proliferation in murine spleen. The coculture of CD8+ T cells and exosomes in vitro also confirmed the above conclusion.

CONCLUSION

Compared with unstable and impressionable tumoral PD-L1, ExoPD-L1 seems to be better predictor for the efficacy of immunotherapy in CC, which was with easy accessibility and continuation. Exosome PD-L1 played an immunosuppressive role by inhibiting the proliferation and functional factor release of CD8+ T cell.

Determinants of infant behavior and growth in breastfed late preterm and early term infants: a secondary data analysis

BACKGROUND

Late preterm and early term infants are at increased risk of poor growth, behavioral problems, and developmental delays. This study aimed to investigate the impact of maternal and infant characteristics, feeding practices, and breastmilk composition on infant behavior following late preterm and early term delivery, and to evaluate the association between infant behavior and growth.

METHODS

Data from 52 Chinese mothers and their late preterm/early term infants participating in the Breastfeed a Better Youngster study were used. Maternal and infant characteristics were collected using questionnaires at 1 week postpartum. Breastmilk macronutrient content was measured using a human milk analyzer, and infant behavior was assessed using a 3-day infant behavior diary at 8 weeks postpartum. Feeding practices were collected at both time points using questionnaires. Multivariate models were used to assess associations between potential predictors and infant behavior and between infant behavior and growth.

RESULTS

Exclusive breastfeeding was associated with greater sleep duration (P = 0.02) and shorter crying duration (P = 0.01). Mothers with a vocational education reported greater distress duration (P = 0.006). Greater colic duration was associated with higher maternal annual income (P = 0.004). There was no significant association between infant behavior and growth (all P > 0.05).

CONCLUSIONS

Exclusive breastfeeding might promote more favorable infant behaviors in late preterm/early term infants, while the development of infant distress behaviors was associated with some maternal characteristics (maternal education and annual income). However, due to the limitations of diary methods, determinants of infant behavior should ideally be assessed using more objective measures in larger samples.

RUNX1 as a Potential Target for Combined Radioimmunotherapy of Lung Adenocarcinoma

PURPOSE/OBJECTIVE(S)

Radioimmunotherapy for non-small cell lung cancer has good clinical application prospects. The role and mechanism of RUNX1 in DNA damage repair were explored for its potential role in lung adenocarcinoma radioimmunotherapy.

MATERIALS/METHODS

To study the effect of RUNX1 expression level on the expression of DNA damage repair system related factors and radiation sensitivity of lung adenocarcinoma cells. As an important nuclear transcription factor, RUNX1 was explored whether directly regulating the expression of Nrf2, Rad51, BRCA1, and verifying their respective DNA binding sites in the promoter region through relevant databases. To observe the effect of RUNX1 knockout and overexpression on the expression level of PD-L1 in tumor cells at the cell level; The effect of RUNX1 expression level on the sorting and presentation of PD-L1 cells was investigated by the method of nucleocytoplasmic separation. According to literature reports, CMTM6 and ALIX play a key role in the process of PD-L1 cell sorting and presentation, and explore whether RUNX1 plays a role through this factor. The effect of phosphorylation level of different splicing bodies of RUNX1 (RUNX1a/b/c) on the expression level and DNA damage repair system related factors on tumor radiosensitivity were also explored.

RESULTS

According to TCGA database, RUNX1 is highly expressed and phosphorylated in lung adenocarcinoma. Through gene comparison with the database, it was found that RUNX1 binding sites existed in the promoter region of several factors related to this study, including ALIX, Nrf2, BRCA1, RAD51, ATM, H2AX, etc. After being activated by MAPKp38 phosphorylation, RUNX1a can positively regulate Nrf2 signal pathway. The expression of RUNX1 and p-RUNX1 is time-dependent on ionizing radiation. At the same time, it was found that the expression of RUNX1 and p-RUNX1 was dose-dependent on ionizing radiation, and the expression trend of Nrf2 signal pathway related factors was consistent with RUNX1. RUNX1 regulates the expression of PD-L1, BRCA1, ALIX and Nrf2. Bioinformatics analysis and flow cytometry data show that RUNX1 has inhibitory effect on tumor microenvironment of lung adenocarcinoma.

CONCLUSION

RUNX1 regulates DNA damage repair system and has inhibitory effect on tumor immunity. Inhibiting the expression of RUNX1 in lung adenocarcinoma cells can enhance the effect of radioimmunotherapy.

Proposals for the Delineation of Neck Clinical Target Volume Specific to Oral Squamous Cell Cancer Based on Lymph Node Distribution

PURPOSE/OBJECTIVE(S)

To establish the regional lymph node (LN) distribution probability map and draw the neck clinical target volume specific to oral squamous cell cancer (OSCC).

MATERIALS/METHODS

A total of 293 patients with pathologically proven OSCC were enrolled from Jan 2014 to Jun 2022. The patients were divided into two groups according to the ≤1 cm or>1 cm of minimal distance from the lesion's edge to the midline of body. The center point of the LNs with a minimal axial diameter of ≥10 mm was marked on a single treatment planning computed tomography scan. The neck LN levels I to X were based on 2013 updated international consensus guidelines. LN distribution probability maps were established. The relationships between the LN distribution and consensus guidelines were analyzed to propose modifications for clinical target volume boundaries specific to OSCC.

RESULTS

A total of 1033 LNs were marked. Compared with the >1 cm group, The ≤1 cm group has following feature tendencies: strong addiction to smoking and drinking, predilection for tongue and oral floor cancer, larger primary lesion with mainly infiltrative growth pattern, more frequent extra-nodal extension with mainly contralateral LNs. For the ≤1cm group, the distribution probability of LNs was: ipsilateral II (42.67%), ipsilateral Ib (17.35%), contralateral II (11.18%), ipsilateral III (8.74%), contralateral Ib (7.46%), Ia (6.43%). The other group was: ipsilateral Ib (43.14%), ipsilateral II (37.64%), contralateral Ib (4.31%), ipsilateral III (3.92%), contralateral II (3.53%), Ia (0.78%). Accordingly, the proposals for the delineation of neck clinical target volume were: 1. the inferior boundary of level Ia extends until the level of the thyroid cartilage plate; 2. the upper boundary of level Ib descends to the level of the mandibular angle, and the inner posterior boundary only includes the lateral and posterior margin of the submandibular gland within 5mm; 3. the upper boundary of level II changes to the transverse process of the second cervical vertebra, and the posterior boundary retracts to the posterior edge of the levator scapula. 4. the anterior inner border of level IVa contains only the internal jugular arteriovenous sheath.

CONCLUSION

This is the first description of LN topographic spread patterns for OSCC. Optimization of CTV delineation is helpful to improve the treatment outcome and reduce adverse events.

Proton Based Stereotactic Radiotherapy for Skull Base Patients: Dosimetric Comparison to 4 Modern Radiation Treatment Modalities

PURPOSE/OBJECTIVE(S)

Re-irradiation with ablative doses to a smaller target volume and strict critical structure constraint is a challenge for modern radiation planning and delivery systems. Several advanced radiation treatment techniques can be used for fractionated stereotactic ablative radiosurgery (FSRS) in select patients with unresectable recurrent head and neck tumors. In this study, in order to better understand the dosimetry advantage of each technique, we compare the stereotactic treatment plans of our new small spot size Hitachi proton treatment unit to those of CyberKnife stereotactic radiosurgery (CK), Gamma Knife radiosurgery (GK), volumetric modulated arc therapy (VMAT), and MR Linac radiotherapy (MRL).

MATERIALS/METHODS

Ten FSRS skull base patients treated at our institution using VMAT (n = 5) or GK (n = 5) techniques. Intensity-modulated proton therapy (IMPT) plans were created in Raystation using Monte Carlo dose calculation algorithm. VMAT, CK, GK and MRL plans were generated in RayStation, Accuray Precision, Leksell Gamma Plan, and Monaco treatment planning systems, separately. Planning goals were to achieve the best target coverage of prescribed dose without compromising the critical organs at risk dose volume constraints of the clinical treatment plans. Plans were compared based on percent CTV coverage, Paddick conformity index (PCI), gradient index (GI, V50/V100), dose homogeneity index (HI, (D2-D98)/D50), low dose bath volume (LDBV, ratio of total volume irradiated between 20% and 50% prescription dose and the target volume), beam-on-time (BOT), and mean/maximum doses to brainstems.

RESULTS

The median target volume was 15.5 cm3 (range 1.0 - 36.23 cm3). The prescription was 45 Gy in 5 fractions for VMAT patients, and 21 - 27 Gy in 3 fractions for GK patients. The comparison of the treatment plans of these 5 delivery modalities was shown in table. All techniques achieved comparable CTV coverage. GI was superior for GK plans and outstanding in CK and IMPT plans. IMPT plans were also outstanding in regard to BOT and PCI. Significantly improved HI, LDBV and brainstem mean doses were achieved in IMPT plans. For adjacent brainstem and other OARs, maximum doses were comparable among all techniques.

CONCLUSION

In these five advanced radiation therapy modalities, proton therapy SBRT showed dosimetric advantage over other modalities to spare nearby OARs without sacrifice of target coverage. Further studies are needed to utilize this clinical benefit and investigate plan robustness.

A Multiomics Analysis of the Close Connection between Intratumoral Microbiota and Immune Cell Infiltration in Colorectal Cancer

PURPOSE/OBJECTIVE(S)

The colorectal intratumoral microbiome and its association with the expression of the tumor genome and immune cell infiltration remain poorly characterized. Our study aims to investigate the relationship between intratumoral microbiota with tumor immune infiltration, patient prognosis, and potential downstream signaling pathways.

MATERIALS/METHODS

We collected biopsy samples of tumor tissue and paracancerous tissue from 92 patients with colorectal cancer, and acquired microbiota profiling in these samples using 16s rRNA sequencing. Meanwhile, the immune markers including CD8, FOXP3, CD163, PD-1 and PD-L1 were stained by immunohistochemistry (IHC) to identify the immune infiltration in tumors. Furthermore, we used The Cancer Genome Atlas and The Cancer Microbiome Atlas databases to conduct multiomics analysis on tumor flora and patient survival, tumor gene expression profile and potential downstream pathways.

RESULTS

There was a significant difference in α-diversity (p = 0.00051) and β-diversity (p = 0.004) between tumor and paracancerous tissues. The β-diversity of intratumoral bacterial differed by colorectal cancer tumor stage (early vs. late stage, p = 0.049) and location (left vs. right colon, p = 0.04). Stage-related flora cluster (Porphyromonas, Lachnoclostridium, Bacteroides, Aggregatibacter, and Hungatella) were identified and found to be associated with poor prognosis in colorectal cancer patients (HR = 1.79, p = 0.015). By IHC staining, we found that expression of PD-1 and FOXP3 was significantly reduced at low abundance of stage-related bacterial cluster (p<0.05). Among of them, Hungatella was negatively associated with CD8+T cell infiltration (p<0.05) in tumor. Besides, tumor-location related flora cluster (Bacteroides and Blautia) were identified and found to be associated with good prognosis in colorectal cancer patients (HR = 0.52, p = 0.011). Expression of CD163 was decreased at high abundance of location-related bacterial cluster (p<0.05). Among of them, Blautia was negatively correlated with tumor-associated macrophage infiltration(p<0.05). Furthermore, we found that the stage-related flora cluster was positively connected with the pathway of bile acid metabolism, whereas the location-dependent cluster was negatively correlated with this pathway.

CONCLUSION

We found specific intratumoral bacterial clusters that were related to tumor stage and location, and the clusters were strongly associated with tumor immune infiltration and patient prognosis. Our findings may provide new viewpoint for future research between intratumoral microbiota, metabolism pathway and tumor microenvironment.

IKBKE Promotes Radioresistance of Glioblastoma through AKT/FOXO3a Pathway

PURPOSE/OBJECTIVE(S)

Glioblastoma is an intracranial highly malignant primary tumor, and postoperative radiotherapy is a common treatment of glioblastoma. While radiotherapy resistance of glioblastoma is an important reason for treatment failure. IKBKE is overexpressed in gliomas, but its role in radiotherapy is unknown. This study confirmed that IKBKE can directly phosphorylate AKT protein to regulate FOXO3a, thus promoting the radioresistance of glioblastoma, and proposed a new therapeutic strategy to enhance the efficacy of radiotherapy.

MATERIALS/METHODS

We used flow cytometry, tunel staining, plate cloning, a cell counting kit and WB to confirm the effects of IKBKE and FOXO3a on radioresistance of glioblastoma, and immunofluorescence and WB were used to detect the expression of γ-H2AX. Subcutaneous tumor formation in mice and immunohistochemical staining was performed. IP combined with mass spectrometry, immunofluorescence, endogenous and exogenous IP were used to confirm the interaction between IKBKE and AKT. Point mutation, IP and WB were used to confirm the phosphorylation site of AKT. IP and some small molecule inhibitors were used to confirm the relationship between IKBKE, AKT and PI3K. The effect of IKBKE on FOXO3a was confirmed by WB and qPCR. The protein relationship among IKBKE, FOXO3a and 14-3-3 was confirmed by CHX, MG132, ubiquitin test, immunofluorescence and IP. The above experiments were carried out to verify the effect of Amlexanox, an IKBKE inhibitor, on glioblastoma. And its pharmacokinetics in the brain was determined by LC-MS to provide a theoretical basis for further clinical use.

RESULTS

It was found that IKBKE could increase the radioresistance of glioblastoma in vitro and in vivo. IKBKE could directly phosphorylate AKT, and its phosphorylation sites were Ser473 and Thr308. We also certified that IKBKE activated AKT independent of PI3K. IKBKE inhibited the expression of FOXO3a on protein level, promoted its ubiquitin degradation, enhanced its interaction with 14-3-3, and inhibited its transportation into the nucleus. FOXO3a can increase the radiosensitivity of glioblastoma. Amlexanox, an IKBKE inhibitor, can inhibit the radiosensitivity of glioblastoma and partially pass through the blood-brain barrier to enhance the radiosensitivity of intracranial tumors.

CONCLUSION

IKBKE can activate AKT independent of PI3K by directly phosphorylating AKT Ser473 and Thr308, thus increasing the phosphorylation of FOXO3a. Phosphorylated FOXO3a promoted its ubiquitin degradation, and inhibited its transportation into the nucleus, causing radioresistance in glioblastoma. IKBKE inhibitor Amlexanox can pass through the blood-brain barrier and increase the radiosensitivity of intracranial tumor cells.

Perturbation of Gut Microbiota Modulated the Abscopal Effects of Immunoradiotherapy in Rectal Cancer

PURPOSE/OBJECTIVE(S)

The abscopal effect-the regression of malignancies outside the irradiation zone-can be increased by combining radiotherapy (RT) with immunotherapy. In this study, we aimed to investigate whether the gut microbiota affected the abscopal effect following immunoradiotherapy (iRT) in rectal cancer.

MATERIALS/METHODS

Bilateral MC38 subcutaneous tumors (primary and abscopal tumor) were established in C57/B6 mice with or without oral antibiotic treatment (preadministration of vancomycin, streptomycin, and ampicillin 14 days before therapy). Mice with or without antibiotic therapy were then randomized into eight groups to receive one of four treatments: (1) RT to the primary tumor + anti-PD-1 therapy (iRT), (2) RT to the primary tumor (RT), (3) anti-PD-1 therapy (anti-PD-1), and (4) no treatment. Flow cytometry was used to determine the composition and function of immune cells in the primary and abscopal tumors as well as in the spleen. 16S rRNA sequencing was used to assess the gut microbiome alteration following antibiotic intervention. Multiple bioinformatics were then explored to investigate the impact of specific flora that related to abscopal antitumor effect.

RESULTS

We found that radiation on primary tumors exhibited cytotoxic effect in nonirradiated (abscopal) tumors (p=0.0057, RT vs. untreated group; p=0.0037, iRT vs. anti-PD-1 group). In contrast, abscopal tumors were resistant to the anticancer effects of RT when antibiotics were given (p=0.5374, RT + antibiotics vs. untreated group + antibiotics; p=0.42, iRT + antibiotics vs. anti-PD-1 + antibiotics group). Comparing the RT+antibiotics group to the RT group, we discovered that the number of CD8+CD44+ T cells decreased significantly in both abscopal tumors (p<0.001) and spleens (p=0.0061). In anti-PD-1-treated groups, antibiotics significantly reduced the number of CD8+GranzymeB+ T cells in primary tumors (p=0.0061) and CD4+CD25+ T cells in spleens (p<0.001). In iRT-treated groups, the antibiotic reduced the fraction of CD4+INF-γ+ cells in abscopal tumors (p=0.0134), and increased the number of CD4+PD-1+ T cells in spleens (p<0.001). Moreover, we found that both α- and β-diversity decreased significantly in the gut microbiota after antibiotic treatment (p=0.0079 and p<0.001, respectively). The abundance of g_Alistipes, g_Lactobacillus, g_Lachnospiraceae and g__Lactobacillus fell dramatically in the presence of antibiotics. In addition, functional analyses of Picrust2 and KEGG revealed that antibiotic therapy had the most profound impact on the D-Alanine metabolism pathway (p<0.001).

CONCLUSION

We found that the alteration of the gut microbiome by antibiotics significantly affects the local and systemic antitumoral effect of iRT, our results may provide new insight on how gut modification converts the local anticancer effects of RT into a systemic response that targets metastatic tumors.

Focused Ultrasound for Blood-Brain Barrier Opening and Delivery of Anti-PD1 in Diffuse Midline Gliomas

PURPOSE/OBJECTIVE(S)

Diffuse midline glioma with H3K27 mutation is a fatal pediatric brain tumor, most commonly arising in the brainstem. This tumor remains universally fatal, despite a multitude of clinical trials, with a median overall survival of only 9-12 months. While immune-checkpoint inhibitors (ICIs) have transformed the treatment landscape of multiple solid tumors, delivery past the blood brain barrier (BBB) remains challenging. Programmed cell death protein 1 (PD1) is an immune checkpoint protein expressed on the surface of activated T cells; interaction with its ligand, PDL1, is tumor-protective, dampening T cell response. Recent phase I clinical trials have shown that ICIs targeting proteins along the PD1/PDL1 axis are well tolerated in patients with DMG; however, efficacy remains low. The blood-brain barrier (BBB) poses a major challenge to the efficacious delivery of therapeutic agents with large molecular size, such as anti-PD1. We hypothesize that BBB opening (BBBO) using focused ultrasound (FUS), a form of non-ionizing acoustic radiation, can enhance delivery and efficacy of anti-PD1 for treatment of DMG.

MATERIALS/METHODS

We established a syngeneic mouse DMG model with intracranial injection of cell line 4423 (PDGFB+, H3.3K27M, p53-/-). Magnetic resonance imaging (MRI) was utilized to evaluate BBBO and tumor progression. We measured delivery of anti-PD1 after BBBO using Western Blot and 3D in vivo optical fluorescent imaging/CT (OI/CT) of Cy7 labeled anti-PD1.

RESULTS

We demonstrate that delivery of anti-PD1 can be enhanced over 3.5-fold after reversible BBBO with FUS and concurrent microbubble administration. OI/CT revealed enhanced real-time antibody distribution peritumorally. Furthermore, we demonstrate that combined treatment of FUS and anti-PD1 led to benefit in local control of tumor growth using volumetric analysis of MRI. Preliminary survival studies suggest a positive trend for overall survival.

CONCLUSION

Our results support that FUS-mediated BBBO can increase treatment efficacy of anti-PD1 in a DMG murine model, due to improved targeted delivery to the tumoral region after systemic antibody administration. We consider these findings strong rationale for further investigation of the therapeutic effects of combinatorial treatment using FUS-mediated BBBO and ICIs for the treatment of DMG.

Linking the Mechanics of Chewing to Biology of the Junctional Epithelium

The capacity of a tissue to continuously alter its phenotype lies at the heart of how an animal is able to quickly adapt to changes in environmental stimuli. Within tissues, differentiated cells are rigid and play a limited role in adapting to new environments; however, differentiated cells are replenished by stem cells that are defined by their phenotypic plasticity. Here we demonstrate that a Wnt-responsive stem cell niche in the junctional epithelium is responsible for the capability of this tissue to quickly adapt to changes in the physical consistency of a diet. Mechanical input from chewing is required to both establish and maintain this niche. Since the junctional epithelium directly attaches to the tooth surface via hemidesmosomes, a soft diet requires minimal mastication, and consequently, lower distortional strains are produced in the tissue. This reduced strain state is accompanied by reduced mitotic activity in both stem cells and their progeny, leading to tissue atrophy. The atrophied junctional epithelium exhibits suboptimal barrier functions, allowing the ingression of bacteria into the underlying connective tissues, which in turn trigger inflammation and mild alveolar bone loss. These data link the mechanics of chewing to the biology of tooth-supporting tissues, revealing how a stem cell niche is responsible for the remarkable adaptability of the junctional epithelium to different diets.

Establishing a Chinese older hip fracture registry for older patients: a Delphi study to define the focus and key variables for this registry

A national hip fracture registry does not yet exist in China. This is the first to recommend a core variable set for the establishment of a Chinese national hip fracture registry. Thousands of Chinese hospitals will build on this and improve the quality of management for older hip fracture patients. The rapidly ageing population of China already experiences over half a million hip fractures every year. Many countries have developed national hip fracture registries to improve the quality of hip fracture management, but such a registry does not exist in China. The study is aimed at determining the core variables of a national hip fracture registry for older hip fracture patients in China. A rapid literature review was conducted to develop a preliminary pool of variables from existing global hip fracture registries. Two rounds of an e-Delphi survey were conducted with experts. The e-Delphi survey used a Likert 5-point scale and boundary value analysis to filter the preliminary pool of variables. The list of core variables was finalised following an online consensus meeting with the experts. Thirty-one experts participated. Most of the experts have senior titles and have worked in a corresponding area for more than 15 years. The response rate of the e-Delphi was 100% for both rounds. The preliminary pool of 89 variables was established after reviewing 13 national hip fracture registries. With two rounds of the e-Delphi and the expert consensus meeting, 86 core variables were recommended for inclusion in the registry. This study is the first to recommend a core variable set for the establishment of a Chinese national hip fracture registry. The further development of a registry to routinely collect data from thousands of hospitals will build on this work and improve the quality of management for older hip fracture patients in China.

A Comparative Population-Based Study of Tracheal and Lung Adenoid Cystic Carcinoma

PURPOSE/OBJECTIVE(S)

Thoracic adenoid cystic carcinoma (ACC) is very rare, and its clinicopathological characteristics, treatment and prognosis have not been fully elucidated. Previous studies did not differentiate between tracheal and lung lesions.

MATERIALS/METHODS

We identified tracheal ACC (TACC) and lung and bronchus ACC (LACC) patients from our cancer center (from 2005 to 2022) and the Surveillance, Epidemiology, and End Results (SEER) database (from 2000 to 2009). Incidence was calculated and trends were quantified. Significant prognostic factors for overall survival (OS) were reviewed and analyzed by using Cox proportional hazards regression. Then, two nomograms predicting OS of TACC and LACC were constructed based on the SEER database and validated externally by using the separate cohort.

RESULTS

There was an upward trend from 2000 to 2019 for LACC while a downward trend from 2000 to 2009 was shown for TACC. Totally, 55 TACC and 25 LACC were included in our cohort, 121 TACC and 162 LACC included in the SEER cohort. There were larger tumor sizes, more lymph nodes and distant metastases for LACC patients than TACC patients. The proportion of patients receiving radiotherapy were higher for TACC than LACC. More patients with TACC received surgery and perioperative radiotherapy than those with LACC. Patients with LACC had significantly worse OS than patients with TACC (SEER cohort: 93.7 mons vs. 127.0 mons, p = 0.001, our cohort: 72.2 months vs. 130.8months, p = 0.061). Age, lymph node metastasis, distant metastasis and radiation and/or surgery were identified as independent prognostic factors for OS of TACC. Laterality, distant metastasis and surgery were identified for LACC. The discrimination of the nomogram revealed good prognostic accuracy and clinical applicability as indicated by C-index values of 0.753 and 0.833 for the training cohort and the external validation cohort for TACC, and 0.739 and 0.786 for LACC.

CONCLUSION

TACC and LACC are different in incidence, clinical features, prognosis. Compared with LACC, radiotherapy combined with surgery is more important for TACC. Two nomograms were established for TACC and LACC respectively to help physicians make more individualized survival predictions and clinical decisions.

18F-AlF-NOTA-FAPI-04 PET/CT can Predict Treatment Response and Survival in Patients with Inoperable Pancreatic Adenocarcinoma

PURPOSE/OBJECTIVE(S)

We investigated whether uptake of 18F-AlF-NOTA-FAPI-04 on positron emission tomography/computed tomography (PET/CT) could predict treatment response and survival in patients with pancreatic adenocarcinoma (PAAD).

MATERIALS/METHODS

We prospectively evaluated 47 patients with histopathologically confirmed primary PAAD and pretreatment 18F-FAPI PET/CT scans to determine uptake of fibroblast activation protein (FAP) and compare the findings with those from blood tests and immunohistochemically stained tumor specimens. Cox regression and Kaplan-Meier methods were used to assess relationships between disease progression and potential predictors. Receiver operating characteristic (ROC) curve analysis was used to define the optimal cutoff points for distinguishing patients according to good response vs poor response per RECIST v. 1.1.

RESULTS

The FAPI PET variables maximum and mean standardized uptake values (SUVmax, SUVmean); metabolic tumor volume (MTV); and total lesion FAP expression (TLF) were positively correlated with cancer-associated fibroblast (CAF) markers (FAP, α-smooth muscle actin, vimentin, S100A4, and platelet-derived growth factor receptor α/β, all P<0.05). MTV and Log2TLF were associated with survival in patients with inoperable PAAD (all P<0.05). Analyses controlling for sex, age, cTNM, and performance status showed that MTV and Log2TLF were associated with overall survival (MTV hazard ratio [HR] = 1.016, P = 0.016 and Log2TLF HR = 4.093, P = 0.003). ROC cutoff analysis indicated that elevated MTV and TLF were associated with poorer survival. Greater changes from before to after chemotherapy in SUVmax, MTV, and TLF were associated with good treatment response (all P<0.05). ΔMTV, ΔTLF and ΔSUVmax had larger areas under the curve than ΔCA19-9 for predicting treatment response. Kaplan-Meier analysis showed that the extent of change in MTV and TLF from before to after treatment predicted progression-free survival, with cutoff values (based on medians) of -4.95 for ΔMTV (HR = 8.09, P = 0.013) and -77.83 for ΔTLF (HR = 4.62, P = 0.012).

CONCLUSION

Higher baseline MTV on 18F-FAPI-04 PET/CT scans was associated with poorer survival in patients with inoperable PAAD. ΔMTV was more sensitive for predicting response than ΔCA19-9. These results are clinically meaningful for identifying patients with PAAD who are at high risk of disease progression.

CDC73 Impairment of MAPK1 Ubiquitination and Activation of the mTOR Signaling Pathway

PURPOSE/OBJECTIVE(S)

CDC73 has been reported to be upregulated in breast cancer. This study aimed to illuminate the underlying mechanism by which CDC73 mediates breast cancer.

MATERIALS/METHODS

Here, a breast cancer tissue microarray and three breast cancer cell lines MDA-MB-231, BT-549 as well as MCF-7 were employed. Using RNAi method, we knocked down CDC73 and MAPK1 in breast cancer cells. CDC73 overexpression plasmids (LV-013) were generated through pMD2.G and pSPAX2 vectors. Cell events related to tumor development were analyzed through Celigo cell counting assay, a cell counting kit, wound healing assay, Transwell assay and flow cytometry analysis. The exploration on the underlying mechanism was based on PrimeView human gene expression array. Xenograft tumor models were constructed to visualize the effects of CDC73/MAPK2 on breast cancer progression.

RESULTS

CDC73 was abundantly expressed in breast cancer tissues and cell lines, and the expression of CDC73 was related to poor prognosis of patients. In breast cancer, CDC73 could promote the proliferation and migration of tumor cells, while disrupting apoptosis. Also, we found that CBL, an E3 ubiquitin ligase, could interact with CDC73 and promote MAPK1 ubiquitination and degradation of this protein. In addition, silencing MAPK1 led to a suppression of breast cancer cell growth in vitro and in vivo, and even abolished the promoting effects of CDC73 overexpression. We also found that mTOR pathway played a role in CDC73-mediated breast cancer. mTOR pathway inhibitor reversed cell phenotypes induced by CDC73 overexpression.

CONCLUSION

CDC73 promoted MAPK1 ubiquitination and degradation so that affected MAPK1 level and subsequently led to breast cancer progression, providing a novel therapeutic strategy to combat cancer.

Hybrid Immuno-RT for Bulky Tumors: Standard Fractionation with Partial Tumor SBRT

PURPOSE/OBJECTIVE(S)

Bulky tumors remain challenging to be treated. Stereotactic body radiation therapy (SBRT) is effective against radioresistant tumor cells and can induce immunogenic cell death (ICD) that leads to T-cell-mediated antitumor effects. Low-dose radiation (LDRT) can inflame the tumor microenvironment (TME) by recruiting T cells. We designed a novel radiotherapy technique (RT, ERT) whose dose distribution map resembles the "eclipse" by concurrently delivering LDRT to the whole tumor, meanwhile SBRT to only a part of the same tumor. This study examined the safety and efficacy of ERT to bulky lesions with PD-1 inhibitors in mice and patients.

MATERIALS/METHODS

In mice with CT26 colon or LLC1 lung bulky tumors (400 - 500 cm3), the whole tumor was irradiated by LDRT (2 Gy x 3), meanwhile the tumor center was irradiated by SBRT (10 Gy x 3); αPD-1 was given weekly. The dependence of therapeutic effects on CD8+ T cells was determined using depleting antibodies. Frequencies of CD8+ T cells and M1 macrophages (Mφ) were determined by flow cytometry. Multiplex Immunohistochemistry (mIHC) was applied to analyze the number and the location of CD8+ T cells and their subpopulations, as well as the phospho-eIF2α level (the ICD marker) of tumor cells in TME. Patients with advanced lung or liver bulky tumors who failed standard treatment or with oncologic emergencies were treated. Kaplan-Meier method was applied to estimate patients' progression-free survival (PFS) and overall survival (OS).

RESULTS

ERT/αPD-1 is superior to SBRT/αPD-1 or LDRT/αPD-1 in controlling bulky tumors in both mouse models in a CD8+ T-cell dependent manner. In the CT26 model, ERT/αPD-1 resulted in complete tumor regression in 3/11 mice and induced more CD8+ T cells and M1 Mφ in TME compared to other groups. mIHC analysis showed that ERT/αPD-1 induced higher bulk, stem-like (TCF1+ TIM3- PD-1+), and more differentiated (TCF1- TIM3+ PD-1+) CD8+ T cells infiltration into the tumor center and periphery compared to other groups. Compared to untreated or LDRT-treated tumor centers, tumor centers irradiated with ERT or SBRT showed elevated phospho-eIF2α accompanied by higher dendritic cell infiltration. In total, 39 advanced cancer patients were treated with ERT/αPD-1 or plus chemotherapy. Radiation-induced pneumonitis occurred in 1 of 26 patients receiving thoracic ERT. There were two cases of grade III toxicity associated with PD-1 inhibitors. No toxicity above grade III was observed. The objective response rate was 38.5%. The median PFS was 5.6 months and median OS was not reached at a median follow-up of 11.7 months.

CONCLUSION

ERT/αPD-1 showed superior efficacy in controlling bulky tumor in two mouse models. The hybrid immuno-RT (ERT) combing PD-1 inhibitors was safe and effective in patients with bulky tumors. Further clinical trials in combination with bioimaging to identify the optimal SBRT target region for the bulky tumor are warranted.

[Predictive value of plasma exosomal miR-124-3p for the risk of chronic cerebral hypoperfusion]

Objective: To investigate the predictive value of plasma exosomal microRNA (miR)-124-3p in the risk of chronic cerebral hypoperfusion (CCH). Methods: A case-control study. Thirty patients who were diagnosed with CCH (CCH group) based on cranial artery spin labeling (ASL) in the neurology outpatient clinic of Sichuan Provincial People's Hospital from March 2022 to June 2022 and 30 healthy volunteers (control group) were included. Age, gender, smoking history, alcohol consumption history, diabetes history, hypertension, hyperlipidemia history, uric acid, fasting blood glucose, homocysteine and plasma exosomal miR-124-3p expression level were compared between the two groups. Comparisons of categorical variables were analyzed by either χ2 test or Fisher's exact test. If the data of continuous variables followed a normal distribution, they were expressed as mean±standard deviation (SD) and compared by t-test for two independent samples; otherwise, the data were expressed as M(Q1, Q3), and analyzed by Mann-Whitney U test for comparison between two groups. The correlation between cerebral blood flow and exosomal miR-124-3p levels was analyzed by Pearson's correlation. Binary multifactorial logistic regression analysis was used to determine the risk factors associated with CCH, and corresponding odds ratios (OR) and 95% confidence intervals (CI) were calculated. P<0.05 was considered significant. Results: There was no significant difference in age (64±8 vs. 60±8 years old), gender (33.3% vs. 30.0%), history of smoking (20.0% vs. 3.3%), alcohol consumption (20.0% vs. 6.7%), diabetes mellitus (13.3% vs. 13.3%), hypertension (53.3% vs. 30.0%), history of hyperlipidemia (46.7% vs. 36.7%), uric acid (288±60 vs.319±67 μmol/L), and fasting glucose [4.99(4.63, 5.91) vs. 5.28(5.09, 6.05) mmol/L] and homocysteine [11.35(10.18, 13.08) vs.11.00(9.78, 13.03) μmol/L] between the CCH and control groups (P>0.05). Plasma exosomal miR-124-3p expression was significantly higher in the CCH group than in the control group [13.08 (8.59, 21.55) vs. 2.85 (1.44, 5.10), respectively; U=169.50, P<0.001]. Pearson's correlation test showed that the level of exosomal miR-124-3p was negatively correlated with cerebral blood flow in the hypoperfused region in patients with CCH (r=-0.932, P<0.001). Multi-factor logistic regression analysis showed that plasma exosomal miR-124-3p was independently associated with the risk of CCH (OR=1.169,95%CI 1.063-1.286,P=0.001). Conclusions: The expression of plasma exosomal miR-124-3p is negatively correlated with cerebral blood flow in areas of low perfusion and is an independent risk factor for CCH. Plasma exosomal miR-124-3p may thus serve as a valid biomarker for CCH risk prediction.

An Effective Dose Rate Optimization Algorithm for Efficient Conventional-Dose-Rate Proton Therapy and Ultra-High-Dose-Rate FLASH Proton Therapy

PURPOSE/OBJECTIVE(S)

The treatment delivery with high dose rate is desirable for efficient conventional-dose-rate proton therapy (IMPT and proton ARC) and essential for achieving biological sparing effect to normal tissues for ultra-high-dose-rate FLASH proton therapy. The minimum-monitor-unit (MMU) problem is mathematically fundamental to these high-dose-rate proton therapy problems, since the dose rate is proportionally associated with the MMU threshold. However, the MMU problem is nonconvex and larger MMU threshold that leads to higher dose rate makes the nonconvex problem more difficult to solve, for which the conventional optimization methods (e.g., alternating direction method of multipliers (ADMM) or proximal gradient descent (PGD) usually cannot satisfactorily solve. This work will develop an effective dose rate optimization algorithm for the MMU problem.

MATERIALS/METHODS

The new method is based on orthogonal matching pursuit (OMP), and consists of two essential components. First, the iterative convex relaxation method is used to determine the active sets for dose-volume planning constraints and decouple the MMU constraint from the rest. Second, a modified OMP optimization algorithm is used to handle the MMU constraint: the non-zero spots are greedily selected via OMP to form the solution set to be optimized, and then a convex constrained subproblem is formed and can be conveniently solved to optimize the spot weights restricted to this solution set via OMP. During this iterative process, the new non-zero spots localized via OMP will be adaptively added to or removed from the optimization objective.

RESULTS

The new method via OMP is validated in comparison with conventional methods (ADMM and PGD) and a recently proposed new method (called stochastic coordinate descent (SCD) method) for high-dose-rate IMPT, ARC, and FLASH problems of large MMU thresholds, and the results suggest that OMP substantially improved the plan quality from PGD, ADMM and SCD in terms of both target dose conformality (e.g., quantified by max target dose and conformity index) and normal tissue sparing (e.g., mean and max dose). A brain case is provided in the table: compared to PGD/ADMM/SCD, OMP improved the conformity index from 0.42/0.52/0.33 to 0.65 for IMPT and 0.46/0.60/0.61 to 0.83 for ARC.

CONCLUSION

A new dose rate optimization algorithm via OMP is developed to solve the MMU problem with large MMU thresholds, and validated using examples of IMPT, ARC, and FLASH with substantially improved plan quality from conventional methods (ADMM and PGD) and a recently proposed new method SCD.

Retrospective study of preservation and transection of the round ligament of uterus during laparoscopic transabdominal preperitoneal inguinal hernia repair in adult women

PURPOSE

The processing of the round ligament of uterus in laparoscopic transabdominal preperitoneal (TAPP) repair of inguinal hernia in women has contended. This study aimed to explore whether there is any difference in the surgical outcome and postoperative complications between the two processing modalities, preservation, and transection of the round ligament of uterus, in adult female inguinal hernia patients undergoing TAPP.

METHODS

Retrospective analysis of 84 female patients (117 sides) who underwent TAPP in XXX Hospital from July 2013 to August 2022. Patient characteristics and technical details of the surgical procedure were collected and divided into two groups according to whether the round ligament of uterus was severed intraoperatively or not. There were 52 cases (77 sides) in the group with preservation of the round ligament of uterus and 32 cases (40 sides) in the group with transection of the round ligament of uterus, comparing the general condition, surgical condition, and the occurrence of postoperative related complications between the 2 groups.

RESULTS

The operative time for unilateral primary inguinal hernia was (129.2 ± 35.1) and (89.5 ± 42.6) minutes in the preservation and transection groups, respectively. There were no statistical differences between the two groups in terms of age, length of hospital stay, ASA, BMI, history of lower abdominal surgery, type and side of hernia, intraoperative bleeding, and time to surgery for primary bilateral hernia (P > 0.05). In addition, there was likewise no statistical difference in the occurrence of postoperative Clavien-Dindo classification, VAS, seroma, mesh infection, labia majora edema, chronic pain or abnormal sensation in the inguinal region, and hernia recurrence in the two groups as well (P > 0.05).

CONCLUSION

There is no evidence that the transection of the round ligament of the uterus during TAPP has an impact on postoperative complications in patients. However, given the important role of the uterine round ligament in the surgical management of patients with uterine prolapse and the high incidence of uterine prolapse in older women, hernia surgeons should also be aware of the need to protect the round ligament of uterus in older women.

[Clinical characteristics and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia arising from malignant tumors]

Objective: To investigate the clinical characteristics, cytogenetics, molecular biology, treatment, and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) secondary to malignancies. Methods: The clinical data of 86 patients with t-MDS/AML in West China Hospital of Sichuan University between January 2010 and April 2023 were retrospectively analyzed. The clinical characteristics, primary tumor types, and tumor-related therapies were analyzed. Results: The study enrolled a total of 86 patients with t-MDS/AML, including 67 patients with t-AML, including 1 patient with M(0), 6 with M(1), 27 with M(2), 9 with M(3), 12 with M(4), 10 with M(5), 1 with M(6), and 1 with M(7). Sixty-two patients could be genetically stratified, with a median overall survival (OS) of 36 (95% CI 22-52) months for 20 (29.9%) patients in the low-risk group and 6 (95% CI 3-9) months for 10 (14.9%) in the intermediate-risk group. The median OS time was 8 (95% CI 1-15) months in 32 (47.8%) patients in the high-risk group. For patients with non-acute promyelocytic leukemia (APL) and AML, the median OS of the low-risk group was 27 (95% CI 18-36) months, which was significantly longer than that of the non-low-risk group (χ(2)=5.534, P=0.019). All 9 APL cases were treated according to the initial treatment, and the median OS was not reached, and the 1-, 2-, and 3-year OS rates were 100.0%, (75.0±6.2) %, and (75.0±6.2) % respectively. Of the 58 patients with non-APL t-AML (89.7%), 52 received chemotherapy, and 16 achieved complete remission (30.8%) after the first induction chemotherapy. The 1-, 2-, and 3-year OS rates of the non-APL t-AML group were (42.0 ± 6.6) %, (22.9±5.7) %, and (13.4±4.7) %, respectively. The median OS of patients who achieved remission was 24 (95% CI 18-30) months, and the median OS of those who did not achieve remission was 6 (95% CI 3-9) months (χ(2)=10.170, P=0.001). Bone marrow CR was achieved in 7 (53.8%) of 13 patients treated with vineclar-containing chemotherapy, with a median OS of 12 (95% CI 9-15) months, which was not significantly different from that of vineclar-containing chemotherapy (χ(2)=0.600, P=0.437). In 19 patients with t-MDS, the 1-, 2-, and 3-year OS rates were (46.8±11.6) %, (17.5±9.1) %, and (11.7±9.1) % with a median OS of 12 (95% CI 7-17) months, which was not significantly different from that in t-AML (χ(2)=0.232, P=0.630) . Conclusions: Breast cancer, bowel cancer, and other primary tumors are common in patients with t-MDS/AML, which have a higher risk of adverse genetics. Patients with APL had a high induction remission rate and a good long-term prognosis, whereas patients without APL had a low remission rate and a poor long-term prognosis.