Burden and trend of dietary risk-related colorectal cancer in China and its provinces: findings from the Global Burden of Disease Study 2019

OBJECTIVES

The objective of this experiment was to evaluate the spatial pattern and temporal trend of colorectal cancer (CRC) burden attributed to dietary risk factors in China from 1990 to 2019 using data from the Global Burden of Diseases, Injuries, and Risk Factors study (GBD) 2019.

METHODS

Numbers and age-standardised rates of deaths, disability-adjusted life years (DALYs) and corresponding average annual percentage change (AAPC) were determined. The joinpoint regression analysis was used to assess the temporal trends of CRC deaths and DALYs from 1990 to 2019.

RESULTS

In China, the number of diet-attributable CRC deaths and DALYs in 2019 were 90.41 (95% uncertainty interval: 65.69, 114.67) and 2234.06 (1609.96, 2831.24) per-1000 population, marking 2.05% and 1.68% annual increases since 1990, respectively. The region with the highest increase in age-standardised rates (ASRs) of diet-related CRC deaths and DALYs was in Taiwan with an AAPC of 2.00% (1.51, 2.48), whereas the highest decline in ASRs of CRC deaths and DALYs was observed in Hong Kong with an AAPC of -0.63% (-0.90, -0.35) (all P < 0.05). Nationally, men suffered higher CRC deaths and DALY burdens attributable to dietary risks than did women. Regarding the specific diet group, diets low in calcium, milk, and whole grains contributed to CRC deaths and DALYs the most.

CONCLUSIONS

Diet is an important contributor to increasing CRC burden in China. Necessary measures should be taken to kerb the growing burden attributed to dietary factors, particularly in males and in regions with middle Socio-demographic Index or lower.

First Measurement of the |t| Dependence of Incoherent J/ψ Photonuclear Production

The first measurement of the cross section for incoherent photonuclear production of J/ψ vector mesons as a function of the Mandelstam |t| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |y|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV. This rapidity interval corresponds to a Bjorken-x range (0.3-1.4)×10^{-3}. Cross sections are given in five |t| intervals in the range 0.04<|t|<1  GeV^{2} and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |t| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.

Data Linkages for Wildfire Exposures and Human Health Studies: A Scoping Review

Wildfires are increasing in frequency and intensity, with significant consequences that impact human health. A scoping review was conducted to: (a) understand wildfire-related health effects, (b) identify and describe environmental exposure and health outcome data sources used to research the impacts of wildfire exposures on health, and (c) identify gaps and opportunities to leverage exposure and health data to advance research. A literature search was conducted in PubMed and a sample of 83 articles met inclusion criteria. A majority of studies focused on respiratory and cardiovascular outcomes. Hospital administrative data was the most common health data source, followed by government data sources and health surveys. Wildfire smoke, specifically fine particulate matter (PM2.5), was the most common exposure measure and was predominantly estimated from monitoring networks and satellite data. Health data were not available in real-time, and they lacked spatial and temporal coverage to study health outcomes with longer latency periods. Exposure data were often available in real-time and provided better temporal and spatial coverage but did not capture the complex mixture of hazardous wildfire smoke pollutants nor exposures associated with non-air pathways such as soil, household dust, food, and water. This scoping review of the specific health and exposure data sources used to underpin these studies provides a framework for the research community to understand: (a) the use and value of various environmental and health data sources, and (b) the opportunities for improving data collection, integration, and accessibility to help inform our understanding of wildfires and other environmental exposures.

Decline in Cancer Diagnoses during the 'Zero COVID' Policy in Hong Kong: Indirect Spillover Impact of the COVID-19 Pandemic

AIMS

Despite a largely successful 'zero COVID' policy in 2020, the COVID-19 pandemic disrupted routine cancer services in the city of Hong Kong. The aims of this study were to examine the trends in cancer incidence before and during the COVID-19 pandemic and estimate missed cancer diagnoses.

MATERIALS AND METHODS

We used population-based data from the Hong Kong Cancer Registry 1983-2020 to examine the trends of age- and sex-standardised cancer incidence before and during the COVID-19 pandemic. We applied: (i) the annual average percentage change (AAPC) calculated using the Joinpoint regression model and (ii) the autoregressive integrated moving average (ARIMA) model to forecast cancer incidence rates in 2020. Missed cancer diagnoses in 2020 were estimated by comparing forecasted incidence rates to reported rates. A subgroup analysis was conducted by sex, age and cancer site.

RESULTS

The cancer incidence in Hong Kong declined by 4.4% from 2019 to 2020 (male 8.1%; female 1.1%) compared with the long-term AAPC of 0.5% from 2005 to 2019 (95% confidence interval 0.3, 0.7). The gap between the reported and forecasted incidence for 2020 ranged from 5.1 to 5.7% (male 8.5%, 9.8%; female 2.3%, 3.5%). We estimated 1525-1596 missed cancer diagnoses (ARIMA estimate -98, 3148; AAPC 514, 1729) in 2020. Most missed diagnoses were in males (ARIMA 1361 [327, 2394]; AAPC 1401 [1353, 1460]), with an estimated 479-557 missed cases of colorectal cancer (ARIMA 112, 837; AAPC 518, 597) and 256-352 missed cases of prostate cancer (AAPC 231, 280; ARIMA 110, 594).

CONCLUSION

The incidence of new cancer diagnoses declined in 2020 contrary to the long-term increase over the previous decades. Significantly lower diagnoses than expected were observed in males, particularly for colorectal and prostate cancers. Fewer reported cancer cases indicate missed diagnoses and could lead to delayed treatment that could impact future health outcomes.

ψ(2S) Suppression in Pb-Pb Collisions at the LHC

The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.5 Collapse

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Review of standard paediatric neuroradiology MRI protocols from 12 UK tertiary paediatric hospitals: is there much variation between centres?

AIM

To investigate how magnetic resonance imaging (MRI) examinations are protocolled in tertiary paediatric neuroradiology centres around the UK for some of the more common presentations encountered in paediatric neuroradiology, and to identify any variations of note.

MATERIALS AND METHODS

All 19 UK tertiary paediatric neuroradiology centres registered with the British Society of Neuroradiologists-Paediatric Group were contacted and asked if they could provide a copy of their standard MRI protocols. Twelve responded (63%) and 10 of the more common presentations were selected and the standard acquired sequences obtained at each participating centre were compared. Where available the collated protocols were also compared against current published guidance.

RESULTS

The basic sequences carried out by centres around the UK are similar; however, there are lots of variations overall. The only standardised protocol currently being implemented nationally in paediatric imaging is that for brain tumours. Otherwise, chosen protocols are generally dependent on the preferences and technical capabilities of individual centres. Suggested published protocols also exist for non-accidental injury (NAI), multiple sclerosis, epilepsy, and head and neck imaging.

CONCLUSIONS

The differences in MRI protocolling depend in part on technical capabilities and in part on the experience and preferences of the paediatric neuroradiologists at each centre. For most presentations, there is no consensus as to what constitutes the perfect protocol. The present results will be useful for specialist centres who may wish to review their current protocols, and for more generalist centres to use as a reference to guide their MRI protocolling.

Measurements of Groomed-Jet Substructure of Charm Jets Tagged by D^{0} Mesons in Proton-Proton Collisions at sqrt[s]=13 TeV

Understanding the role of parton mass and Casimir color factors in the quantum chromodynamics parton shower represents an important step in characterizing the emission properties of heavy quarks. Recent experimental advances in jet substructure techniques have provided the opportunity to isolate and characterize gluon emissions from heavy quarks. In this Letter, the first direct experimental constraint on the charm-quark splitting function is presented, obtained via the measurement of the groomed shared momentum fraction of the first splitting in charm jets, tagged by a reconstructed D^{0} meson. The measurement is made in proton-proton collisions at sqrt[s]=13  TeV, in the low jet transverse-momentum interval of 15≤p_{T}^{jet ch}<30  GeV/c where the emission properties are sensitive to parton mass effects. In addition, the opening angle of the first perturbative emission of the charm quark, as well as the number of perturbative emissions it undergoes, is reported. Comparisons to measurements of an inclusive-jet sample show a steeper splitting function for charm quarks compared with gluons and light quarks. Charm quarks also undergo fewer perturbative emissions in the parton shower, with a reduced probability of large-angle emissions.

Dosimetric Study of Total Marrow and Lymphoid Irradiation on a Ring Gantry-Based Medical Linac with a Two-Layer Multi-Leaf Collimator

PURPOSE/OBJECTIVE(S)

In this study, we aimed to evaluate dosimetric quality of total marrow and lymphoid irradiation (TMLI) plans for a ring gantry-based medical Linac with a two-layer multi-leaf collimator.

MATERIALS/METHODS

We retrospectively retrieved treatment planning CT images, structure sets, and plan dose for four adult patients, two male and two female, who previously received TMLI treatments on helical tomotherapy (HT) at our institution. TMLI plans were optimized for a ring gantry-based medical Linac with a two-layer multi-leaf collimator (Halcyon, Varian Medical Systems, Inc., Palo Alto, CA). A prescription dose of 12 Gy in 8 fractions was prescribed to the skeletal bones from the skull to mid-thigh, spleen, spinal canal, and lymphoid volume. Five or six isocenters were placed with equal spacing along the patient's longitudinal direction in each TMLI plan with two 6-MV flattening filter-free volumetric modulated arc therapy (VMAT) fields at each isocenter. Isocenter separation ranged from 15 cm to 16.5 cm. Each VMAT field has a field size of 28 cm to 28 cm with the collimator at 90° and a full gantry rotation. The nominal dose rate was 800 MU/minute, and the maximum gantry rotation speed was 24°/sec. Institutional dosimetric constraints were used for optimization including a mean lung dose limit of less than 8 Gy. All the plans were normalized so that 85% the primary planning target volume received the prescription dose.

RESULTS

The average mean doses to the target volumes ranged from 12.2 to 12.6 Gy in the Halcyon TMLI plans, while they ranged from 12.1 to 12.5 Gy in the HT TMLI plans. Relative to the prescription dose, the average mean dose for normal organs ranged from 21.3% to 56.6% in the Halcyon TMLI plans, while it ranged from 10.1% to 68.4% in the clinical HT plans. The difference in the average mean dose to normal organs was less than 0.5 Gy except two organs between the Halcyon and HT TMLI plans. The average median dose for normal organs ranged from 18.2% to 48.8% relative to the prescription dose in the Halcyon TMLI plans. The mean lung dose (MLD) in the Halcyon TMLI plans met the institutional limit with an average dose of 6.75±0.42 Gy (range: 6.44 - 7.36 Gy), while the average MLD was 6.54±0.77 Gy (range: 6.24 - 7.22 Gy) in the HT plans (p-value = 0.71 in the paired t-test). The average total monitor unit in the Halcyon TMLI plans was 4,425±906 MU (range: 3,470 - 5,575 MU) with an average beam-on time of 5.1±1.3 minutes (range: 4.1 - 7.0 minutes), which excludes isocenter setup time, while the average beam-on time was 22.2±3.2 minutes (range: 19.6 - 26.1 minutes) with the HT plans.

CONCLUSION

Halcyon TMLI plans met our institutional dosimetric constraints with adequate normal organ sparing and target dose coverage. The beam-on time with the Halcyon plans was significantly shorter than that with the HT plans, which could lead to shorter treatment time and increased patient comfort. This study showed the feasibility of TMLI treatments on the Halcyon machine. The same method could be used for total body irradiation on Halcyon.

Hippocampal Sparing Whole Brain Radiation Therapy: 2 Arc Coplanar and 4 Arc Noncoplanar Planning Comparison

PURPOSE/OBJECTIVE(S)

Whole brain radiation therapy (WBRT) has been shown to provide palliation but with negative neurocognitive effects associated with radiation-induced damage to the hippocampus. Sparing of the hippocampus has been shown to reduce the risk of neurocognitive deficit. Hippocampal sparing WBRT plan optimization is commonly done using 2 arc coplanar technique. The purpose of this work is to show that 4 arc noncoplanar plans will improve hippocampal sparing without compromising PTV coverage.

MATERIALS/METHODS

Retrospective WBRT with hippocampal sparing using 2 arc coplanar and 4 arc noncoplanar VMAT technique were done on 10 patients previously treated for intracranial lesions. CT and MRI fused images were used to delineate the whole brain and hippocampus. Strictly following RTOG 0933 atlas guidelines, the hippocampus was manually delineated by a single Radiation Oncologist. Plans with prescription dose of 30 Gy in 10 fractions were generated using the 2 techniques. The 4 arc noncoplanar plan included 2 partial field arcs with couch angle at 90 degrees and 2 coplanar arcs. The 2 noncoplanar partial arcs consisted of a clockwise arc and a counterclockwise arc with gantry angles between 5 and 179 degrees. Lens were kept to < 7 Gy and pituitary gland to < 30 Gy. Dosimetric parameters from both techniques were compared by paired t-test.

RESULTS

Radiation dose to the hippocampus was significantly reduced using 4 arc noncoplanar plan when compared to 2 arc coplanar plan. While hippocampus D100% were similar (7.25 Gy vs 7.32 Gy, p = 0.557), the mean dose (9.46 Gy vs 9.87 Gy, p = 0.003) and D0.03cc (12.48 Gy vs 12.94 Gy, p < 0.001) were significantly reduced with 4 arc noncoplanar plans. Whole brain PTV coverage remained at V100% = 95% for both techniques. However, the 4 arc noncoplanar plans showed significantly improved D2% (32.56 Gy vs 32.97 Gy, P = 0.003), D98% (28.11 Gy vs 27.91 Gy, P = 0.01), and homogeneity index (0.141 vs 0.159, P < 0.001).

CONCLUSION

The 4 arc noncoplanar plans improved hippocampal sparing without compromising PTV coverage or compromise to other nearby organs at risk.

Evaluation of a Deep-Learning Auto-Segmentation Model of Cardiac Substructures

PURPOSE/OBJECTIVE(S)

Increasing evidence has suggested that limiting dose not only to the whole heart but also to cardiac substructures can potentially reduce cardiac toxicities. Manual contouring of cardiac substructure can be challenging and time-consuming. To address this concern, we developed a deep learning (DL) model, trained on convolutional neural network algorithms in large external datasets, for auto-segmentation of cardiac substructures. This study aimed to evaluate the quality of the cardiac substructure contours generated by the DL algorithm.

MATERIALS/METHODS

We identified 28 patients with esophagus or gastroesophageal junction cancer from a single institution who received radiation to the esophagus between January 2017 and December 2022. For each case, the DL-generated cardiac substructures (4 heart chambers - left/right atrium [L/RA] and L/R ventricle [L/RV], 4 coronary arteries - L common [LCA], L anterior descending [LAD], L circumflex [LCx], and R common [RCA], and great vessels - ascending aorta [AA], pulmonary artery [PA], and superior vena cava [SVC]) were modified by two radiation oncologists (RO) using the contouring atlas developed by Duane et al. Spatial overlapping of the contours were then assessed using the Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (HD-95), and normalized surface dice at 2 mm tolerance (NSD-2).

RESULTS

The mean values of DSC, HD-95, and NSD-2 are shown in Table 1. Overall, the mean DSC, HD-95, and NSD-2 for the heart chambers ranged from 0.82 to 0.92, 0.40 cm to 1.52 cm, and 0.68 to 0.85, respectively. Ranges of the mean DSC, HD-95, and NSD-2 for the coronary vessels were 0.41 to 0.74, 0.18 cm to 0.98 cm, and 0.66 to 0.77, respectively. Lastly, comparison of the great vessel contours yielded the following ranges for mean DSC, HD-95, and NSD-2 respectively: 0.72 to 0.92, 0.30 cm to 1.64 cm, and 0.65 to 0.83.

CONCLUSION

Our study demonstrates that auto-segmentation of cardiac substructures by DL-powered models can be comparable to manual contours for certain cardiac substructures, namely the four heart chambers and great vessels. Further improvement of the DL on contouring of coronary vessels would be needed prior to the autosegmentation model being widely adopted.

Evaluation of 68Ga-Fibroblast Activation Protein Inhibitor vs. 18F-FDG as a Novel Radiotracer for Biologically Guided Radiation Therapy

PURPOSE/OBJECTIVE(S)

Real-time biology guided radiation therapy (BgRT) uses real-time positron emissions from a PET tracer during treatment to guide targeted radiation to cancerous lesions. Fibroblast activation protein alpha (FAP) is highly expressed on cancer-associated fibroblasts in tumors with low expression in normal tissues. While 18F-FDG-PET requires fasting and has background in the liver and brain, 68-Gallium labeled FAP inhibitor (FAPI) does not require fasting and has less background uptake. The goal of this study was to investigate the utility of FAPI as a potential universal fiducial for BgRT. We hypothesized that 68Ga-FAPI would be a better radiotracer than 18F-FDG, as assessed by the Normalized Minimal kBq/mL and the Normal Target Signal (NTS), two parameters used to gauge the suitability of BgRT.

MATERIALS/METHODS

PET-CTs were obtained for 50 patients with pancreatic, liver, lung, head & neck, and cervical cancer using 18F-FDG and 68Ga-FAPI (n = 10 for each). Four DICOM images were obtained per patient (FDG PET + CT, FAPI PET + CT). Radiation oncologists delineated the gross tumor volume (GTV) on PET images. A separate set of auto-contours were generated from the PET using an auto-threshold of 40% maximum SUV for all tumors. A 1 cm expansion was added to the GTV to create a ring around the physician-generated contours and auto-contours. The following parameters were measured: GTV volume, SUV max of GTV, SUV mean of GTV, Normalized Minimal kBq/mL within the GTV, and NTS (= SUV max/Ring SUV mean). Values were compared using paired t-test. For the BgRT product with similar calculations, the required Normalized Minimal kBq/mL is > 5 kBq/mL; the required NTS is > 2.7 for treatment planning and > 2.0 for BgRT delivery.

RESULTS

The Normalized Minimal kBq/mL for FAPI was > 5 kBq/mL for all tumors and greater for auto-contoured GTVs compared to physician-contoured GTVs. The mean NTS for the auto-contours for all tumor sites was > 2.0. In addition, there was a statistically significant increase in the NTS for FAPI compared to FDG in pancreatic, liver and head & neck cancers. In pancreatic cancer, there was a statistically significant increase in Normalized Minimal kBq/mL for FAPI compared to FDG (26.0 vs 14.2) (p = 0.01) and the SUVmax of FAPI was almost double that of FDG (15.9 vs 8.2) (p = 0.01). FAPI had no background in the liver, but had high background in the uterus, suggesting it may have a role in liver cancer but not cervical cancer.

CONCLUSION

This is the first study demonstrating the potential superiority of 68Ga-FAPI compared to 18F-FDG as a biologic fiducial for BgRT when treating pancreatic, liver and head & neck cancers, with a similar efficacy for lung cancer. Our results indicate that auto-contoured GTVs generate a higher NTS than physician-contoured GTVs but all are > 2.0. In addition, the Normalized Minimal kBq/mL for auto-contours is > 5 kBq/mL for all tumors. As hypothesized, FAPI-based BgRT is most likely to be successful when treating tumors with significant desmoplastic stroma, such as pancreatic cancer.

Spatiotemporal Optimization of Pelvic Radiation Therapy

PURPOSE/OBJECTIVE(S)

Conformal and adaptive Radiation Therapy (RT) remains critical in the treatment of locally advanced pelvic cancers despite acute and late bowel complications. This work introduces spatiotemporal optimization of pelvic RT including mathematical modelling of intestinal radiobiology to evaluate a novel treatment planning approach for fractionated pelvic RT.

MATERIALS/METHODS

A single-plan fractionated RT delivery has n-fractions at dose/fraction = d and has biologically effective dose BED = nd ( 1 + d / [α/β] ) - ln(2) ([T - Tk] / [αTp]), where Tk and Tp are the kickoff time and doubling time of repopulation, and T is the time to deliver all fractions (including off-days). We present a parameterization of the repopulation BED-term to estimate a range of daily recovered BED including uncertainties in α and Tp. Recovery of BED as currently formulated is independent of the delivered dose; however, the assumption of spatiotemporal optimization is that a regional reduction of dose during RT by mixing treatment plans is critical to allow for normal tissue healing. We evaluate an achievable spatiotemporal optimization treatment planning strategy for an advanced stage prostate and a cervical cancer patient using 25-fraction delivery over 5-weeks and 4-weekends (T = 33 days) and propose 3 treatment plans: (1) a conformal "clinical standard" plan, (2) a right-bowel sparing plan, and (3) a left-bowel sparing plan. The plans are optimized to ensure no increased dose in opposing bowel or normal organs at risk (OARs).

RESULTS

For radiobiological parameters ranging from α = 0.2-0.35/Gy, α/β = 2-3 Gy, Tk = 5-10 days, and Tp = 3-7 days, parameterization shows daily BED recovery of 0.44±0.08 Gy (range = 0.28-0.69 Gy), or an average of 4Gy BED recovery for 5-days treatment surrounded by 2 weekends. Conservatively evaluating the 3.6Gy BED distribution in treatment planning may identify regions for complete recovery (after Tk days). In a prostate 3-plan set, the right- and left- bowel sparing plans deliver equivalent mean dose to targets and OARs to within 5cGy/fx. The clinical plan includes 298cc of bowel under 14Gy, but this same bowel will be spared throughout treatment. Delivery of the clinical plan in week 1 to achieve Tk days, followed by alternating the left and right plan each week has the potential to reduce BED to zero for an additional 116cc of bowel using the left-sparing plan in weeks 2 and 4, and 91cc using the right-bowel sparing plan in weeks 3 and 5. The cervical cancer plan-set was more challenging due to right-sided nodal volumes and higher clinical bowel dose; OAR mean dose variations were >8cGy/fx in a few organs, but the left- and right- sided sparing plans results in 394 cc and 139cc, respectively of unique spared bowel at the 3.6Gy/week threshold to potentially reach zero BED during treatment.

CONCLUSION

A novel spatiotemporal optimization of pelvic RT has the potential to preserve bowel, allow for increased intra-treatment intestinal tissue regeneration, and reduce radiation-induced complications.

Pilot Study of a Novel Ring Gantry-Based PET/CT Linear Accelerator in Patients with Prostate Cancer Receiving [18F]-DCFPyL for PSMA PET Imaging

PURPOSE/OBJECTIVE(S)

The RefleXion X1® system is a hybrid PET imaging-radiotherapy system that uses real-time positron emissions from a PET tracer to deliver biologically guided radiotherapy (BgRT). This study (NCT05470699) evaluated the hypothesis that the X1 PET imaging subsystem would be able to detect [18F]-DCFPyL PSMA PET signal sufficient to generate a deliverable BgRT plan in patients with prostate cancer.

MATERIALS/METHODS

Patients with prostate cancer scheduled for a diagnostic [18F]-DCFPyL PSMA PET scan as part of standard of care were eligible. Upon completion of the diagnostic PSMA PET scan, images were transferred to the radiotherapy planning system for target identification and contouring. If at least one PET avid tumor lesion was identified, the patient was then scanned on the X1 unit. BgRT planning was performed on each X1 scanned patient. The target lesion volume, activity concentration (AC) and normalized target signal (NTS) were acquired. Successful and deliverable BgRT plans required that the target AC was ≥ 5 kBq/ml and NTS ≥ 2.7.

RESULTS

Twenty-six patients underwent [18F]-DCFPyL PET scans (13 with rising PSA after surgery or radiotherapy, 6 with known metastases and 7 with newly diagnosed high-risk prostate cancer). Median (range) PSA was 3.40 (0.04-122). In 16 patients a PET avid tumor was identified and contoured for planning (4 lymph nodes, 5 bone, 6 prostate gland, and 1 prostate bed). In 13 patients the target lesion was visualized on the X1 PET scan, while in 3 patients the target lesion was too close to the bladder to be clearly visualized. BgRT planning was feasible and met standard of care published SBRT organ dose constraints in 8 patients (3 prostate gland, 3 bone, 2 lymph nodes). BgRT planning was not feasible in 8 patients due to insufficient AC, low NTS or proximity of the target lesion to the PET avid bladder. The accompanying table compares median (range) target volume, AC and NTS for feasible versus not feasible plans.

CONCLUSION

This is the first study to investigate the feasibility of using [18F]-DCFPyL PET imaging for BgRT plan generation on the X1 system in patients with prostate cancer. Lesions that are relevant to radiotherapy of prostate cancer can be visualized including lymph node and bone metastases. A dedicated BgRT workflow with PSMA PET imaging on the X1 at 60 minutes post injection will result in higher target AC and will optimize BgRT planning. PET avid lesions < 1 cm or close to the bladder may make BgRT planning challenging. [18F]-DCFPyL-guided BgRT is technically feasible using the RefleXion X1. BgRT using targeted PET radiopharmaceuticals to biologically guide external beam radiotherapy represents a promising new dimension in radiation oncology and warrants further investigation.

Dosimetric Plan Evaluation of Biology Guided Radiotherapy Using [18F]-DCFPyL PSMA Radiotracer in Patients with Prostate Cancer

PURPOSE/OBJECTIVE(S)

The X1 system represents a cutting-edge solution in radiotherapy delivery, with its capability to perform Biology Guided Radiotherapy (BgRT). The system utilizes real-time positron emission tomography (PET) signal as biological fiducials to provide tracked dose delivery and is initially available for use with [18F]-Fluorodeoxyglucose (FDG). The aim of this research study is to assess the quality of BgRT treatment plans for prostate cancer using patients' PSMA PET images obtained on the X1 system.

MATERIALS/METHODS

Sixteen patients with at least one PET-avid tumor identified on their whole-body diagnostic PSMA PET scan were selected. These patients were scanned on X1 following their diagnostic scan without additional radiotracer administration. Based on the X1 PET images, a BgRT plan was created for each patient, with the prescription dose determined by the location of treatment sites. The planning objectives of organs-at-risk (OARs) were established in accordance with the 2018 Timmerman guidelines. Target coverage objective was the dose covering 95% (D95%) of the planning target volume (PTV) to be higher than 100%. The following parameters were analyzed: PTV D95%, the minimal dose (Dmin) of gross tumor volume (GTV), plan maximum dose (Dmax), conformity index (CI), gradient index (GI), and maximum point dose (D0.03cc) to the nearest OARs. The X1 BgRT planning system also generated dose volume histogram (DVH) bounds, which model variations in BgRT delivery. The low boundary of GTV Dmin, representing the minimum GTV dose in the worst-case scenario, was recorded.

RESULTS

BgRT plans were created for all patients, except for one where the target signal was indistinguishable from the bladder. The prescription dose was 2700 cGy or 3000 cGy in 3 fractions for lymph node lesions, 2400 cGy to 3000 cGy in 3 fractions for bone metastasis, and 4500 cGy in 5 fractions for lesions in prostate. All plans met the dose constraints for OARs as per the Timmerman guidelines. The Dmax of all plans was 129.9% ± 6.9% (mean ± standard deviation). The PTV D95% and GTV Dmin were 101.7% ± 1.0% and 111.0% ± 7.6%, respectively. The low boundary of GTV Dmin was 95.9% ± 5.8%. The CI and GI were 1.22 ± 0.11 and 9.40 ± 2.12, respectively. The D0.03cc to nearest OARs was 84.6% ± 25.4%. The estimated treatment time was 699 ± 228 seconds.

CONCLUSION

This study is a pioneering effort to evaluate the quality of BgRT plans for prostate cancer patients using the [18F]-DCFPyL PSMA radiotracer. Our results showed that all BgRT plans met the planning objectives defined in the Timmerman protocol. BgRT with [18F]-DCFPyL represents a promising treatment modality for patients with prostate cancer. Further research is needed to validate this approach, including a comprehensive assessment of the dosimetric and tracking accuracy through physical measurements.

First-in-Human Phase I Trial Combining Biologically Guided Radioimmunotherapy (RIT) Using a 90Y-Anti-CD25 Monoclonal Antibody (Mab) with CT-guided Total Marrow and Lymphoid Irradiation (TMLI) in Relapsed and Refractory (R/R) Acute Leukemia

PURPOSE/OBJECTIVE(S)

Patients with R/R acute leukemia after allogeneic hematopoietic cell transplant (alloHCT) have a dismal prognosis with 3-year survival rates of < 20%. To improve outcomes, innovative targeted forms of organ sparing radiotherapy, such as tumor-specific RIT and TMLI, are needed to dose escalate with acceptable toxicities, especially in patients ≥ age 60 years who cannot tolerate total body irradiation (TBI) / myeloablative regimens and who have a poor prognosis. CD25 is an ideal RIT target given its expression in acute leukemias, association with poor prognosis, and expression by leukemia stem cells. In this phase I trial (NCT05139004) we hypothesized that combining dose escalated 90Y-anti-CD25 RIT with fixed dose TMLI 12 Gy, fludarabine (flu), and melphalan (mel) in patients with R/R disease is safe and associated with acceptable toxicities.

MATERIALS/METHODS

The primary objective of this trial is to determine the maximum tolerated dose and recommended phase 2 dose of 90Y-anti-CD25 Mab (Day -15) with 12 Gy TMLI (1.5 Gy twice a day, days -8 to -5), flu (30 mg/m2/d days -5 to -2), and mel (100 mg/m2, day -2) in patients ≥ 60 years old or with a HCT-comorbidity index ≥ 2 and with R/R AML, ALL or myelodysplastic syndrome (MDS) scheduled to undergo alloHCT from a matched donor. TMLI mean organ dose constraints for kidney, lung and liver were 4 Gy. Planned dose levels of 90Y-anti-CD25 were 0.3, 0.4, and 0.5 mCi/kg. 111In-anti-CD25 (5 mCi) was co-infused followed by serial nuclear scans to assess dosimetry and biodistribution.

RESULTS

To date 5 patients (ages 31-74) with R/R AML have been treated. Marrow and circulating blasts ranged from 10-36% and 9-44%, respectively. For the 3 patients at 0.3 mCi/kg, follow-up ranged from 89-191+ days. 90Y/111In-anti-CD25 nuclear scans demonstrated persistent uptake in bone out to 144 hours, which was associated with a decline in circulating blasts. After combined RIT and TMLI, mean doses (Gy) to lungs ranged from 5.7-6.5, to kidneys from 7.5-8.2 and to liver from 7.2-11.6. No dose-limiting toxicities (DLT) were observed. All 3 patients achieved CR on day +30 bone marrow biopsies and 2 remained in CR on day +90 biopsies. Two patients have recently been treated at the 0.4 mCi/kg dose level. The results of patients treated at the higher dose levels will be provided.

CONCLUSION

Dose escalation by adding 90Y-anti-CD25 RIT at 0.3 mCi/kg to 12 Gy TMLI was safe, including in older patients, with no dose-limiting toxicities, mean critical organ doses lower than conventional myeloablative TBI, and encouraging response rates. The toxicity profile and dose estimates at 0.3 mCi/kg predict that the planned higher dose levels will also be feasible with acceptable toxicities. RIT and TMLI are complementary and when combined address the limitations of each modality. Combining these targeted therapies may be a superior strategy to intensify dose to leukemia compared to dose escalation of either modality alone.

Phase I Study of Bortezomib, Fludarabine, and Melphalan, with or without Total Marrow Irradiation as Conditioning for Allogeneic Hematopoietic Stem Cell Transplantation in Patients with High-Risk or Relapsed/Refractory Multiple Myeloma

PURPOSE/OBJECTIVE(S)

Though outcomes of patients with multiple myeloma (MM) have improved, cure remains elusive. Allogeneic hematopoietic stem cell transplantation (allo-sCT) is associated with a lower relapse rate, but its role is hindered due to toxicities. We hypothesized that targeted total body irradiation in the form of total marrow irradiation (TMI) could safely facilitate allo-SCT via an improved toxicity profile. Therefore, we conducted a phase I study to investigate the safety and feasibility of a bortezomib (BTZ), fludarabine (FLU), and melphalan (MEL), with or without TMI, prior to allo-SCT for patients with high-risk (HR) or relapsed/refractory (R/R) MM.

MATERIALS/METHODS

Between 2012 and 2018 this study enrolled patients with HR or R/R MM on one of two strata, each comprising BTZ dose-escalation cohorts. Patients aged 18-60 with no prior radiation (RT) received TMI at 900 cGy (in 6 fractions delivered twice-daily), FLU, and MEL conditioning, with BTZ added in the second cohort (stratum I). Patients aged 18-70 with prior RT received FLU, MEL, and BTZ, without TMI (stratum II). The primary endpoint was feasibility of escalating doses of BTZ, with or without TMI, defined using a 3+3 design. Dose-limiting toxicity (DLT) was defined as any Grade 3+ Bearman toxicity or prolonged CTCAE v4.0 Grade 4+ neutropenia. Secondary endpoints included treatment response, time to neutrophil and platelet engraftment, incidence of acute (a) and chronic (c) graft-versus-host disease (GVHD), progression-free-survival (PFS), and overall survival (OS).

RESULTS

Eight patients were enrolled on stratum I. One of three patients in the first cohort of stratum I experienced DLT, which led to expansion to three more patients with no DLT. Cohort 2 enrolled only 2 patients due to low accrual, with BTZ added at 0.5 mg/m2; neither experienced DLT. Nine patients were enrolled on stratum II. Three patients were enrolled on cohort 1 (BTZ 0.5 mg/m2) and none experienced DLT. Three were enrolled on cohort 2 (bortezomib 0.7 mg/m2), and one experienced DLT. Therefore, the cohort expanded to three more patients. One more patient experienced DLT and 0.5 mg/m2 was considered the maximum tolerated dose. There were no primary or secondary graft failures. Complete response was achieved in 7 and 4 patients in strata I and II, respectively. Median follow-up for all patients was 30.7 months (mos) and was 99.8 mos for surviving patients. Median overall survival (OS) on strata I and II were 44.5 mos and 21.6 mos, respectively. Median PFS on strata I and II were 18.1 mos and 8.9 mos, respectively. In strata I, 5 patients developed Grade 2+ aGVHD and 8 developed extensive cGVHD. In strata II, 4 patients developed Grade 2+ aGVHD and 6 developed extensive cGVHD.

CONCLUSION

The TMI 900 cGy, FLU, and MEL conditioning regimen is considered safe as conditioning for allo-SCT and may warrant further investigation due to favorable response rates and survival; the conditioning regimen of FLU, MEL, and BTZ (0.7 mg/m2) is associated with unacceptable toxicities.

Dosimetric Evaluation of Cardiac Substructures in Irradiation of Esophagus

PURPOSE/OBJECTIVE(S)

Due to the anatomic proximity of the heart, cardiac toxicity is a major concern in radiation treatment (RT) of esophageal cancer. Historically, the entire heart is considered an organ at risk. However, more recent studies have demonstrated that dose to cardiac substructures may better predict cardiac toxicities. We retrospectively reviewed patients (pts) who had RT to the distal esophagus and evaluated the dose-volume constraints (DVCs) of the cardiac substructures and the whole heart. We hypothesized that the majority of the treatment plans would not meet the DVCs to cardiac substructures noted in the current literature, albeit meeting commonly accepted whole heart DVCs.

MATERIALS/METHODS

We identified 27 pts with esophagus or gastroesophageal junction cancer who received RT to the esophagus between January 2017 and December 2022. For each case, the cardiac substructures (4 heart chambers - left/right atrium [L/RA] and left/right ventricle [L/RV], 4 coronary arteries - left common [LCA], left anterior descending [LAD], left circumflex [LCx], and right common [RCA], and great vessels - ascending and descending aorta [A/DA], pulmonary artery [PA], and superior vena cava [SVC]) were contoured based on the contouring atlas developed by Duane et al. DVCs based on existing literature for the whole heart and each cardiac substructure were reviewed and retrospectively analyzed for each treatment plan (Table 1).

RESULTS

Eighteen (66.7%) pts received 50 Gy/25 fractions, and nine (33.3%) pts received 50.4 Gy/28 fractions. The dose-volume constraints for the whole heart and each cardiac substructure are shown in Table 1. When considering the heart as a whole organ, all the treatment plans met the V45 and V40 objectives, with a mean V45 of 7.1% and V40 of 10.8%. All the cases also met the constraints for RV and PA. However, none of the cases met the DVCs for RA or LV. Only 6 (22.2%) of cases met the constraint for LCx or AA.

CONCLUSION

We found that despite all the treatment plans meeting the whole heart V45 and V40 constraints, none of the cases met the dose constraints to all cardiac substructures. This suggests that dosimetric evaluation of the whole heart alone may not be sufficient in minimizing cardiac toxicities from RT, and thus further supports the importance of defining the cardiac substructures. Future studies will be needed to standardize the dose constraints to these substructures to ensure patient safety.

Reproducibility and Repeatability of Pelvic Radiomics Features with Daily Imaging on a Novel Biology-Guided Radiotherapy Machine Compared to Daily Imaging on Other Radiotherapy Delivery Systems

PURPOSE/OBJECTIVE(S)

Radiomics features extracted from computed tomography (CT) images have the potential of being used as imaging biomarkers in diagnostic and prognostic models for prostate cancer. This study aims to evaluate reproducibility and repeatability of radiomics features using daily CT images from a novel biology-guided radiotherapy (BgRT)-capable machine compared to other daily CT imaging modalities from other radiotherapy delivery systems.

MATERIALS/METHODS

We retrospectively selected thirty male patients treated to the pelvic region at our institution. Among the thirty patients, ten patients were treated on a BgRT-capable machine with daily fan-beam kilovoltage CT (kVCT) scans, ten patients were treated on a conventional Linac with daily cone-beam CT (CBCT) scans, and ten patients were treated on helical tomotherapy with daily megavoltage CT (MVCT) scans. The prostate gland and femoral heads were delineated on planning CT images and on CT images at the first treatment fraction. After all the CT images were resampled to have an identical voxel size, 107 radiomics features were calculated for the prostate and femoral heads on both the planning CT images and daily CT images. Concordance correlation coefficient (CCC) and Pearson's correlation coefficient (r) were calculated to evaluate radiomics feature reproducibility between the planning CT images and pre-treatment CT scans at the first treatment fraction. To evaluate radiomics feature repeatability with kVCT images on the BgRT-capable machine, a total of ten treatment sessions with repeat kVCT scans on the BgRT-capable machine were retrieved and radiomics features were compared between the first and the second kVCT scans.

RESULTS

For the prostate gland volume, high concordance (CCC > 0.8) was found for 8, 6, and 0 radiomics features with the first-fraction kVCT, CBCT, and MVCT images, respectively, in relation to the planning CT images, while there was strong correlation (r > 0.8) in 38, 22, and 5 radiomics features in the kVCT, CBCT, and MVCT images, respectively, in relation to the planning CT images. For the left and right femoral heads, high concordance (CCC > 0.8) was found in no more than two radiomics features with the kVCT, CBCT, or MVCT images in relation to the planning CT images. Based on repeat kVCT scan data, 97 (90.7%) radiomics features showed high concordance (CCC > 0.8) in repeat kVCT scans with 98 (91.6%) features showing high correlation (Pearson's correlation coefficient > 0.8) for the prostate gland volume.

CONCLUSION

A small number of radiomics features were found to show strong reproducibility between daily CT images on the first fraction and the planning CT images with the three IGRT CT modalities in this study. On the other hand, our results indicated that strong reproducibility was found with more radiomics features with daily kVCT images from the BgRT-capable machine compared to daily CBCT and MVCT images for the prostate gland. Strong repeatability was also found with most radiomics features in daily kVCT images.

Comparison of AI-Based Auto-Segmentation Quality with Different Daily IGRT Imaging Modalities for Adaptive Radiotherapy Treatment Planning

PURPOSE/OBJECTIVE(S)

Modern AI-based auto-segmentation tools may be applied on daily computed tomography (CT) images in an image-guided radiotherapy course to facilitate evaluation of anatomical variations and adaptive treatment planning. However, most AI auto-segmentation models are trained with high-quality diagnostic or planning CT image data. This study aims to evaluate and compare auto-segmentation quality by an AI-based auto-segmentation system with different daily CT imaging modalities.

MATERIALS/METHODS

We retrospectively retrieved daily IGRT images for sixty patients. Among them, twenty patients were treated on helical tomotherapy with daily megavoltage CT (MVCT) scans, twenty patients were treated on conventional Linacs with daily cone-beam CT (CBCT) scans, and twenty patients were treated on a biology-guided radiotherapy (BgRT)-capable machine with daily fan-beam kilovoltage CT (kVCT) scans. With each treatment modality, ten patients received daily CT scans in the pelvic region while the other ten received daily CT scans in the thoracic region. An auto-segmentation system using a convolutional neural network algorithm was trained in-house with historical treatment planning CT and contouring data to generate auto-segmentation models for the pelvic and thoracic regions, respectively. Normal organs were first delineated the auto-segmentation system on the daily CT images and then drawn by an experienced planner. A set of metrics including the dice similarity coefficient (DSC), Jaccard similarity index, and Hausdorff distance were used to evaluate the quality of the auto segmentation results compared with manual contours.

RESULTS

The auto-segmentation contours on the kVCT images showed higher average DSC compared to those on the MVCT and CBCT images for all the major organs in both the pelvic and thoracic regions including the bladder, rectum, bowel, left and right femurs, esophagus, heart, left and right lung, and spinal cord. With the kVCT images, the average DSC ranged from 0.52±0.22 to 0.996±0.005. In the pelvic region, the largest absolute difference in DSC was observed for the bowel volume with an average DSC of 0.69±0.16, 0.49±0.27, and 0.32±0.25 for the kVCT, MVCT, and CBCT images, respectively (p-value < 0.05 with unpaired t-tests between kVCT and the other two imaging modalities); in the thoracic region, the largest absolute difference in DSC was observed for the esophagus with an average DSC of 0.63±0.16, 0.22±0.08, and 0.15±0.18 for the kVCT, MVCT, and CBCT images, respectively (p-value < 0.05 with unpaired t-tests between kVCT and the other two imaging modalities). Similar results were observed with other metrics.

CONCLUSION

The AI-based auto segmentation system showed improved agreement with manual contouring when using kVCT images from the BgRT capable machine compared to MVCT or CBCT images. However, manual correction is necessary on auto-segmentation results from all imaging modalities especially for organs with limited contrast from surrounding tissues.

Measurement of the Lifetime and Λ Separation Energy of _{Λ}^{3}H

The most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process). The measured values τ=[253±11(stat)±6(syst)]  ps and B_{Λ}=[102±63(stat)±67(syst)]  keV are compatible with predictions from effective field theories and confirm that the _{Λ}^{3}H structure is consistent with a weakly bound system.

Height-based formulas for predicting intravascular length of tunnelled neck central venous catheter in paediatric population

INTRODUCTION

Central venous catheter (CVC) placement is commonly performed in children. We aim to develop simple formulas to predict CVC intravascular length to minimise radiation exposure associated with the procedure.

METHODS

124 paediatric patients who received tunnelled neck CVCs and subsequent CT thorax at Hong Kong Children's Hospital from January 2020 to July 2022 were reviewed retrospectively. Formula development cohorts were subdivided by insertion sites-9 right external jugular vein (REJV), 41 right internal jugular vein (RIJV), 14 left external jugular vein (LEJV), 10 left internal jugular vein (LIJV). Using measurements from CT by two radiologists, formulas predicting the CVC intravascular length based on height and insertion sites were developed using a linear regression model. These formulas were tested with validation cohorts (10 randomly selected cases in REJV and RIJV groups respectively). Validation cohorts were not available for LEJV and LIJV groups due to small sample sizes.

RESULT

The goodness-of-fit (R^2) of all formulas are above 0.8. In the validation cohorts, the REJV formula was predictive of intravascular CVC length within 1 cm in 70% of CVC with mean absolute difference of 0.63 cm (SD 0.48 cm), and the RIJV formula was predictive of intravascular CVC length within 1 cm in 80% of CVC with mean absolute difference of 0.67 cm (SD 0.53 cm).

CONCLUSION

Intravascular CVC length can be estimated using simple formulas based on height and insertion sites. Further prospective validation of the LEJV and LIJV formulas is needed.

Bevacizumab biosimilar candidate TAB008 compared to Avastin® in patients with locally advanced, metastatic EGFR wild-type non-squamous non-small cell lung cancer: a randomized, double-blind, multicenter study

BACKGROUND

Bevacizumab (Avastin®) is a monoclonal antibody targeting the vascular endothelial growth factor (VEGF). Used alone or in combination with chemotherapy and/or immunotherapy, Avastin® has shown promising efficacy in many cancers. This study compared the efficacy and safety of TAB008 with Avastin® sourced from the EU (bevacizumab-EU), in patients with non-squamous non-small cell lung cancer (nsNSCLC).

METHOD

In this randomized, double-blind, multicenter, phase III similarity study, treatment naïve for metastatic lung cancer., EGFR wild-type, locally advanced, metastatic, or recurrent non-squamous, non-small cell, lung cancer (nsNSCLC) patients were enrolled and randomized (1:1) into TAB008 or Avastin® groups. Patients received TAB008 or Avastin® 15 mg/kg intravenously plus paclitaxel/carboplatin for 4-6 cycles followed by TAB008 or Avastin® 7.5 mg/kg until disease progression, unacceptable toxicity or death. The primary endpoint compared the objective response rate (ORR) within 6 cycles as read by an independent radiological review committee (IRRC). Secondary endpoints compared disease control rate (DCR) Within 6 cycles, duration of response (DoR), progression-free survival (PFS), a year overall survival rate (OSR), overall survival (OS), safety, immunogenicity, and steady-state pharmacokinetics.

RESULTS

A total of 549 nsNSCLC patients were enrolled (277 in TAB008 group and 272 in Avastin® group). In the full analysis set, ORRs were 55.957% for TAB008 and 55.720% for Avastin®, and the ORR ratio was 1 (90% CI 0.89-1.14), well within the predefined equivalence margin of 0.75-1.33. No significant differences were found in DCR within 6 cycles (95.703% vs 95.367%, p = 0.8536), DoR (8.17 vs 7.3 months, p = 0.3526), PFS (9.10 vs. 7.97 months, p = 0.9457), 1 year overall survival rate (66.2% vs 68%, p = 0.6793), or OS (20.4 vs 17.6 months, p = 0.6549). Serious adverse events (SAEs) occurred in 37.55% (104/277) of patients in the TAB008 group and 34.32% (93/271) in the Avastin® group. Anti-drug antibodies were reported in 3 of 277 (1.08%) TAB008 patients, and 5 of 271 (1.85%) Avastin® patients, neutralizing antibody (Nab) was positive in 1 patient on Avastin®, which became negative upon follow-up. The steady-state trough concentrations (Cssmin) were 106.13 μg/mL in TAB008 group and 96.03 μg/mL in Avastin® groups, with the treatment group ratio of LS geometric means fully contained within the bioequivalence limits of 80.00-125.00% (90% CI was 101.74-120.05%).

CONCLUSIONS

TAB008 is similar to Avastin® in terms of efficacy, safety, and pharmacokinetic parameters, with comparable immunogenicity.

TRIAL REGISTRATION

ClinicalTrials.gov number; NCT05427305.

Measurement of the J/ψ Polarization with Respect to the Event Plane in Pb-Pb Collisions at the LHC

We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.5 Collapse

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First Measurement of Antideuteron Number Fluctuations at Energies Available at the Large Hadron Collider

The first measurement of event-by-event antideuteron number fluctuations in high energy heavy-ion collisions is presented. The measurements are carried out at midrapidity (|η|<0.8) as a function of collision centrality in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV using the ALICE detector. A significant negative correlation between the produced antiprotons and antideuterons is observed in all collision centralities. The results are compared with a state-of-the-art coalescence calculation. While it describes the ratio of higher order cumulants of the antideuteron multiplicity distribution, it fails to describe quantitatively the magnitude of the correlation between antiproton and antideuteron production. On the other hand, thermal-statistical model calculations describe all the measured observables within uncertainties only for correlation volumes that are different with respect to those describing proton yields and a similar measurement of net-proton number fluctuations.

Enhanced Deuteron Coalescence Probability in Jets

The transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrt[s]=13  TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5  GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons in the jet cone as compared with the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase-space distributions of nucleons are generated using pythia8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in pythia8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the B_{2}^{Jet} is not reproduced by the models, which instead give a decreasing trend.

Photo-induced high-temperature ferromagnetism in YTiO3

In quantum materials, degeneracies and frustrated interactions can have a profound impact on the emergence of long-range order, often driving strong fluctuations that suppress functionally relevant electronic or magnetic phases^1-7. Engineering the atomic structure in the bulk or at heterointerfaces has been an important research strategy to lift these degeneracies, but these equilibrium methods are limited by thermodynamic, elastic and chemical constraints⁸. Here we show that all-optical, mode-selective manipulation of the crystal lattice can be used to enhance and stabilize high-temperature ferromagnetism in YTiO₃, a material that shows only partial orbital polarization, an unsaturated low-temperature magnetic moment and a suppressed Curie temperature, T_c = 27 K (refs. ^9-13). The enhancement is largest when exciting a 9 THz oxygen rotation mode, for which complete magnetic saturation is achieved at low temperatures and transient ferromagnetism is realized up to T_neq > 80 K, nearly three times the thermodynamic transition temperature. We interpret these effects as a consequence of the light-induced dynamical changes to the quasi-degenerate Ti t_2g orbitals, which affect the magnetic phase competition and fluctuations found in the equilibrium state^14-20. Notably, the light-induced high-temperature ferromagnetism discovered in our work is metastable over many nanoseconds, underscoring the ability to dynamically engineer practically useful non-equilibrium functionalities.

Long-Term Biochemical Control of a Prospective Cohort of Prostate Cancer Patients Treated With Interstitial Brachytherapy Versus Radical Prostatectomy

AIMS

To report long-term oncological outcomes of men treated prospectively as part of the American College of Surgeons Oncology Group phase III Surgical Prostatectomy Versus Interstitial Radiation Intervention Trial (SPIRIT) at our institution.

MATERIALS AND METHODS

In 2003-2004, patients eligible for SPRIT attended a multidisciplinary educational session, following which they could choose radical prostatectomy, low dose rate brachytherapy (LDR-BT) or randomisation to SPIRIT. Biochemical failure was determined by the accepted definitions of a prostate-specific antigen (PSA) level ≥0.2 ng/ml after radical prostatectomy and the Phoenix definition of PSA ≥2 ng/ml above the nadir after LDR-BT. A sensitivity analysis, using a PSA >0.5 ng/ml to define biochemical failure after LDR-BT and a threshold PSA ≥0.2 ng/ml, was carried out to test the robustness of the results. To account for the competing risk of death, Gray's test was used to test the equality of the cumulative incidence function of biochemical failure between treatment groups. The Kaplan-Meier method was used to estimate overall survival and prostate cancer-specific survival. A P-value ≤0.05 was considered statistically significant.

RESULTS

Of 156 patients, 100 received LDR-BT (15 after randomisation) and 56 underwent radical prostatectomy (15 after randomisation). The median follow-up was 12.6 and 14.7 years for LDR-BT and radical prostatectomy, respectively. The median age was 60 years; the median pre-treatment PSA was 5.5 (interquartile range 4.3-7.1). No significant differences in patient characteristics were found between groups. Two patients received adjuvant radiotherapy after radical prostatectomy. The cumulative incidence function of biochemical failure was 0%, 1.1% and 2.4% at 5, 10 and 15 years, respectively, in the LDR-BT arm versus 8.5%, 15.8% and 15.8% in the radical prostatectomy arm (P < 0.001). These results were consistent when varying the definition of biochemical failure defined as PSA ≥0.5 ng/ml (P = 0.01). At 15 years, overall survival was higher in patients treated with radical prostatectomy compared with those treated with LDR-BT; however, no statistical difference was found in prostate cancer-specific survival.

CONCLUSION

In low-risk prostate cancer patients, LDR-BT offers excellent long-term oncological outcomes comparable with radical prostatectomy, in addition to the previously reported advantage for LDR-BT in urinary and sexual quality of life domains and patient satisfaction.

[Efficacy of transcatheter pulmonary valve perforation in neonates with pulmonary atresia with intact ventricular septum]

Objective: To explore the efficacy and safety of transcatheter pulmonary valve perforation in the treatment of neonatal pulmonary atresia with intact ventricular septum (PA-IVS). Methods: The clinical data on surgical treatment and follow-up in 16 patients with PA-IVS who underwent transcatheter pulmonary valve perforation in Women and Children's Hospital, Qingdao University from October 2018 to October 2021 were analyzed retrospectively. The right ventricular systolic pressure and percutaneous oxygen saturation (SpO₂) were compared before and after operation. In addition, the SpO₂ and echocardiographic data at preoperative and the last follow-up were compared. Comparisons between groups were performed using paired-samples t test. Results: Among the 16 patients (10 males and 6 females) with the age at operation of 19 (14, 26) days, 12 cases underwent transcatheter pulmonary valve perforation successfully, 2 cases were transferred to surgery department for open-heart pulmonary valvulotomy, and the remaining 2 cases were transmitted to surgery department for transthoracic pulmonary valve perforation. The age at operation of the 12 patients who underwent transcatheter pulmonary valve perforation was 18 (14, 27) days, and the weight was (3.6±0.4) kg. The immediate postoperative right ventricular systolic pressure decreased significantly ((57±16) vs. (95±19) mmHg (1 mmHg=0.133 kPa), t=7.49, P<0.001), and the postoperative SpO₂ was improved effectively (0.90±0.48 vs.0.75±0.09, t=-5.61, P<0.001). The follow-up time was 22 (7, 33) months for 12 patients who underwent transcatheter pulmonary valve perforation successfully. At the last follow-up, the ratio of right to left ventricular transverse diameter was significantly higher than that before operative (0.55±0.05 vs. 0.45±0.05, t=-3.27,P=0.007). Furthermore, the Z-scores of pulmonary valvular diameter (-0.78±0.23 vs. -1.73±0.56, t=-8.52, P<0.001) and the tricuspid valvular diameter (-0.52±0.12 vs. -1.46±0.38, t=-10.40, P<0.001) were all significantly higher than preoperative data. At last, all the patients achieved biventricular circulation without death or major complications. Conclusion: Transcatheter pulmonary valve perforation is a safe and effective therapy for neonatal PA-IVS, and its curative effect has been confirmed by the medium follow-up data.

Identification of ovarian endometriotic cysts in cystic lesions of the ovary by amide proton transfer-weighted imaging and R2∗ mapping

AIM

To investigate the value of amide proton transfer weighted (APTw) imaging and R2∗ mapping of cystic fluid in differentiating ovarian endometriotic cysts (OE) from other ovarian cystic (OOC) lesions.

MATERIALS AND METHODS

A total of 42 patients who underwent 3 T pelvic magnetic resonance imaging (MRI) were enrolled. Nineteen lesions were OE and 27 lesions were OOC. The APTw imaging and R2∗ values of the cystic fluid were measured and compared between the two groups using the independent sample t-test or Mann-Whitney U-test. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy of different parameters. The area under ROC curves (AUCs) was compared using the Delong test. Spearman's correlation analysis was used to assess the correlation between APTw imaging and R2∗ values.

RESULTS

APTw imaging values of OE were lower, while R2∗ values were higher in OE than those in OOC (p=0.001 and < 0.001). The AUCs of APTw imaging and R2∗ values to identify OE from OOC were 0.910 and 0.975. The AUC increased to 0.990 when combining APTw imaging and R2∗ values, yet without a significant difference to the APTw imaging or R2∗ value alone (p=0.229 and 0.082, respectively). APTw imaging values were negatively correlated with R2∗ values (r=-0.522, p<0.001).

CONCLUSION

Both APTw imaging and R2∗ values of OE are significantly different from other ovarian cystic lesions. APTw imaging combined with R2∗ values show excellent diagnostic efficacy to differentiate between OE and OOC.

Role of sex and stature on the biomechanics of normal and loaded walking: implications for injury risk in the military

Load carriage and marching 'in-step' are routine military activities associated with lower limb injury risk in service personnel. The fixed pace and stride length of marching typically vary from the preferred walking gait and may result in overstriding. Overstriding increases ground reaction forces and muscle forces. Women are more likely to overstride than men due to their shorter stature. These biomechanical responses to overstriding may be most pronounced when marching close to the preferred walk-to-run transition speed. Load carriage also affects walking gait and increases ground reaction forces, joint moments and the demands on the muscles. Few studies have examined the effects of sex and stature on the biomechanics of marching and load carriage; this evidence is required to inform injury prevention strategies, particularly with the full integration of women in some defence forces. This narrative review explores the effects of sex and stature on the biomechanics of unloaded and loaded marching at a fixed pace and evaluates the implications for injury risk. The knowledge gaps in the literature, and distinct lack of studies on women, are highlighted, and areas that need more research to support evidence-based injury prevention measures, especially for women in arduous military roles, are identified.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Hypertriton Production in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The study of nuclei and antinuclei production has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. The first measurement of the production of _{Λ}^{3}H in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV is presented in this Letter. Its production yield measured in the rapidity interval -1<y<0 for the 40% highest-multiplicity p-Pb collisions is dN/dy=[6.3±1.8(stat)±1.2(syst)]×10^{-7}. The measurement is compared with the expectations of statistical hadronization and coalescence models, which describe the nucleosynthesis in hadronic collisions. These two models predict very different yields of the hypertriton in charged particle multiplicity environments relevant to small collision systems such as p-Pb, and therefore the measurement of dN/dy is crucial to distinguish between them. The precision of this measurement leads to the exclusion with a significance larger than 6.9σ of some configurations of the statistical hadronization model, thus constraining the theory behind the production of loosely bound states at hadron colliders.

POS0712 YEAR-4 OBSERVATIONAL FOLLOW-UP OF BELIMUMAB SAFETY (MORTALITY AND MALIGNANCIES) IN PATIENTS WITH SLE WHO COMPLETED A PHASE 4, 52-WEEK, RANDOMISED, DOUBLE-BLIND PLACEBO-CONTROLLED SAFETY STUDY

Background

Belimumab (BEL) is an approved systemic lupus erythematosus (SLE) treatment. Despite BEL clinical studies demonstrating a favourable benefit–risk profile, varying incidence rates of mortality and adverse events of special interest, including malignancies, require further evaluation.

Objectives

To assess long-term safety following BEL therapy.

Methods

This was a Year (Yr)-4 post-treatment follow-up of the Phase 4, double-blind, placebo (PBO)-controlled Belimumab Assessment of Safety in SLE (BASE) study (GSK Study BEL115467; NCT01705977).1 Overall, 4003 adults with active, autoantibody-positive SLE received BEL (10 mg/kg IV) or PBO, plus standard therapy (ST), for 48 weeks. Patients (pts) then entered a Yr 2–5 follow-up period in which they received physician-directed ST. All pts were contacted annually by telephone, including pts who discontinued treatment. Mortality and new malignancies (including nonmelanoma skin cancer) were the endpoints collected, and rates summarised. We present Yr-4 follow-up data by Yr-1 treatment received.

Results

Baseline characteristics for the Yr-4 follow-up population (N=3204) were similar to the Yr-1 double-blind study population (N=4003). By the Yr-4 follow-up, cumulatively 12.7% and 11.0% of pts in the BEL and PBO Yr-1 groups had received BEL as part of physician-directed care, respectively (data not shown). As shown in the Table 1, cumulative follow-up adjusted mortality rates were lower in the BEL vs PBO Yr-1 treatment group for Yrs 2 to 4. Cumulative follow-up adjusted new primary malignancy rates were lower in the BEL vs PBO Yr-1 treatment group for Yrs 2 and 3, but similar in Yr 4.

Table 1.

Yr 1 plus Yrs 2–4 post-treatment* follow-up mortality and new primary malignancy rates by Yr-1 study treatment

Pts with events per yr, n (%)Pt incidence rate per 100 pt-yrs(Cumulative rate, %)BELPBOTotalBELPBOTotalYr-1 (as-treated) populationN=2002N=2001N=4003Deaths13 (0.65)22 (1.10)35 (0.87)0.66 (0.65)1.11 (1.10)0.87New primary malignancies†9 (0.45)10 (0.50)19 (0.47)0.450.500.47Yr-2 (as-treated in Yr-1) populationN=1695N=1670N=3365Deaths9 (0.53)21 (1.26)30 (0.89)0.60 (1.10)1.18 (2.15)0.89 (1.62)New primary malignancies3 (0.18)7 (0.42)10 (0.30)0.34 (0.60)0.48 (0.85)0.41 (0.72)Yr-3 (as-treated in Yr-1) populationN=1659N=1630N=3289Deaths9 (0.54)17 (1.04)26 (0.79)0.58 (1.55)1.14 (3.00)0.86 (2.27)New primary malignancies, n (%)7 (0.42)9 (0.55)16 (0.49)0.37 (0.95)0.49 (1.25)0.43 (1.10)Yr-4 (as-treated in Yr-1) populationN=1622N=1582N=3204Deaths by MedDRA SOC14 (0.86)13 (0.82)27 (0.84)0.65 (2.25)1.07 (3.65)0.86 (2.95)Infections/infestations4 (0.25)5 (0.32)9 (0.28)Cardiac disorders2 (0.12)1 (0.06)3 (0.09)General disorders/ administration site conditions2 (0.12)2 (0.13)4 (0.12)Respiratory/thoracic/ mediastinal disorders2 (0.12)1 (0.06)3 (0.09)Nervous system disorders2 (0.12)1 (0.06)3 (0.09)Other‡2 (0.12)3 (0.18)5 (0.15)New primary malignancies10 (0.62)5 (0.32)15 (0.47)0.43 (1.45)0.44 (1.45)0.43 (1.45)

*Pts in the post-treatment follow-up period are no longer receiving study treatment. †Includes nonmelanoma skin cancer.

‡Contains 1 event for 5 distinct pts of each of renal/urinary disorders, and neoplasms (BEL); musculoskeletal/connective tissue disorders, injury/poisoning/procedural complications, and vascular disorders (PBO).

MedDRA, Medical Dictionary for Regulatory Activities; SOC, system organ class

Conclusion

Post-treatment Yr-4 follow-up results in BASE, the largest double-blind trial in pts with SLE to date, support the safety of BEL therapy, with no new BEL safety concerns identified in this analysis.

References

[1]Sheikh SZ, et al. Lancet Rheumatol 2020;3:e122–30

Acknowledgements

This analysis was funded by GlaxoSmithKline (GSK). Medical writing support was provided by Lulu Hill, MPharmacol, Fishawack Indicia Ltd. UK, part of Fishawack Health, and was funded by GSK.

Disclosure of Interests

Saira Sheikh Consultant of: GSK, Grant/research support from: Pfizer, Morton Scheinberg Consultant of: GSK, Pfizer, Alnylam, AbbVie, PTC Therapeutics, James Cheng-Chung Wei Consultant of: TSH Biopharm, AbbVie, BMS, Celgene, Chugai, Eisai, Janssen, Novartis, Pfizer, Sanofi-Aventis, and UCB Pharma, Grant/research support from: AbbVie, Amgen, Astellas, BMS, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, Sun and UCB Pharma, Dana Tegzová: None declared, William Stohl Consultant of: GSK, Grant/research support from: GSK, Pfizer, Gilead, RICARDO ACAYABA DE TOLEDO Speakers bureau: AbbVie, Janssen, UCB, Novartis, Celltrion, Consultant of: AbbVie, Janssen, Novartis, UCB, Grant/research support from: Pfizer, AbbVie, Novartis, GSK, Tamara Mucenic Speakers bureau: Novartis, Janssen, BMS, AbbVie, Pfizer, Roche, Grant/research support from: GSK, Janssen, Roche, Eli Lilly, Gilead, UCB, Mauricio R Abello Banfi: None declared, Kathleen Maksimowicz-McKinnon Grant/research support from: Chemocentryx, Carlos Abud-Mendoza Speakers bureau: GSK, Lilly, Pfizer, Sandra Navarra Speakers bureau: Pfizer, Novartis, Johnson & Johnson, Consultant of: Biogen, Boehringer Ingelheim, Grant/research support from: Astellas, Mercedes García Speakers bureau: GSK, Janssen, Pfizer, Ignacio Garcia-De La Torre: None declared, Andrew Liu Shareholder of: GSK, Employee of: GSK, Abhishek Roy Employee of: GSK, Paul Wilde Shareholder of: GSK, Employee of: GSK, Sofia Fernandes Shareholder of: GSK, Employee of: GSK, Julia Harris Shareholder of: GSK, Employee of: GSK, David Roth Shareholder of: GSK, Employee of: GSK

Polarization of Λ and Λ[over ¯] Hyperons along the Beam Direction in Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

The polarization of the Λ and Λ[over ¯] hyperons along the beam (z) direction, P_{z}, has been measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded with ALICE at the Large Hadron Collider (LHC). The main contribution to P_{z} comes from elliptic flow-induced vorticity and can be characterized by the second Fourier sine coefficient P_{z,s2}=⟨P_{z}sin(2φ-2Ψ_{2})⟩, where φ is the hyperon azimuthal emission angle and Ψ_{2} is the elliptic flow plane angle. We report the measurement of P_{z,s2} for different collision centralities and in the 30%-50% centrality interval as a function of the hyperon transverse momentum and rapidity. The P_{z,s2} is positive similarly as measured by the STAR Collaboration in Au-Au collisions at sqrt[s_{NN}]=200  GeV, with somewhat smaller amplitude in the semicentral collisions. This is the first experimental evidence of a nonzero hyperon P_{z} in Pb-Pb collisions at the LHC. The comparison of the measured P_{z,s2} with the hydrodynamic model calculations shows sensitivity to the competing contributions from thermal and the recently found shear-induced vorticity, as well as to whether the polarization is acquired at the quark-gluon plasma or the hadronic phase.