Cost-effectiveness of avelumab first-line maintenance therapy for adult patients with locally advanced or metastatic urothelial carcinoma in France

BACKGROUND

This study evaluated the cost-effectiveness of avelumab first-line (1L) maintenance therapy plus best supportive care (BSC) versus BSC alone for adults with locally advanced or metastatic urothelial carcinoma (la/mUC) that had not progressed following platinum-based chemotherapy in France.

METHODS

A three-state partitioned survival model was developed to assess the lifetime costs and effects of avelumab plus BSC versus BSC alone. Data from the phase 3 JAVELIN Bladder 100 trial (NCT02603432) were used to inform estimates of clinical and utility values considering a 10-year time horizon and a weekly cycle length. Cost data were estimated from a collective perspective and included treatment acquisition, administration, follow-up, adverse event-related hospitalization, transport, post-progression, and end-of-life costs. Health outcomes were measured in quality-adjusted life-years (QALYs) and life-years gained. Costs and clinical outcomes were discounted at 2.5% per annum. Incremental cost-effectiveness ratios (ICERs) were used to compare cost-effectiveness and willingness to pay in France. Uncertainty was assessed using a range of sensitivity analyses.

RESULTS

Avelumab plus BSC was associated with a gain of 2.49 QALYs and total discounted costs of €136,917; BSC alone was associated with 1.82 QALYs and €39,751. Although avelumab plus BSC was associated with increased acquisition costs compared with BSC alone, offsets of -€20,424 and -€351 were observed for post-progression and end-of-life costs, respectively. The base case analysis ICER was €145,626/QALY. Sensitivity analyses were consistent with the reference case and showed that efficacy parameters (overall survival, time to treatment discontinuation), post-progression time on immunotherapy, and post-progression costs had the largest impact on the ICER.

CONCLUSIONS

This analysis demonstrated that avelumab plus BSC is associated with a favorable cost-effectiveness profile for patients with la/mUC who are eligible for 1L maintenance therapy in France.

Whole-genome sequencing analysis in fetal structural anomalies: novel phenotype-genotype discoveries

OBJECTIVES

The identification of structural variants and single-nucleotide variants is essential in finding molecular etiologies of monogenic genetic disorders. Whole-genome sequencing (WGS) is becoming more widespread in genetic disease diagnosis. However, data on its clinical utility remain limited in prenatal practice. We aimed to expand our understanding of implementing WGS in the genetic diagnosis of fetal structural anomalies.

METHODS

We employed trio WGS with a minimum coverage of 40× on the MGI DNBSEQ-T7 platform in a cohort of 17 fetuses presenting with aberrations detected by ultrasound, but uninformative findings of standard chromosomal microarray analysis (CMA) and exome sequencing (ES).

RESULTS

Causative genetic variants were identified in two families, with an increased diagnostic yield of 11.8% (2/17). Both were exon-level copy-number variants of small size (3.03 kb and 5.16 kb) and beyond the detection thresholds of CMA and ES. Moreover, to the best of our knowledge, we have described the first prenatal instance of the association of FGF8 with holoprosencephaly and facial deformities.

CONCLUSIONS

Our analysis demonstrates the clinical value of WGS in the diagnosis of the underlying etiology of fetuses with structural abnormalities, when routine genetic tests have failed to provide a diagnosis. Additionally, the novel variants and new fetal manifestations have expanded the mutational and phenotypic spectrums of BBS9 and FGF8. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Real-world evidence in the reassessment of oncology therapies: payer perceptions from five countries

Aim: This study explored the perceived value of real-world evidence (RWE) in the reassessment of oncology therapies by collecting the perspectives of health technology assessment/payer decision-makers. Materials & methods: A web-based survey was conducted using the Market Access Transformation Rapid Payer Response online portal. 30 participants from France, Germany, Spain, the UK and the USA were recruited based on their expertise. Results: Participants agreed that the most common uses of RWE are to confirm efficacy and safety results from randomized controlled trials and to reevaluate the projected utilization of an oncology therapy. We found variability in other reported uses of RWE. Conclusion: The organizations developing RWE should ensure that their plans recognize the heterogeneity in payer perceptions.

Application of deep learning in radiation therapy for cancer

In recent years, with the development of artificial intelligence, deep learning has been gradually applied to clinical treatment and research. It has also found its way into the applications in radiotherapy, a crucial method for cancer treatment. This study summarizes the commonly used and latest deep learning algorithms (including transformer, and diffusion models), introduces the workflow of different radiotherapy, and illustrates the application of different algorithms in different radiotherapy modules, as well as the defects and challenges of deep learning in the field of radiotherapy, so as to provide some help for the development of automatic radiotherapy for cancer.

Abdominal wall mass resections: single-center closure practices and outcomes following oncologic resections of abdominal wall fascia

PURPOSE

Radical resections for abdominal wall tumors are rare, thus yielding limited data on reconstruction of defects. We describe surgical management and long-term outcomes following radical tumor resection.

METHODS

This was a single-center retrospective review of patients between January 2010 and December 2022. Variables included operative characteristics, wound complications, hernia development, tumor recurrence, and reoperation. A multivariable analysis compared wound morbidity for suture and mesh repairs while adjusting for defect width, fascial closure, and CDC wound class.

RESULTS

120 patients were identified. Mean follow-up was 3.9 ± 3.4 years. Seventy-five (62.5%) of the masses were primary; most commonly desmoid (n = 25) and endometrioma (n = 27). Forty-five masses were metastases. Mean tumor width was 6.2 ± 3.4 cm; mean defect width was 8.1 ± 4.1 cm. Sixty-one patients (50.8%) had mesh placed, with variation in technique. Postoperative CT scans were available for 88 (73.3%) patients. Forty SSOs (33.3%), 11 SSIs (9.2%), and 18 (15%) SSOPIs occurred within 30 days. On multivariable analysis, increased defect width was associated with SSOPI (OR 1.17, p = 0.041) and CDC wound class II-III was associated with SSI (OR 8.38 and 49.1, p < 0.05) and SSOPI (OR 5.77 and 17.4, p < 0.05); mesh was not associated with these outcomes. Seven patients (5.8%) underwent 30-day reoperations and 35 (20.8%) required additional operations after 30 days. Thirteen percent developed abdominal wall (n = 8) or intra-abdominal tumor recurrence (n = 8) requiring reoperation. Twenty-seven (22.5%) patients developed hernias with a mean fascial defect width of 9.8 ± 7.2 cm.

CONCLUSION

Abdominal wall mass resections are morbid, often contaminated cases with high postoperative complication rates. Risks and benefits of mesh implantation should be tailored on an individual basis.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15  PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

Treatment Patterns and Clinical Outcomes Among Patients With Metastatic Prostate Cancer Harboring Homologous Recombination Repair Mutations

BACKGROUND

There is currently limited literature assessing the real-world treatment patterns and clinical outcomes of patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) mutations.

METHODS

Medical charts were abstracted for mCRPC patients with ≥ 1 of 12 HRR somatic gene alterations treated at US oncology centers participating in the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange. Treatment patterns and clinical outcomes were assessed from the initiation of first-line or later (1L+) mCRPC therapy received on or after July 1, 2014.

RESULTS

Among 138 patients included in the study, the most common somatic HRR mutations were CDK12 (47.8%), BRCA2 (22.5%), and ATM (21.0%). Novel hormonal therapy and taxane chemotherapy were most commonly used in 1L; taxane use increased in later lines. Median overall survival (95% confidence interval [CI]) was 36.3 (30.7-47.8) months from initiation of 1L therapy and decreased for subsequent lines. Similarly, there was a trend of decreasing progression-free survival and prostate-specific antigen response from 1L to 4L+ therapy.

CONCLUSIONS

Treatment patterns identified in this study were similar to those among patients with mCRPC regardless of tumor HRR mutation status in the literature.

Physician reported treatment patterns and outcomes in metastatic bladder cancer in the USA: the CancerMPact® Survey 2020

Aim: This study assessed physician-reported treatment patterns for metastatic bladder cancer. Materials & methods: A total of 106 USA-based physicians were surveyed in 2020 using the CancerMPact® online survey. Results: Among cisplatin-eligible patients, 86.1% received first-line (1L) platinum-containing chemotherapy, most commonly cisplatin plus gemcitabine, and 9.8% received immune checkpoint inhibitor monotherapy. Among cisplatin-ineligible patients, 46.5% received 1L platinum-containing chemotherapy, most commonly carboplatin plus gemcitabine and 46.2% received 1L immune checkpoint inhibitor therapy. Approximately 44% of patients who received 1L treatment received second-line (2L) therapy after progression. Conclusion: Platinum-containing chemotherapy was the most widely reported 1L treatment approach. A high proportion of patients received no 2L therapy. Validation in an updated dataset is warranted following the practice-changing approvals of avelumab 1L maintenance and additional 2L options.

Cost-effectiveness analysis for avelumab first-line maintenance treatment of advanced urothelial carcinoma in Scotland

Aim: The cost-effectiveness of avelumab first-line maintenance treatment for locally advanced or metastatic urothelial carcinoma in Scotland was assessed. Materials & methods: A partitioned survival model was developed comparing avelumab plus best supportive care (BSC) versus BSC alone, incorporating JAVELIN Bladder 100 trial data, costs from national databases and published literature and clinical expert validation of assumptions. Incremental cost-effectiveness ratio (ICER) was estimated using lifetime costs and quality-adjusted life-years (QALY). Results: Avelumab plus BSC had incremental costs of £9446 and a QALY gain of 0.63, leading to a base-case (deterministic) ICER of £15,046 per QALY gained, supported by robust sensitivity analyses. Conclusion: Avelumab first-line maintenance is likely to be a cost-effective treatment for locally advanced or metastatic urothelial carcinoma in Scotland.

Patient experience and unmet needs in high-risk nonmuscle-invasive bladder cancer: Insights from qualitative interviews and a cross-sectional survey

OBJECTIVES

To evaluate patient experience, unmet needs, and burden among patients with high-risk nonmuscle-invasive bladder cancer (HR-NMIBC) treated with Bacillus Calmette-Guérin (BCG).

METHODS

This cross-sectional study included HR-NMIBC patients who received BCG treatment in the past 3 years. The study, preceded by a focused literature review, was conducted in 2 phases: 1) qualitative interviews with 32 patients in the United States (US), France, Germany, and United Kingdom (UK) and 2) quantitative survey of 150 patients in the US. Both phases of the study assessed patient characteristics, treatment history, experience, and perceptions, as well as side effects, pain, discomfort, and time burden associated with BCG treatment. The quantitative survey included additional items related to BCG treatment satisfaction, health-related quality of life (HRQoL), productivity, and healthcare resource utilization. Descriptive statistics and bivariate subgroup comparisons were reported.

RESULTS

All patients in both study phases received transurethral resection of the bladder tumor (TURBT). Nearly all patients reported keeping their bladder/avoiding radical cystectomy (RC) was important (99%). Results from the quantitative survey reported a substantial impact to cancer-specific HRQoL of patients, with lower mean scores on physical (64.7), social (62.8), and role functioning (56.7) as measured by the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-30). Most patients (69%) were satisfied overall with BCG treatment, although satisfaction declined with increased number of side effects, higher numbers of BCG administrations, and greater discomfort (all P < 0.05).

CONCLUSIONS

Most HR-NMIBC patients were satisfied overall with BCG treatment. Approximately half of the patients had stopped BCG treatment, notably, most during the induction phase, suggesting nonadherence to guidelines which recommend maintenance treatment after induction. Future treatments should focus on delaying or avoiding recurrence and cystectomy while reducing patient discomfort and discontinuation prior to completing the recommended course of treatment.

Treatment patterns in metastatic bladder cancer in Japan: results of the CancerMPact® survey 2020

Aim: To assess physician-reported treatment of metastatic bladder cancer in Japan. Methods: 76 physicians completed the CancerMPact® survey in July 2020, considering patients treated within 6 months. Results: Physicians treated a mean of 38.1 patients per month. Of cisplatin-eligible and -ineligible patients, 97.6 and 89.3%, respectively, received first-line platinum-based therapy, most commonly cisplatin plus gemcitabine (72.9%) and carboplatin plus gemcitabine (59.7%). 1.6 and 5.6% received first-line immune checkpoint inhibitors, respectively. 48.4 and 45.0%, respectively, progressed and received second-line therapy, most commonly with pembrolizumab (61.7%). Conclusion: In 2020, most patients with metastatic bladder cancer in Japan received first-line platinum-based chemotherapy; however, >50% received no subsequent treatment, highlighting the need for new treatment regimens to improve outcomes and maximize first-line treatment benefits.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Building knowledge using a novel web-based intervention to promote HPV vaccination in a diverse, low-income population

OBJECTIVES

HPV vaccination rates remain suboptimal despite proven efficacy. Data suggest misconceptions or lack of knowledge are leading barriers. Our study aimed to develop and pilot a novel interactive education resource designed to educate parents and patients about HPV vaccines.

METHODS

This is a prospective pilot study conducted in an urban teaching hospital pediatric clinic. The Patient Activated Learning System (PALS) intervention included 3 web-based videos with HPV vaccine-related educational content. Participants were parents of adolescent patients, aged 11-17 years, and young adult patients, aged 18-26 years. Enrolled participants completed an HPV vaccine knowledge survey before and after watching PALS; paired scores were evaluated. Acceptability and participant-reported impact of PALS modules were measured via Likert-scale surveys.

RESULTS

132 individuals were approached; 101 (76%) enrolled and completed the study. Participants self-identified as Hispanic (50%), non-Hispanic Black (23%), non-Hispanic White (7%), Asian (6%), American/Alaskan/Hawaiian Native or Pacific Islander (5%). Half reported earning ≤$40,000 annually; 57% had only a high school education. Post-intervention knowledge scores were increased compared to baseline (9.87/27 points vs 17.53/27 points, p < 0.01). PALS modules were reported as enjoyable to use and understandable (89% and 93%, respectively), and improved participants' understanding of the importance of HPV vaccination (90%). Of the 18 patients unvaccinated at baseline, 39% received 1 shot of the HPV vaccine within one month.

CONCLUSION

The PALS HPV vaccine educational intervention was feasible, acceptable, and improved knowledge among a diverse, underserved population. Our intervention may positively influence HPV vaccination rates, with potential to overcome HPV vaccine hesitancy.

Real-World Analysis of Treatment Patterns and Platinum-Based Treatment Eligibility of Patients With Metastatic Urothelial Cancer in 5 European Countries

INTRODUCTION

The global treatment landscape for metastatic urothelial cancer (mUC) is evolving, with the recent approval of several new therapeutics. To enable informed treatment decisions, a need exists to understand both treatment patterns and how physicians determine platinum-based treatment eligibility status. This study investigated physicians' current approaches to first-line (1L) chemotherapy, treatment patterns, and assessment of platinum-based treatment eligibility of patients with mUC in real-world clinical practice.

PATIENTS AND METHODS

Data were derived from the Adelphi mUC Disease Specific Programme™, a large, independent, multinational, cross-sectional survey of physicians and their consulting patients with mUC presenting in a real-world clinical setting, conducted in France, Germany, Italy, Spain, and the United Kingdom between November 2020 and April 2021. Physicians completed record forms for their next 8 consecutively consulting patients (≤3 1L, ≤2 second-line, and ≤3 third-line) with a physician-confirmed diagnosis of mUC, reporting data on demographics, clinical characteristics, eligibility for platinum-based chemotherapy, and treatments received.

RESULTS

Overall, 232 physicians provided data for 1922 patients. Renal function impairment (72%), Eastern Cooperative Oncology Group performance status (59%), and age (38%) were the most commonly reported criteria physicians used to determine eligibility for platinum-based chemotherapy. At 1L, 82% of patients received platinum-based chemotherapy (cisplatin, 51%; carboplatin, 31%) and 10% received immune checkpoint inhibitor (ICI) therapy. At second-line, 12% received platinum-based chemotherapy, 63% ICI therapy, and 21% non-platinum-based chemotherapy. At third-line, 4% received platinum-based chemotherapy, 41% best supportive care only, and 36% other non-platinum-based chemotherapy.

CONCLUSIONS

The results of this real-world study indicate that in accordance with European guidelines, the majority of patients with mUC received standard-of-care 1L platinum-based chemotherapy and use of ICIs was limited. Future research should assess how physicians' perceptions toward determining platinum eligibility status evolve with newer guideline recommendations and the introduction of new therapy options for mUC.

Multi-peak Light-emitting Diode Curing Units and Polymerization of 3D-printed Crown and Bridge Resin

PURPOSE

This study aimed to evaluate the substitutive and additive efficacy of multi-peak light-emitting diode (LED) curing units for post-curing of a three-dimensional- (3D-) printed crown and bridge resin.

METHODS

A total of 792 disc- and 180 bar-shaped specimens were printed with a crown and bridge resin (NextDent C&B MFH) and post-cured using two LED curing units (VALO Cordless and Bluephase N G4) in fast and standard modes. Conventional post-curing (LC-3D Print Box, Group PC) was compared with LED-only curing (Groups V1, V2, B1, and B2) and LED-combined curing (Groups PV1, PV2, PB1, and PB2) in terms of microhardness, flexural strength, degree of conversion (DC), and CIE L*a*b* color and translucency parameters. Cytotoxicity of the resin eluates was evaluated using the WST-1 assay. Temperature increases on the resin surface were measured with infrared thermography. Data were statistically analyzed using ANOVA and Kruskal-Wallis tests (α=0.05).

RESULTS

The microhardness and flexural strength in Groups V1, V2, B1, and DC in all LED-only groups were lower than in other groups (p<0.05). Larger color disparities existed between Group PC and all LED-only groups than between Group PC and the others (p<0.05). There was no significant difference in cytotoxicity among the groups. The temperature increase was lowest in Groups V1 and PV1 during light curing (p<0.05).

CONCLUSIONS

Post-curing by multi-peak LED curing units was not as effective as the conventional post-curing device. Additional post-curing by LED curing units did not improve the material properties.

Reliability, validity, and change thresholds of the NCCN/FACT Bladder Symptom Index (NFBlSI-18) in patients with advanced urothelial cancer

BACKGROUND

The NCCN/FACT Bladder Symptom Index-18 (NFBlSI-18) is a bladder cancer-specific instrument. We aimed to psychometrically evaluate the reliability and validity of NFBlSI-18 and estimate change thresholds for total, disease-related symptoms-physical (DRS-P), DRS-emotional (DRS-E), and function/well-being (F/WB) scales in patients with locally advanced/metastatic urothelial cancer (la/mUC).

METHODS

JAVELIN Bladder 100 trial data were analyzed. Anchors to evaluate validity included: 5-level EuroQoL-5D utility index (EQ-5D-5L UI), visual analog scale (VAS), Eastern Cooperative Oncology Group (ECOG) performance status, and number of symptoms. Responsiveness to change was tested by anchoring to time to tumor progression (TTP), best overall response (BOR), and differences in means between ECOG categories to estimate meaningful between-group differences. Meaningful within-group change thresholds were estimated using receiver operating characteristic curve analysis, anchoring to change in EQ-5D-5L UI. Significant within-individual patient change thresholds were estimated with reliable and likely change indexes.

RESULTS

Correlations with EQ-5D-5L UI and VAS ranged from 0.53 to 0.73. Standardized effect sizes were >0.20. Compared with patients with TTP of ≥6 months, patients with TTP of >0-2 and 3-5 months had larger declines; results for BOR were similar. Thresholds (points) for meaningful between-group differences were: total, 6-11; DRS-P, 3-6; and DRS-E and F/WB, 1. Thresholds (points) for meaningful within-group worsening were: total, 4; and DRS-P, 3, and for significant individual change they were: total, 3-9; DRS-P, 2-6; DRS-E, 1-3; and F/WB, 2-4.

CONCLUSIONS

NFBlSI-18 exhibited evidence of reliability, validity, and responsiveness to assess quality of life in studies of la/mUC, and change thresholds are established for future studies.

PLAIN LANGUAGE SUMMARY

The NCCN/FACT Bladder Symptom Index-18 (NFBlSI-18) is a questionnaire used to assess quality of life for people with advanced bladder cancer. People with advanced bladder cancer who took part in the JAVELIN Bladder 100 study completed the NFBlSI-18 when they joined the study and after each treatment with avelumab maintenance or best supportive care. This study showed that NFBlSI-18 is suitable for capturing bladder cancer symptoms and is able to detect important changes in a person's quality of life over time. This study also provides thresholds for changes in NFBlSI-18 scores, which will be useful for future studies.

Minimally invasive colectomies can be performed with similar outcomes to open counterparts for colorectal cancer emergencies: a propensity score matching analysis utilizing ACS-NSQIP

PURPOSE

The safety and feasibility of minimally invasive surgery (MIS) in the setting of colorectal cancer emergencies have been debated. We sought to compare postoperative outcomes of MIS with open techniques in the setting of colorectal cancer emergencies from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

METHODS

We included patients undergoing colectomy for colorectal cancer emergency between 2012 and 2019 "2012-2019" from the ACS-NSQIP dataset. We compared short-term morbidity, mortality, short-term oncological outcomes, and secondary outcomes for MIS vs open colectomies using propensity score matching. We then evaluated the trends of MIS versus open colectomies using linear regression analysis.

RESULTS

We examined a total of 5544 patients (open n = 4070; MIS n = 1474) and included 1352 patients for our postoperative outcome analyses after propensity score matching 1:1 (open n = 676; MIS n = 676). Within the matched cohort, mortality was significantly higher in the open group (open 6.95% vs MIS 3.99%, OR 1.8, p = 0.023). Anastomotic leak rates were comparable between the  two groups (open 4.46% vs MIS 4.02%, OR 1.12, p = 0.787). Pulmonary complications were significantly higher after open surgery (open 10.06% vs MIS 4.73%, OR 2.25, p < 0.001). Rates of ileus were significantly higher amongst open patients (open 29.08% vs MIS 19.94%, p < 0.001). Patients stayed on average 1 day longer in the hospital after open surgery (p < 0.001). Rates of MIS for early tumors (N0 and T1/T2, n = 289) did not significantly change over 7 years (p = 0.597, rate = - 0.065%/year); however, utilization of MIS for late tumors (N1 or T3/T4, n = 4359) increased by 2.06% per year (p < 0.001).

CONCLUSIONS

This study demonstrates that MIS was associated with superior postoperative outcomes compared to open surgery without compromising oncological outcomes in patients undergoing emergency colectomy for colon cancer. Within the matched cohort, MIS was associated with lower rates of mortality, pulmonary complications, ileus, and shorter postoperative length of stay.

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.

Proton Single-Energy Bragg-Peak FLASH Using Clinical Systems Can Achieve IMPT-Equivalent Plan Quality for Breast and Prostate Cancers

PURPOSE/OBJECTIVE(S)

Most current proton FLASH-RT studies focus on transmission proton techniques. In this study, we propose a novel method for achieving FLASH dose rate in hypofractionated proton radiotherapy using the Bragg peak of a single-energy proton beam. The dosimetric characteristics using this novel technique for proton pencil beam scanning (PBS) stereotactic body radiation therapy (SBRT) of prostate and breast cancers were first investigated based on the clinically available cyclotron beam parameters.

MATERIALS/METHODS

This novel approach uses the distal tracking technique that enables PBS Bragg-peak of the highest proton energy to adapt to the target distally. Positioning of the Bragg peak at different depths is achieved using a universal range shifter and range compensator. To investigate the feasibility of this approach, we developed an in-house treatment planning platform for intensity-modulated proton therapy (IMPT) delivery and performed dosimetric studies on prostate and breast SBRT cases previously treated with conventional proton PBS technique. FLASH plans were generated using a similar clinical beam arrangement to deliver 40 Gy (RBE) in 5 fractions. Dose metrics were compared between the clinical and FLASH plans. Dose-rate volume histograms (DRVH) were also calculated to investigate the 40 Gy/s coverage (V40 Gy/s) of organs-at-risk (OARs) for FLASH plans.

RESULTS

The distal tracking can precisely stop the Bragg peak at the target distal edge, and Bragg peak plans achieved tumor coverage and dose conformality equivalent to IMPT plans. The clinical IMPT plans yielded slightly superior target dose uniformity -CTV Dmax of FLASH plans was 10% higher for prostate and 2% higher for breast. There was no significant difference between the clinical and FLASH plans in dose metrics for major OARs, including rectum, large bowel, heart, and lung. Higher maximal doses to femoral heads (∼2 Gy) and urethra (∼6 Gy) were observed in prostate FLASH plans than in the clinical plans but were still within clinically accepted dose limits. The V40 Gy/s for OARs were >90% for prostate FLASH plans and >76.5% for breast FLASH plans.

CONCLUSION

The proposed single-energy Bragg-peak FLASH technique eliminates exit dose associated with transmission proton FLASH and can still yield comparable plan quality and OAR sparing while preserve sufficient FLASH dose rate coverage for prostate and breast proton SBRT. This study demonstrates the potential application of Bragg peaks for highly conformal FLASH-RT using clinical cyclotron systems to treat prostate and breast cancer patients, which moves towards clinical application.

Phase II Study of Hemithoracic Intensity-Modulated Pleural Radiation Therapy (IMPRINT) for Patients with Pleural Metastases from Thymic Malignancies

PURPOSE/OBJECTIVE(S)

Pleural metastases are common sites for recurrence and progression in patients with thymic malignancies. The management of pleural metastases typically involves surgical resection with or without neoadjuvant or adjuvant systemic therapy. After surgical resection of pleural metastases, the 5-year progression-free survival (PFS) rate is about 29-45%. While radiation therapy (RT) is standardly used in the management of locally-advanced thymic malignancies, the role of RT in patients with pleural metastases in unclear. Intensity-modulated pleural radiation therapy (IMPRINT) is a RT technique currently being used to treat malignant pleural mesothelioma (MPM) patients with 2 intact lungs at centers that specialize in MPM treatment. This IMPRINT technique can potentially be extrapolated to thymic patients with pleural metastases. Because the risk of toxicity is of greater concern for thymic patients given their overall relatively favorable prognosis, the rate of toxicity, particularly radiation pneumonitis, needs to be established in the thymic patient population.

MATERIALS/METHODS

This is a single-arm, single institution Phase II study of hemithoracic IMPRINT for patients with pleural metastases from thymic malignancies. The primary endpoint of this study is grade 3 or higher radiation pneumonitis within 4 months of completing RT. Secondary endpoints include any toxicity, progression-free survival, patterns of failure and overall survival. Patients must have a pathologically confirmed diagnosis of a thymic malignancy with radiologic or pathologic evidence of pleural metastases. Thymoma or thymic carcinoma are allowed. Patients may have de novo stage IVA disease or recurrent disease in the pleura. There must be no evidence of extrathoracic metastatic disease or contralateral pleural/pericardial disease. Surgical resection of the pleural nodules (ex: pleurectomy/decortication, debulking/metastasectomy) are allowed. Extrapleural pneumonectomy is not allowed. Patients are excluded if they have undergone prior thoracic radiation therapy preventing hemithoracic pleural IMRT, whereas prior thymic bed radiation and/or prior pleural SBRT are allowed. RT will be administered to the ipsilateral pleura to 50.4 Gy in 28 fractions. An optional dose-painting boost to gross disease up to 60 Gy while respecting normal tissue constraints is allowed. Patients can be treated with photon or proton therapy. Simulation, contouring and RT planning guidelines have been developed. Patients will be followed per protocol at regular intervals for at least 12 months following RT. The expected accrual is 36 patients over 4 years. Further information can be found on clinicaltrials.gov (NCT05354570).

RESULTS

To be determined.

CONCLUSION

To be determined.

Biological Effective Dose (BED) in Evaluation of Rectal Dose in Prostate Cancer Patients with Hydrogel Spacer Who Underwent an EBRT with Different Fractionation Schemes

PURPOSE/OBJECTIVE(S)

To evaluate rectal dose sparing in prostate cancer patients with hydrogel spacer who underwent an external beam radiotherapy (EBRT) with different fractionation schemes.

MATERIALS/METHODS

In a previous study, we have reported that rectal sparing was achieved in prostate cancer patients with hydrogel spacer who underwent a combination therapy of EBRT and LDR brachytherapy (Zhang H, et al. J Appl Clin Med Phys, 2022). In this study, we focused on evaluation of spacer-related rectal sparing in patients who underwent an EBRT with conventional fractionation (81 Gy in 45 fractions), hypofractionation (70 Gy in 28 fractions), or stereotactic body radiotherapy (SBRT) for 40 Gy or 42.5 Gy in 5 fractions. In 172 patients, 119 patients were applied with injection of polyethylene-glycol hydrogel and others without the injection as control. In VMAT plans, doses to rectal wall were examined and converted to BED according to AAPM TG-137 (α/β ratio = 4 Gy).

RESULTS

On average, an interspace of 1cm between prostate and rectum was achieved by spacer insertion. Rectal wall was defined as 0.4cm thickness inside the outer contour of rectum, and the volume ranged from 4.5 cm3 to 21.3cm3 for patients with spacer and from 8.2cm3 to 35.1cm3 for those with no spacer. In conventional scheme, an average rectal BED was 120.0 Gy, 116.9 Gy, 114.0 Gy, 108.6 Gy, 87.6 Gy and 55.6 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3, respectively, and BEDmean was 55.3 Gy in patients with no spacer. The BED decreased to 105.1 Gy, 96.3 Gy, 86.1 Gy, 75.4 Gy, 51.7 Gy and 26.9 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3, respectively (p < 0.01), and BEDmean was 46.0 Gy in patients with spacer. In hypofractionation, rectal BED was in average of 115.8 Gy, 112.3 Gy, 109.8 Gy, 103 Gy, 81.6 and 52.8 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3, respectively, and BEDmean was 48.6 Gy in patients with no spacer. Patients with spacer had significantly decreases of rectal BED, an average of 103 Gy, 91.7 Gy, 84.1 Gy, 72.8 Gy, 48.8 Gy and 26.0 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3, respectively (p < 0.01), BEDmean was 42.4 Gy. In SBRT, average rectal BED in patients with spacer decreased to 93.6 Gy, 78.4 Gy, 69 Gy, 57.5 Gy, 38.5 Gy and 21.5 Gy, in comparison of 124.1 Gy, 117,4 Gy, 110.9 Gy, 97.3 Gy, 59.7 Gy and 32.3 Gy to the volume of 0.1, 0.5, 1, 2, 5 and 10cm3 in those without spacer, respectively (p <0.01). BEDmean decreased to 32.0 Gy in patient with spacer, compared with 43.2 Gy in those with no spacer.

CONCLUSION

Insertion of hydrogel spacer significantly improved rectal dose sparing, about 11.1% to 50.8% in conventional scheme, 12.4% to 51.6% in hypofractionation scheme, and 24.6% to 40.9% in SBRT patients. Furthermore, relatively more dose sparing on rectum was seen on the volume from 0.1cm3 to 2cm3 in SBRT patients.

Implementation of L4 Automation for Patient-Specific Quality Assurance Using the AUTOFRAME Platform and a Robotic Mechanism

PURPOSE/OBJECTIVE(S)

The AUTOFRAME platform has been previously developed for automating clinical workflows and has achieved L3 automation for patient-specific quality assurance (PSQA). The aim of this study is to further develop the platform to achieve L4 automation, which extends AUTOFRAME to operate Varian's control console (VCC) for the linear accelerator. The goal is to automate all PSQA operations outside of the treatment room.

MATERIALS/METHODS

The automated stages, listed in Table 1, are ranging from L0 to L5. The current study focuses on L4 automation of PSQA, which uses a 6-axis robot arm to control buttons on the VCC. The robotic arm is mounted on a custom frame that is attached onto the VCC to maintain its relative position. The arm is controlled through python scripts, which is run on a raspberry pi and communicates with the AUTOFRAME platform via the PyFlow and AutoFlow subsystems. This integration allows the robotic arm to receive commands from AutoFlow and execute them through PyFlow, activating real-time button-pressing actions.

RESULTS

The integrated L4 system was tested using real PSQA verification plans, which involved a minimum of 4 actions and a maximum of 9 actions on the VCC, including a couch kick that required overriding the couch position. The results showed that the 6-axis arm was able to correctly execute the action groups and guide the robotic arm to consistently press and hold each button with sufficient force and accuracy. All buttons on the VCC, including the Motion-enable, Preparing, Readying, and Delivering buttons, were correctly pushed and held according to the PSQA steps. The system successfully delivered all beams without interruption, and all beam delivery data was collected by the detector for PSQA analysis.

CONCLUSION

The study has further developed the AUTOFRAME platform for L4 automation of PSQA procedures can be achieved. The robotic arm is capable of pushing all required buttons, eliminating all human interactions on the VCC. When combined with previous L0-L3 automations, this will move towards full automation of PSQA procedures. Future work will focus on improving the system's flexibility, stability, and extending its operations to other QA tasks.

Comparison of Early Outcomes of Stereotactic Accelerated Partial Breast Irradiation vs. Volumetric Modulated Arc Therapy-Based FAST-FORWARD Whole Breast Irradiation for Breast Cancer

PURPOSE/OBJECTIVE(S)

Despite evidence supporting APBI from 8 published prospective randomized trials enrolling over 10,000 women, the uptake of APBI in clinical practice is surprisingly low. This is being exacerbated by a new, convenient, and safe shortened WBI schedule. Here, we report the dosimetric and early outcome analyses of the first >1000 patients treated at our institution since the first adoption of stereotactic APBI and the ultra-hypofractionated WBI regimen.

MATERIALS/METHODS

From 2016 to 2022, 801 women with breast cancers in the suitable or cautionary categories according to the ASTRO APBI consensus panel guidelines, received 30 Gy in 5 fractions (92%) either using a robotic stereotactic radiation system (83%) or stereotactic volumetric-based arc therapy (VMAT, 17%). Between 2020 and 2022, 468 women, who were not candidates for APBI and not undergoing any regional irradiation received 26 Gy in 5 fractions using VMAT to the whole breast with the addition of cardiac sparing technique in left-sided breast cancer patients. Tumor bed boosts were delivered in 99% of FF-WBI patients. We evaluated dose-volume histogram parameters for target volumes and organs-at-risk and radiation-related toxicities during RT or within 6 months after the end of RT.

RESULTS

Target volume coverage was acceptable in both groups, with mean 96% of the target volumes receiving 95% of the prescribed doses and 0 cm3 within target volumes exceeding 105% of the prescribed doses. S-APBI resulted in small, but statistically significant, reductions in the radiation dose delivered to the ipsilateral breast, contralateral breast, lungs, heart, and coronary artery compared with FF-WBI. Comparing WBI to APBI, the mean contralateral breast dose, ipsilateral lung V20 Gy, mean contralateral lung dose, and mean heart dose, were reduced by 89%, 78%, 73%, and 29%, respectively. With median follow-up periods of 32 months for s-APBI and 19 months for FF-WBI, acute toxicity was assessable in all patients. The risks of any grade acute toxicity were 21% for s-APBI and 25% for FF-WBI (p = .117). Among them, grade 2 rates were 1.3% in both groups and no severe toxicity has been reported.

CONCLUSION

We found s-APBI and VMAT-based FF WBI were associated with favorable dosimetric and acute toxicity profiles. However, considering significantly less irradiated volume in the breast, lungs, and heart, APBI with advanced available technique options should be considered over any WBI-based approach for patients at low risk for local recurrence.

Final Analysis of a Phase III Controlled Randomized Study of Stereotactic Body Proton Therapy or Conventionally Fractionated Proton Therapy for Early Prostate Cancer: PCG GU002

PURPOSE/OBJECTIVE(S)

To determine if stereotactic body proton therapy (SBPT) is non-inferior to conventionally fractionated proton therapy (CFPT) in patients with early prostate cancer.

MATERIALS/METHODS

Multicenter, randomized, controlled, open-label, non-inferiority phase 3 trial that included patients with histologically confirmed low-risk prostate adenocarcinoma defined by Gleason score ≤6, PSA <10 ng/mL, and clinical stage T1-2a N0 M0 by AJCC 7th Ed. Eligible participants were randomly assigned (initially 1:1 and later 2:1 ratio) to CFPT (79.2 Gy in 44 fractions for 9 weeks) or SBPT (38 Gy in 5 fractions for 1 week). Concurrent or adjuvant androgen deprivation therapy was not allowed. The primary endpoint was freedom from failure (FFF) at 2 years, defined as the first occurrence of local, regional, or distant recurrence, biochemical failure by the Phoenix definition (increase of PSA ≥2 ng/mL over the nadir PSA), or the start of salvage therapy including ADT. Secondary endpoints included GI and GU grade ≥2 toxicity according to CTCAE v4 criteria, as well as health-related quality of life (HRQoL) metrics assessed by AUASI and EPIC scores. Non-inferiority would be declared if the 1-sided 95% confidence interval limit for the difference in 2-year FFF rate was below 4.2% between both groups by Clopper-Pearson exact method.

RESULTS

Between November 2010 and September 2020, 133 patients were enrolled and randomly assigned to CFPT (n = 45) or SBPT (n = 88). Median follow-up was 5 years (IQ 3.9-5.2), with the last patient enrolled followed for at least 2 years. The 2-year FFF was 100% for both groups, fulfilling the pre-specified criteria for non-inferiority of SBPT compared to CFPT. By KM estimates, 5-year FFF was 97.4% and 100% (P = 0.1), and the 5-year OS was 97.1% and 95.5% (P = 0.46) for patients treated with CFPT and SBPT, respectively. The cumulative incidence of any grade ≥3 toxicities at 5 years was 0% and 5.7% (P = 0.14) for patients treated with CFPT and SBPT, respectively. The frequency of GI grade ≥2 toxicity at 6 months was of 0% and 2.3% (P = 0.55), and at 2 years was of 6.7% and 3.4% (P = 0.69) for patients treated with CFPT and SBPT, respectively. The frequency of GU grade ≥2 toxicity at 6 months was of 2.2% and 5.7% (P = 0.42), and at 2 years was of 8.9% and 5.7% (P = 0.54) for patients treated with CFPT and SBPT, respectively. Changes in HRQoL scores at 2 years were similar between groups (Table).

CONCLUSION

SBPT is non-inferior to CFPT regarding FFF and associated with similar long-term toxicity rates and HRQoL metric scores.

Development of the Independent Dose Verification Method for the Ring Gantry PET/CT Linac

PURPOSE/OBJECTIVE(S)

The RefleXion Xi is a new external beam radiotherapy delivery modality combining kilovoltage fan-beam CT and on-board PET for Biology-guided Radiotherapy. Although the machine shares similar components with the Tomotherapy machine, it has unique hardware features such as stationary beam delivery system with couch increments. The goal of this study is to develop an in-house independent secondary dose calculation method for this ring gantry PET/CT Linac.

MATERIALS/METHODS

The method aggregates the beam intensities at each discrete firing gantry angle and couch moving position. The non-uniform intensity map is decomposed into a series of segments of uniform beam intensities, and then coordinates of beam segments were modified based on the relative distance from the dose calculation point to keep the calculation point in the same spot along the gantry rotation. The dose to the calculation point of each segment is determined by using measured tissue-maximum-ratio, output factors, and off-axis ratio by independent binary collimators. Two-dimensional convolution method is applied to integrate all dose contribution components in segment areas for efficient calculation. The final dose is obtained by summing all dose to the calculation point of segments for all firing gantry angle and couch position.

RESULTS

Twenty patients with different treatment sites including head and neck, prostate, and lung regions were analyzed. Comparison of the point dose calculated by the independent program to that calculated by the planning system has shown reasonable agreement within ±5%.

CONCLUSION

The independent dose verification program has been developed as an initial patient specific QA for improving patient safety. Further study will be performed to enhance the accuracy and reliability by including additional leakage and scatter models.