Hypofractionated proton therapy for non-small cell lung cancer: Ready for prime time? A systematic review and meta-analysis

Innovations in modern low-LET radiotherapy regimens for locally advanced non-small cell lung cancer: a meta-analysis and systematic review of high-dose-rate brachytherapy, stereotactic body radiotherapy, and hypofractionated proton therapy

BACKGROUND

This study assesses recent treatments for locally advanced non-small cell lung cancer (LA-NSCLC) ineligible for surgery, comparing high-dose-rate (HDR) brachytherapy with conventional low linear energy transfer (LET) hypofractionated radiotherapy methods.

METHODS

From 9435 papers, 8 meeting criteria were selected, covering 484 LA-NSCLC patients (2005-2019). Analysis focused on comparing outcomes, exploring biologically effective doses (BED), and examining toxicities.

RESULTS

HDR brachytherapy had better effectiveness. Specific data revealed that the median overall survival (OS) with HDR brachytherapy was 38 months, with a significant 2-year OS rate of 68.0% (95% CI, 58.2-79.4%). In comparison, stereotactic body radiation (SBRT) and proton treatment had 2-year OS rates of 54% (95% CI, 36-71%), and 56% (95% CI, 42-70%), respectively. In terms of local control (LC), the 2-year LC rate for HDR brachytherapy stood at 87.1% (95% CI, 79-95%), whereas the 2-year LC rates for SBRT and proton therapy were 75% (95% CI, 63-86%) and 84% (95% CI, 68 -100%), respectively. The 2-year OS for BED10 equal to or greater than 78 Gy was 62% (95% CI, 51-72%), compared to 38% (95% CI, 17-58%) for BED10 less than 78 Gy. Acute toxicity was lower with HDR brachytherapy (95% CI, 0-10%) versus SBRT (95% CI, 8-16%), with no grade 3 + events reported for proton therapy. Furthermore, the rate of late toxicity events above grade 3 was 3% (95% CI, 0-6%) for SBRT and 14% (95% CI, 4-24%) for proton therapy, while no late toxicities above grade 3 were observed with brachytherapy.

CONCLUSIONS

Hypofractionated low LET irradiation is efficacious and safe for LA-NSCLC, while HDR brachytherapy provides significant OS and LC advantages with few toxicities. Achieving BED10 ≥ 78 Gy significantly impacts OS. These findings guide clinical practice and stimulate further LA-NSCLC treatment advancements.

Facing the climate change: Is radiotherapy as green as we would like? A systematic review

PURPOSE

To focus on the ecological footprint of radiotherapy (RT), on opportunities for sustainable practices, on future research directions.

METHODS

Different databases were interrogated using the following terms: Carbon Footprint, Sustainab*, Carbon Dioxide, Radiotherapy, and relative synonyms.

RESULTS

931 records were retrieved; 15 reports were included in the review. Eight main thematic areas have been identified. Nine research works analyzed the environmental impact of photon-based external beam RT. Particle therapy was the subject of one work. Other thematic areas were brachytherapy, intra-operative RT, telemedicine, travel-related issues, and the impact of COVID-19.

CONCLUSION

This review demonstrates the strong interest in identifying novel strategies for a more environmentally friendly RT and serves as a clarion call to unveil the environmental impact of carbon footprints entwined with radiation therapy. Future research should address current gaps to guide the transition towards greener practices, reducing the environmental footprint and maintaining high-quality care.

Stereotactic Body Radiotherapy for Centrally Located Inoperable Early-Stage NSCLC: EORTC 22113-08113 LungTech Phase II Trial Results

INTRODUCTION

The international phase II single-arm LungTech trial 22113-08113 of the European Organization for Research and Treatment of Cancer assessed the safety and efficacy of stereotactic body radiotherapy (SBRT) in patients with centrally located early-stage NSCLC.

METHODS

Patients with inoperable non-metastatic central NSCLC (T1-T3 N0 M0, ≤7cm) were included. After prospective central imaging review and radiation therapy quality assurance for any eligible patient, SBRT (8 × 7.5 Gy) was delivered. The primary endpoint was freedom from local progression probability three years after the start of SBRT.

RESULTS

The trial was closed early due to poor accrual related to repeated safety-related pauses in recruitment. Between August 2015 and December 2017, 39 patients from six European countries were included and 31 were treated per protocol and analyzed. Patients were mainly male (58%) with a median age of 75 years. Baseline comorbidities were mainly respiratory (68%) and cardiac (48%). Median tumor size was 2.6 cm (range 1.2-5.5) and most cancers were T1 (51.6%) or T2a (38.7%) N0 M0 and of squamous cell origin (48.4%). Six patients (19.4%) had an ultracentral tumor location. The median follow-up was 3.6 years. The rates of 3-year freedom from local progression and overall survival were 81.5% (90% confidence interval [CI]: 62.7%-91.4%) and 61.1% (90% CI: 44.1%-74.4%), respectively. Cumulative incidence rates of local, regional, and distant progression at three years were 6.7% (90% CI: 1.6%-17.1%), 3.3% (90% CI: 0.4%-12.4%), and 29.8% (90% CI: 16.8%-44.1%), respectively. SBRT-related acute adverse events and late adverse events ≥ G3 were reported in 6.5% (n = 2, including one G5 pneumonitis in a patient with prior interstitial lung disease) and 19.4% (n = 6, including one lethal hemoptysis after a lung biopsy in a patient receiving anticoagulants), respectively.

CONCLUSIONS

The LungTech trial suggests that SBRT with 8 × 7.5Gy for central lung tumors in inoperable patients is associated with acceptable local control rates. However, late severe adverse events may occur after completion of treatment. This SBRT regimen is a viable treatment option after a thorough risk-benefit discussion with patients. To minimize potentially fatal toxicity, careful management of dose constraints, and post-SBRT interventions is crucial.

Adebrelimab plus chemotherapy and sequential thoracic radiotherapy as first-line therapy for extensive-stage small-cell lung cancer (ES-SCLC): a phase II trial

Background

This phase II prospective trial aimed to investigate the efficacy and safety of adebrelimab (PD-L1 antibody) plus first-line chemotherapy followed by sequential thoracic radiotherapy (TRT) combined with adebrelimab in extensive-stage small-cell lung cancer (ES-SCLC). Biomarkers associated with potential therapeutic effects were also explored.

Methods

Patients with previously untreated ES-SCLC were enrolled at Shandong Cancer Hospital and Institute (Jinan, China). Patients received 4-6 cycles of adebrelimab (20 mg/kg, D1, Q3W) combined with EP/EC (etoposide, 100 mg/m2, D1-3, Q3W and cisplatin, 75 mg/m2, D1, Q3W or carboplatin, AUC = 5, D1, Q3W). Then patients with response sequentially underwent consolidative TRT (≥30 Gy in 10 fractions or ≥50 Gy in 25 fractions, involved-field irradiation), and maintenance adebrelimab until disease progression or intolerable adverse events (AEs). The primary endpoint was overall survival (OS). Genomic and circulating tumour DNA (ctDNA) profiling were also analyzed with tumour tissues and peripheral blood. This trial was registered with ClinicalTrials.gov, NCT04562337.

Findings

From October 2020 to April 2023, 67 patients diagnosed with ES-SCLC were enrolled and received at least one dose of study treatment. All patients were included in the efficacy and safety analyses. 45 patients received sequential TRT as planned. The median OS and progression-free survival (PFS) was 21.4 months (95% CI: 17.2-not reached months) and 10.1 months (95% CI: 6.9-15.5 months), respectively. The confirmed objective response rate was 71.6% (48/67, 95% CI: 59.3-82.0%) and disease control rate was 89.6% (60/67, 95% CI: 79.7-95.7%). There were no treatment-related deaths. The most common grade 3 or higher treatment-related adverse events (TRAEs) were hematological toxicities. The incidence of any grade and G3+ pneumonitis was 25% (17/67) and 6% (4/67), respectively. No unexpected adverse events were observed. Patients without co-mutations of TP53/RB1 in both tissue and peripheral blood displayed longer PFS (tissue, P = 0.071; ctDNA, P = 0.060) and OS (tissue, P = 0.032; ctDNA, P = 0.031).

Interpretation

Adebrelimab plus chemotherapy and sequential TRT as first-line therapy for ES-SCLC showed promising efficacy and acceptable safety.

Funding

This study was funded by the National Natural Science Foundation of China (82172865), Jiangsu Hengrui Pharmaceuticals Co., Ltd. and Amoy Diagnostics Co., Ltd.

Long-term survival outcomes and quality of life of image-guided proton therapy for operable stage I non-small cell lung cancer: A phase 2 study

BACKGROUND AND PURPOSE

This study evaluated long-term efficacy, safety, and changes in quality of life (QOL) of patients after image-guided proton therapy (IGPT) for operable stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

This single-institutional prospective phase 2 study enrolled patients with operable histologically confirmed stage IA or IB NSCLC (7th edition of UICC). The prescribed dose was 66 Gy relative biological effectiveness equivalents (GyRBE) in 10 fractions for peripheral lesions, or 72.6 GyRBE in 22 fractions for central lesions. The primary endpoint was the 3-year overall survival (OS). The secondary endpoints included disease control, toxicity, and changes in QOL score.

RESULTS

We enrolled 43 patients (median age: 68 years; range, 47-79 years) between July 2013 to January 2021, of whom 41 (95 %) had peripheral lesions and 27 (63 %) were stage IA. OS, local control, and progression-free survival rates were 95 % (95 % CI: 83-99), 95 % (82-99), and 86 % (72-94), respectively, at 3 years, and 83 % (66-92), 95 % (82-99), and 77 % (60-88), respectively, at 7 years. Four patients (9 %) developed grade 2, and one patient (2 %) developed grade 3 radiation pneumonitis. No other grade 3 or higher adverse events were observed. In the QOL analysis, global QOL remained favorable; however, approximately 40 % of patients reported dyspnea at 3 and 24 months.

CONCLUSION

Our findings suggest that IGPT provides effective disease control and survival in operable stage I NSCLC, particularly for peripheral lesions. Moreover, toxicity associated with IGPT was minimal, and patients reported favorable QOL.

A multicenter high-quality data registry for advanced proton therapy approaches: the POWER registry

BACKGROUND

Paucity and low evidence-level data on proton therapy (PT) represent one of the main issues for the establishment of solid indications in the PT setting. Aim of the present registry, the POWER registry, is to provide a tool for systematic, prospective, harmonized, and multidimensional high-quality data collection to promote knowledge in the field of PT with a particular focus on the use of hypofractionation.

METHODS

All patients with any type of oncologic disease (benign and malignant disease) eligible for PT at the European Institute of Oncology (IEO), Milan, Italy, will be included in the present registry. Three levels of data collection will be implemented: Level (1) clinical research (patients outcome and toxicity, quality of life, and cost/effectiveness analysis); Level (2) radiological and radiobiological research (radiomic and dosiomic analysis, as well as biological modeling); Level (3) biological and translational research (biological biomarkers and genomic data analysis). Endpoints and outcome measures of hypofractionation schedules will be evaluated in terms of either Treatment Efficacy (tumor response rate, time to progression/percentages of survivors/median survival, clinical, biological, and radiological biomarkers changes, identified as surrogate endpoints of cancer survival/response to treatment) and Toxicity. The study protocol has been approved by the IEO Ethical Committee (IEO 1885). Other than patients treated at IEO, additional PT facilities (equipped with Proteus®ONE or Proteus®PLUS technologies by IBA, Ion Beam Applications, Louvain-la-Neuve, Belgium) are planned to join the registry data collection. Moreover, the registry will be also fully integrated into international PT data collection networks.

Patients' needs in proton therapy: A survey among ten European facilities

Aims

The number of Proton Therapy (PT) facilities is still limited worldwide, and the access to treatment could be characterized by patients' logistic and economic challenges. Aim of the present survey is to assess the support provided to patients undergoing PT across Europe.

Methods

Through a personnel contact, an online questionnaire (62 multiple-choice and open-ended questions) via Microsoft Forms was administered to 10 European PT centers. The questionnaire consisted of 62 questions divided into 6 sections: i) personal data; ii) general information on clinical activity; iii) fractionation, concurrent systemic treatments and technical aspects of PT facility; iv) indication to PT and reimbursement policies; v) economic and/ or logistic support to patients vi) participants agreement on statements related to the possible limitation of access to PT. A qualitative analysis was performed and reported.

Results

From March to May 2022 all ten involved centers filled the survey. Nine centers treat from 100 to 500 patients per year. Paediatric patients accounted for 10-30%, 30-50% and 50-70% of the entire cohort for 7, 2 and 1 center, respectively. The most frequent tumours treated in adult population were brain tumours, sarcomas and head and neck carcinomas; in all centers, the mean duration of PT is longer than 3 weeks. In 80% of cases, the treatment reimbursement for PT is supplied by the respective country's Health National System (HNS). HNS also provides economic support to patients in 70% of centers, while logistic and meal support is provided in 20% and 40% of centers, respectively. PT facilities offer economic and/or logistic support in 90% of the cases. Logistic support for parents of pediatric patients is provided by HNS only in one-third of centers. Overall, 70% of respondents agree that geographic challenges could limit a patient's access to proton facilities and 60% believe that additional support should be given to patients referred for PT care.

Conclusions

Relevant differences exist among European countries in supporting patients referred to PT in their logistic and economic challenges. Further efforts should be made by HNSs and PT facilities to reduce the risk of inequities in access to cancer care with protons.