The Dutch Lung Cancer Audit-Radiotherapy (DLCA-R): Real-World Data on Stage III Non-Small Cell Lung Cancer Patients Treated With Curative Chemoradiation

INTRODUCTION

Chemoradiotherapy (CRT) is the standard of care in inoperable non-small-cell lung cancer (NSCLC) patients, favoring concurrent (cCRT) over sequential CRT (seqCRT), with adjuvant immunotherapy in responders. Elderly and frail NSCLC patients have generally been excluded from trials in the past. In elderly patients however, the higher treatment related morbidity of cCRT, may outweigh the possible lower tumor control of seqCRT. For elderly patients with locally advanced NSCLC real-world data is essential to be able to balance treatment toxicity and treatment outcome. The aim of this study is to analyze acute toxicity and 3-month mortality of curative chemoradiation (CRT) in patients with stage III NSCLC and to analyze whether cCRT for elderly stage III NSCLC patients is safe.

METHODS

The Dutch Lung Cancer Audit-Radiotherapy (DLCA-R) is a national lung cancer audit that started in 2013 for patients treated with curative intent radiotherapy. All Dutch patients treated for stage III NSCLC between 2015 and 2018 with seqCRT or cCRT for (primary or recurrent) stage III lung cancer are included in this population-based study. Information was collected on patient, tumor- and treatment characteristics and the incidence and severity of acute non-hematological toxicity (CTCAE-4 version 4.03) and mortality within 3 months after the end of radiotherapy. To evaluate the association between prognostic factors and outcome (acute toxicity and mortality within 3 months), an univariable and multivariable analysis was performed. The definition of cCRT was:radiotherapy started within 30 days after the start of chemotherapy.

RESULTS

Out of all 20 Dutch departments of radiation oncology, 19 centers participated in the registry. A total of 2942 NSCLC stage III patients were treated with CRT. Of these 67.2% (n = 1977) were treated with cCRT (median age 66 years) and 32.8% (n = 965) were treated with seqCRT (median age 69 years). Good performance status (WHO 0-1) was scored in 88.6% for patients treated with cCRT and in 71.0% in the patients treated with seqCRT. Acute nonhematological 3-month toxicity (CTCAE grade ≥3 or radiation pneumonitis grade ≥2) was scored in 21.9% of the patients treated with cCRT and in 17.7% of the patients treated with seqCRT. The univariable analysis for acute toxicity showed significantly increased toxicity for cCRT (P = .008), WHO ≥2 (P = .006), and TNM IIIC (P = .031). The multivariable analysis for acute toxicity was significant for cCRT (P = .015), WHO ≥2 (P = .001) and TNM IIIC (P = .016). The univariable analysis for 3-month mortality showed significance for seqCRT (P = .025), WHO ≥2 (P < .001), higher cumulative radiotherapy dose (P < .001), higher gross tumor volume total (P = .020) and male patients (p < .001). None of these variables reached significance in the multivariable analysis for 3-month mortality.

CONCLUSION

In this national lung cancer audit of inoperable NSCLC patients, 3-month toxicity was significantly higher in patients treated with cCRT (21.9% vs. 17.7% for seqCRT) higher TNM stage IIIC, and poor performance (WHO≥2) patients.The 3-months mortality was not significantly different for tested parameters. Age was not a risk factor for acute toxicity, nor 3 months mortality.

Outcomes of Hypofractionated High-Dose Radiotherapy in Poor-Risk Patients with "Ultracentral" Non-Small Cell Lung Cancer

INTRODUCTION

We defined "ultracentral" lung tumors as centrally located non-small cell lung cancers with planning target volumes overlapping the trachea or main bronchi. Increased toxicity has been reported after both conventional and stereotactic radiotherapy for such lesions. We studied outcomes after 12 fractions of 5 Gy (BED10 = 90 Gy, heterogeneous dose distribution) to ultracentral tumors in patients unfit for surgery or conventional chemoradiotherapy.

METHODS

Clinical outcomes and dosimetric details were analyzed in 47 consecutive patients with single primary or recurrent ultracentral non-small cell lung cancer treated between 2010 and 2015. Those irradiated previously or with metastasis to sites other than the brain and adrenal glands were excluded. Treatments were delivered using volumetric modulated arc therapy.

RESULTS

The median age was 77.5 years, 49% of patients had a World Health Organization performance score of 2 or higher, and the median planning target volume was 104.5cm(3) (range 17.7-508.5). At a median follow-up of 29.3 months, median overall survival was 15.9 months, and 3-year survival was 20.1%. No isolated local recurrences were observed. Grade 3 or higher toxicity was recorded in 38% of patients, with 21% scored as having a "possible" (n = 2) or "likely" (n = 8) treatment-related death between 5.2 and 18.2 months after treatment. Fatal pulmonary hemorrhage was observed in 15% of patients.

CONCLUSIONS

Unfit patients with ultracentral tumors who were treated using this scheme had a high local control and a median survival of 15.9 months. Despite manifestation of rates of a fatal lung bleeding comparable to those seen with conventional radiotherapy for endobronchial tumors, the overall rate of G5 toxicity is of potential concern. Additional work is needed to identify tumor and treatment factors related to hemorrhage.

Blinded assessment of radiological changes after stereotactic ablative radiotherapy (SABR) for early-stage lung cancer: Local recurrences versus fibrosis

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Background: Stereotactic ablative radiotherapy (SABR) is a guideline-recommended treatment for unfit patients with early-stage lung cancer. The 5-year local recurrence rates are approximately 10% but fibrotic changes are common during follow-up, leading to difficulty with timely detection and salvage therapies. Previously reported high-risk features (HRFs) on computed tomography (CT) are 1) enlarging opacity at the primary site; 2) sequential enlarging opacity; 3) enlarging opacity after 12 months; 4) bulging margin; 5) loss of linear margin and 6) loss of air bronchograms. We performed a blinded assessment of CT imaging of patients with and without local recurrences. Methods: Patients treated with SABR for early stage lung cancer between 2003 and 2012, who developed pathology-proven local recurrence (n=12), were matched 1:2 to patients without recurrences (n=24), based on baseline factors. The median age at diagnosis was 68 years and median post-SABR imaging follow-up was 24 months (range 6 to 67 months). Patients were well-matched in the recurrence and non-recurrence groups. A total of 153 CT scans were available. Serial CT images were assessed by 3 radiation oncologists blinded to outcomes, viewing anonymized images projected onto a large screen. Results: All established HRFs were significantly associated with local recurrence (p<0.01), and one additional HRF was identified: cranio-caudal growth (p<0.001). The best individual predictor of local recurrence was opacity enlargement after 12 months(100% sensitivity, 83% specificity, p<0.001). The odds of recurrence increased 4-fold for each additional HRF detected in an individual patient. The presence of ≥3 HRFs in an individual patient was highly sensitive and specific for recurrence (both >90%). The HRFs enlarging opacity and cranio-caudal growth were each detected ≥3 months prior to the actual diagnosis of local recurrence in 42% of patients. Conclusions: Local recurrences following SABR can be accurately predicted by the presence of HRF’s on post-treatment CT scans. This approach may reduce unnecessary diagnostic procedures, and ensure earlier use of salvage therapies.