ABSTRACT
PURPOSE: There is limited clinical data for recommendations on how to deliver thoracic radiation therapy (TRT) concurrently with chemotherapy in limited-stage small cell lung cancer. We reviewed radiation therapy treatment plans in a randomized phase 2 trial comparing high-dose with standard-dose twice-daily TRT to assess treatment planning techniques, dose-volume data for target volumes and organs at risk (OARs), evaluate compliance with the protocol, associations with radiation-induced toxicity, and whether an imbalance in treatment planning parameters might be a reason for the large survival benefit of the higher dose (median overall survival 43.6 vs 22.6 months). METHODS AND MATERIALS: In the study, 170 patients were to receive 4 courses of platinum/etoposide and were randomized to receive twice-daily TRT of 60 Gy/40 fractions (fx) or 45 Gy/30 fx. TRT treatment plans for those who received 1 or more fx of TRT (n = 166) were analyzed. RESULTS: The most common treatment planning technique was 3-dimensional conformal radiation therapy (67%). The 75th percentile of the reported dose-volume parameters for the OARs were within the protocol-recommended limits for both groups. Mean doses to the esophagus of 25.5 Gy (IQR, 20.2-31.3; 60 Gy/40 fx) and 24.3 Gy (IQR, 20.3-27.5; 45 Gy/30 fx) were associated with 21% and 18% ≥ grade 3 acute esophagitis, respectively. In the 60 Gy/40 fx group, a mean dose to the lungs of 16.5 Gy (IQR, 15.8-16.9), V20 Gy of 29.5% (IQR, 28.8-30.4), and V5 Gy of 65.6% (IQR, 61.5-68.7) led to ≥ grade 3 pneumonitis in 4% of the patients. There was no ≥ grade 3 pneumonitis in the 45 Gy/30 fx group. The treatment planning techniques, the percentage change in volumes between original and redelineated OARs, planning target volumes, relative doses, and laterality were well balanced between the randomly assigned groups. CONCLUSIONS: Considering the incidences of severe radiation-induced toxicities were within the range of other recent trials, the reported doses to the OARs appear to be safe. Treatment planning parameters were well balanced between the randomly assigned groups, supporting that the survival benefit of the twice-daily 60 Gy/40 fx TRT schedule was due to the higher dose.
ABSTRACT
Background: The Glasgow prognostic score (GPS) is an established inflammatory prognostic index in cancer patients. Most studies have only measured GPS at baseline (B-GPS). Effective cancer therapy may reduce inflammation, and we investigated whether re-assessing GPS after first-line chemotherapy (E-GPS) provided more prognostic information than B-GPS in a phase III trial of advanced non-squamous non-small cell lung cancer (NSCLC). Methods: Glasgow prognostic score was assessed before and after carboplatin/vinorelbine chemotherapy. When assessing GPS, C-reactive protein (CRP) ⩾ 10 mg/L and albumin < 35 mg/L are defined as abnormal values. GPS 0: both values normal, GPS 1: one abnormal value, and GPS 2: both values abnormal. Results: Glasgow prognostic score at baseline and E-GPS were available in 138 patients. Median age was 67 years, 51% were women, and 94% had performance status 0-1. B-GPS was not a statistically significant prognostic factor (B-GPS 1 vs 0: hazard ratio [HR] = 1.32, 95% confidence interval [CI] = 0.9-2.0; B-GPS 2 vs 0: HR = 1.46, 95% CI = 0.9-2.3), while E-GPS was (E-GPS 1 vs 0: HR = 1.57, 95% CI = 1.0-2.4; E-GPS 2 vs 0: HR = 2.77, 95% CI = 1.7-4.5). E-GPS was associated with treatment response (P < .01), whereas B-GPS was not. Conclusion: Glasgow prognostic score at baseline after first-line chemotherapy provided more prognostic information than baseline GPS in patients with advanced non-squamous NSCLC and was associated with treatment response. ClinicalTrialsgov Identifier: NCT02004184.
ABSTRACT
Objectives: Two phase III trials show that maintenance pemetrexed therapy after platinum-doublet chemotherapy prolongs overall survival (OS) and progression free survival (PFS) in advanced non-squamous non-small-cell lung cancer (NSCLC). However, few patients in the control arms received pemetrexed at progression in these trials, performance status (PS) two patients were ineligible and few of the participants were elderly. Thus, we designed this study comparing immediate switch-maintenance pemetrexed therapy with pemetrexed at progression after platinum-doublet chemotherapy.Methods: Patients with stage IIIB/IV non-squamous NSCLC, ≥18 years, PS 0-2, and non-progression after four courses of carboplatin/vinorelbine were randomized to receive immediate maintenance pemetrexed therapy or observation followed by pemetrexed at progression. The primary endpoint was OS, secondary endpoints were PFS, toxicity and health related quality of life (HRQoL).Results: 105 patients were randomized between May 2014 and September 2017. Median age was 67 years, 36% were >70 years, 9% had PS 2, 91% stage IV and 47% were women. In the observation arm, 73% received pemetrexed at progression. Patients in the maintenance arm had a numerically longer OS (median 12.0 vs. 10.0 months; p = .10) and a statistically significant longer PFS (median 3.1 vs. 1.9 months; p < .01). In multivariable analyses adjusting for baseline characteristics, there was a trend toward improved OS (HR 0.65, 95% CI 0.42-1.01); p = .05), and a significantly improved PFS (HR 0.53, 95% CI 0.35-0.80; p < .01). There were no significant differences in toxicity or HRQoL between the treatment arms.Conclusion: There was a trend toward prolonged OS and significantly longer PFS from switch- maintenance pemetrexed therapy when 73% of patients in the control arm received pemetrexed at progression. ClinicalTrials.gov Identifier: NCT02004184.
