Adaptive escalation of radiation therapy (RT) based on midtreatment residual tumor FDG-PET may improve local control among patients with locally advanced non–small cell lung cancer (NSCLC), according to a study published in JAMA Oncology.1
This study evaluated whether RT dose escalation based on midtreatment FDG-PET improved outcomes without increasing RT-induced lung toxicity (RILT).
This phase 2 trial (ClinicalTrials.gov Identifier: NCT01190527) treated 42 patients with inoperable or unresectable stage II to III NSCLC with conformal RT individualized to a fixed risk of RILT, resulting in a mean lung dose of less than 20 Gy. The RT dose was escalated up to 86 Gy in 30 daily fractions at midtreatment based on residual tumor as measured by FDG-PET.
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Concurrent weekly carboplatin and paclitaxel followed by 3 cycles of consolidation therapy were also administered to medically fit patients.
The median age at baseline was 63, 93% of patients were smokers or former smokers, and 90% had stage III disease. The median dose of RT delivered to the tumor was 83 Gy (range, 63-86 Gy) in 30 daily fractions.
The 2-year infield and overall local regional tumor control was 82% (95% CI, 62-92%) and 62% (95% CI, 43-77%), respectively, during a median follow-up of 47 months. The median local-regional progression-free survival (PFS) was 14 months, with a 2-year rate of 38% (95% CI, 24-52%).
The median PFS was 13 months, resulting in a 2-year PFS of 31%. The median overall survival (OS) was 25 months (95% CI, 12-32 months), with the 2- and 5-year OS rates of 52% (95% CI, 36-66%) and 30% (95% CI, 16-45%), respectively.
RT-induced adverse events included grade 3 esophagitis (12%), pneumonitis (7%), and dyspnea (5%). Cardiac events occurred in 28% of patients, which included pericardial effusions and chronic heart failure. Death due to massive bleeding occurred among 4 patients, with bleeding originating from the lung, upper gastrointestinal tract, and unknown.
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Results are awaited from an ongoing randomized phase 2 trial; the authors noted that these results must be confirmed by a randomized phase 3 trial prior to routine adoption.
Reference
- Kong FM, Ten Haken RK, Schipper M, et al. Effect of midtreatment PET/CT-adapted radiation therapy with concurrent chemotherapy in patients with locally advanced non-small-cell lung cancer: a phase 2 clinical trial. JAMA Oncol. 2017 Jun 1. doi: 10.1001/jamaoncol.2017.0982 [Epub ahead of print]
