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M.S. O'Reilly
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P3.01 - Poster Session/ Treatment of Advanced Diseases – NSCLC (ID 208)
- Event: WCLC 2015
- Type: Poster
- Track: Treatment of Advanced Diseases - NSCLC
- Presentations: 1
- Moderators:
- Coordinates: 9/09/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)
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P3.01-065 - PET Tumor Response by PERCIST Predicts Local-Regional Control in Locally Advanced NSCLC after Concurrent Chemoradiotherapy with Erlotinib (ID 1242)
09:30 - 09:30 | Author(s): M.S. O'Reilly
- Abstract
Background:
Assessing response of locally advanced non-small cell lung cancer (NSCLC) after concurrent chemoradiotherapy by computed tomography (CT) can be complicated by treatment-related pneumonitis or fibrosis. Hypothesizing that measurements of tumor response by [18]F-fluorodeoxyglucose standardized uptake values (SUVs) on positron emission tomography (PET) are more reliably associated with treatment outcomes than those by CT, we compared outcomes and responses according to PET SUV vs. CT among patients in a phase II study of erlotinib+chemoradiation for stage III NSCLC.
Methods:
Trial 2005-1023 enrolled 46 patients in 2007–2010; patients received 63 Gy in 35 fractions over 7 weeks with daily erlotinib and weekly paclitaxel-carboplatin. Tumor response was assessed on diagnostic CT scans with contrast or CT from PET-CT and scored according to RECIST 1.1. Tumor response was also assessed by PERCIST 1.0 (based on SUV) as follows: complete response (CR), disappearance of all measurable tumors; partial response (PR), ≥30% reduction in the sum of SUVs of target lesions; progressive disease (PD), ≥30% increase in the sum of SUVs of target lesions; and stable disease (SD), insufficient change in SUV to qualify for PR or PD. The longest diameter of measurable primary lesions and the short axis of measurable lymph nodes were measured. All non-target lesions were also measured. Two-sided Pearson’s chi-square tests were used to assess frequency associations. Overall survival (OS) and local-regional control (LRC) rates were assessed from treatment start by Kaplan-Meier analysis and log-rank tests; P≤0.05 indicated significance.
Results:
One patient did not have CT and PET after treatment. For the 45 evaluable patients, best response by PET-CT at 6 months after treatment was CR for 15 patients (33%), PR for 19 (42%), SD for 0, PD for 4 (9%), and not available due to did not have baseline or post treatment PET for 7 (16%). Best response by CT at 6 months was CR for 11 (24%), PR for 27 (60), SD for 3 (7%), and PD for 4 (9%) (P<0.001). The 3 patients with SD by CT all died within 7 months after treatment; the 4 patients with PD had new distant metastases. Four-year OS was associated with best overall response on both PET and CT at 6 months (P<0.05) and at 1 year (P<0.05). LRC was associated with best overall response on PET (P<0.01) and best primary tumor response on PET (P<0.05) at 6 and 12 months. Lymph node response was not associated with OS or LRC by PET or CT.
Conclusion:
The CR rate was higher with PET than with CT. Tumor response at 6 months by PET or CT predicted treatment outcomes after chemoradiotherapy for stage III NSCLC. The best overall and primary tumor response by PET within 6 months after treatment was more reliably associated with LRC than was response on CT because of difficulty to assess response due to pneumonitis/lung fibrosis.
