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MINI 33 - Radiotherapy and Complications (ID 164)
- Event: WCLC 2015
- Type: Mini Oral
- Track: Treatment of Locoregional Disease – NSCLC
- Presentations: 1
MINI33.04 - Acute Radiation Pneumonitis in Lung Cancer Treated with Volumetric Modulated Arc Therapy (ID 2634)
18:30 - 20:00 | Author(s): R. Zhao
Thoracic radiotherapy plays an important role in the treatment of lung cancer. However, the safety of thoracic radiotherapy delivery is restricted to the risk of radiation pneumonitis(RP), which is the major dose limiting toxicity for patients undergoing thoracic radiotherapy. Few studies to date have assessed risk factors associated with the development of RP in lung cancer patients treated with volumetric modulated arc therapy (VMAT). This study aimed to report the RP incidence and clinical and dosimetric risk factors associated with RP in lung cancer patients treated with VMAT at a single institution.
In this retrospective study, lung cancer patients treated with VMAT from 2013 through 2015 were reviewed. RP was graded according to Common Terminology Criteria for Adverse Events (CTCAE) version.4.0. Clinical factors and dosimetric parameters were evaluated using logistic multivariate regression for estimating the correlation with RP. The results were considered statistically significant when the p-value was<0.05.
Thoracic radiotherapy with VMAT was administered in 77 lung cancer patients. Of these patients, 58 were men and 19 were women, with a median age of 60 years (range 22-84 years); 25 patients received concurrent chemoradiotherapy, and the median radiation dose was 60Gy (range 45-64Gy). VMAT plans were performed with single arc in 9 patients, double in 55 patients, triple in 4 patients, and the mean (±SD) delivery time was 189.1s±42.0s. VMAT allowed us to respect most planning objectives on target volumes and organs at risk, for PTV V~95% ~= 96.8 ± 6.1%; for lung V~5~ = 41.3 ± 8.7%, V~10~ = 29.9 ± 7.1%, V~20~ = 20.9 ± 5.7%, mean dose=1150.9±277.6Gy. With regard to acute RP after thoracic radiotherapy, 10.4% were grade 1 (G1), 16.9% G2, 9.1% G3, 2.6% G5. The overall incidence rate of symptomatic RP (grade ≥ 2 by CTCAE) was 28.6% in the entire cohort. Based on the clinical data and dosimetric parameters analysis, factors predictive of symptomatic RP were lung volume receiving ≥10Gy (V~10~) [OR: 1.39, 95% CI 1.07–1.80, p=0.014], PS score[OR:5.44, 95% CI 1.29–23.08, p=0.021], concurrent chemotherapy[OR:3.85, 95% CI 1.07–13.86, p=0.039]and CRP changing level[OR:1.06, 95% CI 1.01–1.12, p=0.014].
VMAT, a novel technique, provides a viable option for the thoracic radiotherapy of lung cancer with acceptable toxicities. However, for patients with higher V~10~, poorer PS score, greater increasing level of CRP and undergoing concurrent chemotherapy, VAMT technique should be administrated with cautions. Several molecular biomarkers have been reported that correlated with the development of RP, which will be tested in our further analysis.
P1.02 - Poster Session/ Treatment of Localized Disease – NSCLC (ID 209)
- Event: WCLC 2015
- Type: Poster
- Track: Treatment of Localized Disease - NSCLC
- Presentations: 1
- Coordinates: 9/07/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)
P1.02-033 - Pemetrexed plus Platinum as Adjuvant Therapy in Patients with Resected Lung Adenocarcinoma and Exploratory Biomarkers Analysis (ID 2524)
09:30 - 17:00 | Author(s): R. Zhao
Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death around the world. Currently, adjuvant platinum-based chemotherapy is recommended as the standard treatment for patients with completely resected stage IB-IIIA NSCLC. Pemetrexed, a multitargeted antifolate agent, has been shown to have definite activity in non-squamous NSCLC and has proven to be efficacious in the first-line metastatic NSCLC. Hence, the aim of this study was to evaluate the efficacy and toxicity of pemetrexed/ platinum in patients with completely resected lung adenocarcinoma and identify prognostic factors in this setting.
A retrospective study was performed in patients with completely resected stage IB-IIIA lung adenocarcinoma who received pemetrexed and a platinum as adjuvant therapy. Generally, pemetrexed 500mg/m2 d1 and cisplatin 30mg/ m2 day1-3 were administrated every 21-28 days for 4 cycles. Study endpoints included overall survival (OS), progression-free survival (PFS) and treated-related toxicities. Immunohistochemical (IHC) was used to examine the protein expression of p53, thymidylate synthase (TS), dihydrofolate reductase (DHFR), Lipocalin 2 and nm23-H1 in surgical resection specimens of 23 patients. The associations between protein expression level and clinical outcome were evaluated using cox proportional hazards model.
Between Feb. 2012 and Jan.2014, 49 patients were treated with pemetrexed-based chemotherapy. Median age 57(range35-79, years), males 47%; stage IB 41%, II 18%, IIIA 41%; ever smokers 35%; lobectomy 92%, wedge resection 8%. The completion of 4-cycle chemotherapy was 67.3%. Grade 3+ hematologic and gastrointestinal toxicities were observed in 5 (10%) patients and 4 (8%) patients, respectively. The median PFS was 39.63 months (95%CI 26.55-52.71 months), and the median OS was unreachable. 1-, 2- and 3-year survival rates were 95.9%, 93.6%, 83.2%, respectively. 1-, 2- and 3-year PFS rates were 93.9%, 75.3% and 56.8%, respectively. Of 23 patients measured by IHC, 19 expressed TS, 9 expressed p53, 10 expressed DHFR, and none expressed Lipocalin 2 or nm23-H1. No significant correlations of these protein expression and clinical outcome were observed.
The regimen of pemetrexed/platinum showed lower incidence rates of toxicities and promising treatment outcomes in patients with completely resected stage IB-IIIA lung adenocarcinoma. However,no prognostic biomarker was identified in our study, which may be related to the small sample size.