Concurrent chemoradiotherapy (CCRT) of locally advanced NSCLC is considered a standard of care last two decades without important improvement except of adjuvant check-point inhibitor therapy. We present one-institutional results of chemoradiotherapy of inoperable NSCLC using daily 3D IGRT with TomoTherapy HD unit. A total of 39 patients with inoperable NSCLC staged by UICC7 and treated since April 2015 till September 2018 were included. Clinical data and radiation plans were retrospectively reviewed. Survival was analysed using Kaplan-Meier method, univariate analysis was done using Cox regression model. Our preferential chemotherapy regimen was cisplatin/vinorelbine three-weekly, carboplatin doublet with vinorelbine or paclitaxel was acceptable as well. Standard radiation dose was 66Gy/33fractions/6.5 weeks, daily MVCT was done. Minimal and median follow-up was 7/30 months, respectively. Patient characteristics were as follows: mean age 66 years, male 46%, stage II+IIIA/IIIB/locoregional recurrences 44%/33%/23%, respectively. PET/CT was done in 77% of patients. Histology: adenocarcinoma 41%, squamous 38.5%, NOS 20.5%. All patients had chemotherapy, 59% cisplatin-based, 41% carboplatin-based, full radiation dose of 66Gy was delivered to 69% of patients, mean size of PTV was 366ml. CCRT had 69% patients. Subsequently, only one patient passed radical surgery, check-point inhibitors were used in 5 patients as second line palliative therapy. We observed low treatment toxicity, radiation esophagitis grade 1-2 in 64%, grade 3 in one patient. Radiation pneumonitis of grade 1-2 started in 13% of patients. Median survival and median time to progression (TTP) was 35.3 and 22.3 months, 2-year survival and TTP 63% and 44%, respectively. The reason of progression was mainly distant metastases alone (26%) or with locoregional failure (15%). Only locoregional progression occurred in 8% of patients. Univariate analysis did not find any difference in survival or TTP by age, gender, tumour location, regimen and length of chemotherapy, or concurrent treatment delivery. Non-significant trend of better outcome of stage II+IIIA, squamous cancer, higher dose of radiation and shorter interval between chemotherapy and radiotherapy start was observed. Only significant variable was size of PTV. With cut-off 440ml the patients having greater size of PTV had significantly worse survival in compare with those with smaller one (HR 4.209, 95%CI: 1.519;11.665). Chemoradiation of inoperable NSCLC with IGRT technique using TomoTherapy HD has excellent results with 77% of durable local control, 63% of 2-year survival and nearly 3-year median survival. Only negative prognostic factor was higher size of PTV.
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