BMC Cancer 2007, 7:189 http://www.biomedcentral.com/1471-2407/7/189 response rate and a reasonable median survival time about 26.1 weeks [7,11,12]. Obviously, neither physi- cians nor patients are satisfied with this. appeared, a dose reduction was of 25% in subsequent cycles. Docetaxel infusion could not be delayed for over 2 weeks since patient discontinuation. Empirical studies indicated that heat played a lethal effect to human tumor cell lines, and heat enhanced cytotoxic effect of chemotherapeutics [13-15]. Along with the devel- opment of technology, hyperthermia improves therapeu- tic effect of superficial tumors, soft tissue sarcoma, osteosarcoma, prostate cancer, breast cancer and some recurrent or advanced solid tumors [16-21]. There are rare reports that demonstrate the advantage of adding hyper- thermia to chemotherapy as the second-line therapy for pretreated locally advanced non-small cell lung cancer. In present study, we combined docetaxel weekly chemother- apy with external regional radio frequency (RF) hyperther- mia as the second-line treatment for patients with inoperable stage III non-small cell lung cancer who had failed to response to the prior platinum-containing chem- otherapy. The toxicities and progression free survive (PFS) were primarily investigated. Methods Patients selection Eligible patients must had histological or cytological proof to be inoperable stage IIIa or IIIb non-small cell lung cancer, and should have at least one measurable lesion. They experienced only one platinum-containing regimen as the first-line treatment, whether accompanied with irradiation or not. They failed to respond to the first- line treatment, and proved to be still inoperable by spiral computed tomograph. In addition, patients should be with a ECOG performance status ≤ 2, and have normal hematological index (neutrophil count ≥ 2 × 109/l, plate- let count ≥ 100 × 109/l, haemoglobin ≥ 100 g/l) and acceptable biochemical analysis result (normal bilirubin level, alanine aminotransferase ≤ 2.5 × upper limit of nor- mal (ULN) and serum creatinine level ≤ 1.5 × ULN). Patients with metal foreign matter, fever (≥ 38°C), signif- icant hemorrhagic tendency, and seriously impaired func- tion of lung or heart were excluded. Every patient enrolled in this study had signed a written informed consent form approved by Si Chuan University Hua Xi Medical Ethics Committee, which also approved the study protocol. Chemotherapy regimen A regimen of docetaxel 40 mg/m2 intravenous infusion on day1, 8 and 15, repeated every 4 weeks was chosen. Docetaxel was administered intravenously within 1 hour. Prophylactic oral corticosteroid premedication (dexame- thasone 8 mg) was given 3 times over 2 days. Target sum of chemotherapy would be 4 cycles. Dose adjustment should be done when grade 4 hemato- logical or grade 3,4 non-hematological toxicities Hyperthermia regimen We used a radio frequency external heat system (Ho Kai company, China) working frequency was 13.8 MHz to perform regional hyperthermia. Primary lesion was cho- sen to be the target area, covered by an applicator 20 cm in diameter. Hyperthermia was administered 1 hour after chemotherapeutics were given, the total heated time was up to 60 minutes, twice a week, aimed to 32 times, inter- val between 2 procedures should exceed 48 hours. Target temperature ranged from 41°C to 43°C, we instructed every patient to mention any abnormal feelings, so that we could adjust settings such as power output, or place a water bolus to ease the uncomfortable. Evaluation of response and toxicity The response had been estimated within a week after every 2 cycles of chemotherapy were given, and to be confirmed in 4 weeks of responding patients. We used contrast- enhanced spiral computed tomograph to measure the largest diameter of target tumor, response criteria was based on Response Evaluation Criteria In Solid Tumors (RECIST)[22]. Toxicity evaluation was done in all patients according to NCI CTC version 2.0 [23]. Follow up Eligible patients were visited once a month after treatment starting, their PFS and overall survival (OS) time was recorded. Disease evaluation was performed every 3 months or when necessary. The time limit of follow-up was 18 months in present study. Statistical analysis Main objective of present study was to evaluate the safety and therapeutic effect of docetaxel weekly chemotherapy combined with RF hyperthermia for pretreated locally advanced non-small cell lung cancer. The primary end points were grade 3,4 hematological or non-hematologi- cal toxicities and PFS, the secondary end points were response rate, tumor control rate and OS. Kaplan-Meier survival curve was used to describe PFS and OS. Statistical work was performed by soft ware SPSS 13.0 (SPSS Inc. USA). Lost patients were recorded as death, their PFS were calculated up to the last visit as well as OS, except they had already experienced tumor progression. Results Patients' characteristics From June 2005 to December 2005, 29 pretreated patients with stage III non-small cell lung cancer were included in this study, 8 patients in stage IIIb accompanied with pleu- Page 2 of 5 (page number not for citation purposes)