Effect of PET/CT standardized uptake values on complete response to treatment before definitive chemoradiotherapy in stage III non-small cell lung cancer.

PURPOSE: The standard treatment for patients with stage III non-small cell lung cancer (NSCLC), unsuitable for resection and with good performance, is definitive radiotherapy with cisplatin-based chemotherapy. Our aim is to evaluate the effect of the maximum value of standardized uptake values (SUVmax) of the primary tumor in positron emission tomography-computed tomography (PET/CT) before treatment on complete response (CR) and overall survival. METHODS: The data of 73 stage III NSCLC patients treated with concurrent definitive chemoradiotherapy (CRT) between 2008 and 2017 and had PET/CT staging in the pretreatment period were evaluated. ROC curve analysis was performed to determine the ideal cut-off value of pretreatment SUVmax to predict CR. RESULTS: Median age was 58 years (range 27-83 years) and 66 patients were male (90.4%). Median follow-up time was 18 months (range 3-98 months); median survival was 23 months. 1-year overall survival (OS) rate and 5-year OS rate were 72 and 19%, respectively. Median progression-free survival (PFS) was 9 months; 1-year PFS rate and 5-year PFS rate were 38 and 19%, respectively. The ideal cut-off value of pretreatment SUVmax that predicted the complete response of CRT was 12 in the ROC analysis [AUC 0.699 (0.550-0.833)/P < 0.01] with a sensitivity of 83%, and specificity of 55%. In patients with SUVmax < 12, CR rate was 60%, while, in patients with SUV ≥ 12, it was only 19% (P = 0.002). Median OS was 26 months in patients with pretreatment SUVmax < 12, and 21 months in patients with SUVmax ≥ 12 (HR = 2.93; 95% CI 17.24-28.75; P = 0.087). CR rate of the whole patient population was 26%, and it was the only factor that showed a significant benefit on survival in both univariate and multivariate analyses. CONCLUSION: Pretreatment SUVmax of the primary tumor in PET/CT may predict CR in stage III NSCLC patients who were treated with definitive CRT. Having clinical CR is the only positive predictive factor for prolonged survival.

Concurrent chemoradiotherapy with low dose weekly gemcitabine in medically inoperable muscle-invasive bladder cancer patients.

PURPOSE: We aimed to determine the efficacy and the toxicity of low dose weekly gemcitabine with radiation therapy in medically unfit muscle-invasive bladder cancer patients. METHODS: Twenty-six patients were included into the retrospective analysis. Weekly gemcitabine was administered 75 mg/m(2) with a median dose of 63 Gy radiation therapy. Clinical target volume was defined as the urinary bladder only in conformal treatment planning. RESULTS: Median follow-up was 51 months (range 14-118 months). Complete response rate was 62.5 %. The 5-year local progression-free survival, disease-specific survival and overall survival rates were 40.6, 59.5 and 58.5 %, respectively. Concurrent chemotherapy was continued in 80.7 % of patients without any interruption. Gemcitabine was stopped due to grade 3 thrombocytopenia (n = 1), cardiac angina (n = 1), chronic obstructive pulmonary disease exacerbation (n = 1) or patients' reluctance (n = 2). CONCLUSIONS: Low dose weekly gemcitabine with concurrent radiotherapy is a tolerable regimen and have comparable outcomes with platinum-based combined treatments in muscle-invasive bladder cancer. Prospective randomized trials can help in understanding the safety and efficacy of this treatment specially in medically unfit patients.