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Purpose To test if the relative change in FDG-PET SUVmax over the course of treatment was associated with disease progression and overall survival. Additionally, the prognostic values of other first-order PET-metric changes were investigated. Methods The study included 38 patients with stage II–III NSCLC, who underwent concurrent chemoradiotherapy. Patients received two pre-treatment FDG-PET scans and four during-treatment scans at weekly intervals. SUVmax was normalized to the start of treatment and analyzed using linear regression. Linear regression coefficients of other first order PET-metrics were grouped according to dissimilarity. Associations to patient outcome were analyzed using Cox hazard ratio. Results Twenty-eight patients satisfied the criteria for analysis. All PET-metrics demonstrated a strong linear correlation with time during treatment [median R-range: −0.87: −0.97]. No strong associations (p > 0.10) were found for the relative slope of SUVmax to patient outcomes. Other first-order metrics did correlate with outcome but the single imaging time-point maximizing the association of PET response with outcome varied per PET metric and outcome parameter. Conclusion All investigated FDG PET metrics linearly decreased during treatment. Relative change in SUVmax was not associated to patient outcome while several other first order PET-metrics were related to patient outcome. A single optimal imaging time-point could not be identified.

Item does not contain fulltext BACKGROUND AND PURPOSE: (Chemo)Radiotherapy for locally advanced non-small lung cancer (LA-NSCLC) causes severe dysphagia due to the radiation dose to the mediastinal lymphadenopathy. Reducing the dose to the mediastinum and the margins to the planning target volume (PTV) might reduce severe toxicity rates. The results of both adaptations in LA-NSCLC patients receiving (chemo)radiotherapy were analysed. MATERIALS AND METHODS: 308 LA-NSCLC patients were included in an observational study. Both cohorts received hypofractionated RT (24 × 2.75 Gy) of 70 Gy (EQD2(10)) to the primary tumour. The reference-cohort (N = 170) received the same dose of 70 Gy (EQD2(10)) to the involved lymph nodes, while the reduction-cohort (N = 138) received 24 × 2.42 Gy, biologically equivalent to 60 Gy (EQD2(10)). Furthermore, the patient-specific PTV-margins for both the primary tumour and lymph nodes were reduced by 2-3 mm in the reduction-cohort after implementing a carina based correction strategy. The effects on toxicity, regional failure and overall survival (OS) were assessed. RESULTS: The acute grade 3 (G3) dysphagia and G3 pulmonary toxicity decreased significantly from 12.9% to 3.6% and 4.1% versus 0%, respectively. The regional failures were comparable: 5.9% versus 4.3% (p = 0.546). The median OS was significantly different: 26 months (reference-cohort) versus 35 months (reduction-cohort). After correction for confounders, the association between the reduction-cohort and OS remained significant (HR 0.63 versus HR 0.70). CONCLUSION: A reduction in PTV-margins and dose from 70 Gy to 60 Gy to the involved lymph nodes in LA-NSCLC patients receiving (chemo)radiotherapy did not result in an increase in regional failures. Moreover, significantly lower acute toxicities and an improved OS were observed in the reduction-cohort.

Background Intensity modulated radiotherapy (IMRT) is increasingly used with concurrent chemotherapy but toxicity data are not well investigated. We correlated clinical and dosimetric parameters with acute toxicity grade ≥ 3 in patients with locally advanced NSCLC treated with IMRT and concurrent low-dose cisplatin. Patients and Methods We analyzed age, PS, comorbidities, gross tumor volume, and the volume of the esophagus irradiated with 50 Gy (V50 oes ) in relation with acute toxicity. The mean lung dose (MLD) and pulmonary toxicity was described. Treatment consisted of 24 × 2, 75 Gy, and daily cisplatin 6 mg/m². Patients with an MLD ≥ 20 Gy or a PS > 2 were excluded from CCRT. Toxicity was prospectively scored using the Common Toxicity Criteria for adverse events version 3.0. The Charlson Comorbidity Index (CCI) was applied for scoring comorbidities. Multivariable logistic regressions for toxicity and survival estimates (Kaplan-Meier) were used for evaluation. Results From 2008 to 2011, 188 patients received standard CCRT. In 35% of the patients, acute toxicity grade ≥ 3 was reported. Grade 5 toxicity was scored in 1% of the patients. V50 oes (odds ratio [OR], 1.33 per 10% increase; P = .01) and PS ≥ 2 (OR, 3.45; P = .07) were significantly correlated with acute toxicity ≥ grade 3. No differences in toxicity were observed between age groups ( P = .26), and those with a CCI score P = .36). Grade ≥ 3 pulmonary toxicity was seen in 7%. The 1- and 2-year overall survival in stage III disease were 78% and 52%, respectively. Patients with a poor PS or a high CCI score had similar survival outcomes. Conclusion Concurrent low-dose cisplatin using IMRT is effective in a large cohort of consecutive patients with NSCLC and life threatening toxicity is rare (1%). PS ≥ 2 and V50 oes are correlated with acute toxicity grade ≥ 3.