Adjuvant chemoradiotherapy (gemcitabine-based) in pancreatic adenocarcinoma: the Pisa University experience.

INTRODUCTION: The role of adjuvant chemoradiotherapy in patients with pancreatic adenocarcinoma (PA) is controversial. In this study we aimed to assess the feasibility, disease-free survival (DFS) and overall survival (OS) of adjuvant chemoradiotherapy (gemcitabine based) in patients with resected PA and their correlation with prognostic factors. METHODS: 122 resected patients (stage ≥IIa) treated between February 1999 and December 2013 were analyzed. Two cycles of gemcitabine (1,000 mg/m2 on days 1, 8 and 15 every 28 days) were administered before concomitant radiotherapy (45 Gy/25 fractions) and chemotherapy (gemcitabine 300 mg/m2 weekly). RESULTS: Median follow-up was 22.7 months (range 4-109). Gastrointestinal toxicity (G3), neutropenia (G3-G4) and cardiac toxicity (G2-G3) were observed in 2.4%, 10.6% and 1.6% of patients, respectively. OS at 12, 24 and 60 months was 79%, 55% and 31%, respectively (median 25 months). Two-year OS in patients with postoperative Karnofsky performance status (KPS) ≤70 and ≥80 was 37.1% and 62.3%, respectively (p<0.0001). OS was better in the group of patients with a postoperative CA 19-9 level ≤100 U/mL (p = 0.014). Median DFS was 17 months. CONCLUSIONS: The combination of concomitant gemcitabine and radiotherapy in patients with radically resected PA was well tolerated and associated with a low incidence of local recurrences. Five-year OS was significantly influenced by postoperative KPS and CA 19-9 values.

Inter-observer variability of clinical target volume delineation in radiotherapy treatment of pancreatic cancer: a multi-institutional contouring experience.

BACKGROUND: An observational multi-institutional study has been conducted aimed to evaluate the inter-observer variability in clinical target volume (CTV) delineation among different radiation oncologists in radiotherapy treatment of pancreatic cancer. METHODS: A multi-institutional contouring dummy-run of two different cases of pancreatic cancer treated by postoperative and preoperative radiotherapy (RT) was performed. Clinical history, diagnostics, and planning CT imaging were available on AIRO website (http://www.radioterapiaitalia.it). Participants were requested to delineate CTVs according to their skills and knowledge. Aiming to quantify interobserver variability of CTVs delineations, the total volume, craniocaudal, laterolateral, and anteroposterior diameters were calculated. Descriptive statistic was calculated. The 95% Confidence Interval (95% CI) for coefficient of variation (CV) was estimated. The Dice Similarity Index (DSI) was used to evaluate the spatial overlap accuracy of the different CTVs compared with the CTVs of a national reference Centre considered as a benchmark. The mean DSI (mDSI) was calculated and reported. RESULTS: A total of 18 radiation oncologists from different Institutes submitted the targets. Less variability was observed for the Elective CTV rather than the Boost CTV, in both cases. The estimated CV were 28.8% (95% CI: 21.2-45.0%) and 20.0% (95% CI: 14.9-30.6%) for the Elective CTV, in adjuvant (Case 1) and neoadjuvant (Case 2) case, respectively. The mDSI value was 0.68 for the Elective CTVs in both cases (range 0.19-0.79 in postoperative vs range 0.35-0.79 in preoperative case). The mDSI was increased to 0.71 (Case 1) and 0.72 (Case 2) if the observers with a worse agreement have been excluded. On the other hand, a CV of 42.4% (95% CI: 30.1-72.4%) and 63.8% (95% CI: 43.9-119.2%) with a mDSI value of 0.44 and 0.52, were calculated for the Boost CTV in Case 1 and Case 2, respectively. CONCLUSIONS: The CV and mDSI obtained values for Elective CTVs showed an acceptable agreement among participants either in postoperative as well in preoperative setting. Additional strategies to reduce the variability in Boost CTV delineation need to be found and promoted.