Elisa Bertocchi1, Giuliano Barugola1, Luca Nicosia2, Rosario Mazzola3, Francesco Ricchetti3, Paolo Dell'Abate4, Filippo Alongi3,5, Giacomo Ruffo1. 1. Department of Surgery, IRCCS - Ospedale Sacro Cuore Don Calabria, Via Don A. Sempreboni 5, 37024, Negrar, Verona, Italy. 2. Department of Advanced Radiation Oncology, IRCCS - Ospedale Sacro Cuore Don Calabria, Via Don A. Sempreboni 5, 37024, Negrar, Verona, Italy. luca.nicosia@sacrocuore.it. 3. Department of Advanced Radiation Oncology, IRCCS - Ospedale Sacro Cuore Don Calabria, Via Don A. Sempreboni 5, 37024, Negrar, Verona, Italy. 4. Department of Surgical Science, University Hospital of Parma, Via Gramsci, 14 - 43126, Parma, Italy. 5. University of Brescia, Brescia, Italy.
Abstract
PURPOSE: The potential role of neoadjuvant radiation dose intensification in locally advanced rectal cancer (LARC) is still largely debated. In the present study, a comparative analysis between radiation dose intensification and conventional fractionation was performed. MATERIALS AND METHODS: In the current prospective observational study (protocol ID RT-03/2011), 56 patients diagnosed with LARC were enrolled between January 2013 and December 2016. More specifically, 25 patients underwent preoperative conventional radiation dose [i.e., 50.4 Gy in 28 fractions here defined as standard dose radiotherapy (SDR)-group 1], whereas 31 patients were candidate for radiation dose intensification (RDI) (i.e., 60 Gy in 30 fractions-group 2). The primary endpoint was the complete pathological response (pCR) rate. Secondary endpoints were postoperative complications and ChT-RT-related toxicity. RESULTS: No statistical significance was observed in pCR rate (20.8% and 22.6% in SDR and RDI group, respectively, p = 0.342). Of contrast, the RDI group showed a significantly higher primary tumor downstaging in case of T3 tumor compared to SDR group (p = 0.049). Sphincter-preserving surgery was 84% and 93.5% in SDR and RDI groups, respectively (p = 0.25). All patients had R0 margins. No surgical-related death was recorded. No statistically significant difference was observed regarding surgical complications and incomplete mesorectal excision. Acute genitourinary toxicity was significantly higher in RDI group (p = 0.015). CONCLUSIONS: The intensification of the neoadjuvant radiotherapy for LARC seems to produce a major pathological response in T3 tumors. The radiation dose intensification appears probably associated with a higher rate of genitourinary toxicity.
PURPOSE: The potential role of neoadjuvant radiation dose intensification in locally advanced rectal cancer (LARC) is still largely debated. In the present study, a comparative analysis between radiation dose intensification and conventional fractionation was performed. MATERIALS AND METHODS: In the current prospective observational study (protocol ID RT-03/2011), 56 patients diagnosed with LARC were enrolled between January 2013 and December 2016. More specifically, 25 patients underwent preoperative conventional radiation dose [i.e., 50.4 Gy in 28 fractions here defined as standard dose radiotherapy (SDR)-group 1], whereas 31 patients were candidate for radiation dose intensification (RDI) (i.e., 60 Gy in 30 fractions-group 2). The primary endpoint was the complete pathological response (pCR) rate. Secondary endpoints were postoperative complications and ChT-RT-related toxicity. RESULTS: No statistical significance was observed in pCR rate (20.8% and 22.6% in SDR and RDI group, respectively, p = 0.342). Of contrast, the RDI group showed a significantly higher primary tumor downstaging in case of T3 tumor compared to SDR group (p = 0.049). Sphincter-preserving surgery was 84% and 93.5% in SDR and RDI groups, respectively (p = 0.25). All patients had R0 margins. No surgical-related death was recorded. No statistically significant difference was observed regarding surgical complications and incomplete mesorectal excision. Acute genitourinary toxicity was significantly higher in RDI group (p = 0.015). CONCLUSIONS: The intensification of the neoadjuvant radiotherapy for LARC seems to produce a major pathological response in T3 tumors. The radiation dose intensification appears probably associated with a higher rate of genitourinary toxicity.