Gürdal, NeclaEmre Merdan FaydaAlishev, NijatBakır, BarışTaştekin, DidemAykan, FarukGezer, UğurBalık, EmreSağlam, Esra KaytanOral, Ethem NezihGüllüoğlu, MineKizir, Ahmet2020-08-302020-08-302018Gurdal, N., Fayda, M., Alishev, N., Bakir, B., Tastekin, D., Aykan, F., ... & Gulluoglu, M. (2018). Neoadjuvant volumetric modulated arc therapy in rectal cancer and the correlation of pathological response with diffusion-weighted MRI and apoptotic markers. Tumori Journal, 104(4), 266-272.0300-89162038-2529https://doi.org/10.5301/tj.5000702https://hdl.handle.net/20.500.12713/756Purpose: In this prospective observational study, we aimed to report the applicability and tolerability of neoadjuvant volumetric modulated arc therapy with simultaneous integrated boost (SIB-VMAT) and concurrent chemotherapy in patients with locally advanced rectal cancer (LARC), and to evaluate the correlation of pathological response with apparent diffusion coefficient (ADC) measurements on diffusion-weighted magnetic resonance imaging (DW-MRI) and apoptotic markers. Methods: The study enrolled 30 patients with T3 to T4 and/or N+ rectal cancer who preoperatively received SIB-VMAT and concurrent chemotherapy. Before and after the neoadjuvant treatment, apoptotic markers including the nucleosomes and cell-free DNA fragments in the serum samples were examined; DNA integrity was assessed by amplifying the ACTB gene; and the ADC measurements on the DW-MRI were analyzed. Results: No patients had acute or chronic grade III-IV toxicity. Pathologic complete response (pCR) was achieved in 8 patients (27%), while in 10 patients (33%) near-complete pathological response was obtained. Posttreatment ADC was significantly higher in patients with pCR compared with the others (1.28 vs. 1.10, p = 0.017). ROC curve analysis showed that posttreatment ADC values had a sensitivity of 75% and a specificity of 77.3% for distinguishing the patients with pCR from other responders. On the other hand, posttreatment DNA integrity values were revealed lower than the pretreatment values (p = 0.36). Also, the results revealed an insignificant increase in the posttreatment serum level of nucleosomes (p = 0.72). Conclusions: Neoadjuvant SIB-VMAT with concurrent chemotherapy was proved to be a feasible treatment regimen in LARC with tolerable side effects, and improved local control rate and pCR rate.eninfo:eu-repo/semantics/closedAccessApoptotic MarkersDiffusion-Weighted MriNucleosomesPathologic Complete ResponseRectal CarcinomaVolumetric Modulated Arc Therapy-Simultaneous Integrated Boost (Sib-Vmat)Article104426627229218690WOS:0004523034000042-s2.0-85054445824Q410.5301/tj.5000702Q3