%0 Journal Article
%T Neoadjuvant volumetric modulated arc therapy in rectal cancer and the correlation of pathological response with diffusion
%A Ahmet Kizir
%A Baris Bakir
%A Didem Tastekin
%A Emre Balik
%A Esra Kaytan Saglam
%A Ethem Nezih Oral
%A Faruk Aykan
%A Merdan Fayda
%A Mine Gulluoglu
%A Necla Gurdal
%A Nijat Alishev
%A Ugur Gezer
%J Tumori Journal
%@ 2038-2529
%D 2018
%R 10.5301/tj.5000702
%X 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. 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. 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). 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
%K Apoptotic markers
%K Diffusion-weighted MRI
%K Nucleosomes
%K Pathologic complete response
%K Rectal carcinoma
%K Volumetric modulated arc therapy-simultaneous integrated boost (SIB-VMAT)
%U https://journals.sagepub.com/doi/full/10.5301/tj.5000702