Objective In this prospective study,the performance between high-resolution diffusion-weighted imaging (DWI) and diffusion kurtosis imaging (DKI) for prediction of radiotherapy response in patients with nasopharyngeal carcinoma was compared. Methods Forty-one patients pathologically diagnosed with NPC received IMRT. All patients underwent conventional MRI,high-resolution DWI and DKI before and after radiotherapy (1-2 d after the plan dose was administered). All patients received conventional MRI during follow-up at 3,6,9 and 12 months after radiotherapy. According to the RECIST 1.1(response evaluation criteria in solid tumors),all patients were divided into the response group (RG;n=36) and non-response group (NRG;n=5). The mean kurtosis coefficient (Kmean) and the mean diffusion coefficient (Dmean) of DKI and apparent diffusion coefficient (ADC) of DWI were analyzed before and after radiotherapy. Results Among 41 patients,36 cases were assigned into the RG group and 5 in the NRG group. Before and after radiotherapy,all parameters significantly differed between two groups (P=0.000-0.013) except for the Dmean and ADC prior to radiotherapy. At the end of radiotherapy,the sensitivity of Kmean was calculated as 87.5% and the specificity was 91.3% for predicting local control (optimal threshold=0.30,AUC:0.924;95%CI:0.83-1.00). Conclusion Kmean value after radiotherapy is a potential biomarker for the early evaluation of clinical efficacy of radiotherapy in NPC patients.

Objective To evaluate the effect of high-dose hypofractionated radiotherapy upon the quality of life (QOL) of patients diagnosed with pancreatic cancer. Methods In this prospective study, 50 patients with pancreatic cancer admitted to our hospital between 2016 and 2017 were recruited. All patients underwent high-dose hypofractionated helical tomotherapy. The prescription doses for PTV, CTV, and GTV were 50, 60, and 70 Gy in 15-20 fractions, 5 times per week. The QOL was evaluated by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ-C30) and pancreatic cancer-specific (European Organization for Research and Treatment of Cancer QLQ-PAN26) questionnaires before, after, 1-month and 3-month after the radiotherapy to statistically compare the QOL changes before and after radiotherapy and subsequent follow-up. Results A total of 50 patients with pancreatic cancer were included. At the end of radiotherapy, the overall QLQ-C30 score did not differ from that before radiotherapy (P=0.330). At 1 month after radiotherapy, the overall QLQ-C30 score was significantly higher than that before radiotherapy (P=0.000). The overall QLQ-C30 scores did not significantly differ at 1-and 3-month after radiotherapy (P=0.665). At 3 months after radiotherapy, social function score was considerably decreased (P=0.047), and the remaining function scores were equal to those at 1 month post-radiotherapy. The symptoms of fatigue in the QLQ-C30 questionnaire were slightly improved at the end of radiotherapy, which were mitigated at 1-month after radiotherapy and became stable at 3-month following radiotherapy. Pain, insomnia, loss of appetite and diarrhea did not significantly change at the end of radiotherapy, whereas were improved at 1 month after radiotherapy. Nausea and vomiting were aggravated at the end of radiotherapy (both P=0.000), restored to the level before radiotherapy at 1 month after radiotherapy, and the symptoms were similar at 1-and 3-month after radiotherapy. Financial difficulty was worsened at the end of radiotherapy (P=0.046), acceptable at 1 month after radiotherapy and worsened at 3 months following radiotherapy. In the QLQ-PAN26 questionnaire, the symptoms of pancreatic pain (backache, nocturnal pain) were mitigated at the end of radiotherapy (P=0.009, P=0.000), and further alleviated at 1 month after radiotherapy. No significant difference was noted at 1-and 3-month after radiotherapy. The body weight loss was slightly mitigated compared with that before radiotherapy (P=0.000), and further improved at 1 month after radiotherapy (P=0.024). No significant difference was noted at 1-and 3-month after radiotherapy (P=0.226). Conclusion High-dose hypofractionated radiotherapy can significantly enhance quality of life of pancreatic cancer patients at 1- and 3- month following radiotherapy.This study further demonstrated the clinical value of high-dose hypofractionated radiotherapy in improving the quality of life on the basis of previous studies showing that high-dose hypofractionated radiotherapy can significantly improve the local control rate and survival rate of pancreatic cancer.

Objective To investigate the effect of three-dimensional conformal intensity-modulated radiotherapy combined with oxaliplatin plus capecitabine chemotherapy upon the postoperative median survival time of patients diagnosed with advanced gastric cancer. Methods A total of 74 patients with advanced gastric cancer admitted to Linyi Central Hospital from February 2010 to January 2012 were recruited and divided into the postoperative chemotherapy group (n=37) and postoperative radiotherapy and chemotherapy group (n=37) according to the treatment plan. All patients in two groups were treated with laparoscopic D2 radical operation. In the postoperative chemotherapy group, patients were treated with oxaliplatin combined with capecitabine. In the postoperative radiotherapy and chemotherapy group, patients were treated with oxaliplatin combined with capecitabine plus three-dimensional conformal radiotherapy. In both groups, 4 cycles of chemotherapy were delivered. The incidence of adverse reactions, median progression-free survival, median overall survival, and 1-, 3-and 5-year recurrence rate and mortality rate were statistically compared between two groups. Results In the postoperative radiotherapy and chemotherapy group, the incidence rate of bone marrow suppression (41%), abnormal liver function (30%), nausea and vomiting (30%) and neutropenia (46%) did not significantly differ from 35%, 35%, 24% and 41% in the postoperative chemotherapy group (all P>0.05).In the postoperative radiotherapy and chemotherapy group, the median progression-free survival and median overall survival were significantly longer compared with those in the postoperative chemotherapy group (both P<0.05).The 1-, 3-and 5-year recurrence rates were 8%, 14% and 16% in the postoperative radiotherapy and chemotherapy group, significantly lower than 32%, 41% and 46% in the postoperative chemotherapy group (all P<0.05).The mortality rate was 11%(4/37) in the postoperative radiotherapy and chemotherapy group, which was significantly lower than 30%(11/37) in the postoperative chemotherapy group (P<0.05). Conclusions Three-dimensional conformal radiotherapy combined with oxaliplatin plus capecitabine chemotherapy can effectively prolong the median survival, reduce the recurrence rate and does not enhance the risk of adverse events for patients with advanced gastric cancer.

Objective To investigate theefficacy of radiotherapy,as well as the prognostic factors of survival in patients with extracranial oligometastases. Methods A total of 164 patients who underwent intensity-modulated radiotherapy (IMRT) of the extracranial oligometastases, from January 2013 to December 2016,were enrolled in the study. The short-term efficacy,local control rate,overall survival,progression free survival and adverse effects of treatment were observed. Results Short-term efficacy was assessed within the first 1-3 months after the end of radiotherapy. The objective response rate (CR+PR) was 78.7% and the short-term efficacy is mainly related to the T stage of primary tumor (P=0.004).Until the last follow-up,all patientswith 1-,2- and 3-year LCwere 89.8%,82.5% and 74.9% respectively. Univariate analysis showed that the influencing factors of LC include tumor size and gross tumor volume dose (all P<0.05),multivariate analysis found no significant influence factors.The 1-,2- and 3-year OSwere 83.4%,69.6% and 54.6% respectively. Univariate and multivariate analysis showed that the primary tumor sources,metastasis organs,whether synchronous or adjuvant chemotherapy and short-term efficacy were independent prognostic factors in patients of OS (P<0.05).Main toxicity-associated events were grade 1-2 acute reactions,with only 6 patients experiencing grade 3 toxicity;no grade ≥ 4 toxic reactions or treatment-related deaths occurred.Conclusions Radiation therapy for the treatment of extracranial oligometastases can achieve good curative effect,is well-tolerated and has low toxicity.

Objective To apply real-time transperineal ultrasound (TPUS) to monitor the intra-fractional prostate motion,collect and analyze the data of the prostate motion,aiming to provide evidence for the optimization of the target area and plan of radiotherapy for prostate cancer. Methods TPUS is a non-invasive monitoring technique that utilizes an automatic scanning ultrasound probe to dynamically monitor and correct the motion of organs during radiotherapy. In this study,TPUS was utilized to collect 1588 intra-fractional data of 70 patients with prostate cancer. Prior to each cycle of radiotherapy,CBCT was adopted to correct the errors between intra-factional data by using VMAT. During radiotherapy,real-time (once per second) ultrasound images were acquired to monitor the 3D motion of the prostate on the x (left+,right-),y (cranial+,caudal-),and z (abdominal+,dorsal-) axes,emphasizing the analysis of 4D motion of the prostate. Results All patients successfully completed the treatment and data collection. The median time of effective monitoring per faction was 179 seconds (132-286 seconds). During 95% of the monitoring time,the distance of prostate motion was 2.22 mm in the left direction,2.17 mm in the right,2.08 mm in the cranial,1.98 mm in the caudal,2.44 mm in the abdominal and 2.97 mm in the dorsal direction,respectively. In the x,y and z axes,the percentage of time in which the distance of prostate motion less than 1 mm among the total time was 83.07%,85.46% and 78.27%,respectively,whereas 97.70%,97.87% and 96.45% for<3 mm,respectively. Conclusions TPUS is a non-invasive real-time monitoring technique,which can detect the 4D motion of the prostate during radiotherapy. By using VMAT,the range of prostate motion is relatively small,and the motion range is less than 3 mm in each direction within 95% of the time.

Nasopharyngeal carcinoma (NPC) is a squamous cell carcinoma originating from the nasopharyngeal epithelial tissues with a high incidence in Southeast Asia and South China. At present, radiotherapy has become the primary therapeutic modality to treat NPC. Resistance to radiotherapy poses a serious obstacle to successful therapy for NPC. It is of great importance to identify the biomarkers related to the NPC radioresistance and unravel the mechanism of radioresistance for the diagnosis and treatment of NPC patients. MicroRNAs induce translational repression or degradation of targeted mRNAs by binding to their 3’UTRs and regulate the expression of protein. MicroRNAs are involved in the regulation of all important cellular processes associated with response to the radiotherapy, such as DNA damage response and repair, cellular apoptosis, proliferation and angiogenesis. In recent years, the study of miRNAs associated with radioresistance of NPC has captivated widespread attention from researchers. In this review, relevant microRNAs and their potential mechanisms were summarized.

The role of three-dimensional brachytherapy (3D-BT) in the radical treatment of cervical cancer has been widely recognized. Obtaining the image information through simulated positioning is a key step of 3D-BT.Currently, MRI/CT positioning has been commonly applied in clinical practice, which has respective limitations when applied in radiosurgery. Consequently, it is of necessity to explore an accurate, highly efficient and convenient positioning approach. Besides MRI and CT, ultrasound is a novel positioning method in clinical settings. Through literature review, the application of ultrasound in 3D-BT was summarized, aiming to provide reliable reference for clinicians.