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Aims: To determine the trend of cancer cases referred to the Department of Clinical Oncology in UMMC in terms of patient volumes over a period of 10 years. To define the stage at presentation of the top five cancers in males and females, respectively. To determine the overall radiotherapy utilization rates. Methods and Material: This is a retrospective analysis of all new cases seen at the Department of Clinical Oncology, University of Malaya Medical Centre (UMMC), from the year 2009 to 2018 inclusive. The top five cancers in males and females were defined in terms of patient volumes and stage at presentation. The overall actual radiotherapy utilization rates were determined. Results: A total of 12,672 patients were included for analysis. A total of 62.9% of the cases were females and 37.1% were males. The median age of presentation was 59 years old. Breast cancer was the most common cancer, followed by colorectal, lung, thyroid, and prostate cancer. The most common presenting stage was stage 4. The overall actual radiotherapy utilization rate (aRTU) was 40.1%. Curative intent makes up 74.3% of radiotherapy and 66.6% of chemotherapy utilization. Conclusions: The cancer distribution and trends among our patients are comparable with national and regional data. The overall actual radiotherapy utilization rate in the UMMC was lower than the estimated optimal rate of 53% but higher than the actual rate of 28% for Malaysia. This study provides valuable insight into current cancer trends and treatment demands to facilitate service planning. [ABSTRACT FROM AUTHOR]

We evaluated the evolving structure of radiation oncology in Japan in terms of equipment, personnel, patient load, and geographic distribution to identify and overcome any existing limitations. From March 2011 to June 2013, the Japanese Society for Radiation Oncology conducted a questionnaire based on the Japanese national structure survey of radiation oncology in 2010. Data were analyzed based on the institutional stratification by the annual number of new patients treated with radiotherapy per institution. The estimated annual numbers of new and total (new plus repeat) patients treated with radiation were 211 000 and 251 000, respectively. Additionally, the estimated cancer incidence was 805 236 cases, with ~26.2% of all newly diagnosed patients being treated with radiation. The types and numbers of treatment devices actually used included linear accelerator (LINAC; n = 829), telecobalt (n = 9), Gamma Knife (n = 46), 60Co remote afterloading system (RALS; n = 28), and 192Ir RALS (n = 131). The LINAC system used dual-energy functions in 586 units, three-dimensional conformal radiotherapy functions in 663, and intensity-modulated radiotherapy (IMRT) functions in 337. There were 564 JASTRO-certified radiation oncologists, 959.2 full-time equivalent (FTE) radiation oncologists, 1841.3 FTE radiotherapy technologists, 131.3 FTE medical physicists, 121.5 FTE radiotherapy quality managers, and 649.6 FTE nurses. The frequency of IMRT use significantly increased during this year. To conclude, although there was a shortage of personnel in 2010, the Japanese structure of radiation oncology has clearly improved in terms of equipment and utility. [ABSTRACT FROM AUTHOR]

Purpose: The accuracy of dose calculation is the prerequisite for CyberKnife (CK) to implement precise stereotactic body radiotherapy (SBRT). In this study, CK-MLC treatment planning for early-stage non-small cell lung cancer (NSCLC) were compared using finite-size pencil beam (FSPB) algorithm, FSPB with lateral scaling option (FSPB_LS) and Monte Carlo (MC) algorithms, respectively. We concentrated on the enhancement of accuracy with the FSPB_LS algorithm over the conventional FSPB algorithm and the dose consistency with the MC algorithm.Methods: In this study, 54 cases of NSCLC were subdivided into central lung cancer (CLC, n=26) and ultra-central lung cancer (UCLC, n=28). For each patient, we used the FSPB algorithm to generate a treatment plan. Then the dose was recalculated using FSPB_LS and MC dose algorithms based on the plans computed using the FSPB algorithm. The resultant plans were assessed by calculating the mean value of pertinent comparative parameters, including PTV prescription isodose, conformity index (CI), homogeneity index (HI), and dose-volume statistics of organs at risk (OARs).Results: In this study, most dose parameters of PTV and OARs demonstrated a trend of MC > FSPB_LS > FSPB. The FSPB_LS algorithm aligns better with the dose parameters of the target compared to the MC algorithm, which is particularly evident in UCLC. However, the FSPB algorithm significantly underestimated the does of the target. Regarding the OARs in CLC, differences in dose parameters were observed between FSPB and FSPB_LS for V10 of the contralateral lung, as well as between FSPB and MC for mean dose (Dmean) of the contralateral lung and maximum dose (Dmax) of the aorta, exhibiting statistical differences. There were no statistically significant differences observed between FSPB_LS and MC for the OARs. However, the average dose deviation between FSPB_LS and MC algorithms for OARs ranged from 2.79% to 11.93%. No significant dose differences were observed among the three algorithms in UCLC.Conclusion: For CLC, the FSPB_LS algorithm exhibited good consistency with the MC algorithm in PTV and demonstrated a significant improvement in accuracy when compared to the traditional FSPB algorithm. However, the FSPB_LS algorithm and the MC algorithm showed a significant dose deviation in OARs of CLC. In the case of UCLC, FSPB_LS showed better consistency with the MC algorithm than observed in CLC. Notwithstanding, UCLC’s OARs were highly sensitive to radiation dose and could result in potentially serious adverse reactions. Consequently, it is advisable to use the MC algorithm for dose calculation in both CLC and UCLC, while the application of FSPB_LS algorithm should be carefully considered. [ABSTRACT FROM AUTHOR]

Background/Aim: A considerable number of patients with lung cancer are scheduled for definitive or adjuvant radiotherapy. Prevalence and potential risk factors of preradiotherapy sleep disturbances were evaluated. Patients and Methods: Nineteen factors were retrospectively investigated for associations with pre-radiotherapy sleep disturbances in 77 lung cancer patients. Factors included COVID-19 pandemic; age; gender; performance score; comorbidity index; history of another malignancy; distress score; number of emotional, physical or practical problems; patient’s request for psychological support; histology; tumor stage; upfront surgery; chemotherapy; and type of radiotherapy. Results: Thirty-one patients (40.3%) reported sleep disturbances that were significantly associated with distress score 6-10 (p=0.019), ≥2 emotional problems (p=0.001), ≥5 physical problems (p<0.001), and request for psychological support (p=0.006). Trends were found for female gender (p=0.064) and stereotactic body radiation therapy (p=0.057). Conclusion: Many lung cancer patients assigned to radiotherapy reported sleep disturbances. Risk factors can be used to identify patients in need of psychological support already before treatment. [ABSTRACT FROM AUTHOR]

Aim: To establish a method of plan optimization in pelvic volumetric-modulated arc therapy (VMAT) for cervical cancer using the central-shielding (CS) principle. Patients and Methods: We created external beam VMAT plans for eight cases with non-bulky stage I-IIb using the CS principle based on the Japanese standard guideline. Clinical target volumes (CTVs) for whole-pelvis (WP) irradiation were created using published guidelines, and CTVs for CS irradiation were created by subtracting the uterus corpus and 4 cm-wide regions centered at the cervix and vagina from the CTVs for WP irradiation. For plan optimization of CS irradiation, a 4-cm diameter cylindrical volume centered in the cervix and vagina was created as the volume receiving a high dose in brachytherapy, and the volume overlapping with the rectum was defined as the Ant-Rectum. Dose– volume histogram (DVH) parameters of two CS VMAT plans with and without (VMATOPT/VMATNO) dose optimization to the Ant-Rectum were compared. Results: VMATOPT plans resulted in significantly lower DVH parameters of the AntRectum and rectum compared to VMATNO plans. These were comparable to the DVH parameters of three-dimensional conformal radiotherapy (3DCRT) plans. Both VMAT plans resulted in significantly better coverage of planning target volumes than did the 3DCRT plans. Conclusion: In the implementation of IMRT/VMAT as the standard treatment for cervical cancer in Japan, our optimization method may be an essential step toward fully benefitting from the CS principle. [ABSTRACT FROM AUTHOR]

This study assessed agreement between radiation oncologist- and cancer patient-reported perceptions about cancer diagnosis, time since diagnosis, treatment purpose, and whether life expectancy had been discussed; and described preferences for prognosis discussions. Adult cancer patients receiving radiotherapy at a Japanese hospital were invited to complete a touchscreen tablet survey. Patient survey responses were linked and comparisons made with a survey completed by their radiation oncologist. Among 146 cancer patient-oncologist dyads, there was almost perfect agreement on cancer diagnosis (ĸ = 0.88, 95% CI: 0.82–0.94), substantial agreement on time since diagnosis (ĸ = 0.70, 95% CI: 0.57–0.83) and moderate agreement on whether treatment goal was curative or palliative (ĸ = 0.44, 95% CI: 0.28–0.57; all p’s < 0.0001). Agreement about whether a life expectancy discussion had occurred was less than expected by chance (κ = -0.06, p = 0.9). Radiation oncologists reported that they had spoken to over two thirds of patients about this, whilst less than one third of patients stated that this discussion had occurred with their radiation oncologist. Over half of the patients who had not discussed life expectancy wanted to. Patients had variable preferences for whether they (80%), their radiation oncologist (78%) or their partner/family (52%) should decide whether they discuss their life expectancy. Although patient self-reported information about diagnosis and time since diagnosis appears to be reasonably accurate (compared with clinician-reported information), limitations of self-reported data about prognostic discussions were highlighted by poor agreement between patient- and clinician-reported information about whether prognostic discussions have occurred. Additional support is needed to improve prognosis communication and understanding in radiation oncology settings. [ABSTRACT FROM AUTHOR]

Radiation therapy has been long utilized as localized cancer treatment. Recent studies have also demonstrated that it has a distant effect by the enhanced immunity, but it rarely occurs. The purpose of this study was to investigate whether X-ray irradiation combined with anti-PD-L1 and anti-CTLA-4 antibodies (P1C4) provides a higher probability of this distant effect as well as enhanced local antitumor efficacy for osteosarcoma. LM8 mouse osteosarcoma cells were inoculated into both legs of C3H mice assigned to one of four groups, namely no treatment (No Tx), P1C4, X-ray irradiation (RAD) to the leg of one side, and combination (COMB) groups. Survival and treatment-related immune molecular changes were analyzed. Administration of P1C4 produced a tumor growth delay on day 30 in 18% of the mice. In contrast, combination therapy produced the strongest tumor growth inhibition not only at the irradiated tumor but also at unirradiated tumor in 67% of the mice. Accordingly, lung metastasis in the COMB group was strongly reduced by 98%, with a significant survival benefit. Unirradiated tumor in mice in the COMB group significantly recruited CD8 + tumor-infiltrating lymphocytes with a moderate reduction of Treg, producing a significant increase in the CD8/Treg ratio. These results suggest that radiation enhances the efficacy of P1C4 treatment against distant metastasis as well as local control in osteosarcoma. Our data suggest that radiation therapy combined with dual checkpoint blockade may be a promising therapeutic option for osteosarcoma. [ABSTRACT FROM AUTHOR]

Purpose: Brachytherapy is a cost-effective method for the management of oral cavity cancers in low to middle income countries. We aimed to evaluate the clinical outcomes of high-dose-rate interstitial brachytherapy (HDR-IBT) in patients with oral cavity cancer. Material and methods: From 2009 to 2013, 78 patients (49 combined external beam radiotherapy [EBRT] plus IBT and 29 IBT monotherapy) with oral cavity cancers had been treated in our center. Slightly more than half the patients were male, and the median age was 54 years. The treatment was planned based on the Paris system. The main outcomes were disease-free and overall survival. Results: The median follow-up duration was 36.5 months (range, 1.17-54.23). The actuarial four-year overall and disease-free survival rates were 83% and 65%, respectively. The local and locoregional control was achieved among 89.74% and 87.17% of patients, respectively. None of the factors including tumor size, node status, gender, and radiation modality (IBT alone vs. IBT + EBRT) had a significant statistical correlation to the local control rate. All the patients tolerated the planned treatment in the IBT alone group. Late complications included a case of trismus and three cases of catheter insertion site fibrosis. Conclusions: HDR-IBT as a monotherapy or in combination with EBRT is an appropriate option for the management of oral cavity squamous cell carcinomas, and supports the improvement in treatment outcomes and toxicity profiles in adjuvant settings. [ABSTRACT FROM AUTHOR]

Background: Because of the high likelihood of multiple brain metastases (BM) from small cell lung cancer (SCLC), the role of focal treatment using stereotactic radiosurgery (SRS) has yet to be determined. We aimed to evaluate the efficacy and limitations of upfront and salvage SRS for patients with BM from SCLC. Methods: This was a retrospective and observational study analyzing 70 consecutive patients with BM from SCLC who received SRS. The median age was 68 years, and the median Karnofsky performance status (KPS) was 90. Forty-six (66%) and 24 (34%) patients underwent SRS as the upfront and salvage treatment after prophylactic or therapeutic whole brain radiotherapy (WBRT), respectively. Overall survival (OS), neurological death-free survival, remote and local tumor recurrence rates were analyzed. Results: None of our patients were lost to follow-up and the median follow-up was 7.8 months. One-and 2-year OS rates were 43% and 15%, respectively. The median OS time was 7.8 months. One-and 2-year neurological death-free survival rates were 94% and 84%, respectively. In total, 219/292 tumors (75%) in 60 patients (86 %) with sufficient radiological follow-up data were evaluated. Six-and 12-month rates of remote BM relapse were 25% and 47%, respectively. Six-and 12-month rates of local control failure were 4% and 23%, respectively. Repeat SRS, salvage WBRT and microsurgery were subsequently required in 30, 8 and one patient, respectively. Symptomatic radiation injury, treated conservatively, developed in 3 patients. Conclusions: The present study suggested SRS to be a potentially effective and minimally invasive treatment option for BM from SCLC either alone or after failed WBRT. Although repeat salvage treatment was needed in nearly half of patients to achieve control of distant BM, such continuation of radiotherapeutic management might contribute to reducing the rate of neurological death. [ABSTRACT FROM AUTHOR]

Intensity modulated brachytherapy (IMBT) is a modern development of classical interventional radiation therapy (brachytherapy), which allows the application of a high radiation dose sparing severe adverse events, thereby further improving the treatment outcome. Classical indications in head and neck (H&N) cancers are the face, the oral cavity, the naso- and oropharynx, the paranasal sinuses including base of skull, incomplete resections on important structures, and palliation. The application type can be curative, adjuvant or perioperative, as a boost to external beam radiation as well as without external beam radiation and with palliative intention. Due to the frequently used perioperative application method (intraoperative implantation of inactive applicators and postoperative performance of radiation), close interdisciplinary cooperation between surgical specialists (ENT-, dento-maxillary-facial-, neuro- and orbital surgeons), as well interventional radiotherapy (brachytherapy) experts are obligatory. Published results encourage the integration of IMBT into H&N therapy, thereby improving the prognosis and quality of life of patients. [ABSTRACT FROM AUTHOR]

Purpose This study evaluated the efficacy of extended field irradiation (EFI) in patients with locally advanced cervical cancer without para-aortic nodal involvement. Materials and Methods A total of 203 patients with locally advanced cervical cancer (International Federation of Gynecology and Obstetrics [FIGO] stage, IB2-IIIB) treated with radiotherapy at Keimyung University Dongsan Medical Center from 1996 to 2010 were retrospectively analyzed. The median patient age was 59 years (range, 29 to 83 years). None of the patients had para-aortic node metastases. Of the 203 patients, 88 underwent EFI and 115 underwent irradiation of the pelvis only. Concurrent chemoradiotherapy (CCRT) was administered to 133 patients. EFI field was used for treatment of 26 patients who received radiotherapy alone and 62 who received CCRT. Results The median follow-up period was 60 months. The 2- and 5-year overall survival (OS) rates were 87.8% and 73.5%, respectively, and the 2- and 5-year disease-free survival rates were 81.7% and 75.0%, respectively, however, no survival differences were observed between the two treatment field groups. EFI tended to increase OS in the radiotherapy alone group, but not in the CCRT group. Conclusion These findings suggest that EFI does not have a significant effect in patients with locally advanced cervical cancer, especially in patients receiving CCRT. Conduct of additional studies will be required in order to confirm these findings. [ABSTRACT FROM AUTHOR]

It has been known for about sixty years that proton and heavy ion therapy is a very powerful radiation procedure for treating tumors. It has an innate ability to irradiate tumors with greater doses and spatial selectivity compared with electron and photon therapy and, hence, is a tissue sparing procedure. For more than twenty years, powerful lasers have generated high energy beams of protons and heavy ions and it has, therefore, frequently been speculated that lasers could be used as an alternative to radiofrequency (RF) accelerators to produce the particle beams necessary for cancer therapy. The present paper reviews the progress made towards laser driven hadron cancer therapy and what has still to be accomplished to realize its inherent enormous potential. [ABSTRACT FROM AUTHOR]

Proton beam irradiation is a form of advanced radiotherapy providing superior distributions of a low LET radiation dose relative to that of photon therapy for the treatment of cancer. Even though this clinical treatment has been developing for several decades, the proton radiobiology critical to the optimization of proton radiotherapy is far from being understood. Proteomic changes were analyzed in human melanoma cells treated with a sublethal dose (3 Gy) of proton beam irradiation. The results were compared with untreated cells. Two-dimensional electrophoresis was performed with mass spectrometry to identify the proteins. At the dose of 3 Gy a minimal slowdown in proliferation rate was seen, as well as some DNA damage. After allowing time for damage repair, the proteomic analysis was performed. In total 17 protein levels were found to significantly (more than 1.5 times) change: 4 downregulated and 13 upregulated. Functionally, they represent four categories: (i) DNA repair and RNA regulation (VCP, MVP, STRAP, FAB-2, Lamine A/C, GAPDH), (ii) cell survival and stress response (STRAP, MCM7, Annexin 7, MVP, Caprin-1, PDCD6, VCP, HSP70), (iii) cell metabolism (TIM, GAPDH, VCP), and (iv) cytoskeleton and motility (Moesin, Actinin 4, FAB-2, Vimentin, Annexin 7, Lamine A/C, Lamine B). A substantial decrease (2.3 x) was seen in the level of vimentin, a marker of epithelial to mesenchymal transition and the metastatic properties of melanoma. [ABSTRACT FROM AUTHOR]

The article reports results of a series of surveys conducted across Canada to determine the number of cancer centers that provide Intensity Modulated Radiotherapy (IMRT) and stereotactic radiosurgery (SRS). The article also explores how these technologies are being used and challenges in their implementation. It has been informed that study results found that in 2006, IMRT was available in 37% of responding centers, which increased to 87% in 2010.

Carbon ion radiotherapy (C-ion RT) offers superior dose conformity in the treatment of deep-seated tumors compared with conventional X-ray therapy. In addition, carbon ion beams have a higher relative biological effectiveness compared with protons or X-ray beams. C-ion RT for the first patient at Gunma University Heavy Ion Medical Center (GHMC) was initiated in March of 2010. The major specifications of the facility were determined based on the experience of clinical treatments at the National Institute of Radiological Sciences (NIRS), with the size and cost being reduced to one-third of those at NIRS. The currently indicated sites of cancer treatment at GHMC are lung, prostate, head and neck, liver, rectum, bone and soft tissue. Between March 2010 and July 2011, a total of 177 patients were treated at GHMC although a total of 100 patients was the design specification during the period in considering the optimal machine performance. In the present article, we introduce the facility set-up of GHMC, including the facility design, treatment planning systems, and clinical preparations. [ABSTRACT FROM AUTHOR]

The article presents a study which aims at analyzing the effects of pulsed and continuous proton beams of proton irradiation in cancer radiation therapy. It explains the methodology of the study in which Munich tandem accelerator was used to compare the relative biological effectiveness (RBE) of pulsed and continuous proton beams. It reveals no significant difference in the RBE of pulsed and continuous irradiation proton beams.

Background: To determine the outcome of patients with brain metastasis (BM) from lung cancer treated with an external beam radiotherapy boost (RTB) after whole brain radiotherapy (WBRT). Methods: A total of 53 BM patients with lung cancer were treated sequentially with WBRT and RTB between 1996 and 2008 according to our institutional protocol. Mean age was 58.8 years. The median KPS was 90. Median recursive partitioning analysis (RPA) and graded prognostic assessment (GPA) grouping were 2 and 2.5, respectively. Surgery was performed on 38 (71%) patients. The median number of BM was 1 (range, 1-3). Median WBRT and RTB combined dose was 39 Gy (range, 37.5 - 54). Median follow-up was 12.0 months. Results: During the period of follow-up, 37 (70%) patients died. The median overall survival (OS) was 14.5 months. Only 13 patients failed in the brain. The majority of patients (n = 29) failed distantly. The 1-year OS, -local control, extracranial failure rates were 61.2%, 75.2% and 60.8%, respectively. On univariate analysis, improved OS was found to be significantly associated with total dose (= 39 Gy vs. > 39 Gy; p < 0.01), age < 65 (p < 0.01), absence of extracranial metastasis (p < 0.01), GPA ⩾ 2.5 (p = 0.01), KPS ⩾ 90 (p = 0.01), and RPA < 2 (p = 0.04). On multivariate analysis, total dose (p < 0.01) and the absence of extracranial metastasis (p = 0.03) retained statistical significance. Conclusions: The majority of lung cancer patients treated with WBRT and RTB progressed extracranially. There might be a subgroup of younger patients with good performance status and no extracranial disease who may benefit from dose escalation after WBRT to the metastatic site. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate intensity-modulated radiation therapy (IMRT) as an alternative to conformal radiotherapy (CRT) or 4-field box boost (4FB) in women with gynecologic malignancies who are unsuitable for brachytherapy for technical or medical reasons. Methods: Dosimetric and toxicity information was analyzed for 12 patients with cervical (8), endometrial (2) or vaginal (2) cancer previously treated with external beam pelvic radiotherapy and a CRT boost. Optimized IMRT boost treatment plans were then developed for each of the 12 patients and compared to CRT and 4FB plans. The plans were compared in terms of dose conformality and critical normal tissue avoidance. Results: The median planning target volume (PTV) was 151 cm3 (range 58-512 cm3). The median overlap of the contoured rectum with the PTV was 15 (1-56) %, and 11 (4-35) % for the bladder. Two of the 12 patients, both with large PTVs and large overlap of the contoured rectum and PTV, developed grade 3 rectal bleeding. The dose conformity was significantly improved with IMRT over CRT and 4FB (p ⩽ 0.001 for both). IMRT also yielded an overall improvement in the rectal and bladder dose-volume distributions relative to CRT and 4FB. The volume of rectum that received the highest doses (>66% of the prescription) was reduced by 22% (p < 0.001) with IMRT relative to 4FB, and the bladder volume was reduced by 19% (p < 0.001). This was at the expense of an increase in the volume of these organs receiving doses in the lowest range (<33%). Conclusion: These results indicate that IMRT can improve target coverage and reduce dose to critical structures in gynecologic patients receiving an external beam radiotherapy boost. This dosimetric advantage will be integrated with other patient and treatment-specific factors, particularly internal tumor movement during fractionated radiotherapy, in the context of a future image-guided radiation therapy study. [ABSTRACT FROM AUTHOR]

The article focuses on a study on the use of prostate radiation for the treatment of non-metastatic castrate refractory prostate cancer. The study involved a review of 13 patients with prostate cancer who were initially treated with hormone monotherapy and then with prostate radiation. The study demonstrated the beneficial effects of prostate radiation in patients with potential micrometastatic disease, supporting the importance of primary tumour in the progression of prostate cancer.

Purpose:To analyze the clinicopathological characteristics, treatment modalities, and potential prognostic factors of radiation-related second malignant neoplasms (SMNs) in a large group of nasopharyngeal carcinoma (NPC) cases. Methods and Materials:Institutional electronic medical records of 39,118 patients with NPC treated by definitive radiotherapy between February 1964 and December 2003 were reviewed. A total of 247 patients with confirmed SMN attributable to radiotherapy were included. Results:Median latency between radiotherapy for NPC and the diagnosis of SMN was 9.5 years (range, 3.1–36.8 years). Squamous cell carcinoma was the most common histologic type, followed by fibrosarcoma and adenocarcinoma. Median progression-free survival and overall survival (OS) of the 235 patients who underwent treatment were 17.3 months and 28.5 months, respectively. The 5-year OS rates were 42.9%, 23.7%, and 0% for the surgery, radiotherapy, and chemotherapy groups, respectively. The independent prognostic factors associated with survival were sex, histologic type, and treatment modality in both the early stage subgroup and the advanced stage subgroup of SMN. Conclusions:Sex, histologic type, and treatment modality were the significant prognostic factors for SMN. Complete resection offers the best chance for long-term survival. In select patients with locally advanced and unresectable SMN, reirradiation should be strongly considered as a curative option. [ABSTRACT FROM AUTHOR]

Background:Rapidly growing evidence suggests that microRNAs (miRNAs) are involved in a wide range of cancer malignant behaviours including radioresistance. Therefore, the present study was designed to investigate miRNA expression patterns associated with radioresistance in NPC. Methods:The differential expression profiles of miRNAs and mRNAs associated with NPC radioresistance were constructed. The predicted target mRNAs of miRNAs and their enriched signaling pathways were analyzed via biological informatical algorithms. Finally, partial miRNAs and pathways-correlated target mRNAs were validated in two NPC radioreisitant cell models. Results:50 known and 9 novel miRNAs with significant difference were identified, and their target mRNAs were narrowed down to 53 nasopharyngeal-/NPC-specific mRNAs. Subsequent KEGG analyses demonstrated that the 53 mRNAs were enriched in 37 signaling pathways. Further qRT-PCR assays confirmed 3 down-regulated miRNAs (miR-324-3p, miR-93-3p and miR-4501), 3 up-regulated miRNAs (miR-371a-5p, miR-34c-5p and miR-1323) and 2 novel miRNAs. Additionally, corresponding alterations of pathways-correlated target mRNAs were observed including 5 up-regulated mRNAs (ICAM1, WNT2B, MYC, HLA-F and TGF-β1) and 3 down-regulated mRNAs (CDH1, PTENP1 and HSP90AA1). Conclusions:Our study provides an overview of miRNA expression profile and the interactions between miRNA and their target mRNAs, which will deepen our understanding of the important roles of miRNAs in NPC radioresistance. [ABSTRACT FROM AUTHOR]