共查询到20条相似文献，搜索用时 15 毫秒
1.
This study investigates the impact of breathing motion on proton breast treatment plans. Twelve patients with CT datasets acquired during breath-hold-at-inhalation (BHI), breath-hold-at-exhalation (BHE) and in free-breathing (FB) were included in the study. Proton plans were designed for the left breast for BHI and subsequently recalculated for BHE or designed for FB and recalculated for the extreme breath-hold phases. The plans were compared from the point of view of their target coverage and doses to organs-at-risk. The median amplitude of breathing motion determined from the positions of the sternum was 4.7 mm (range 0.5–14.6 mm). Breathing motion led to a degradation of the dose coverage of the target (heterogeneity index increased from 4–7% to 8–11%), but the degraded values of the dosimetric parameters of interest fulfilled the clinical criteria for plan acceptance. Exhalation decreased the lung burden [average dose 3.1–4.5 Gy (RBE)], while inhalation increased it [average dose 5.8–6.8 Gy (RBE)]. The individual values depended on the field arrangement. Smaller differences were seen for the heart [average dose 0.1–0.2 Gy (RBE)] and the LAD [1.9–4.6 Gy (RBE)]. Weak correlations were generally found between changes in dosimetric parameters and respiratory motion. The differences between dosimetric parameters for various breathing phases were small and their expected clinical impact is consequently quite small. The results indicated that the dosimetric parameters of the plans corresponding to the extreme breathing phases are little affected by breathing motion, thus suggesting that this motion might have little impact for the chosen beam orientations with scanned proton beams. 相似文献
2.
PurposeTo use Discrete Cosine Transform to include tumor motion variations on ITV definition of SBRT patients.MethodsData from 66 patients was collected. 2D planar fluoroscopy images (FI) were available for 54 patients. Daily CBCT projections (CBCTp) from 29 patients were employed to measure interfraction amplitude variability. Systematic amplitude variations were obtained from 17 patients with data from both FI and CBCTp.Tumor motion curves obtained from FI were characterized with a Cosine model (CM), based on cosine functions to the power of 2, 4 or 6, and DCT. Performance of both models was evaluated by means of R2 coefficient and by comparing their results on Internal Target Volume (ITV) margins against those calculated from original tumor motion curves.Amplitude variations from CBCTp, as well as estimations of baseline shift variations were added to the DCT model to account for their effect on ITV margins.ResultsDCT replicated tumor motion curves with a mean R2 values for all patients of 0.86, 0.91 and 0.96 for the lateral (LAT), anterior-posterior (AP) and cranio-caudal (CC) directions respectively. CM yielded worst results, with R2 values of 0.64, 0.61 and 0.74 in the three directions.Interfraction amplitude variation increased ITV margins by a 9%, while baseline shift variability implied a 40% and 80–100% increase for normalized values of baseline shift of 0.2 and 0.4 respectively.ConclusionsProbability distribution functions of tumor positions can be successfully characterized with DCT. This permits to include tumor motion variablilities obtained from patient population into patient specific ITVs. 相似文献
3.
Shuhei Sekii Yoshinori Ito Ken Harada Mayuka Kitaguchi Kana Takahashi Koji Inaba Naoya Murakami Hiroshi Igaki Ryohei Sasaki Jun Itami 《Reports of Practical Oncology and Radiotherapy》2018,23(5):398-401
Aim
To investigate the intrafraction movement of the esophagus using fiducial markers.Background
Studies on intrafraction esophageal motion using the fiducial markers are scarce.Materials and methods
We retrospectively analyzed patients with clinical T1N0 esophageal cancer who had received fiducial markers at our hospital between July 2007 and December 2013. Real-Time Position Management System to track the patient's respiration was used, and each patient underwent three-dimensional computed tomography of the resting expiratory and inspiratory level. We used the center of the marker to calculate the distance between the expiratory and inspiratory breath-holds, which were measured with the radiotherapy treatment planning system in three directions: left–right (LR), superior–inferior (SI), and anterior–posterior (AP). The movements at each site were compared with the Kruskal–Wallis analysis and Wilcoxon rank sum test with a Bonferroni correction.Results
A total of 101 patients with 201 fiducial markers were included. The upper, middle and lower thoracic positions had 40, 77, and 84 markers, respectively. The mean absolute magnitudes of the shifts (standard deviation) were 0.18 (0.19)?cm, 0.68 (0.46)?cm, and 0.24 (0.24)?cm in the LR, SI, and AP directions, respectively. From the cumulative frequency distribution, we assumed that 0.35?cm LR, 0.8?cm SI, and 0.3?cm AP in the upper; 0.5?cm LR, 1.55?cm SI, and 0.55?cm AP in the middle; and 0.75?cm LR, 1.9?cm SI, and 0.95?cm AP in the lower thoracic esophagus covered 95% of the cases.Conclusions
The internal margin based on the site of esophagus was estimated. 相似文献4.
PurposeTo compare the planning target volume (PTV) margins needed for prostate patients who have used hydrogel spacer or rectal balloon during proton treatments.MethodTotal of 190 prostate patients treated with proton therapy during 2017 were selected for this study. Of these patients, 96 had hydrogel spacer injection and 94 patients had only rectal balloons insertion. All patients had implanted gold markers inside the prostate for daily target alignment. Post-treatment radigraphs were obtained to evaluate prostate intrafraction motion. The systematic and random components of patient setup residual error and prostate intrafraction motion error were obtained. PTV margins were calculated using the van Herk formula for both patient groups.ResultsFor setup residual error, the mean values in the superior-inferior (SI) direction and the variances in the left–right (LR) direction were statistically different between the two groups. For intrafraction motion, there were significant differences of the mean values in the SI direction and of the variances in both LR and anterior-posterior (AP) directions. The population PTV margins for hydrogel spacer group were 2.6 mm, 3.3 mm, and 1.6 mm in LR, SI, AP directions, respectively. For the rectal balloon group, the PTV margins were 2.1 mm, 3.1 mm, and 2.0 mm in LR, SI, AP directions, respectively.ConclusionStatistically significant differences were observed in the patient setup and prostate intrafraction motion errors of the two patient groups. However, under the current protocol of bladder preparation and daily marker-based x-ray image-guidance, population PTV margins were comparable between the two patient groups. 相似文献
5.
Breast-conserving surgery including whole breast irradiation has long been a recommended procedure for early breast cancer. However, conventionally fractionated radiotherapy requires a lengthy hospitalisation or prolonged commuting to a hospital for radiotherapy. In recent years, hypofractionated radiotherapy has increasingly been used. This method involves higher fraction doses (above 2 Gy) as compared to conventional radiotherapy, so the total dose can be delivered in fewer fractions and in a shorter overall treatment time. This review aims at presenting most important outcomes of four randomised studies comparing conventional and hypofractionated radiotherapy schemes including a total of 7000 patients. These studies have not shown apparent differences in treatment efficacy, incidence of late post-radiotherapy complications or cosmetic effects during a 5–10 year follow-up, but longer observation is warranted to fully evaluate the safety of this method. Currently, major societies consider modestly hypofractionated radiotherapy schemes as a routine management in selected groups of patients undergoing breast-conserving surgery. However, this method should be used cautiously in patients with lymph node metastases, big breasts, receiving chemotherapy or trastuzumab, or those under 50 years of age. 相似文献
6.
The aim of this study was to evaluate the localization accuracy of electromagnetic (EM) tracking systems RayPilot (Micropos Medical AB) and Calypso (Varian Medical Systems) in prostate cancer radiotherapy. The accuracy was assessed by comparing couch shifts obtained with the EM methods to the couch shifts determined by simultaneous fiducial marker (FM) based orthogonal kilovoltage (kV) imaging. Agreement between the methods was compared using Bland-Altman analysis. Interfractional positional stability of the FMs, RayPilot transmitters and Calypso transponders was investigated. 582 fractions from 22 RayPilot patients and 335 fractions from 26 Calypso patients were analyzed. Mean (± standard deviation (SD)) differences between RayPilot and kV imaging were 0.3 ± 2.2, −2.2 ± 2.4 and −0.0 ± 1.0 mm in anterior-posterior (AP), superior-inferior (SI) and left-right (LR) directions, respectively. Corresponding 95% limits of agreement (LOA) were ±4.3, ±4.7 and ±2.1 mm around the mean. Mean (±SD) differences between Calypso and kV imaging were −0.2 ± 0.6, 0.1 ± 0.5 and −0.1 ± 0.4 mm in AP, SI and LR directions, respectively, and corresponding LOAs were ±1.3, ±1.0 and ±0.8 mm around the mean. FMs and transponders were stable: SD of intermarker and intertransponder distances was 0.5 mm. Transmitters were unstable: mean caudal transmitter shift of 1.8 ± 2.0 mm was observed. Results indicate that the localization accuracy of the Calypso is comparable to kV imaging of fiducials and the methods could be used interchangeably. The localization accuracy of the RayPilot is affected by transmitter instability and the positioning of the patient should be verified by other setup techniques. The study is part of clinical trial NCT02319239. 相似文献
7.
目的：分析在乳腺癌图像引导放射治疗（IGRT）过程中,图像引导对于放射治疗的精确度的影响;同时观察图像引导放射治疗的毒性反应及放射治疗近期的治疗效果。方法：搜集2012年1月-2013年2月间,于哈尔滨医科大学附属第三医院放疗科收治的乳腺癌患者25例。使用医科达SynergyTM锥形束CT（CBCT）进行治疗前扫描,通过图像引导放射治疗技术对25例患者进行误差纠正,调整后行调强放疗。患者在进行放疗前,用锥形柬CT对射野的偏差进行校正,其偏差利用锥形束CT图像与计划螺旋CT图像进行手动匹配,在X、Y、Z三个方向上进行调整。根据误差调整治疗床位置后治疗。对急性放射性反应采用RTOG5级评价标准进行评价：急性放射性皮肤反应、急性放射性肺损伤及急性放射性心脏损伤。结果：25例乳腺癌患者治疗前经锥形束CT扫描采集的图像与计划参考图像比较在X、Y、Z方向上平均误差分别为0．429±1．683mm、0．431±1．728mm、0．583±2．041mm：摆位误差纠正后,误差值分别为：0．068±0．429、0．019±0．438、0．158±0．697,调整后摆位误差控制在1mm之内进行治疗。放疗后2周急性皮肤反应为0级23例、1级2例;4周为0级21例、1级4例。无急性放射性肺损伤及心脏损伤的病例出现。结论：目前调强放疗是乳腺癌临床放射治疗的重要手段,图像引导放射治疗的应用能够使放疗精度显著提高。 相似文献
8.
《Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)》2016,32(11):1428-1436
PurposeTo investigate different volumetric modulated arc therapy (VMAT) field designs for lymph node positive breast cancer patients when compared to conventional static fields and standard VMAT designs.MethodsNineteen breast cancer patients with lymph node involvement (eleven left and eight right sided) were retrospectively analyzed with different arc designs. Proposed split arc designs with total rotations of 2 × 190° and 2 × 240° were compared to conventional field in field (FinF) and previously published non-split arc techniques with the same amount of total rotations.ResultsAll VMAT plans were superior in dose conformity, when compared to the FinF plans. Split arc design decreased significantly ipsilateral lung dose and heart V5Gy for both left and right sided cases, when compared to non-split VMAT designs. For left sided cases no significant differences were seen in contralateral lung mean dose or V5Gy between different VMAT designs. For right sided cases the contralateral lung dose V5Gy was significantly higher in split VMAT group, when compared to non-split VMAT designs. The contralateral breast dose V5Gy increased significantly for split VMAT plans for both sides, when compared to non-split VMAT designs or FinF plans.ConclusionsThe proposed split VMAT technique was shown to be superior to previously published non-split VMAT and conventional FinF techniques significantly reducing dose to the ipsilateral lung and heart. However, this came with the expense of an increase in the dose to the contralateral breast and for right-sided cases to the contralateral lung. 相似文献
9.
Lisa Paoletti Corrado Ceccarelli Claudia Menichelli Cynthia Aristei Simona Borghesi Enrico Tucci Paolo Bastiani Salvatore Cozzi 《Reports of Practical Oncology and Radiotherapy》2022,27(1):1
Stereotactic radiotherapy (SRT ) is a multi-step procedure with each step requiring extreme accuracy. Physician-dependent accuracy includes appropriate disease staging, multi-disciplinary discussion with shared decision-making, choice of morphological and functional imaging methods to identify and delineate the tumor target and organs at risk, an image-guided patient set-up, active or passive management of intra-fraction movement, clinical and instrumental follow-up. Medical physicist-dependent accuracy includes use of advanced software for treatment planning and more advanced Quality Assurance procedures than required for conventional radiotherapy. Consequently, all the professionals require appropriate training in skills for high-quality SRT.Thanks to the technological advances, SRT has moved from a “frame-based” technique, i.e. the use of stereotactic coordinates which are identified by means of rigid localization frames, to the modern “frame-less” SRT which localizes the target volume directly, or by means of anatomical surrogates or fiducial markers that have previously been placed within or near the target. This review describes all the SRT steps in depth, from target simulation and delineation procedures to treatment delivery and image-guided radiation therapy. Target movement assessment and management are also described. 相似文献
10.
The aim of this study was to evaluate the dosimetric effect of continuous motion monitoring based localization (Calypso, Varian Medical Systems), gating and intrafraction motion correction in prostate SBRT. Delivered doses were modelled by reconstructing motion inclusive dose distributions for different localization strategies. Actually delivered dose (strategy A) utilized initial Calypso localization, CBCT and additional pre-treatment motion correction by kV-imaging and Calypso, and gating during the irradiation. The effect of gating was investigated by simulating non-gated treatments (strategy B). Additionally, non-gated and single image-guided (CBCT) localization was simulated (strategy C). A total of 308 fractions from 22 patients were reconstructed. The dosimetric effect was evaluated by comparing motion inclusive target and risk organ dose-volume parameters to planned values. Motion induced dose deficits were seen mainly in PTV and CTV to PTV margin regions, whereas CTV dose deficits were small in all strategies: mean ± SD difference in CTVD99% was –0.3 ± 0.4%, −0.4 ± 0.6% and –0.7 ± 1.2% in strategies A, B and C, respectively. Largest dose deficits were seen in individual fractions for strategy C (maximum dose reductions were −29.0% and –7.1% for PTVD95% and CTVD99%, respectively). The benefit of gating was minor, if additional motion correction was applied immediately prior to irradiation. Continuous motion monitoring based localization and motion correction ensured the target coverage and minimized the OAR exposure for every fraction and is recommended to use in prostate SBRT. The study is part of clinical trial NCT02319239. 相似文献
11.
《Reports of Practical Oncology and Radiotherapy》2020,25(5):775-779
Aim and backgroundTo assess the use of hypofractionated (HG-RT) versus normofractionated radiation therapy (NF-RT) in Breast Cancer in German speaking countries.Materials and methodsBetween July 2017 and August 2017, an email-based survey was sent to all 1408 physicians that are members of the German Society of Radiation Oncology (DEGRO). The survey was completed by 180 physicians including 10 private practice owners and 52 heads of departments. The majority (82.1%) of the participants had >15 years of experience in radiation therapy (RT).ResultsThe majority (83.9%) of the heads of the departments agreed on using the normofractionated regimen of RT as standard treatment for breast cancer. Several physicians were skeptical about HF-RT with 6.5% of the heads refusing to use HF-RT. 40.3% of the departments had not seen the new German guidelines suggesting HF-RT as the standard treatment for all patients as positive or merely adopted a neutral position toward the guidelines (33.9%). The main points of criticism were increased side effects, an impaired toxicity profile and insufficient data. Most departments (46.8%) that perform HF-RT do so in an individual based manner.ConclusionsHF-RT remains controversial in German speaking countries. Our data shows that NF-RT remains the predominant method of treatment. HF-RT is only used in a defined group of patients as most German physicians agree that particular patients, especially those at higher risk of RT late effects, may benefit from a less intense, extended fractionation schedule. 相似文献
12.
PurposeIn image-guided particle radiotherapy of abdominal lesions, respiratory motion hinders treatment accuracy. In this study, 2D cineMRI data were used to quantify the tumor (GTV) motion and to evaluate the clinical approach based on deriving an internal target volume (ITV) from a planning 4DCT for gating treatments.MethodsSeven patients with abdominal lesions were treated with carbon-ion therapy at the National Centre of Oncological Hadron-therapy (Italy). The MR scan was performed on the same day of the 4DCT acquisition. For four patients, an additional MR was acquired approximately after 1 week. The cineMRI combined with deformable image registration algorithm was used to quantify tumor motion. Afterwards, two ITVs were defined considering (1) all phases (ITVFB) and (2) only phases within the gating window (ITVG), and then compared with the clinical (4DCT-derived) ITVs (ITVCG and ITVCFB).ResultsTumor residual motion estimated by cineMRI data in the two MRI sessions resulted not significantly different from 4DCT, although cineMRI accounted for cycle-to-cycle variations. The ITV normalized for the GTV median values were higher for ITVFB with respect to ITVG, ITVCFB and ITVCG. The Hausdorff distances with respect to the GTV were up to 10.55 mm, 3.13 mm, 5.56 mm and 2.51 mm, for ITVFB, ITVG, ITVCFB and ITVCG, respectively. According to both metrics, ITVCG and ITVG were not found significantly different.ConclusionsCineMRI acquisitions allowed to quantify organ motion without delivering additional dose to the patient and to verify treatment margins in gated carbon-ion therapy of abdominal lesions. 相似文献
13.
ObjectiveThis work investigates the time and frequency to observe fiducial markers in MLC-modulated fields during intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) beam delivery for real-time prostate localization.MethodsThirty seven prostate patients treated with IMRT or VMAT were included in this retrospective study. DRR images were generated for all MLC segments/control points using the TPS. The MLC leaf pattern of each control point was overlaid on the DRR, and the number of fiducials within the MLC opening was analyzed. EPID images of fiducials in a pelvic phantom were obtained to demonstrate the fiducial visibility during modulated beam delivery.ResultsGold fiducials were visible on EPID images. The probability of seeing a number of fiducials within the MLC opening was analyzed. At least one fiducial was visible during 42 ± 2% and 52 ± 2% beam-on time for IMRT of the prostate with and without lymph nodes, and during 81 ± 4% and 80 ± 5% beam-on time for VMAT of the prostate with and without lymph nodes, respectively. The mean time interval to observe at least one fiducial was 8.4 ± 0.7 and 5.9 ± 0.5 s for IMRT of the prostate with and without the lymph nodes, respectively, and 1.6 ± 0.1 s for VMAT prostate patients. The estimated potential dosimetric uncertainty was 7% and 2% for IMRT and VMAT, respectively.ConclusionsOur results demonstrated that the time and frequency to observe fiducial markers in MLC-modulated fields during IMRT/VMAT beam delivery were adequate for real-time prostate localization. The beam’s eye view fiducial positions could be used for intrafractional target monitoring and motion correction in prostate radiotherapy. 相似文献
14.
《Reports of Practical Oncology and Radiotherapy》2020,25(2):271-275
AimThe goal of this study was to determine whether a delay in starting treatment via surgery or neoadjuvant chemotherapy is related to a decrease in cancer-specific survival (CSS) in women with operable breast cancer (BrCr).BackgroundLimited medical infrastructure and a lack of cancer prevention awareness in low- and middle-income countries have caused high BrCr incidence and mortality rates.MethodsWe analyzed a retrospective cohort of 720 women treated at a single center from 2005 to 2012. CSS estimates were obtained by the Kaplan-Meier method. A Cox model of proportional risks was performed to obtain the risk of dying from BrCr. We also obtained the risk according to the category of treatment initiation.ResultsWomen with locally advanced stages and without hormone receptor expression were more likely to initiate treatment after 45 days. Patients in Stage IIIA had a 78.1% survival if treatment was initiated before 45 days (95% CI, 0.70–0.84) and 63.6% survival if treatment was started after 45 days (95% CI, 0.44–0.78; p < 0.001). Patients in Stage IIIB had a 62.9% survival if treatment was initiated before 45 days (95% CI, 0.53–0.72) and 57.4% survival if treatment started after 45 days (95% CI, 0.31-0.89; p < 0.001). Prognostic factors in which lower survival was recognized were Stage IIIA, Stage IIIB, treatment initiation after 45 days, and triple-negative tumors.ConclusionsThe initiation of treatment within the first 45 days of diagnosis of BrCr in women portends better survival compared with those who began treatment longer than 45 days from diagnosis. 相似文献
15.
16.
PurposeTo evaluate the respiratory motion influence on the tridimensional (3D) dose delivery to breast-shaped phantoms using conformal radiotherapy (3D-RT), Field-in Field (FiF), and IMRT planning techniques.MethodsThis study used breast-shaped phantoms filled with MAGIC-f gel dosimeter to simulate the breast, and an oscillation platform to simulate the respiratory motion. The platform allowed motion in the anterior-posterior direction with oscillation amplitudes of 0.34 cm, 0.88 cm, and 1.22 cm. CT images of the static phantom were used for the 3D-RT, FiF, and IMRT treatment planning. Five phantoms were prepared and irradiated for each planning technique evaluated. Phantom 1 was irradiated static, phantoms 2–4 were irradiated moving with the three different motion amplitudes, and phantom 5 was used as a reference. The 3D dose distributions were obtained by relaxometry of magnetic resonance imaging, and the respiratory motion influence in the doses distribution was accessed by gamma evaluations (3%/3mm/15% threshold) comparing the measurements of the phantoms irradiated under movement with the static ones.ResultsThe mean gamma approvals for three oscillatory amplitudes were 96.44%, 93.23%, and 91.65%; 98.42%, 95.66%, and 94.31%; and 94.49%, 93.51%, and 86.62% respectively for 3D-RT, FiF and IMRT treatments. A gamma results profile per slice along the phantom showed that for FiF and IMRT irradiations, most of the failures occurred in the central region of the phantom.ConclusionsBy increasing the respiratory motion movement, the dose distribution variations for the three planning techniques were more pronounced, being the FiF technique variations the smallest one. 相似文献
17.
With the development of precision medicine, searching for potential biomarkers plays a major role in personalized medicine. Therefore, how to predict radiosensitivity to improve radiotherapy is a burning question. The definition of radiosensitivity is complex. Radiosensitive gene/biomarker can be useful for predicting which patients would benefit from radiotherapy. The discovery of radiosensitivity biomarkers require multiple pieces of evidence. A prediction model of breast cancer radiosensitivity based on six genes was established. We had put forward some supplements on the basis of the present study. We found that there were no differences between high- and low-risk scores in the non-radiotherapy group. Patients who received radiotherapy had a significantly better overall survival than non-radiotherapy patients in the predicted low-risk score patients. Furthermore, there was no difference between radiotherapy group and non-radiotherapy group in the high-risk score group. Those results firmly supported the prediction model of radiosensitivity. In addition, building a radiosensitivity prediction model was systematically discussed. Genes of model could be screened by different methods, such as Cox regression analysis, Lasso Cox regression method, random forest algorithm and other methods. In the future, precision radiotherapy might depend on the combination of multi-omics data and high dimensional image data. 相似文献
18.
Guilherme Rocha Melo Gondim Fabiana Baroni Alves Makdissi Ricardo Cesar Fogaroli Juan Bautista Donoso Collins Hirofumi Iyeyasu Douglas Guedes de Castro Maria Letícia Gobo Silva Michael Jenwei Chen Tharcisio Machado Coelho Henderson Ramos Antônio Cássio Assis Pellizzon 《Reports of Practical Oncology and Radiotherapy》2019,24(6):551-555
BackgroundWhole breast irradiation reduces loco-regional recurrence and risk of death in patients submitted to breast-conserving treatment. Data show that radiation to the index quadrant alone may be enough in selected patients.AimTo report the experience with intra-operative radiotherapy (IORT) with Electron-beam Cone in Linear Accelerator (ELIOT) and the results in overall survival, local control and late toxicity of patients submitted to this treatment.Materials and Methods147 patients treated with a median follow up of 6.9 years (0.1?11.5 years). The actuarial local control and overall survival probabilities were estimated using the Kaplan Meier method. All tests were two-sided and p ? 0.05 was considered statistically significant.ResultsOverall survival of the cohort in 5 years, in the median follow up and in 10 years was of 98.3%, 95.1% and 95.1%, respectively, whereas local control in 5 years, in the median follow up and in 10 years was of 96%, 94.9% and 89.5%, respectively. Two risk groups were identified for local recurrence depending on the estrogen or progesterone receptors, axillary or margin status and lymphovascular invasion (LVI) (p = 0.016).ConclusionsIORT is a safe and effective treatment. Rigorous selection is important to achieve excellent local control results. 相似文献
19.
Breast cancer (BRCA) represents the most common malignancy among women worldwide with high mortality. Radiotherapy is a prevalent therapeutic for BRCA that with heterogeneous effectiveness among patients. Here, we proposed to develop a gene expression-based signature for BRCA radiotherapy sensitivity estimation. Gene expression profiles of BRCA samples from the Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) were obtained and used as training and independent testing dataset, respectively. Differential expression genes (DEGs) in BRCA samples compared with their paracancerous samples in the training set were identified by using the edgeR Bioconductor package. Univariate Cox regression analysis and LASSO Cox regression method were applied to screen optimal genes for constructing a radiotherapy sensitivity estimation signature. Nomogram combining independent prognostic factors was used to predict 1-, 3-, and 5-year OS of radiation-treated BRCA patients. Relative proportions of tumor infiltrating immune cells (TIICs) calculated by CIBERSORT and mRNA levels of key immune checkpoint receptors was adopted to explore the relation between the signature and tumor immune response. As a result, 603 DEGs were obtained in BRCA tumor samples, six of which were retained and used to construct the radiotherapy sensitivity prediction model. The signature was proved to be robust in both training and testing sets. In addition, the signature was closely related to the immune microenvironment of BRCA in the context of TIICs and immune checkpoint receptors’ mRNA levels. In conclusion, the present study obtained a radiotherapy sensitivity estimation signature for BRCA, which should shed new light in clinical and experimental research. 相似文献
20.
Alejandro Floriano Icíar Santa-Olalla Alberto Sanchez-Reyes 《Reports of Practical Oncology and Radiotherapy》2013,18(3):173-178