Background and Purpose:This study aimed to investigate inter-/intra-observer delineation variability in GTVs of primary esophageal carcinomas (ECs) based on planning CT with reference to different combinations of diagnostic multimodal images from endoscopy/EUS, esophagography and FDG-PET/CT.Materials and Methods:Fifty patients with pathologically proven thoracic EC who underwent diagnostic multimodal images before concurrent chemoradiotherapy were enrolled. Five radiation oncologist independently delineated the GTVs based on planning CT only (GTVC), CT combined with endoscopy/EUS (GTVCE), CT combined with endoscopy/EUS and esophagography (X-ray) (GTVCEX), and CT combined with endoscopy/EUS, esophagography, and FDG-PET/CT (GTVCEXP). The intra-/inter-observer variability in the volume, longitudinal length, generalized CI (CIgen), and position of the GTVs were assessed.Results:The intra-/inter-observer variability in the volume and longitudinal length of the GTVs showed no significant differences (p>0.05). The mean intra-observer CIgen values for all observers was 0.73 ± 0.15. The mean inter-observer CIgen values for the four multimodal image combinations was 0.67 ± 0.11. The inter-observer CIgen for the four combined images was the largest, showing significant differences with those for the other three combinations. The intra-observer CIgen among different observers and inter-observer CIgen among different combinations of multimodal images showed significant differences (p<0.001). The intra-observer CIgen for the senior radiotherapists was larger than that for the junior radiotherapists (p<0.001).Conclusion:For radiation oncologists with advanced medical imaging training and clinical experience, using diagnostic multimodal images from endoscopy/EUS, esophagography, and FDG-PET/CT could reduce the intra-/inter-observer variability and increase the accuracy of target delineation in primary esophageal carcinomas.

Background and Purpose The low rate of internal mammary node (IMN) recurrence was attributed to systemic therapy and internal mammary chain (IMC) coverage by the tangential fields of irradiation. This study aimed to evaluate the incidental irradiation dose to the IMC in breast cancer patients after surgery and to estimate the clinical predictive parameters affecting the magnitude of the IMC. Materials and Methods A total of 138 patients treated with postmastectomy radiotherapy and 210 patients undergoing radiotherapy after breast-conserving surgery (BCS) in our hospital were retrospectively analyzed. The mean dose (Dmean) to the IMC and the first to third intercostal spaces of IMC levels (ICS1–3) were evaluated. We evaluated the IMC coverage according to the type of surgery and whether the ipsilateral supraclavicular fossa (SCF) was included in the irradiation field. Results The incidental radiation dose to the IMC was 29.69 Gy, and the dose delivered to the IMC, ICS1, and ICS2 showed a greater coverage in the modified radical mastectomy (MRM) group when compared with the BCS group (32.85 vs. 27.1 Gy, 26.6 vs. 12.5 Gy, 34.63 vs. 30.42 Gy). The dose delivered to ICS3 showed no difference between the MRM and BCS groups (37.41 vs. 36.24 Gy). Furthermore, 131 patients (37.64%) received radiotherapy to the chest wall and ipsilateral SCF. In the univariate analysis, both surgery type and SCF irradiation were parameters affecting the Dmean of incidental radiation to the IMC ( r = −0.179, P = 0.001; r = −0.175, P = 0.001). In the multivariate analysis, surgery type was the only correlative factor that affected incidental radiation dose to the IMC ( r = –3.534, P = 0.000). Conclusion The real influencing factor of incidental dose to the IMC was the surgery form rather than the accession of SCF irradiation.

Background The application of delayed-enhancement magnetic resonance (DE-MR) simulation imaging in lumpectomy cavity (LC) delineation for prone radiotherapy in patients with an invisible seroma or a low seroma clarity score (SCS) after breast-conserving surgery (BCS) based on deformable image registration (DIR) was assessed. Methods Twenty-six patients who were suitable for radiotherapy in prone positions after BCS were enrolled, and both computed tomography (CT) and DE-MR simulation scans were acquired. The LC delineated based on titanium surgical clips on CT images was denoted as LC CT . The LC delineated based on the signal of cavity boundaries on fat-suppressed T2-weighted imaging (T2WI) and multiphase delayed-enhancement T1-weighted imaging (DE-T1WI), which was performed at 2 min, 5 min and 10 min postinjection, were denoted as LC T2 , LC 2T1 , LC 5T1 and LC 10T1 , respectively. Afterwards, DIR was performed to compare the volumes and locations of the LCs with MIM software. The generalized conformity index (CIgen) of inter (intra) observer (Inter-CIgen and Intra-CIgen) was also used to explore the inter(intra) observer variation for LC delineation on each image modality. Results LC CT –LC 10T1 provided the best conformal index (CI) and degree of inclusion (DI), increasing by 2.08% and 4.48% compared to LC CT –LC T2 , 11.36% and 2.94% for LC CT –LC 2T1 , and 8.89% and 7.69% for LC 5T1 –LC CT , respectively. The center of mass (COM) of LC CT –LC 10T1 decreased by 17.86%, 6.12% and 13.21% compared with that of LC CT –LC T2 , LC CT –LC 2T1 and LC CT –LC 5T1 , respectively. The agreement of LC delineation was strongest for 10th min DE-TIWI (coefficient of variation, COV = 2.30%, Inter-CIgen = 87.06%, Intra-CIgen = 92.64%). Conclusion For patients with a low SCS (SCS ≤ 2) after BCS, it is feasible to contour the LC based on prone DE-MR simulation images. Furthermore, the LC derived from prone DE-T1WI at 10 min was found to be most similar to that derived from prone CT simulation scans using titanium surgical clips regardless of the volume and location of the LC. Inter (intra) variability was minimal for the delineation of the LC based on 10th min DE-TIWI.

This study explored the dosimetric difference between hypofractionated whole-breast irradiation (HFWBI) with sequential boost (SEB) and simultaneous integrated boost (SIB) based on supine and prone positions to identify the superior boost mode and superior position. Thirty breast cancer patients eligible for HFWBI after breast-conserving surgery were enrolled. All patients underwent 3DCT simulation scanning in both supine and prone positions. For the SEB-HFWBI plan, the dose prescribed for the planning target volume (PTV) of whole breast (WB) was 2.67 Gy per fraction with a total of 15 fractions, followed by a sequential boost of 3.2 Gy per fraction to the PTV of tumor bed (TB) in 3 fractions. For the SIB-HFWBI plan, the dose prescribed for the PTV of WB was 2.67 Gy per fraction with a total of 15 fractions, with a simultaneously integrated boost of 3.2 Gy per fraction to the PTV of TB with a total of 15 fractions. Regardless of the position, for the PTV of TB, the conformal index (CI) in the SIB-HFWBI plans was greater than those in the SEB-HFWBI plans ( T = − 8.114, − 8.114; both P < 0.05). The CI for the PTV of WB increased significantly in the prone position relative to the supine position in both two plans( Z = − 3.340, − 3.501; all P < 0.05). The study suggested that prone SIB-HFWBI might be more suitable for postoperative radiotherapy after breast-conserving surgery for early-stage breast cancer patients.

Objective: To investigate the effect of anatomic and technical parameters on the incidental internal mammary lymph node (IMN) irradiation (IIMNI) dose among postmastectomy patients. Methods: We retrospectively delineated the IMN on planning CT images from 138 patients who had undergone postmastectomy radiotherapy (PMRT). We analyzed the IIMNI dose coverage and its relationship with anatomic and technical parameters. Results: The IIMNI mean dose was 32.85 ± 9.49 Gy, and 10 of 138 patients (7.25%) treated with PMRT received ≥45 Gy. In univariate analysis, the body weight, body mass index, body surface area, thoracic transverse diameter (DT), ratio of DT to the thoracic anteroposterior diameter (DAP)(RT/AP), planning target volume of IMN (PTVIMN) included in PTV (IMNin) and the ratio of IMNin to PTVIMN (RIMNin) and PTV posterior border were the parameters affecting IIMNI dose. In multivariate analysis, body weight, RT/AP, and RIMNin were correlative factors that affected IIMNI dose. Conclusions: For patients who underwent PMRT without IMN irradiation (IMNI), there was a wide variety in IIMNI doses. A minority of patients had adequate IIMNI dose coverage, and the higher IIMNI doses were associated with the less body weights and more RIMNin.

AbstractPurposeThe application value of 18F‐FDG PET‐CT combined with MRI in the radiotherapy of esophageal carcinoma was discussed by comparing the differences in position, volume, and the length of GTVs delineated on the end‐expiration (EE) phase of 4DCT, 18F‐FDG PET‐CT, and T2W‐MRI.MethodsA total of 26 patients with thoracic esophageal cancer sequentially performed 3DCT, 4DCT, 18F‐FDG PET‐CT, and MRI simulation for thoracic localization. All images were fused with the 3DCT images by deformable registration. GTVCT and GTV50% were delineated on 3DCT and the EE phase of 4DCT images, respectively. The GTV based on PET‐CT images was determined by thresholds of SUV ≥ 2.5 and designated as GTVPET2.5. The images of T2‐weighted sequence and diffusion‐weighted sequence were referred as GTVMRI and GTVDWI, respectively. The length of the abnormality seen on the 4DCT, PET‐CT, and DWI was compared.ResultsGTVPET2.5 was significantly larger than GTV50% and GTVMRI (P = .000 and 0.008, respectively), and the volume of GTVMRI was similar to that of GTV50% (P = .439). Significant differences were observed between the CI of GTVMRI to GTV50% and GTVPET2.5 to GTV50% (P = .004). The CI of GTVMRI to GTVCT and GTVPET2.5 to GTVCT were statistically significant (P = .039). The CI of GTVMRI to GTVPET2.5 was significantly lower than that of GTVMRI to GTV50%, GTVMRI to GTVCT, GTVPET2.5 to GTV50%, and GTVPET2.5 to GTVCT (P = .000‐0.021). Tumor length measurements by endoscopy were similar to the tumor length as measured by PET and DWI scan (P > .05), and there was no significant difference between the longitudinal length of GTVPET2.5 and GTVDWI (P = .072).ConclusionThe volumes of GTVMRI and GTV50% were similar. However, GTVMRI has different volumes and poor spatial matching compared with GTVPET2.5.The MRI imaging could not include entire respiration. It may be a good choice to guide target delineation and construction of esophageal carcinoma by combining 4DCT with MRI imaging. Utilization of DWI in treatment planning for esophageal cancer may provide further information to assist with target delineation. Further studies are needed to determine if this technology will translate into meaningful differences in clinical outcome.

Purpose: Mapping the distribution of internal mammary sentinel lymph nodes (IM-SLNs) presented on single photon emission computed tomography in conjunction with computed tomography (SPECT/CT) images to explore the value of IM-SLN to guide tailored clinical target volume (CTV) delineation of postoperative prophylactic IMNI.Materials and methods: Ninety-seven patients who underwent preoperative lymphoscintigraphy by SPECT/CT and had imaging of IM-SLN were selected in this study. The imaging IM-SLNs on SPECT/CT of eligible patients were projected onto corresponding anatomical positions of a representative axial CT image. The IMN CTVs were delineated on the representative axial CT images according to the Radiation Therapy Oncology Group (RTOG) and Danish Breast Cancer Cooperative Group (DBCG) guideline, and defined as CTVRTOG and CTVDBCG. The location of the IM-SLNs was compared with the RTOG and DBCG guidelines of IMN target volume delineations, respectively. The intercostal space distribution of IM-SLNs was recorded. The distances from the CTVRTOG and CTVDBCG to the IM-SLNs were measured, respectively.Results: The total number of imaging IM-SLNs was 136. IM-SLNs were mostly found in the first intercostal space (40.4%), with 30.2, 24.3, 4.4, and 0.7% of IM-SLNs in the second, third, fourth, and fifth intercostal space, respectively. The average distance from the edge of the CTVRTOG and the edge of CTVDBCG to the central points of the IM-SLNs was 4.10 mm (SD, 3.3 mm) and 1.60 mm (SD, 2.6 mm), respectively (t = 16.640, P = 0.000). The average distance from the edge of CTVRTOG and the edge of CTVDBCG to the lateral border IM-SLN was 6.40 mm (SD, 3.5 mm) and 3.34 mm (SD, 3.3 mm), respectively (t = 19.815, P = 0.000). Only 18.4% of IM-SLN central points were included in the CTVRTOG, and 60.3% of IM-SLN central points were included in the CTVDBCG. When covering 90 and 100% of the IM-SLN center points, the CTVRTOG needs to expand 8 and 15 mm, respectively, and the CTVDBCG needs to expand 5 and 13 mm, respectively.Conclusion: Neither the RTOG nor DBCG consensus guideline about the delineation of IMN CTV was sufficient to cover 90% of IM-SLNs. For 90% coverage of IM-SLN central points, CTVRTOG needed to be expanded by 8 mm, and CTVDBCG needed to be expanded by 5 mm.

Background: The study aimed to compare normal oesophageal wall thickness based on 3-dimensional computed tomography (3DCT), 4-dimensional computed tomography (4DCT) and cone beam computed tomography (CBCT). Methods: Contrast-enhanced 3DCT, 4DCT, and CBCT scans were acquired from 50 patients with lung cancer or metastatic lung cancer. The outer oesophageal wall was manually contoured on each 3DCT, the maximum intensity projection of 4DCT (4DCT MIP ) the end expiration phase of 4DCT (4DCT 50 ) (the end expiration phase of 4DCT) and the CBCT data sets. The average wall thicknesses were measured (defined as R 3DCT , R 50 , R MIP , and R CBCT ). Results: Whether for thoracic or for intra-abdominal segments, there were no significant differences between R 3DCT and R 50 , but significant differences between R 3DCT and R MIP , R 3DCT and R CBCT . For upper and middle oesophagus, R CBCT were larger than R MIP . There was no significant difference between upper and middle segments on 3DCT, 4DCT, and CBCT. Intra-abdominal oesophageal wall thickness was greater than that of thoracic oesophagus. There were no differences between upper and lower, and middle and lower oesophagus on CBCT. Conclusion: Our findings indicate normal oesophageal wall thickness differed along the length of oesophagus whatever it was delineated on 3DCT, 4DCT (4DCT 50 and 4DCT MIP ) or CBCT. It is reasonable to use uniform criterion to identify normal esophageal wall thickness when delineating gross tumor volume on 3DCT and 4DCT 50 , the same is true of delineating internal gross tumor volume on 4DCT MIP or CBCT images for lower and intra-abdominal oesophagus. But, in spite of using contrast-enhanced scanning, relatively blurred boundary on the CBCT images is noteworthy, especially for upper and middle thoracic esophagus.

Purpose: To explore the efficacy and safety of fast-track surgery (FTS) in the perioperative period of single-hole thoracoscopic radical resection of lung cancer. Methods: The clinical data of 152 lung cancer patients undergoing single-hole thoracoscopic radical resection of lung cancer in our hospital from October 2016 to March 2019 were collected. Among them, 76 patients were treated with perioperative FTS (FTS group) following in-depth information and education, effective analgesia, early ambulation and early extubation, while the other 76 patients received conventional perioperative treatments (Control group). Results: The intraoperative volumes of blood loss and fluid infusion in FTS group were smaller than those in Control group. Moreover, the mean time to postoperative drainage tube removal, time to the first postoperative ambulation and length of postoperative hospital stay in FTS group were substantially shorter than those in Control group. Moreover, the visual analog scale (VAS) scores of patients at 48 and 72 h after operation in FTS group were considerably lower than those in Control group. Besides, the total incidence rate of postoperative complications in FTS group was considerably lower than that in Control group. Compared with those before operation, all pulmonary function indicators declined substantially after operation, and the postoperative forced vital capacity (FVC), forced expiratory volume in the first second (FEV1) and maximum voluntary ventilation (MVV) in FTS group were remarkably higher than those in Control group. Conclusion: FTS in the perioperative period of single-hole thoracoscopic radical resection of lung cancer can effectively accelerate the recovery of patients, alleviate their pain, shorten the length of hospital stay, reduce hospitalization expense and improve patient's satisfaction, so it is worth clinically applying.

Objective To explore the target definition for internal mammary lymph nodes ( IMLNs) irradiation based on the distribution of internal mammary sentinel lymph nodes ( IM-SLNs ) developing on SPECT/CT fusion imaging. Methods A total of 709 breast cancer patients who underwent preoperative SPECT/CT fusion imaging examination in IM-SLN from 2014 to 2018 were selected. All of the selected patients were first diagnosed and did not receive neoadjuvant treatment before SPECT/CT examination. Finally, totally 97 patients with 136 positive imaging IM-SLNs were included in this study. The clinical target volumes ( CTVs) were delineated according to the consensus guidelines from RTOG and DBCG and defined as CTVRTOG and CTVDBCG , respectively. The positional relationship of CTVRTOG , CTVDBCG and IM-SLNs were determined. Results The number of IM-SLNs from the first to fifth intercostal spaces were 55, 40, 33, 6 and 1, respectively. And the number of IM-SLNs in the first three intercostal spaces accounted for 94. 85％ of the total. The average distance from the edge of CTVRTOG to the centre points and the edges of IM-SLNs were 4. 10 mm ( 95％CI 3. 54-4. 65 mm) and 6. 40 mm ( 95％CI 5. 81-6. 98 mm), respectively (t=-30. 486,P<0. 05). For the CTVDBCG, the average distance was 1. 60 mm ( 95％CI 1. 16-2. 05 mm) and 3. 34 mm ( 95％CI 2. 78-3. 89 mm) , respectively ( t=-16. 364,P<0. 05) . The average distances from the edge of CTV to the centre points and the edge of IM-SLNs for CTVRTOG were all significantly greater than those for CTVDBCG(t=16. 640, 19. 815, P<0. 05). The rate of covering IM-SLN center points for CTVRTOG and CTVDBCG were 18. 4％ and 60. 3％, respectively. In order to cover 90％or 100％ of the IM-SLN center points, the edge of CTVRTOG should be expanded by 8 or 15 mm, respectively, and the edge of CTVDBCG should be expanded by 5 or 13 mm, respectively. If the diameter of IM-SLN was assumed as 5 mm, the edge of CTVRTOG needed an expansion of 11 or 17 mm to contain 90％or 100％ of IM-SLNs, respectively, while the edge of CTVDBCG needed 7 or 16 mm to cover 90％ or 100％of IM-SLNs, respectively. Conclusions It is reasonable to include the first three intercostal spaces IMLNs for prophylactic irradiation based on the distribution of IM-SLNs. However, CTVs based on the two guidelines are both insufficient to cover 90％ of IM-SLNs.

Objective: To evaluate the incidental coverage dose to the internal mammary nodes (IMN) in patients treated with postmastectomy radiotherapy (PMRT) and its relationship with the treatment plan. Patients and methods: We retrospectively analyzed 138 patients undergoing PMRT and divided them into three groups: three-dimensional conformal radiotherapy (3D-CRT), fieldin-field forward intensity-modulated radiotherapy (F-IMRT), and inverse intensity-modulated radiotherapy (I-IMRT). The IMN were contoured according to the Radiation Therapy Oncology Group consensus and not included in the planning target volume. We analyzed incidental IMN dose coverage and its relationship with the lung and heart. Results: The mean dose (Dmean) to the IMN was 32.85 Gy for all patients, and the dose delivered to the IMN showed no differences in 3D-CRT, F-IMRT, and I-IMRT (33.80, 29.65, and 32.95 Gy, respectively). In addition, 10.42%, 2.04%, and 9.76% of patients achieved >= 45 Gy with 3D-CRT, F-IMRT, and I-IMRT, respectively. No differences were evident among the three treatment plans regarding IMN dose in the first three intercostal spaces (ICS1-3). The Dmean, V20, V30, V40, and V50 of ICS2 and ICS3 were superior to those of ICS1 for all three plans. For 3D-CRT, a moderate positive correlation was evident between the Dmean to the IMN and the Dmean to the heart. For IF-IMRT and I-IMRT, positive correlations were evident between the Dmean of the IMN and the Dmean and V20 of the lung. Conclusion: The mean incidental dose to the IMN for IMRT (F-IMRT and I-IMRT) and 3D-CRT after modified radical mastectomy was insufficient to treat subclinical disease. A substantial dose was delivered to the IMN in some patients. Higher incidental doses to the IMN were associated with a higher heart mean dose for 3D-CRT and a higher dose to the lung for IMRT. Future prospective studies should further explore subgroups that do not require IMN irradiation.

Objective: To compare differences in setup error assessment and correction between planar kilovolt images and cone beam computed tomography images for external beam partial breast irradiation during free breathing. Methods: Nineteen patients who received external beam partial breast irradiation after breast-conserving surgery were recruited. Interfraction setup error was acquired using planar kilovolt images and cone beam computed tomography. After online setup correction, the residual error was calculated, and the setup error was compared. The residual error and setup margin were quantified for planar kilovolt and cone beam computed tomography images. Results: The largest setup error was observed in the anteroposterior direction for both cone beam computed tomography and planar kilovolt imaging (−1.45 mm, 1.74 mm). The cone beam computed tomography–based setup error (systematic error [Σ]) was less than the planar kilovolt images based on Σ in the anteroposterior direction (–1.2 mm vs 2.00 mm; P = .005), and no significant differences were observed for random error (σ) in 3 dimensions (P = .948, .376, .314). After online setup correction, cone beam computed tomography significantly reduced the residual setup error compared with planar kilovolt images in the anteroposterior direction (Σ: −0.20 mm vs 0.50 mm, P = .008; σ: 0.45 mm vs 1.34 mm, P = .002). The cone beam computed tomography–based setup margin was smaller than the planar kilovolt image-based setup margin in the anteroposterior direction (−1.39 mm vs 5.57 mm, P = .003; 0.00 mm vs 3.20 mm, P = .003). Conclusions: Discrepancy between the setup errors observed with planar kilovolt and cone beam computed tomography was obvious in the anteroposterior direction. Compared to cone beam computed tomography, the elapsed treatment time was smaller when the initial alignment used kilovolt planar imaging. Whether using planar kilovolt or cone beam computed tomography, residual errors can be reduced to 1.5 mm for external beam partial breast irradiation procedures.

Background: The study aimed to evaluate and compare the dosimetric parameters of incidental irradiation to internal mammary node (IMN) from inverse intensity-modulated radiotherapy (I-IMRT) and field-in-field IMRT (F-IMRT), and 3-dimensional conformal radiotherapy (3D-CRT) in patients after breast-conservation surgery (BCS). Methods: Eighty-four patients with BCS were selected. The breast, tumor bed, and IMN, including intercostal spaces (ICS) 1 to 3, were contoured. Three plans were generated. The prescription doses for the breast and tumor bed were 50.4Gy/28 F and 60.2Gy/ 28 F, respectively. If there was no tumor bed boost, patient was treated with 50Gy/25 F for the whole breast only. The IMN was not included in planning target volume. Results: The median mean dose (Dmean) of the IMNtotal (ICS 1-3) was 2740.2cGy, 2973.9cGy, and 2951.4cGy for I-IMRT, F-IMRT, and 3D-CRT, respectively. Differences were not detected between any of the plans. After separating ICS 1 to 3 for further analysis, neither of the Dmean of ICS 1 to 2 was significantly different between the plans. However, for ICS 3, the median Dmean was highest for IIMRT, and those for 3D-CRT and F-IMRT were not significantly different. After separating the 3 techniques for further analysis, the median Dmean was highest in ICS 3 and lowest in ICS 1 for all the 3 techniques. Conclusion: All 3 techniques failed to attain an adequate dose to cure subclinical disease, and there were no significant differences among the 3 techniques. It is risky to avoid IMN irradiation (IMNI) using any of the 3 techniques during whole-breast radiotherapy in women with indications for elective IMNI. However, in era of systematic therapy, whether the incidental dose could meet clinical acquirements needs further follow-up.

Purpose: We aimed to investigate whether MRI-based radiomics analysis can be used to distinguish patients with prostate cancer (PCa) with Gleason scores (GS) <7, =7, and >7. We further aimed to develop a non-invasive prediction tool based on these findings.Methods and Materials: We retrospectively examined preoperative MRI results, clinical data, and postoperative pathological findings from 492 patients with PCa. Radiomic features were extracted from manually segmented regions of lesions on diffusion-weighted, apparent diffusion coefficient, and T2-weighted images. The Kruskal-Wallis test, minimum redundancy-maximum relevance test, Boruta, and sequential backward elimination algorithms were used to determine the significance of features. We then developed a radiomic signature via multi-class linear regression (MLR) based on key features identified in these analyses. We created a Gleason score (GS) prediction model (GSPM) based on the radiomic signature and significant clinical characteristics by MLR. Logistic regression analyses were employed to estimate the prediction results of the GSPM. The area under the receiver operating characteristic (ROC) curve (AUC), accuracy, specificity, sensitivity, and concordance index (C-index) were also calculated.Results: For predicting GS<7 vs. GS=7 vs. GS>7, the C-index of our GSPM reached 0.774 in the primary cohort while 0.742 in the validation cohort. The GSPM yielded an average AUC of 0.795 for subgroups prediction in the validation cohort.Conclusion: MRI-based radiomic features can be used to distinguish patients with PCa. These features may aid in the development of a non-invasive preoperative tool in clinic.Funding Statement: This work was supported by the National Key R&D Program of China (2017YFC1308700, 2017YFA0205200, 2017YFC1309100, 2017YFC0114300), National Natural Science Foundation of China (81771924, 81501616, 81227901, 81671851, 81527805, 81271629), the Beijing Natural Science Foundation (L182061), the Bureau of International Cooperation of Chinese Academy of Sciences (173211KYSB20160053), the Instrument Developing Project of the Chinese Academy of Sciences (YZ201502), and the Youth Innovation Promotion Association CAS (2017175).Declaration of Interests: The authors state: "There are no conflicts of interest to declare."Ethics Approval Statement: We enrolled patients with PCa treated at Wuxi People’s Hospital from June 2008 to January 2018. All patients offered the informed consent to be involved in the study, which were authorized via the ethics committee of the hospital.

Abstract Objective To determine the correlation of displacement of the mediastinal metastatic lymph nodes with adjacent organs in non‐small cell lung cancer using four‐dimensional computed tomography. Methods The displacements of 51 mediastinal metastatic lymph nodes located in the left–right, anterior–posterior, and superior–inferior directions were measured using four‐dimensional computed tomography. Correlation analyses were carried out to determine the association between the displacement of lymph nodes and volumetric change of the lungs and heart. Results A significant correlation of displacement of the left group lymph nodes in left–right and the right group in anterior–posterior directions with volumetric change of the ipsilateral lung was observed. There were significant correlations between displacement of the left group lymph nodes and volumetric change of the heart. Conclusion Displacement of the mediastinal metastatic lymph nodes was relevant to the adjacent organs.

Objective To explore the dosimetric variance in incidental irradiation to the internal mammary nodes among inverse intensity-modulated radiotherapy (I-IMRT), forward intensity-modulated radiotherapy (F-IMRT),and three-dimensional conformal radiotherapy (3DCRT) after breast-conserving surgery,and to provide a basis for deciding whether to spare the internal mammary nodes in clinical treatment. Methods A total of 84 patients undergoing breast-conserving surgery were enrolled as subjects. The internal mammary nodes in the first three intercostal spaces were contoured. Three radiotherapy plans were designed for each patient. The internal mammary nodes were not included in the planning target volume. Comparison was made among the three plans. The results were compared using Wilcoxon signed rank test. Results The I-IMRT, F-IMRT,and 3DCRT plans had similar median Dmeanvalues for the internal mammary nodes,which were 2 740.2,2973.9,and 2951.4 cGy,respectively. The analyses of the three individual intercostal spaces showed that there was no difference in Dmeanfor the first intercostal space or the second intercostal space between the three plans;For the third intercostal space,however,I-IMRT had a significantly higher Dmeanthan 3DCRT and F-IMRT. The analyses of the three individual plans showed that for each plan,the Dmeanwas the highest in the third intercostal space,followed by the second intercostal space and the first intercostal space. Conclusions All the three plans fail to attain an adequate prescribed dose to cure subclinical disease,and there is no significant difference among the three plans. Therefore,it is risky to exclude the internal mammary nodes using any one of the three radiotherapy techniques for patients with clinical indications for internal mammary nodes radiation. In the combination therapy including chemotherapy,endocrine therapy,and targeted therapy,however,further follow-up is needed to determine whether the incidental irradiation dose to the internal mammary nodes could meet clinical requirement.

To investigate the differences in target volumes and dosimetric parameters between the supine and prone positions for external-beam partial breast irradiation (EB-PBI) after breast-conserving surgery (BCS) for Chinese breast cancer patients, thirty breast cancer patients who underwent three-dimensional conformal radiation therapy (3DCRT) EB-PBI after BCS were enrolled. Supine and prone scan sets were acquired during free breathing for all patients. Target volumes and organs at risk (OARs) including the heart, ipsilateral lung and bilateral breast were contoured by the same radiation oncologist. For each patient, supine and prone EB-PBI plans were generated based on the same planning criteria. The clinical target volume (CTV) and planning target volume (PTV) in the prone position were significantly greater than those in the supine position (P = 0.003, 0.004, respectively). A 0.95 Gy reduction in the mean dose (D-mean) to the heart (P= 0.000) was apparent in the supine position compared to the prone position. The D(mean )to the ipsilateral lung was significantly lower in the prone position than in the supine position (1.59 Gy vs. 1.72 Gy, P= 0.029). Therefore, for Chinese breast cancer patients, carrying out 3DCRT EB-PBI in the prone position during free breathing is feasible.

To explore the differences and correlations between the target volumes defined using preoperative prone diagnostic magnetic resonance imaging (MRI) and postoperative prone computed tomography (CT) simulation imaging based on deformable image registration (DIR) for external-beam partial breast irradiation (EB-PBI) after breast-conserving surgery (BCS). Eighteen breast cancer patients suitable for EB-PBI were enrolled. Preoperative prone diagnostic MRI and postoperative prone CT scan sets for all the patients were acquired during free breathing. Target volumes and ipsilateral breast were all contoured by the same radiation oncologist. The gross tumor volume (GTV) delineated on the preoperative MRI images was denoted as the GTVpreMR and the tumor bed (TB) delineated on the postoperative prone CT images was denoted as the GTVpostCT. The MIM software system was used to deformably register the MRI and CT images. When based on the coincidence of the compared target centers, there were statistically significant increases in the conformity index (CI) and degree of inclusion (DI) values for GTVpostCT-GTVpreMR, GTVpostCT-CTVpreMR + 10, CTVpostCT + 10-GTVpreMR, and CTVpostCT + 10-CTVpreMR + 10 when compared with those based on the DIR of the thorax (Z = − 3.724, − 3.724, − 2.591, − 3.593, all P < 0.05; Z = -3.724, − 3.724, − 3.201, − 3.724, all P < 0.05, respectively). Although based on DIR, there was relatively poor spatial overlap between the preoperative prone diagnostic MRI images and the postoperative prone CT simulation images for either the whole breast or the target volumes. Therefore, it is unreasonable to use preoperative prone diagnostic MRI images to guide postoperative target delineation for EB-PBI.

Concurrent chemoradiotherapy is considered curative intent treatment for patients with non-operative esophageal cancer. Radiation-induced heart damage receives much attention. The aim of this study was to detect the change of cardiac volume over the course of radiotherapy for esophageal cancer based on repeated enhanced 4DCT and to explore the factors that might affect the change in cardiac volume during radiotherapy. In this prospective study, forty-six patients with pathologically proven thoracic esophageal squamous cell carcinoma who were scheduled to receive concurrent chemoradiotherapy with a total dose of 60Gy in 30 fractions in our department were enrolled in the study. All the patients underwent enhanced 4DCT and 3DCT scans before radiotherapy and then repeated the CT scans every 10 fractions during treatment. The heart was contoured on 3DCT, end expiratory (EE) of 4DCT and maximum intensity projection (MIP) of 4DCT by the same radiation oncologist according to the same guidelines. Heart volumes and other relative parameters during radiotherapy were analyzed. Compared with the initial value, heart volume decreased significantly at the tenth fraction (reduction = 3.27%, 4.45% and 4.52%, respectively, on 3DCT, EE and MIP, p < 0.05) and the twentieth fraction (reduction = 6.05%, 5.64% and 4.51%, respectively, on 3DCT, EE and MIP, p < 0.05). The reduction between the initial measurement and the measurement at the thirtieth fraction was not significant (p > 0.05). There was a decrease in both systolic (16.95 ± 16.69 mmHg, p < 0.05) and diastolic blood pressure (7.14 ± 11.64 mmHg, p < 0.05) and an increase in heart rate with 5.27 ± 6.25 beats/min (p < 0.05) after radiotherapy. The patients with mid-thoracic esophageal cancer were found to have significantly greater heart dose than the upper and lower tumors (p <0.05). None of the potential explanatory variables correlated with heart volume changes. By eliminating the effect of respiratory motion on the heart, 4DCT better reflects changes in cardiac volume during radiotherapy of esophageal cancer. Heart volume was significantly reduced in the early treatment stage and maintained the reduction until the middle treatment stage, then showed a tendency to restore to the initial level at the thirtieth fraction. The blood pressure decreased and the heart rate increased during radiotherapy. These observed changes may be valuable indicators of cardiac impairment and target dose changes.

Objective To detect the changes of heart volume during concurrent chemoradiotherapy for esophageal cancer based on repeated enhanced 4DCT. Methods Patients with squamous cell esophageal cancer underwent repeated enhanced 4DCT and 3DCT scans before and after 10, 20 and 30 fractions of radiotherapy, respectively. The heart was contoured on 3DCT, end expiratory (EE) and maximum intensity projection (MIP) of 4DCTimages. The changes in theheart volume, blood pressure and heart rate were statistically compared at different time points. Results A total of forty-six patients completed 4 fractions of 3DCT and enhanced 4DCT scans. Compared with the initial values, the heart volume was significantly decreased by 3.27%, 4.45% and 4.52% after 10 fractions of radiotherapy, and reduced by 6.05%, 5.64% and 4.51% following 20 fractions of radiotherapy on 3DCT, EE and MIP, respectively (P=0.000-0.027). The heart volume after 30 fractions of radiotherapy did not significantly differ from the initial volume (P>0.05). After radiotherapy, there was a significant decrease inboth systolic and diastolic blood pressure (P=0.000 and P=0.009) and a significant increase in the heart rate (P=0.001) compared with those measured before radiotherapy. Conclusions Enhanced 4DCT scan can clearly reflect the changes of heart volume throughout concurrent chemoradiotherapy. The heart volume starts to shrink during the early stage of radiotherapy and continue to decrease until the middle-and late-stage, whereas it restores to the initial volume after radiotherapy. Simultaneously, blood pressure declines and heart rate is accelerated during radiotherapy. Key words: Esophageal neoplasm/concurrent chemoradiotherapy; Tomography, X-ray computed, four-dimensional; Heart volume