Advances in prevention and treatment of radiation-induced lymphopenia / 中华放射肿瘤学杂志

Currently, radiotherapy has been found to induce lymphopenia in multiple solid tumors, which has been proven to be associated with poor prognosis. Radiation-induced lymphopenia (RIL) is associated with age, baseline lymphocyte count, tumor size and location and radiotherapy regimens (radiation fractionation, field size and technique), etc. In addition, several drugs and cytokines may help restore lymphocytes. Exploration of effective strategies to prevent or treat RIL may be an important future direction to improve prognosis of cancer patients.

Toxicities of hypofractionated radiotherapy after breast-conserving surgery: a literature review / 中华放射肿瘤学杂志

Hypofractionated radiotherapy, which provides equivalent efficacy and dose not increase toxicity compared with conventional fractionated radiotherapy following breast-conserving surgery, has become a preferred choice for whole breast irradiation. Given the low local recurrence risk and long survival time for early breast cancer survivors, radiation-associated toxicities are the focus of clinical practice. However, in the era of hypofractionated radiotherapy, the risk factors for radiation-associated toxicity remain undefined and further research is warranted. In this review, we aim to provide an overview of the toxicities of hypofractionated radiotherapy following breast-conserving surgery.

Application of project-based learning in clinical teaching of radiation physics for radiotherapy residents / 中华放射肿瘤学杂志

Objective:To observe the effect of project-based learning (PBL) in the clinical teaching of radiation physics.Methods:Thirty-two residents specializing in radiotherapy were included in the study. In the experimental group ( n=16), PBL was adopted, while traditional clinical teaching method was employed in the control group ( n=16). After the rotation, the assessment was conducted, as well as a questionnaire survey was performed, including five aspects: overall satisfaction, understanding of radiation physics knowledge, learning motivation, learning burden, and learning efficiency. Results:The assessment score in the experimental group was 86.31±5.41, which was higher than 75.28±5.91 in the control group, and the difference was statistically significant. Residents in the experimental group were satisfied with the effect of PBL.Conclusion:Compared with the traditional teaching method, PBL can improve the learning motivation, efficiency, and performance of radiotherapy residents, which is highly recognized by the residents.

Simultaneous integrated tumor bed boost during whole breast radiotherapy in breast cancer patients after breast-conserving surgery: a review of the current evidence / 中华放射肿瘤学杂志

Radiotherapy is an important treatment modality in breast-conserving therapy of breast cancer. At present, hypofractionation has become the preferred dose schedule for whole breast irradiation. Tumor bed boost can further improve the local control, and sequential boost is recommended for high-risk patients. The widespread application of intensity-modulated radiation therapy provides dosimetric advantages and practical convenience for simultaneous integrated boost. In this review, the indications of tumor bed boost and recent research progress on simultaneous integrated boost were summarized, specifically focusing on the safety and efficacy of simultaneous integrated boost during conventional fractionated or hypofractionated whole breast radiotherapy. Ongoing phase Ⅲ randomized clinical trials of simultaneous integrated boost during hypofractionated whole breast radiotherapy were also illustrated.

Long-term outcomes of watch&wait (W&W) after neoadjuvant treatment in patients with rectal cancer / 中华放射肿瘤学杂志

Objective:To compare the outcomes of watch&wait (W&W) strategy in patients with locally advanced rectal cancer who achieved complete clinical response (cCR) after neoadjuvant therapy, with those who obtained pathological complete response (pCR) after total mesorectal excision (TME).Methods:This is a retrospective cohort analysis study. Patients histologically proven with locally advanced rectal adenocarcinoma (stage Ⅱ-Ⅲ) who had received neoadjuvant chemotherapy were eligible between January 2014 and December 2019. In whom we included patients who had cCR offered management with W&W strategy after completing neoadjuvant therapy and follow-up ≥1 year (W&W group), and patients who did not have cCR but pCR after TME (pCR group). The primary endpoints were 3-year and 5-year overall survival (OS), colostomy-free survival (CFS), disease-free survival (DFS), non-local regrowth disease-free survival (NR-DFS), and organ preservation rate. Kaplan-Meier analysis was used for survival analysis and log-rank test was performed. For comparative analysis, we also derived one-to-one paired cohorts of W&W versus pCR using propensity-score matching (PSM).Results:A total of 118 patients were enrolled, 49 of whom had cCR and managed by W&W, 69 had pCR, with a median follow-up period of 49.5 months (12.1-79.9 months). No difference was observed in the 3-year OS (97.1% vs. 96.7%) and 5-year OS (93.8% vs. 90.9%, P=0.696) between the W&W and pCR groups. Patients managed by W&W had significantly better 3-year and 5-year CFS (89.1% vs. 43.5%, P<0.001), better 3-year DFS (83.6% vs. 97.0%) and 5-year DFS (83.6% vs. 91.2%, P=0.047) compared with those achieving pCR. The 3-year NR-DFS (95.9% vs. 97.0%) and 5-year NR-DFS (92.8% vs. 97.0%, P=0.407) did not significantly differ between the W&W and pCR groups. Local regeneration occurred in six cases, and 87.7% of patients had successful rectum preservation in the W&W group. In the PSM analysis (34 patients in each group), absolutely better CFS (90.1% vs. 26.5%, P<0.001) was noted in the W&W group. A median interval of 17.5 weeks was observed for achieving cCR, while only 23.9% of patients achieved cCR within 5 to 12 weeks from radiation completion. Patients with short-course sequential chemoradiotherapy achieved cCR significantly later when compared with those with long-course concurrent chemoradiotherapy (19.0 vs. 9.8 weeks, P<0.001). Conclusions:The oncological outcomes of W&W strategy in patients with locally advanced rectal cancer are safe and effective, significantly improving the quality of life. Longer interval for cCR evaluation may improve rectal organ preservation rate.

Local recurrence pattern of pT 1-2N 1 breast cancer after modified radical mastectomy—a pooled-analysis of 5442 patients from 12 centers / 中华放射肿瘤学杂志

Objective:To analyze locoregional recurrence (LRR) pattern of patients with pT 1-2N 1 breast cancer after modified radical mastectomy, with and without adjuvant radiotherapy (RT). Methods:A total of 5442 eligible patients with breast cancer from 12 Chinese centers were included. The LRR sites and the effect of RT at different sites on recurrence in patients with and without RT were analyzed. The Kaplan-Meier method was used to calculate the cumulative LRR rate, and the difference was compared by the log-rank test.Results:With a median follow-up time of 63.8 months for the entire cohort, 395 patients developed LRR. The chest wall and supraclavicular fossa were the most common LRR sites, regardless of RT or molecular subtypes. The 5-year chest wall recurrence rates for patients with and without chest wall irradiation were 2.5% and 3.8%( P=0.003); the 5-year supraclavicular lymph nodal recurrence rates for patients with and without supraclavicular fossa irradiation were 1.3% and 4.1%( P<0.001); the 5-year axillary recurrence-free rates for patients with and without axillary irradiation were 0.8% and 1.5%( HR=0.31, 95% CI: 0.04-2.23, P=0.219); and the 5-year internal mammary nodal recurrence-free rates for patients with and without internal mammary nodal irradiation were 0.8% and 1.5%( HR=0.45, 95% CI: 0.11-1.90, P=0.268). Conclusions:The chest wall and supraclavicular fossa are the most common LRR sites of patients with pT 1-2N 1 breast cancer after modified radical mastectomy, which is not affected by adjuvant RT or molecular subtypes. The chest wall and supraclavicular fossa irradiation significantly reduce the risk of recurrence in the corresponding area. However, axillary and internal mammary nodal irradiation has no impact on the risk of recurrence in the corresponding area.

The standard adapt-to-shape workflow for prostate cancer on MR-linac—Experience from National Cancer Institute/Cancer Hospital, Chinese Academy of Medical Sciences / 中华放射肿瘤学杂志

With aligned MR registration, the MR-Linac provides superior soft tissue resolution for prostate cancer. No fiducial markers or electromagnetic transponders insertion is needed to guarantee high-precision radiotherapy. The highly-recommended Adapt-To-Shape (ATS) workflow can resolve all the problems encountered during prostate cancer radiotherapy, including prostate volume changes and adjacent organs motion, both inter-fractionally and intra-fractionally. With all the above advantages, MR-Linac performs outstandingly than conventional linac in prostate cancer RT delivery, and probably helps us to reduce the CTV-PTV margin safely in the near future. Nevertheless, it is difficult to implement the ATS workflow in clinical practice. In this article, the standard ATS workflow for prostate cancer was summarized based on our own experience.

Preliminary application of MR-Linac in breast cancer radiotherapy in a single academic center / 中华放射肿瘤学杂志

Objective:To describe a prospective study of pre-operative tumor-bed boost performed at the 1.5 T MR-Linac in combination with adjuvant whole breast irradiation, and a first case, with an accentuation on clinical feasibility and safety.Methods:A phase II, single arm study recruiting early stage patients follows a paradigm that first boosts the tumor bed and then undergoes breast conservative surgery in 2 weeks, and last irradiates the whole breast in 6 weeks. The primary endpoint is ≥ grade 2 acute breast toxicity. A 43 years old patient affected by a breast carcinoma, not special type of the right-sided lateral quadrant, staged cT 2N 0M 0, was planned and treated. The dose, 8 Gy for one time, was calculated by Monaco on CT simulation images. Both the air electron stream effect (ESE) and the electron return effect (ERE) at the presence of 1.5 T magnetic field were evaluated. During the pre-treatment evaluation, we carried out adaptation-to-position adjustment. Results:The normal organ dosimetry is within toleration. The Dmax to the skin, the chin and the right upper arm was 8.44 Gy, 28.5 cGy and 17.8 cGy, respectively. There was no increased toxicity from ERE and ESE, and the treatment was well tolerated without > grade 1 acute toxicity. The patient received breast conservative surgery on day 7 without delayed wound healing.Conclusions:This is the first case successfully treated within a clinical trial by pre-operative tumor-bed boost under 1.5 T MR-Linac in our institution. More participants are needed to validate and optimize the paradigm.

Preliminary study of clinical application of magnetic resonance linear accelerator in liver malignancies / 中华放射肿瘤学杂志

Objective:To investigate the workflow, efficacy and safety of MR-Linac in liver malignancies.Methods:Clinical data of 15 patients with hepatocellular carcinomas (HCC) or liver metastases treated with MR-Linac between November 2019 and July 2021 were retrospectively analyzed. The workflow of MR-Linac was investigated and image identification rate was analyzed. Patients were followed up for response and toxicity assessment.Results:Fifteen patients (6 HCC, 8 liver metastases from colorectal cancer, 1 liver metastasis from breast cancer) were enrolled. A total of 21 lesions were treated, consisting of 10 patients with single lesion, 4 patients with double lesions and 1 patient with triple lesions. The median tumor size was 2.4 cm (0.8-9.8 cm). The identification rate for gross tumor volume (GTV) in MR-Linac was 13/15. Although GTV of two patients were unclearly displayed in MR-Linac images, the presence of adjacent blood vessel and bile duct assisted the precise registration. All the patients were treated with stereotactic body radiation therapy (SBRT). For HCC, the median fraction dose for GTV or planning gross tumor volume (PGTV) was 6 Gy (5-10 Gy) and the median number of fractions was 9(5-10). The median total dose was 52 Gy (50-54 Gy) and the median equivalent dose in 2 Gy fraction (EQD 2Gy) at α/ β= 10 was 72 Gy (62.5-83.3 Gy). For liver metastases, the median fraction dose for GTV or PGTV was 5 Gy (5-10 Gy) and the median number of fractions was 10(5-10). The median total dose was 50 Gy (40-50 Gy) and the median EQD 2Gy at α/ β=5 was 71.4 Gy (71.4-107.1 Gy). At 1 month after SBRT, the in-field objective response rate (ORR) was 8/13 and the disease control rate was 13/13. At 3-6 months after SBRT, the in-filed ORR was increased to 6/6. During the median follow-up of 4.0 months (0.3-11.6), 4-month local progression-free survival, progression-free survival and overall survival were 15/15, 11/15 and 15/15, respectively. Toxicities were mild and no grade 3 or higher toxicities were observed. Conclusions:MR-Linac provides a platform with high identification rates of liver lesions. Besides, the presence of adjacent blood vessel and bile duct also assists the precise registration. It is especially suitable for liver malignancies with promising local control and well tolerance.

Impact of status determined by comprehensive geriatric assessment on setup error during rectal cancer radiotherapy for elderly patients / 中华放射医学与防护杂志

Objective:To explore the impacts of comprehensive geriatric assessment (CGA) on setup errors during the radiotherapy of elderly patients with rectal cancer.Methods:A total of 45 patients over 70 years of age and receiving radiotherapy were enrolled in the study. A comprehensive geriatric assessment was conducted before the radiotherapy. The enrolled patients had a median age of 77 years, including 28 male and 17 female cases. Meanwhile, 31 patients were determined to be in a good CGA status and 14 were determined to be in a poor CGA status, and 35 patients received radiotherapy in the prone position and 10 in the supine position. Cone beam CT (CBCT) was used for setup correction during radiotherapy. CBCT was performed daily in the first week and once a week from the second week. By fusing and aligning the CBCT images with simulation CT images according to the lumbar vertebra, setup errors in the left-right ( x axis), cranio-caudal ( y axis), and anterior-posterior ( z axis) directions were obtained. A total of 338 CBCT images were obtained. A generalized linear model was used to evaluate the effects of multiple factors on the setup errors. Results:During the radiotherapy, setup errors of all patients were (0.24±0.19) cm in the left-right direction, (0.33±0.25) cm in the cranio-caudal direction, and (0.19±0.15) cm in the anterior-posterior direction. The setup error in the cranio-caudal direction was more than that in the left-right direction and that in the anterior-posterior direction ( Z=-4.86, -7.72, P< 0.001). The setup error in the left-right direction was greater than that in the anterior-posterior direction ( Z=-2.79, P=0.005). The mean setup errors of the good and poor status groups in the left-right direction were (0.21 ± 0.17) and (0.30 ± 0.22) cm, respectively ( Z=2.16, P=0.031). There was no statistically significant difference in the setup errors between cranio-caudal direction and anterior-posterior direction ( P>0.05). The setup errors in the anterior-posterior direction were (0.17 ± 0.13) and (0.27 ± 0.19) cm, respectively for the prone and supine positions during the radiotherapy ( Z=2.85, P=0.004). There was no statistically significant difference in the setup errors between the left-right direction and the cranio-caudal direction ( P>0.05). Conclusion:The status of CGA elderly patients with rectal cancer affects the setup error in the left-right direction. It may be necessary to clinically adjust the PTV margin.

Analysis of setup errors of postoperative intensity-modulated radiotherapy immobilized with integrated cervicothoracic board (mask) system in breast cancer patients / 中华放射肿瘤学杂志

Objective:To investigate the setup errors of postoperative radiotherapy immobilized with integrated cervicothoracic board (mask) system in breast cancer patients.Methods:Thirty-two breast cancer patients treated with postoperative radiotherapy immobilized with integrated cervicothoracic board (mask) system were prospectively recruited in this study. Breast/chest wall (cw) and supra/infraclavicular nodal region (sc) were irradiated with intensity-modulated radiotherapy. CBCT location verification in radiotherapy and target areas of the breast/chest wall and upper and lower collarbone were carried out, respectively. The consistency between setup errors and the position of the upper and lower target areas of 239 CBCT images was analyzed.Results:The translational setup errors of the breast/chest wall in the X-cw (left-right), Y-cw (superior-inferior), Z-cw (anterior-posterior) directions were (1.84±2.36) mm, (1.99±2.48) mm, and (1.75±1.86) mm, respectively. The translational setup errors of the supra/infraclavicular nodal region in the X-sc (left-right), Y-sc (superior-inferior), Z-sc (anterior-posterior) directions were (1.98±2.44) mm, (1.98±2.48) mm, and (1.71±1.79) mm, respectively. The differences of translational setup errors between the breast/chest wall and supra/infraclavicular nodal region in the X, Y, Z directions were (0.38±0.66) mm, (0.07±0.41) mm, and (0.45±0.92) mm, respectively. Conclusion:For the breast cancer patients treated with postoperative radiotherapy covering breast/chest wall and supra/infraclavicular nodal region, the integrated cervicothoracic board (mask) immobilization system provides good reproducibility and yields Sfew setup errors.

Relationship between gastric filling status and intra-or inter-fractional displacement of tumor in the preoperative radiotherapy of adenocarcinoma of the esophagogastric junction / 中华放射肿瘤学杂志

Objective:To investigate the relationship between gastric filling status and intra-or inter-fractional tumor displacement in patients with adenocarcinoma of the esophagogastric junction (AEG) undergoing preoperative radiotherapy.Methods:From October 2018 to June 2019, 10 patients with locally advanced AEG who received totally neoadjuvant therapy were enrolled in this prospective study. Patients received two markers implanted at the cranial and caudal borders of the tumors under gastroscope and a total of 20 fiducial markers were implanted finally. All patients underwent 4DCT scan under the gastric fasting and filling status. Ten images of 0% to 90% respiratory phase were automatically reconstructed by the system (Pinnacle 3, version 9.1, Philips Medical Systems, Eindhoven, The Netherland). Each patient obtained one hundred sets of images. Results:In the tumors proximal to the chest, gastric filling did not significantly affect intrafractional or interfractional tumor displacements. Nevertheless, in the tumors distal to the chest, the interfractional displacement in the cranio-caudal (CC) direction under the gastric fasting status was significantly larger compared with that under the gastric filling status (6.22±4.67 mm vs. 4.13±3.68 mm, P=0.013). To ensure 95% of the prescribed dose irradiated to at least 90% of the tumor volume during the radiotherapy, the margins of tumors proximal to the chest in the left-right (LR), antero-posterior (AP) and CC directions were 9 mm, 8.5 mm, 12.1 mm under gastric filling status with 300 ml semi-fluid. Six patients diagnosed with gastric cancer with proximal thoracic fiducial markers treated by preoperative radiotherapy were included in the validation group, revealing that the fiducial markers of 93% patients were covered in this margin. Conclusion:During the preoperative radiotherapy in AEG patient, the approach of quantitative gastric filling can be considered.

Research progress on the influencing factors and prognosis of radiation-induced lymphopenia / 中华放射肿瘤学杂志

Lymphocyte-led immunity plays an important role in the occurrence and development of tumors. It has been found that radiotherapy can induce lymphopenia in patients with solid tumors, and radiotherapy-induced lymphopenia (RIL) might be caused by the irradiation of circulating blood. The sensitivity to irradiation differs among different subtypes of lymphocytes. RIL can be affected by radiation fractionation, technique and volume. Meanwhile, it has been proven that RIL can significantly reduce the survival of patients with multiple solid tumors. In this article, relevant researches were reviewed, aiming to advance clinical treatment decisions and optimize radiotherapy protocols.

Clinical efficacy and prognosis of 85 patients with extracranial metastatic breast cancer receiving radiotherapy / 中华放射肿瘤学杂志

Objective:To evaluate the clinical efficacy of radiotherapy in the treatment of extracranial metastatic breast cancer, and to investigate the significance and prognostic factors of whole-lesion radiotherapy (WLRT).Methods:Clinical data of 85 patients with extracranial metastatic breast cancer treated with radiotherapy between 2014 and 2019 were retrospectively analyzed. Thirty-six patients were assigned into the WLRT group and 49 in the non-WLRT group. The local control (LC), progression-free survival (PFS) and overall survival (OS) were calculated by Kaplan- Meier method, log-rank test and univariate prognostic analysis. Cox proportional hazards model was used for multivariate prognostic analysis. Results:The median follow-up time was 26.7 months. The 2-year LC, PFS, OS rates were 77%, 26%, 77%, respectively. The 2-year LC (91% vs. 67%, P=0.001), PFS (47% vs. 8%, P<0.001), OS rates (84% vs. 71%, P=0.010) in the WLRT group were significantly higher than those in the non-WLRT group, respectively. Multivariate analysis demonstrated that WLRT was an independent favorable prognostic factor for the LC, PFS and OS. Furthermore, bone metastasis alone was associated with improved LC and positive hormone receptor status was correlated with improved OS. Conclusions:WLRT has the potential to prolong the survival of patients with extracranial metastatic breast cancer. The patients with bone metastases alone obtain better LC, whereas those with negative hormone receptor status has worse OS.

Comparison of the value of two scores for predicting prognosis in patients with locally advanced rectal cancer undergoing concurrent chemoradiotherapy plus surgery / 中华放射肿瘤学杂志

Objective:To evaluate the prognostic significance of neoadjuvant rectal (NAR) score and downstaging depth score (DDS) after neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC).Methods:Retrospective analysis was performed for 200 patients with LARC (T 3-T 4 and/or N 1-N 2, M 0), who were initially treated in the Cancer Hospital of Chinese Academy of Medical Sciences from 2015 to 2018. All patients had baseline MRI data and received preoperative nCRT and radical resection. All patients received preoperative radiotherapy with a dose of 45-50Gy combined with concurrent capecitabine. The effect of NAR and DDS scores on clinical prognosis was statistically compared. The 3-year disease-free survival (DFS) was calculated using the Kaplan- Meier method and compared by the log- rank test. Cox proportional hazards model was used to perform multivariate survival analysis. The predictive performance for 3-year DFS was calculated using the receiver operating characteristic (ROC) curve. Results:The median follow-up time was 30.5(10.6-54.0) months. In terms of DDS, the 3-year DFS rate was 56.4% in the DDS ≤0 group, significantly lower than 83.0% in the DDS >0 group ( P=0.002). In terms of NAR score, the 3-year DFS rates were 90.1%, 73.8% and 53.6% in NAR score ≤8, 8-16 and>16 groups, respectively ( P<0.001). In the whole cohort, the area under the ROC curve (AUC) of DDS and NAR scores for predicting 3-year DFS were 0.683 and 0.756( P=0.037). In yp0-I stage patients ( n=72), the AUC of DDS and NAR scores for predicting 3-year DFS were 0.762 and 0.569( P=0.032). Conclusions:High DDS and low NAR scores after nCRT indicate good prognosis for patients with LARC. NAR score yields better accuracy than DDS in predicting clinical prognosis, but DDS is significantly better than NAR score in yp0-I stage population.

Application of visual feedback coaching bar in deep inspiration breath holding during left breast cancer radiotherapy / 中华放射肿瘤学杂志

Objective:To evaluate the application of visual feedback coaching method, which is embedded in an optical surface monitoring system, in deep inspiration breath holding during the radiotherapy in left breast cancer patients after breast-conserving surgery.Methods:Thirty patients with left breast cancer, who were scheduled to receive the whole breast radiotherapy after breast-conserving surgery, met the requirements of deep inspiration breath holding after respiratory coaching with the visual feedback coaching module in the optical surface monitoring system. Active breathing control equipment was used to control breath-holding state and CT simulation was performed. During treatment, optical surface monitoring system was used to guide radiotherapy. All patients were randomly divided into two groups. In group A ( n=15), visual feedback respiratory training method was utilized and not employed in group B ( n=15). In group A, the visual feedback coaching bar of the optical surface monitoring system was implemented, while audio interactive method was employed to guide patients to hold their breath. Real-time data of optical body surface monitoring were used to compare the interfraction reproducibility and intrafraction stability of breath holding fraction between two groups. Besides, the number of breath holding and treatment time per fraction were also compared. GraphPad prism 6.0 software was used for data processing and mapping, and SPSS 21.0 software was used for analyzing mean value and normality testing. Results:Compared with the control group, the reproducibility in the experiment group was reduced from 1.5 mm to 0.7 mm, the stability was reduced from 1.1 mm to 0.8 mm, the mean number of breath holding required per fraction was decreased from 4.6 to 2.4, the mean beam-on time per fraction from 336 s to 235 s, and the treatment time per fraction was shortened from 847 s to 602 s (all P<0.05), respectively. Conclusions:The application of visual feedback coaching method can improve the reproducibility and stability of breath holding during radiotherapy for left breast cancer, and it can also effectively reduce the number of breath holding and shorten the treatment time per fraction.

Comparison of MRI and CT for target volume delineation and dose coverage for partial breast irradiation in patients with breast cancer / 中华放射肿瘤学杂志

Objective:To compare magnetic resonance imaging (MRI)-based and computed tomography (CT)-based target volume delineation and dose coverage in partial breast irradiation (PBI) for patients with breast cancer, aiming to explore the application value of MRI localization in PBI after breast-conserving surgery.Methods:Twenty-nine patients with early breast cancer underwent simulating CT and MRI scans in a supine position. The cavity visualization score (CVS) of tumor bed (TB) was evaluated. The TB, clinical target volume (CTV), planning target volume (PTV) were delineated on CT and MRI images, and then statistically compared. Conformity indices (CI) between CT- and MRI-defined target volumes were calculated. PBI treatment plan of 40 Gy in 10 fractions was designed based on PTV-CT, and the dose coverage for PTV-MRI was evaluated.Results:The CVS on CT and MRI images was 2.97±1.40 vs. 3.10±1.40( P=0.408). The volumes of TB, CTV, PTV on MRI were significantly larger than those on CT, (24.48±16.60) cm 3vs. (38.00±19.77) cm 3, (126.76±56.81) cm 3vs. (168.42±70.54) cm 3, (216.63±81.99) cm 3vs. (279.24±101.55) cm 3, respectively, whereas the increasing percentage of CTV and PTV were significantly smaller than those of TB. The CI between CT-based and MRI-based TB, CTV, PTV were 0.43±0.13, 0.66±0.11, 0.70±0.09( P<0.001), respectively. The median percentage of PTV-MRI receiving 40 Gy dose was 81.9%(62.3% to 92.4%), significantly lower than 95.6%(95.0%~97.5%) of PTV-CT. Conclusions:The CVS between CT and MRI is not significantly different, but the MRI-based TB, CTV, PTV are significantly larger than CT-based values. The PTV-MRI is of underdose if PBI treatment plan is designed for PTV-CT. As a supplement of CT scan, MRI can enhance the accuracy of TB delineation after breast-onserving surgery.

Efficacy analysis of hypofractionated intensity-modulated radiation therapy combined with hormonal therapy for pelvic lymph node metastatic prostate cancer / 中华放射肿瘤学杂志

Objective:To investigate the efficacy and prognosis of hypofractionated intensity-modulated radiation therapy combined with hormonal therapy in the treatment of pelvic lymph node metastatic prostate cancer.Methods:Clinical data of 42 IV A prostate cancer patients who received hypofractionated intensity-modulated radiation therapy combined with hormonal therapy in Cancer Hospital of Chinese Academy of Medical Sciences between 2006 and 2018 were retrospectively analyzed. The total irradiation doses to the prostate and seminal vesicles were 67.5 Gy/25f, 2.7 Gy/f. The prophylactic irradiation doses to the pelvic lymph nodes were 45-50 Gy with a daily fraction dose of 1.8-2.0 Gy. Thirty-three patients with residual lymph nodes were boosted to 60.0-67.5 Gy for the residual area, 2.4-2.7 Gy/f. Androgen deprivation therapy included surgical castration or luteinizing hormone-releasing hormone agonists combined with antiandrogens. Survival rate was calculated using Kaplan- Meier method. The differences between two groups were analyzed by log-rank test. Prognostic factors were identified by univariate and multivariate analyses. Results:The median follow-up was 65.5 months (range, 5 to 150 months). The 5-year and 10-year failure-free survival (FFS) rates in the whole group were 67% and 45%, respectively. No clinical recurrence was observed in the irradiation field. The 5-year and 10-year prostate cancer-specific survival/overall survival (PCSS/OS) rates were 85% and 60%, respectively. Gleason score (≥8 and<8) and duration of hormonal therapy impacted the FFS (both P<0.05). The duration of hormonal therapy was an independent prognostic factor for PCSS/OS ( P=0.003). Conclusions:Hypofractionated intensity-modulated radiotherapy combined with hormonal therapy yields optimistic clinical efficacy in the treatment of pelvic lymph node metastatic prostate cancer. Gleason score (≥8 and <8) and duration of hormonal therapy are critical prognostic factors.

Radiation oncology residency training programs in China: investigation and comparison with western programs / 中华放射肿瘤学杂志

Objective:To summarize the experience of radiation oncology residency training programs in western coutries, and provide evidence to improve the present Phase-I Radiation Oncology Residency Training Programs in China.Methods:An electronic questionnaire-based survey was conducted among residents and staffs in 6 top cancer centers in China and 5 centers from Europe and North America to collect their feedback regarding the description and comparison of different programs.Results:A total of 70 responses and 4 papers explaining relevant training programs from 26 residents and 23 teachers in Chinese hopsitals and 20 residents and 1 teacher from Europe and North America were received. The Radiation Oncology Residency Training Programs in China were designed into 2 phases, and the results in the current study were involved with the first phase. Program designs were similar in the following aspects: goal, clinical practice-based training, rotation curriculum, interim and final assessment. However, the total timeframe in the investigated Chinese Phase-I programs was shorter than that in western hospitals (2 to 3 years vs. 4 to 5 years). Chinese programs covered major common diseases, whereas rotation design was performed based on each individual disease in western programs. In Chinese programs, the working hours were mainly 40-60 h every week. Although the working hours were commensurate with local workforce regulations, the residents from MSK program had an outstanding longer working time of 60-80 h every week and treated more patients compared with other programs. Conclusions:The investigated Phase-I Radiation Oncology Residency Training Programs in 6 top cancer centers in China share common features in goals, training modes and assessments with western programs. However, our programs have shorter timeframe and less detailed requirements in individual disease than the western programs.

Research progress on stereotactic body radiotherapy for oligometastatic breast cancer / 中华放射肿瘤学杂志

Distant metastasis is the leading cause of death for breast cancer patients, and advanced metastatic breast cancer is mainly considered incurable. Oligometastasis is an" intermediate stage" between local primary tumor and extensive metastasis. As a local treatment approach, radiotherapy plays an important role in the management of oligometastatic breast cancer. The development of stereotactic body radiotherapy (SBRT) allows the delivery of ablative doses to the targets without exceeding the dose constraints of organs-at-risk. Studies have shown that SBRT is safe and effective, with local control rates of more than 80% for breast cancer oligometastasis to the bone, lung, liver, brain, and lymph nodes. However, how to screen the true oligometastasis remains controversial. Randomized clinical trials will be essential to confirm whether SBRT can improve the survival outcomes.