IMRT improves local control in patients with nasopharyngeal carcinoma compared with conventional radiotherapy: propensity score-matched analysis.

BACKGROUND: It is still controversial whether intensity-modulated radiotherapy has an obvious advantage over conventional radiotherapy. The purposes of this study were to evaluate prognostic factors in pre-treatment characteristics for nasopharyngeal carcinoma and to compare treatment outcomes in patients who received intensity-modulated radiotherapy and patients who received two-dimensional radiotherapy or three-dimensional radiotherapy. METHODS: We reviewed patients with nasopharyngeal carcinoma who received chemoradiotherapy in our hospital during the period from 2000 to 2017, and we excluded patients who had a history of surgery for nasopharyngeal carcinoma and those who had distant metastases before treatment. A total of 72 patients who were treated by radiotherapy with concurrent chemotherapy were enrolled. All of the patients were irradiated with a total dose of 58-70 Gy. Overall survival, locoregional control and progression-free survival rates were compared in the groups treated by intensity-modulated radiotherapy and two-dimensional/three-dimensional radiotherapy. Propensity score matching was performed to homogenize the two groups. RESULTS: The median follow-up period was 62.5 months. After propensity score matching, in patients treated with intensity-modulated radiotherapy, the 5-year rate of overall survival, locoregional control and progression-free survival were 73.5, 95.2 and 72.7%, respectively. In patients treated with two-dimensional/three-dimensional radiotherapy, the 5-year rate of overall survival, locoregional control and progression-free survival were 69.1, 67.7 and 51.8%, respectively. There was a significant difference between the groups only in locoregional control. Late toxicities of grade 2 or higher were occurred in 38.5 and 24.2% of the patients treated by two-dimensional/three-dimensional radiotherapy and intensity-modulated radiotherapy, respectively. CONCLUSIONS: Our results suggested that intensity-modulated radiotherapy is more effective than two-dimensional/three-dimensional radiotherapy in patients with nasopharyngeal carcinoma, especially in locoregional control.

Prognostic value of the AJCC 8th edition staging system for Japanese patients treated with surgery followed by radiotherapy for breast cancer.

BACKGROUND: American Joint Committee on Cancer (AJCC) 8th Edition Breast Cancer Staging System, biological information in addition to anatomical information was added as a basis for prognosis evaluation, but its prognostic impact in Japanese patients treated with postoperative radiotherapy has not been discussed. To determine the applicability of the updated prognostic staging system, we evaluated the prognostic value and confirmed the effectiveness of this system in patients in whom postoperative radiotherapy was performed. MATERIALS AND METHODS: Patients who were treated with postoperative radiotherapy for breast cancer in our institution between January 2011 and December 2015 were restaged by the AJCC 8th pathological prognosis staging system, and then overall survival (OS), disease-free survival (DFS) rates and hazard ratios (HR) were analyzed to compare the predictive fit of the two staging systems. RESULTS: Five hundred and seven patients who in whom postoperative radiotherapy was performed for breast cancer were enrolled in this study. 36.1% patients were downstaged and 5.3% patients were upstaged from the 7th to 8th editions staging system classification. Kaplan-Meier curves and HRs showed differences in OS and DFS rates between the 7th edition and 8th edition staging systems. The AJCC 8th edition prognostic stage system has a better prognostic prediction of OS and DFS than does the 7th edition anatomic stage system. CONCLUSIONS: Compared with the 7th edition in breast cancer, AJCC 8th edition prognostic stage system has more precise stratification and superior prognostic value, providing a more accurate reference for the choice of radiotherapy for patients with breast cancer.

Fast Sample Adaptive Offset Jointly Based on HOG Features and Depth Information for VVC in Visual Sensor Networks.

Visual sensor networks (VSNs) can be widely used in multimedia, security monitoring, network camera, industrial detection, and other fields. However, with the development of new communication technology and the increase of the number of camera nodes in VSN, transmitting and compressing the huge amounts of video and image data generated by video and image sensors has become a major challenge. The next-generation video coding standard-versatile video coding (VVC), can effectively compress the visual data, but the higher compression rate is at the cost of heavy computational complexity. Therefore, it is vital to reduce the coding complexity for the VVC encoder to be used in VSNs. In this paper, we propose a sample adaptive offset (SAO) acceleration method by jointly considering the histogram of oriented gradient (HOG) features and the depth information for VVC, which reduces the computational complexity in VSNs. Specifically, first, the offset mode selection (select band offset (BO) mode or edge offset (EO) mode) is simplified by utilizing the partition depth of coding tree unit (CTU). Then, for EO mode, the directional pattern selection is simplified by using HOG features and support vector machine (SVM). Finally, experimental results show that the proposed method averagely saves 67.79% of SAO encoding time only with 0.52% BD-rate degradation compared to the state-of-the-art method in VVC reference software (VTM 5.0) for VSNs.

Evaluation of DIBH and VMAT in Hypofractionated Radiotherapy for Left-Sided Breast Cancers After Breast-Conserving Surgery: A Planning Study.

Background: Dosimetric parameters of the planning target volume (PTV) and organs at risk (OARs) were compared among 3 different radiotherapy (RT) modalities in left breast cancer patients after breast-conserving surgery (BCS). Methods: Eleven patients with left breast cancer after BCS were enrolled and underwent CT simulation in the free breathing (FB) and deep inspiration breath-hold (DIBH) position. Three-dimensional conformal RT (3DCRT) and volumetric modulated arc therapy (VMAT) plans were generated for each patient in the DIBH positions. A 3DCRT plan was also created in the FB position. A dose-volume histogram (DVH) was used to analyze each evaluation index of PTV and OARs. The principal outcomes were PTV dose, heart dose, right breast dose, left anterior descending coronary artery (LADCA) dose, and left lung dose. Results: For 3DCRT plans, significant dose reductions were demonstrated in all evaluation parameters of the heart, LADCA, and left lung doses in the DIBH position compared with those in the FB position (P < 0.05). In the DIBH position, significant dose reductions were found in the heart and LADCA in VMAT plans compared to those in 3DCRT plans (P < 0.05). For the right breast, VMAT reduced Dmean significantly (0.32 Gy vs 0.08  Gy, P < 0.01). There were no significant differences between 3DCRT and VMAT plans for the left lung dose in the DIBH position. The indicators of PTV had no significant difference between the 3 plans. Conclusion: DIBH and VMAT could reduce dosimetric parameters of the OARs in left breast cancer patients after BCS. RT plans for left breast cancer after BCS can be optimized by DIBH and VMAT techniques to minimize radiation-induced toxicity.

Effect of radiotherapy after breast-conserving surgery in elderly patients with early breast cancer according to the AJCC 8th Edition Breast Cancer Staging System in Japan.

BACKGROUND: The number of elderly patients in Japan with breast cancer has been gradually increasing. The aim of this study was to determine the efficacy of radiotherapy (RT) after breast-conserving surgery (BCS) for elderly patients with early breast cancer who were restaged according to the 8th Edition Breast Cancer Staging System. METHODS: We reviewed patients age ≥ 65 years who received BCS and adjuvant RT or BCS alone for breast cancer between 2010 and 2015 in our institution and restaged those patients using the AJCC 8th edition pathological prognostic staging system. We compared relapse-free survival (RFS) and overall survival (OS) rates in the RT group and no RT group. RESULTS: A total of 170 patients were eligible for analysis: 94 (55.3%) were treated with RT and 76 (44.7%) were treated without RT. Age (p < 0.01) was associated with the use of RT. Adjuvant RT significantly improved RFS (95.75% vs 84.21%, p = 0.02). There was no significant difference between the OS rates in the two groups. Univariate analysis showed that pathologic T stage and N stage were significantly associated with both RFS and OS and that histologic grade, chemotherapy, HER2, and RT were significantly associated with RFS, but not with OS. RT reduced the risk of recurrence (HR = 0.56, 95% CI = 0.19-0.96, p = 0.04). CONCLUSIONS: RT was associated with significantly improved RFS, but had no significant impact on OS in elderly patients with breast cancer after BCS. Adjuvant RT should be performed even for elderly patients with early breast cancer.

A case report and review of the literature: cardiotoxicities after radiotherapy for breast cancer patients with high-risk factors of cardiovascular disease.

Cardiovascular disease (CVD) is an important adverse effect of radiotherapy and is responsible for increased morbidity and mortality in long-term survivors with breast cancer. Patients may have pre-existing cardiovascular risk factors before treatment of breast cancer, and the effects of pre-existing cardiovascular risk factors can be compounded by radiotherapy. We report a case of left breast cancer in a 63-year-old female with a high risk of CVD who was suspected of having radiation-induced myocardium injury 1 year after postoperative adjuvant therapy. Radiation oncologists should not only reduce the adverse effects by perfecting radiotherapy technology but also consider reducing other high-risk factors for CVD.

Controversial issues in radiotherapy after breast-conserving surgery for early breast cancer in older patients: a systematic review.

Breast cancer is the most common malignant disease among older women, and the number of new older patients per year is increasing year by year. Radiotherapy has been confirmed as an important treatment after breast conservation for the reduction of local recurrence and mortality for all patients, including node-positive cases. However, there are fewer clinical trials evaluating the toxicity and benefits of radiotherapy for older patients. Whether radiotherapy can provide substantial benefit for older patients after breast-conserving surgery is controversial. This systematic review will focus on the key aspects of this controversial issue.