子野个数限值对宫颈癌固定野调强放疗计划的影响

目的:分析子野个数限值对宫颈癌固定野调强放疗（fixed-field intensity-modulated radiotherapy,ff-IMRT）计划的影响，寻求最优的子野个数限值。方法:选取10例接受ff-IMRT的宫颈癌患者，基于Monaco 5.11.03计划系统，以45 Gy/25 f处方剂量分别对同一患者设计8种ff-IMRT计划（ff-IMRT计划依据子野个数限值命名，子野个数限值分别为40、60、70、80、100、120、130、150），采用SPSS 20.0软件比较除plan100之外7个ff-IMRT计划与plan100剂量学参数、优化时间和治疗参数的差异。结果:8种ff-IMRT计划归一化后，plan40和plan60的D2%、Dmin、CI和HI均劣于plan100（P＜0.05）。8种ff-IMRT计划均能较好保护危及器官（organ at risk,OAR）和正常组织。plan40小肠V45;plan40和plan60小肠D2cc，直肠、膀胱V45、D40%，两侧股骨头V40和正常组织 V35、V40均高于plan100（P＜0.05）。plan40和plan60优化时间、治疗参数均优于plan100（P＜0.05）；plan120、plan130和plan150子野面积、子野个数（51~150 cm2和＞150 cm2）和出束时间均劣于plan100（P＜0.05）。结论:子野个数限值为70~100时，ff-IMRT计划能兼顾剂量学参数满足临床要求、优化时间和治疗参数最优化，建议在设计宫颈癌ff-IMRT计划时在该范围内设置子野个数限值。     

A systematic review of axillary nodal irradiation for the management of the axilla in patients with early-stage breast cancer

BackgroundGiven numerous publications and clinical trials regarding axillary management in breast cancer, we sought to summarize this complex literature to help clarify this field for clinicians. This systematic review focuses on the role of irradiation of the axillary nodes (locoregional nodal irradiation [LRNI]) in the management of the axilla in patients with early-stage breast cancer in various clinical settings.MethodsWe searched MEDLINE and EMBASE databases, the Cochrane library, the proceedings of the ASCO, the ASTRO, the ESMO, the ESTRO, and the San Antonio Breast Cancer Symposium (2016–2019) meetings. The quality of the studies was assessed with design-specific tools. The study was registered in PROSPERO.ResultsWe included one systematic review, one individual patient data (IPD) meta-analysis, and five randomized controlled trials (RCTs). After axillary lymph node dissection (ALND), LRNI resulted in small benefits in breast cancer specific mortality, locoregional recurrence, and distant metastases-free survival but not overall survival. After a positive sentinel node biopsy (SLNB), LRNI may provide equivalent locoregional control and disease-free survival (DFS) compared to ALND with a lower risk of lymphedema. No randomized data is available for the neoadjuvant setting.ConclusionsThe summary of the role of radiation, is relevant to radiation oncologists for choosing the correct cohort of patient requiring LRNI and to surgeons making clinical decisions regarding the timing and type of breast reconstruction offered to patients.     

What information can we gain from performing adaptive radiotherapy of head and neck cancer patients from the past 10 years?

The aim of the review was to present the current literature status about replanning regarding anatomical and dosimetric changes in the target and OARs in the head and neck region during radiotherapy, to discuss and to analyze factors influencing the decision for adaptive radiotherapy of head and neck cancer patients. Significant progress has been made in head and neck patients’ evaluation and qualification for adapted radiotherapy over the past ten years. Many factors leading to anatomical and dosimetric changes during treatment have been identified. Based on the literature, the most common factors triggering re-plan are weight loss, tumor and nodal changes, and parotid glands shrinkage. The fluctuations in dose distribution in the clinical area are significant predictive factors for patients’ quality of life and the possibility of recovery. It has been shown that re-planning influence clinical outcomes: local control, disease free survival and overall survival. Regarding literature studies, it seems that adaptive radiotherapy would be the most beneficial for tumors of immense volume or those in the nearest proximity of the OARs. All researchers agree that the timing of re-planning is a crucial challenge, and there are still no clear consensus guidelines for time or criteria of re-planning. Nowadays, thanks to significant technological progress, the decision is mostly made based on observation and supported with IGRT verification. Although further research is still needed, adaptive strategies are evolving and now became the state of the art of modern radiotherapy.     

Metastasis-directed Therapy in Prostate Cancer: Prognostic Significance of the ESTRO/EORTC Classification in Oligometastatic Bone Disease

AimsOligometastatic disease (OMD) represents a spectrum of clinical scenarios and various classification systems have been proposed. Bone-only OMD can occur in patients with advanced prostate cancer and validated decision-making tools are needed to assist patient selection for metastasis-directed therapy. The aim of the present study was to determine the prognostic utility of a classification system for OMD.Materials and methodsA retrospective review was conducted of all patients with bone-only oligometastatic prostate cancer treated with stereotactic body radiotherapy (SBRT) since November 2011. SBRT was delivered using CyberKnife® and gantry-based linear accelerator platforms. All patients were classified into oligometastatic states based on the European Society for Radiotherapy and Oncology/European Organisation for Research and Treatment of Cancer (ESTRO/EORTC) classification system. Kaplan–Meier and Cox regression analyses were carried out to determine the prognostic utility of this classification system.ResultsIn total, 105 patients with 145 osseous metastases were treated over 119 sessions. The median follow-up after SBRT was 23 months (interquartile range 10–39.8). Twelve patients had died after a median time of 31 months. The 3-year metastatic progression-free survival was 23% (95% confidence interval 13–32) and the 3-year overall survival was 88% (95% confidence interval 80–96). Patients in a metachronous oligometastatic state were 4.50 (95% confidence interval 1.19–17.10, P = 0.03) times more likely to experience metastatic progression compared with those with synchronous oligometastases, and 6.69 (95% confidence interval 1.05–42.50, P = 0.04) times more likely to experience any failure. Hazard ratio magnitudes increased for patients in a repeat oligometastatic state. The multivariate model for both metastatic progression-free survival and failure-free survival found prostate-specific antigen doubling time <4 months (P = 0.002; P = 0.05) to independently predict for progression.ConclusionThe ESTRO/EORTC classification of OMD predicts for progression in patients treated with SBRT for bone-only oligometastatic prostate cancer at our institution. Further validation in prospective series over multiple tumour sites is needed. These characterisation factors should be assessed in patients considered for metastasis-directed therapy together with established prognostic features.     

保乳术后放疗中钛夹动度与乳腺大小及钛夹位置的相关性

【摘要】目的:分析保乳术后放疗患者钛夹动度，并探讨其与乳腺大小、钛夹位置的相关性。方法:随机选取保乳术后放疗患者15例，每周两次锥形束CT。测量乳腺基底面直径（D）和乳高轴（H），以瘤床质心为原点将临床靶区分4个象限。记录各象限内钛夹在左右、腹背、头脚方向动度（MLR、MAP、MSI）以及其与临床靶区最内、最前、最上的距离（DSLR、DSAP、DSSI）。结果:MLR、MAP、MSI分别为（2.2±3.0）、（-1.1±3.6）、（0.8±4.7） mm；系统误差Σ在左、右、腹、背、头、脚分别为1.7、2.2、2.0、2.4、2.9、3.0 mm，随机误差σ分别为2.4、4.0、3.2、4.0、4.7、4.7 mm；靶区对应外放5.9、8.3、7.2、8.8、10.5、10.9 mm。一象限内，当D×H<99.89 cm2，MAP和D×H强相关（r=0.805），MLR、MAP均和DSLR、DSAP、DSSI强正相关（r=0.94, 0.94, 0.91；0.87, 0.91, 0.92），MSI和DSLR、DSAP强正相关（r=0.91, 0.94）；四象限内，当D×H<90.71 cm2，MAP和DSLR，MSI和DSAP均强负相关（r=-0.96；-0.95），MLR和DSLR强正相关（r=0.91）。结论:钛夹动度有各向异性，以SI方向外扩最大，并易受乳腺大小、钛夹位置影响。     

MR引导放疗在胰腺癌中的应用

放疗是治疗胰腺癌的重要手段。但受胰腺运动等因素影响,放疗疗效难以充分发挥。更高效的胰腺癌放疗有赖于运动管理方式的改进与高质量的图像引导。新兴的MR引导放疗技术软组织分辨率高、无额外辐射、能进行功能成像,经过大量研究评估与验证,其在靶区与危及器官的精准勾画、辅助运动管理和自适应放疗等方面有着巨大优势,有望更好地发挥放疗在胰腺癌治疗中的作用。本文就MR引导放疗在胰腺癌治疗中的应用作一综述和展望。     

Predictors of survival following surgical resection of limited-stage small cell lung cancer

BackgroundAdjuvant chemotherapy, postoperative radiation (PORT), and prophylactic cranial irradiation (PCI) have been individually examined in limited-stage small cell lung cancer (SCLC). There is a paucity of data on the effectiveness of each adjuvant treatment modality when used in combination after surgical resection of SCLC.MethodsData were collected from 5 cancer centers on all patients with limited-stage SCLC who underwent surgical resection between 1986 and 2019. Univariate and multivariable models were conducted to identify predictors of long-term outcomes, focusing on freedom from recurrence and survival benefit of adjuvant chemotherapy, PORT, and PCI.ResultsA total of 164 patients were analyzed. Multivariable Cox regression analysis did not identify any adjuvant therapies to significantly influence recurrence in this cohort. Specifically, PORT was not associated with a significant influence on locoregional recurrence and PCI was not significantly associated with intracranial outcomes. Adjuvant chemotherapy improved survival in all stage I through III disease (hazard ratio, 0.49; 95% confidence interval, 0.29-0.81; P = .005) and even in pathologically node negative patients (hazard ratio, 0.49; 95% confidence interval, 0.27-0.91; P = .024). Although PCI was found to improve survival in univariate analysis, it was not significant in a multivariable model. PORT was not found to affect survival on either univariate or multivariable analysis.ConclusionsThis is among the largest multi-institutional studies on surgically resected limited-stage SCLC. Our results highlight survival benefit of adjuvant chemotherapy, but did not identify a statistically significant influence from mediastinal PORT or PCI in our cohort. Larger prospective studies are needed to determine the benefit of PORT or PCI in a surgically resected limited-stage SCLC population.     

A Predictive Model for Reactive Tube Feeding in Head and Neck Cancer Patients Undergoing Definitive (Chemo) Radiotherapy

AimsCareful management of a patient's nutritional status during and after treatment for head and neck squamous cell cancers (HNSCC) is crucial for optimal outcomes. The aim of this study was to develop a model for stratifying a patient's risk of requiring reactive enteral feeding through a nasogastric tube during radiotherapy for HNSCC, based on clinical and treatment-related factors.Materials and methodsA cohort of consecutive patients treated with definitive (chemo)radiotherapy for HNSCC between January 2016 and January 2018 was identified in the institutional electronic database for retrospective analysis. Patients requiring enteral feeding pretreatment were excluded. Clinical and treatment data were obtained from prospectively recorded electronic clinical notes and planning software.ResultsBaseline patient characteristics and tumour-related parameters were captured for 225 patients. Based on the results of the univariate analysis and using a stepwise backwards selection process, clinical and dosimetric variables were selected to optimise a clinically predictive multivariate model, fitted using logistic regression. The parameters found to affect the probability, P, of requiring a nasogastric feeding tube for >4 weeks in our clinical multivariate model were: tumour site, tumour stage (early T0/1/2 stage versus advanced T3/T4 stage), chemotherapy drug (none versus any drug) and mean dose to the contralateral parotid gland. A scoring model using the regression coefficients of the selected variables in the clinical multivariate model achieved an area under the curve (AUC) of 0.745 (95% confidence interval 0.678–0.812), indicating good discriminative performance. Internal validation of the model involved splitting the dataset 80:20 into training and test datasets 10 times and assessing differences in AUC of the model fitted to these.ConclusionsWe developed an easy-to-use prediction model based on both clinical and dosimetric parameters, which, once externally validated, can lead to more personalised treatment planning and inform clinical decision-making on the appropriateness of prophylactic versus reactive enteral feeding.     

A Pre-implementation Study of Volumetric Modulated Arc Therapy for Same-day Planning and Treatment of Vertebral Bone Metastases Within a Rapid-access Palliative Radiotherapy Programme

AimsWe aimed to develop a process for same-day contouring, planning, quality assurance and delivery of volumetric modulated arc therapy (VMAT) for vertebral bone metastases within our institution's rapid-access palliative radiotherapy programme.Materials and methodsTwo thoracic (T6–7, T3–7) and two lumbar (L2–3, L1–5) targets were contoured on computed tomography images acquired from an anthropomorphic phantom and five patient scans. Inverse planning aimed to provide coverage of a prescribed dose of 8 Gy with a combined lung V2Gy < 25% and a combined kidney mean dose <2 Gy. Serial plans were created to identify an efficient combination of six main planning variables specific to our treatment planning system: (i) voxel size (3 mm versus 5 mm), (ii) Monte Carlo statistical uncertainty (1% per calculation versus 3% per control point), (iii) fluence smoothing (medium versus high), (iv) number of iterations of segment shape changes during optimisation (1 versus 5), (v) dose calculation algorithm (Monte Carlo versus pencil beam) and (vi) number of arcs (single versus multiple). Contouring, planning, quality assurance and treatment delivery were timed.ResultsThe combination of planning variables deemed efficient and appropriate was: a 3 mm voxel size, statistical uncertainty of 1% per calculation, medium fluence smoothing, five iterations of segment shape changes, Monte Carlo dose calculation and single full arc delivery. Patient scan contouring times ranged from 7 to 9 min (T6–7), 11–13 min (T3–7), 5–7 min (L2–3) and 8–10 min (L1–5) and planning times ranged from 9 to 15 min (T6–7), 13–25 min (T3–7), 18–25 min (L2–3) and 21–31 min (L1–5). Physics quality assurance times ranged from 15 to 21 min and beam-on times ranged from 3 to 6 min.ConclusionsThe combined elements of VMAT for thoracic and lumbar vertebral bone metastases were completed in under 2 h. This new process makes same-day contouring, planning, quality assurance and treatment delivery of VMAT feasible within our rapid-access palliative radiotherapy programme.