Brachytherapy: An emblematic example of extreme hypofractionated regimen

In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3 Gy), then ultra (dose/fraction: 5.2 to 6.1 Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20 Gy/fraction), the use of a single fraction of 19 to 23 Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.     

Prospective characterization of incident hepatic steatosis in pediatric and adolescent patients after total pancreatectomy with islet autotransplantation

BackgroundHepatic steatosis has been described as a common finding in adults following total pancreatectomy with islet autotransplantation (TPIAT) but it is unknown if this occurs in children and adolescents.ObjectivesTo define the frequency of post-TPIAT hepatic steatosis in a sample of children and adolescents and to identify clinical predictors of incident steatosis post-TPIAT.MethodsIn this prospective study, consecutive participants at least 1-month post-TPIAT underwent a liver MRI with proton density fat fraction (PDFF) and blood draw at our pediatric academic medical center between April 2021 and January 2022. Comparison clinical pre-TPIAT liver MRI or ultrasound and insulin use and graft function data were extracted from the medical record. T-tests were used for the comparison of means across continuous variables between participants with and without post-TPIAT steatosis.ResultsA total of 20 participants (mean: 13 ± 4 years; 12 female) were evaluated. Mean liver PDFF at research MRI was 7.4 ± 6.2% (range: 2–25%). Seven participants (35%) had categorical hepatic steatosis (PDFF>5%) post-TPIAT, five of whom had pre-TPIAT steatosis, reflecting a 13% (2/15; 95% CI: 2–40%) incidence of post-TPIAT steatosis. Participant characteristics were not significantly different between subgroups with and without post-TPIAT steatosis. Mean PDFF at research MRI was not different between graft function subgroups (7.5% optimal/good vs. 7.3% marginal/failure; p = .96).ConclusionOur study shows a moderate prevalence but low incidence of hepatic steatosis in a small sample of children and adolescents post-TPIAT. This study raises questions about a causal relationship between TPIAT and hepatic steatosis.     

碳离子和质子治疗胰腺癌安全性和有效性的系统评价及Meta分析

目的 评价碳离子和质子治疗胰腺癌（PaC）的安全性和有效性。方法 检索数据库纳入碳离子和质子治疗PaC的临床研究，检索时间为自建库至2019年6月。两位研究者独立筛选文献、提取资料。采用STATA 12.0和MetaAnalyst Beta 3.13软件进行Meta分析。结果 共纳入8篇文献，包含459例PaC患者。效应模型Meta分析显示，碳离子和质子治疗PaC的2、3、5级胃肠道溃疡发生率分别为7%、2%、0；2、3、4级厌食症发生率分别为6%、3%、0；1、2年总生存率（OS）分别为77%、45%；2年局部控制率为81%；1年无局部进展率为88%；1年局部复发率为15%。碳离子和质子治疗PaC的2、3、2～3级胃肠道溃疡发生率分别为6.8%、1.5%、9.2%和3.5%、8.3%、6.1%（均P>0.05）；1、2年OS分别为77.1%、44.4%和77.6%、49.7%（P均>0.05）。结论 碳离子和质子治疗PaC安全有效，两者的安全性和有效性相似。     

Effect of a Device-Free Compressed Shell Fixation Method on Hepatic Respiratory Movement: Analysis for Respiratory Amplitude of the Liver and Internal Motions of a Fiducial Marker

Purpose

Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed.

TQA数据趋势与TomoTherapy输出稳定性的联系

目的:探讨TomoTherapy QualityAssurance（TQA）数据趋势与螺旋断层放疗（Helical Tomotherapy，HT）系统输出的 联系。方法:回顾性分析了本院HT系统近3年内TQA各个模块的参数和数据趋势，探讨其与HT系统的静态输出剂量和 输出能量（D20/D10）变化的相关性。结果:楔形阶梯静态模块的z轴偏移参数与HT的静态输出剂量的相关性最强（r=0.883, P<0.01）。基本剂量测定模块的出口检测器平整度值对能量变化最敏感（r=0.902），其次是楔形阶梯静态模块的能量差异 （r=0.897）和楔形阶梯螺旋模块的能量差异（r=0.852），灵敏度分别为2.3×10-4、3.1×10-4和5.7×10-4。结论:TQA有助于用户 追踪HT输出剂量和能量变化，及早进行必要的机器维护或剂量校准。     

应用锥形束CT对种植区牙槽骨质量分类方法的改良研究

目的    应用锥形束CT（cone beam CT，CBCT）测量种植区牙槽骨质量并结合Lekholm和Zarb分类法对骨质量分类方法进行改良，以期为提高牙槽骨质量分类的准确性提供指导。方法    选择2015年10月至2017年10月在呼和浩特市口腔医院种植科进行种植修复的196例患者术前CBCT影像资料，应用 Invivo5诊断设计软件测量306个种植位点的牙槽骨皮质骨厚度和松质骨密度（皮质骨与松质骨的CT值差值），以Lekholm和Zarb分类法为基础结合测量数据对骨质量进行改良后的量化分类。结果    牙槽骨皮质骨厚度为0.18 ~ 2.89 mm，中位数为0.92 mm。皮质骨与松质骨的CT值差值为88.5 ~ 667.8 HU，应用百分位数法找到33.3%和66.6%对应的数值分别为297.8 HU和356.1 HU。依据此数据结合Lekholm和Zarb分类法将196例患者的306个种植位点骨质量分为4类，其中Ⅰ类骨种植位点46个（占15.0%），Ⅱ类骨104个（占34.0%），Ⅲ类骨114个（占37.3%），Ⅳ类骨42个（占13.7%）。结论    结合Lekholm和Zarb分类法，应用CBCT测量种植区牙槽骨质量并进行分类方法的改良，可为临床医生术前评估牙槽骨质量提供一定参考。     

Iron Deficiency Anemia Associated With Acid-Modifying Medications: Two Cases and Literature Review

Iron deficiency anemia is often listed among potential adverse effects of gastric acid-suppressive medications, given that gastric acidity promotes intestinal absorption of nonheme iron. Additionally, the antacid calcium carbonate can inhibit iron absorption. However, there is little direct clinical evidence that proton-pump inhibitors, histamine-2 receptor antagonists, or calcium carbonate cause iron deficiency anemia. Most case reports have had substantial limitations (e.g., minimal follow-up and presence of other causes of iron deficiency), and retrospective cohort studies have lacked sufficient patient-specific detail to make strong causal inferences. We present 2 cases—both with detailed, prospective 10-year follow-up—in which combinations of proton-pump inhibitors, histamine-2 receptor antagonists and calcium carbonate were clearly associated with development of iron deficiency anemia. Overt iron-deficiency anemia is probably uncommon in patients who use acid-modifying medications and who have no other conditions that predispose to iron deficiency. Nevertheless, clinicians should be aware of this potential complication, given widespread use of these agents.