Correlation between mechanical stress by finite element analysis and 18F‐fluoride PET uptake in hip osteoarthritis patients

¹⁸F‐fluoride positron emission tomography (¹⁸F‐fluoride PET) is a functional imaging modality used primarily to detect increased bone metabolism. Increased ¹⁸F‐fluoride PET uptake suggests an association between increased bone metabolism and load stress at the subchondral level. This study therefore examined the relationship between equivalent stress distribution calculated by finite element analysis and ¹⁸F‐fluoride PET uptake in patients with hip osteoarthritis. The study examined 34 hips of 17 patients who presented to our clinic with hip pain, and were diagnosed with osteoarthritis or pre‐osteoarthritis. The hips with trauma, infection, or bone metastasis of cancer were excluded. Three‐dimensional models of each hip were created from computed tomography data to calculate the maximum equivalent stress by finite element analysis, which was compared with the maximum standardized uptake value (SUV_max) examined by ¹⁸F‐fluoride PET. The SUV_max and equivalent stress were correlated (Spearman's rank correlation coefficient ρ = 0.752), and higher equivalent stress values were noted in higher SUV_max patients. The correlation between SUV_max and maximum equivalent stress in osteoarthritic hips suggests the possibility that ¹⁸F‐fluoride PET detect increased bone metabolism at sites of stress concentration. This study demonstrates the correlation between mechanical stress and bone remodeling acceleration in hip osteoarthritis. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:78–83, 2015.     

Ultrasound Modulates the Splenic Neuroimmune Axis in Attenuating AKI

We showed previously that prior exposure to a modified ultrasound regimen prevents kidney ischemia-reperfusion injury (IRI) likely via the splenic cholinergic anti-inflammatory pathway (CAP) and α7 nicotinic acetylcholine receptors (α7nAChR). However, it is unclear how ultrasound stimulates the splenic CAP. Further investigating the role of the spleen in ischemic injury, we found that prior splenectomy (–7d) or chemical sympathectomy of the spleen with 6-hydroxydopamine (6OHDA; –14d) exacerbated injury after subthreshold (24-minute ischemia) IRI. 6-OHDA–induced splenic denervation also prevented ultrasound-induced protection of kidneys from moderate (26-minute ischemia) IRI. Ultrasound-induced protection required hematopoietic but not parenchymal α7nAChRs, as shown by experiments in bone marrow chimeras generated with wild-type and α7nAChR^–/– mice. Ultrasound protection was associated with reduced expression of circulating and kidney-derived cytokines. However, splenocytes isolated from mice 24 hours after ultrasound treatment released more IL-6 ex vivo in response to LPS than splenocytes from sham mice. Adoptive transfer of splenocytes from ultrasound-treated (but not sham) mice to naïve mice was sufficient to protect kidneys of recipient mice from IRI. Ultrasound treatment 24 hours before cecal ligation puncture–induced sepsis was effective in reducing plasma creatinine in this model of AKI. Thus, splenocytes of ultrasound-treated mice are capable of modulating IRI in vivo, supporting our ongoing hypothesis that a modified ultrasound regimen has therapeutic potential for AKI and other inflammatory conditions.     

Feasibility of aspirin continuation during the perioperative period for pulmonary resection in lung cancer patients: a retrospective study at a single institute in Japan

Purpose

To evaluate the feasibility of aspirin continuation during the perioperative period for pulmonary resection in lung cancer patients.

Methods

A retrospective study was conducted in 46 patients who were taking aspirin and underwent pulmonary resection. The indications for aspirin were generally a cardiovascular or cerebrovascular comorbidity. Whether to continue or discontinue aspirin was determined based on the severity of the cardiovascular or cerebrovascular comorbidity, along with the patient’s overall condition. The intraoperative and postoperative outcomes were compared between patients continuing and those discontinuing aspirin.

Results

Twenty patients continued (group C) and 26 patients discontinued (group D) aspirin. The length of the operation (226 ± 97 min in group C vs. 189 ± 90 min in group D), intraoperative bleeding (234 ± 232 vs. 204 ± 367 g) and average pleural discharge on postoperative days 1, 2 and 3 (331, 230 and 215 vs. 304, 210 and 174 ml/day) showed no significant differences between the two groups. The postoperative complication rates were also not significantly different between the two groups [eight patients (40 %) in group C vs. nine patients (35 %) in group D].

Conclusions

Continuous administration of aspirin during the perioperative period for pulmonary resection in lung cancer patients appears to be clinically feasible in the Japanese population.     

Resection of rectal cancer: A historical review

Local control of rectal cancer and patient survival have improved remarkably with advances in surgical techniques and adjuvant therapy. By applying advanced surgical principles, surgeons can now excise most rectal cancers completely, often preserving the anal sphincter and leaving the patient with relatively normal bowel and pelvic function. Historically, the earliest surgical approaches to rectal cancer were via the perineum. As surgical techniques and general anesthesia improved, other approaches such as a posterior approach were undertaken to improve access to the whole rectum. Consequently, abdominoperineal resection became the standard treatment until anterior resection was introduced for proximal rectal cancers. The most important surgical breakthrough in recent years has been the advent of total mesorectal excision (TME). The emphasis in rectal cancer surgery is on preservation of function, with dissection being done in appropriate anatomical planes. Thus, mobilization of the rectum has a long history, and is seen in modern procedures including TME and intersphincter resection. This article reviews the progression of the surgical management of rectal cancer with reference to historical perspectives. We discuss the major surgical considerations for mobilization of the rectum in several surgical procedures, from conventional operations to modern standardized TME.     

Pathology and images of radiation-induced hepatitis: a review article

Recent advances in highly conformal radiotherapies greatly extend the indications for radiotherapy of liver tumors. However, because of poor tolerance to hepatic radiation, estimation of the intensity of irradiation of the liver is important, particularly for a cirrhotic liver. Knowledge of radiation-induced hepatitis is important for understanding how to optimize hepatic radiation therapy. Pathological changes of the irradiated liver, which include perivenular fibrosis, sinusoidal obstruction, and damage to Kupffer cells and hepatocytes, can be visualized using clinical imaging techniques. This review article discusses and illustrates the pathological and radiological changes of hepatic tumors and the surrounding parenchyma of the irradiated liver.     

Comparison between manual and automatic image registration in image-guided radiation therapy using megavoltage cone-beam computed tomography with an imaging beam line for prostate cancer

This study aimed to compare and assess the compatibility of the bone-structure-based manual and maximization of mutual information (MMI)-algorithm-based automatic image registration using megavoltage cone-beam computed tomography (MV-CBCT) images acquired with an imaging beam line. A total of 1163 MV-CBCT images from 30 prostate cancer patients were retrospectively analyzed. The differences between setup errors in three directions (left–right, LR; superior–inferior, SI; anterior–posterior, AP) of both registration methods were investigated. Pearson’s correlation coefficients (r) and Bland–Altman agreements were evaluated. Agreements were defined by a bias close to zero and 95% limits of agreement (LoA) less than ±?3 mm. The cumulative frequencies of the absolute differences between the two registration methods were calculated to assess the distributions of the setup error differences. There were significant differences (p?<?0.001) in the setup errors between both registration methods. There were moderate (SI, r?=?0.45) and strong positive correlation coefficients (LR, r?=?0.74; AP, r?=?0.72), whereas the 95% LoA (bias?±?1.96?×?standard deviation of the setup error differences) were ??1.61?±?4.29 mm (LR), ??0.41?±?5.45 mm (SI), and 0.67?±?4.29 mm (AP), revealing no agreements in all directions. The cumulative frequencies (%) of the cases with absolute setup error differences within 3 mm in each direction were 80.83% (LR), 81.86% (SI), and 90.71% (AP), with all directions having large proportions of >?3-mm differences. The MMI-algorithm-based automatic registration is not compatible with the bone-structure-based manual registration and should not be used alone for prostate cancer.     

Distortion correction in whole-body imaging of live mice using a 1-Tesla compact magnetic resonance imaging system

Purpose  

The aim of this study was to establish a distortion correction applicable to whole-body imaging of live mice.     

Assessment of tumor hypoxia by 62Cu-ATSM PET/CT as a predictor of response in head and neck cancer: a pilot study

Objective

In radiotherapy and chemotherapy tumor hypoxia is recognized as a major obstacle to effective treatment. We undertook a pilot study in patients with locally advanced head and neck cancer to determine whether there is a relationship between tumor uptake of ⁶²Cu-ATSM and response to chemoradiotherapy.

Methods

Seventeen patients were studied using PET/CT with ⁶²Cu-ATSM and ¹⁸F-FDG prior to the initiation of radiotherapy and chemotherapy. All patients had locally advanced head and neck cancer (stage III or IV). Tumor uptake in all patients was measured by region of interest analysis using the maximal standardized uptake value (SUVmax). A total dose of 50.4–70.2 Gy (median 70.2 Gy) was delivered in 29–39 fractions (median 39 fractions) to tumor. In patients with (non CR) and without (CR) residual/recurrent tumors at 2-year post irradiation, the statistical significance of the differences in tumor ⁶²Cu-ATSM SUVmax, T/M ratio, ¹⁸F-FDG SUVmax and tumor volume were analyzed using Student’s t test and Welch test. The relationship between clinical outcome and ⁶²Cu-ATSM/¹⁸F-FDG uptake patterns was analyzed using Kruskal–Wallis test. The correlation between SUVmax of ⁶²Cu-ATSM and ¹⁸F-FDG was compared by Spearman’s rank correlation test.

Results

Two of the 17 patients that were enrolled in our study were excluded from the final analysis. Of the 15 remaining patients, 9 patients were free of disease and 6 patients had residual/recurrent tumors. The SUVmax differed significantly (p < 0.05) between patients with or without residual/recurrent tumor on ⁶²Cu-ATSM PET/CT. Six of the 10 patients with tumors SUVmax >5.00 had residual/recurrent tumor, whereas all of the 5 patients with tumors SUVmax <5.00 were free of disease. There was no significant difference in FDG uptake between patients with and without residual/recurrent tumor.

Conclusions

The results of this pilot study suggested that ⁶²Cu-ATSM uptake may be a predictive indicator of tumor response to chemoradiotherapy in patients with locally advanced head and neck cancer.