Oesophageal squamous cell carcinoma: relationship between fluorine-18 fludeoxyglucose positron emission tomography CT maximum standardised uptake value, metabolic tumour volume, and tumour, node and metastasis classification

OBJECTIVES

We aimed to evaluate the relationships between primary tumour, maximum standardised uptake value, metabolic tumour volume and seventh edition American Joint Committee on Cancer (AJCC) classification in oesophageal squamous cell carcinoma (OSCC) patients.

METHODS

Fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)-CT scans of 41 consecutive newly diagnosed OSCC patients were retrospectively reviewed. Maximum standard uptake value (SUV(max)) and metabolic tumour volume (MTV) were recorded. Two-tailed Spearman's correlation was used to analyse the relationships between the metabolic parameters and the AJCC staging system.

RESULTS

Positive correlations were observed between SUV(max), MTV and tumour (T) stage, in addition to node (N) stage and AJCC stage. Both metabolic parameters were independent variables that significantly affected the N stage and AJCC stage, and SUV(max) was the only independent variable that significantly affected the T stage.

CONCLUSION

The metabolic parameters derived from (18)F-FDG PET-CT were positively correlated with T, N and AJCC stage in primary OSCC. Our findings may suggest a complementary role of these parameters to seventh-edition AJCC staging in the prognostication of OSCC patients.

Early alteration of urinary exosomal aquaporin 1 and transforming growth factor β1 after release of unilateral pelviureteral junction obstruction

BACKGROUND/PURPOSE

Down-regulation of aquaporin 1 (AQP1) and up-regulation of transforming growth factor β(1) (TGF-β(1)) in the renal parenchyma have been demonstrated in children who underwent pyeloplasty for pelviureteral junction obstruction. However, no information about urinary exosomal AQP1 and TGF-β(1) during postobstructive polyuria in children with congenital unilateral hydronephrosis is available. The aim of the present study is to evaluate the urine concentration of exosomal AQP1 and TGF-β(1) on the first and the second day after surgery in children who underwent pyeloplasty.

METHODS

Twenty-two patients (age, 36.2 ± 17.1 months) with unilateral pelviureteral junction obstruction were examined in the study. For the first 2 days after the operation, the urine was collected separately from pyelostomy draining only from the postobstructed kidney and from the bladder catheter draining mostly from the contralateral kidney, which was used as an internal control. Urinary output, urinary osmolality, sodium, β(2)-microglobulin (β(2)-MG), and creatinine, as well as urinary exosomal AQP1 and TGF-β(1) excretion, were tested in each sample.

RESULTS

After pyeloplasty, a significantly decreased urinary excretion of exosomal AQP1 (≈ 64%) was found in the postobstructed kidney. The patients developed polyuria (807 ± 216 mL/24 h vs 484 ± 144 mL/24 h at day 1, 1021 ± 348 mL/24 h vs 603 ± 228 mL/24 h at day 2; P < .01) and reduced urine osmolality (115 ± 44 mOsm/kg vs 282 ± 61 mOsm/kg at day 1, 139 ± 39 vs 303 ± 46 mOsm/kg at day 2; P < .01) that persisted for 48 hours. In parallel, urinary TGF-β(1) and β(2)-MG (normalized for creatinine) from the postobstructed kidney were significantly higher compared with the contralateral kidney. The urine output and urinary sodium concentration from the postobstructed kidney elevated significantly on the second day after the release of obstruction compared with those on the first day. The contralateral kidney also showed same trends.

CONCLUSIONS

The down-regulation of urinary exosomal AQP1 in the postobstructed kidney may account for the polyuria, hypotonic urine, and elevated urinary β(2)-MG. The urinary TGF-β(1) level locally increased in the postobstructed kidney may be involved in renal AQP1 down-regulation.

[Bond strength evaluation of four adhesive systems to dentin in vitro]

OBJECTIVE

To compare the adhesive strength and observe the bonding interface. According to statistic analysis and scanning electron microscope (SEM) observation, the resistance capacity of four adhesive systems is evaluated.

METHODS

Prime & Bond NT (PBNT), Tetric N-Bond (TNB), Clearfil SE Bond (CSEB), G Bond (GB) were bonded to the occlusal surfaces and mesial surfaces of third molars respectively. The mesial resins received shear force experiment and the fracture load were recorded. The tensile bond strength (TBS) of the remaining parts were tested. The interfacial configuration were observed under SEM.

RESULTS

In the shear bond strength (SBS) experiment, PBNT and TNB showed the best result, but there was no significant difference between them (P>0.05). The SBS of PBNT was stronger than that of CSEB and GB (P<0.05). The SBS of TNB was stronger than that of GB (P<0.05). There was no significant difference between TNB and CSEB (P>0.05). In accordance with the shear force result, the TBS of PBNT and TNB was larger than CSEB and GB (P<0.05). Under SEM, resin tags of PBNT and TNB were longer and slender, the bonding layer was thick. Resin tags of CSEB were shorter, the ones of GB were the fewest and shortest.

CONCLUSION

Compared to self-etching system, total-etching system could reach better bonding strength. There is some connection between the interfacial configuration of adhesives and bond strength of them.

TU-E-211-01: Establishing Multidisciplinary Collaboration as a Medical Physicist

Many medical physicists are scientists at heart and their career fulfillment includes a balance of clinical service and research development. Multidisciplinary collaboration is a great way for the medical physicists to advance science and technology of our fields and the fields of our collaborators. Cross-pollination among scientists of different fields has been the key for some of the most significant breakthroughs in science and medicine and produced some of the most rewarding experiences for the individuals involved. However, medical physicists face unique challenges in establishing multidisciplinary collaboration because our time and resources for research are often quite limited compared to basic scientists. Yet we medical physicists are uniquely positioned and have a tremendous opportunity to create/contribute to multidisciplinary research: our fields are already multidisciplinary in nature and hospital environment is problem rich. How do we establish and carry out research collaboration with scientists of other fields? How to balance research with your higher priority clinical service? How do you find the right multidisciplinary collaboration in your own environment? We will discuss the challenges, provide real exemplary solutions to the above questions, and offer advise to medical physicists who are interested in starting or improving their multidisciplinary collaboration. There are different kinds of multidisciplinary collaborations a medical physicist can create and participate at different involvement levels. Multidisciplinary collaboration is not for every medical physicist but for those who seek and devote time to it, the experience can be truly rewarding and the impact can be enormous.

LEARNING OBJECTIVES

1. Learn the types of multidisciplinary collaboration medical physicists can created/participated 2. Learn the approaches and strategies to develop collaborations with scientists and professional of other fields3. Understand the challenges and different approaches to balance clinical service and multidisciplinary research collaboration.

[Effect of Toll-like receptor 2 and Toll-like receptor 4 on expression of receptor activator of nuclear factor-kappaB ligand in human periodontal ligament fibroblasts induced by lipopolysaccharide]

OBJECTIVE

The aim of this study was to survey the influence of Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) repression to receptor activator of nuclear factor-kappaB ligand (RANKL) expression of human periodontal ligament fibroblasts (HPDLFs) under the stimulation of lipopolysaccharide (LPS).

METHODS

The level of RANKL in HPDLFs stimulated by 100 ng x mL(-1), 1 microg x mL(-1) and 10 microg x mL(-1) Escherichia coli (E. coli) LPS after 6, 12, 24 and 48 h was detected by enzyme linked immunosorbent assay (ELISA). The level of RANKL in HPDLFs stimulated by 1 microg x mL(-1) E. coli LPS after pretreatment with different titre anti-TLR2+anti-TLR4, anti-TLR2 and anti-TLR4 antibody were observed respectively.

RESULTS

RANKL was detected at 6 h after stimulation with LPS, and the levels of these cytokine were highest at 24 h, and then gradually decreased. The regularity of each LPS concentration was approximately similar. After pretreatment with anti-TLR2+anti-TLR4, anti-TLR2 and anti-TLR4 antibody, the level of RANKL was significantly decreased under the stimulation of 1 microg x mL(-1) LPS (P<0.05). In the three groups, the expression of RANKL was significantly different (P<0.05). The level of RANKL in anti-TLR2+anti-TLR4 antibody pretreatment group was the lowest, the level in anti-TLR4 antibody pretreatment group was higher, and the level in anti-TLR2 antibody pretreatment group was the highest.

CONCLUSION

TLR2 and TLR4 participate in the process of RANKL expres-in HPDLFs induced by LPS. Anti-TLR4 antibody has better inhibition effect to RANKL expression of HPDLFs stimulated by LPS than anti-TLR2.

SU-D-BRA-01: Accurate Real-Time Tumor Motion Estimation from Respiratory Surrogates via Memory-Based Learning

PURPOSE

Respiratory tumor motion is a major challenge in radiation therapy. Effective beam gating or tracking approaches necessitate an accurate knowledge of the real-time tumor motion. Fluoroscopic tracking with implanted fiducial markers is invasive and exposes the patient to additional imaging dose. Respiratory surrogate signal measured by external noninvasive and non-ionizing devices provides an attractive approach, in which estimating the tumor motion from respiratory surrogates is crucial.

METHODS

We utilize a powerful memory-based learning approach to find the complex relations between tumor motion and respiratory surrogates. The learning method uses locally weighted functions to interpolate between and extrapolate from training data. Due to the local nature of the learning functions, it is inherently robust to outliers. Moreover, both training and adapting to new data is highly efficient and almost free, making it suitable for dynamically following possibly variable internal/external relations. We evaluated the method using respiratory motion data (3D tumor motion plus 1D surrogate) from six patients (three lung and three pancreas patients).

RESULTS

Given only 5-sec (roughly one breath) pretreatment training data, the method achieved an average 3D error of 0.37 mm (range: 0.10 mm - 1.06 mm) and 95th percentile error of 0.86 mm (range: 0.24 mm - 2.47 mm) on 120-sec unseen test data. These errors are well below the average peak- to-peak amplitude (-10 mm). The errors decrease monotonically with an increasing amount of training data. Compared with the best linear model, the learning approach achieved a 21% reduction in error for an average patient (range: 10% - 42%).

CONCLUSIONS

The memory-based learning technique is able to accurately capture the highly nonlinear and complex relations between tumor and surrogate motion in an efficient manner (∼1 ms per prediction). These desirable properties make it an ideal candidate for accurate and robust tumor gating/tracking using respiratory surrogates.

Endometrial carcinoma tumorigenesis and pharmacotherapy research

Endometrial carcinoma is the common malignant tumor of the female genital tract, and its incidence is increasing. Two different clinicopathological subtypes are recognized based on epidemiology, genetic carcinogenesis and clinical behavior. Understanding and identifying molecular biology and genetics is essential to the development of novel therapies. This article reviews the current understanding of its risk factors, recent conceptions on its tumorigenesis and advances on its drug therapies.