• CLI preserves the characteristics of both optical and radionuclide imaging. • CLI provides great potential for clinical translation of optical imaging. • The newly developed endoscopic CLI (ECLI) has quantification and imaging capacities. • GI tract has accessible open surfaces, making ECLI a potentially suitable technique. • Cerenkov endoscopy has great clinical potential in detecting GI disease.
By integrating the clinically used endoscope with the emerging Cerenkov luminescence imaging (CLI) technology, a new endoscopic Cerenkov luminescence imaging (ECLI) system was developed. The aim is to demonstrate the potential of translating CLI to clinical studies of gastrointestinal (GI) tract diseases. We systematically evaluated the feasibility and performance of the developed ECLI system with a series of in vitro and pseudotumor experiments. The ECLI system is comprised of an electron multiplying charge coupled device (EMCCD) camera coupled with a clinically used endoscope via an optical adapter. A 1951-USAF test board was used to measure the white-light lateral resolution, while a homemade test chart filled with 68 Ga was employed to measure the CL lateral resolution. Both in vitro and pseudotumor experiments were conducted to obtain the sensitivity of the ECLI system. The results were validated with that of CLI using EMCCD only, and the relative attenuation ratio of the ECLI system was calculated. Results showed that The white-light lateral resolution of the ECLI system was 198 µm, and the luminescent lateral resolution was better than 1 mm. Sensitivity experiments showed a theoretical sensitivity of 0.186 / KBq l μ ( ) for the in vitro and pseudotumor studies, respectively. The relative attenuation ratio of ECLI to CLI was about 96%. The luminescent lateral resolution of the ECLI system was comparable with that of positron emission tomography (PET). The pseudotumor study illustrated the feasibility and applicability of the ECLI system in living organisms, indicating the potential for translating the CLI technology to the clinic.
. (2012). A real-time in vivo dosimetric verification method for highdose rate intracavitary brachytherapy of nasopharyngeal carcinoma. Medical Physics, 39 (11), 6757-6763.A real-time in vivo dosimetric verification method for high-dose rate intracavitary brachytherapy of nasopharyngeal carcinoma AbstractPurpose: A real-time in vivo dosimetric verification method using metal-oxide-semiconductor field effect transistor (MOSFET) dosimeters has been developed for patient dosimetry in high-dose rate (HDR) intracavitary brachytherapy of nasopharyngeal carcinoma (NPC). Methods: The necessary calibration and correction factors for MOSFET measurements in 192Iridium source were determined in a water phantom. With the detector placed inside a custom-made nasopharyngeal applicator, the actual dose delivered to the tumor was measured in vivo and compared to the calculated values using a commercial brachytherapy planning system. Results: Five MOSFETs were independently calibrated with the HDR source, yielding calibration factors of 0.48 ± 0.007 cGymV. The maximum sensitivity variation was no more than 7 in the clinically relevant distance range of 1-5 cm from the source. A total of 70 in vivo measurements in 11 NPC patients demonstrated good agreement with the treatment planning. The mean differences between the planned and the actually delivered dose within a single treatment fraction were -0.1 ± 3.8 and -0.1 ± 3.7, respectively, for right and left side assessments. The maximum dose deviation was less than 8.5. Conclusions: In vivo measurement using the real-time MOSFET dosimetry system is possible to evaluate the actual dose to the tumor received by the patient during a treatment fraction and thus can offer another line of security to detect and prevent large errors. [Materials and Methods]:The necessary calibration and correction factors for MOSFET measurements in 192 Iridium source were determined in a water phantom.With the detector placed inside a custom-made nasopharyngeal applicator, the actual dose delivered to the tumor was measured in vivo and compared to the calculated values using a commercial brachytherapy planning system (BPS). [Conclusion]: In vivo measurement using the real-time MOSFET dosimetry system is possible to evaluate the actual dose to the tumor received by the patient during a treatment fraction and thus can offer another line of security to detect and prevent large errors.
Objective: To clarify and quantify risk factors among local characteristics of the foot for major amputation in diabetic foot patients. Methods: Articles published before January 2018 on PubMed and Embase were conducted observational studies about risk factors for major amputation in patients with diabetic foot were retrieved and systematically reviewed by using Stata 12.0 statistical software.Results: A total of 4668 major amputees and 65 831 controls were reported in 18 observational studies. Across the studies, the overall odds ratios (ORs) and 95% confidence intervals (CIs) of significant risk factors are ulcer reaching bone (OR, 11.796; 95% CI, 6.905-20.152), gangrene (OR, 6.487; 95% CI, 4.088-10.293), hindfoot position (OR, 3.913; 95% CI, 2.254-6.795), decreased ankle-brachial index (ABI) (OR, 2.522; 95% CI, 1.805-3.523), infection (OR, 2.516; 95% CI, 1.708-3.706), peripheral arterial disease (PAD) (OR, 2.114; 95% CI, 1.326-3.372). While there is no significant difference in the size of the ulcer, neuropathy, Charcot foot, osteomyelitis and intermittent claudication (OR, 1.15; 95% CI, 0.85-1.54). Conclusion:Factors among local characteristics of the foot associated with major amputation in patients with diabetic foot are the ulcer reaching bone, gangrene, hindfoot position, decreased ABI, infection, and PAD, a negative risk factor for the risk of amputation. Further studies are required to provide more details of foot local characteristics. K E Y W O R D S diabetic foot, local characteristics of the foot, major amputation, meta-analysis, risk factors J Cell Biochem. 2019;120:9091-9096.wileyonlinelibrary.com/journal/jcb
Weak intensity and poor penetration depth are two big obstacles toward clinical use of Cerenkov luminescence imaging (CLI). In this proof-of-concept study, we overcame these limitations by using lanthanides-based radioluminescent microparticles (RLMPs), called terbium doped Gd2O2S. The characterization experiment showed that the emission excited by Cerenkov luminescence can be neglected whereas the spectrum experiment demonstrated that the RLMPs can actually be excited by γ-rays. A series of in vitro experiments demonstrated that RLMPs significantly improve the intensity and the penetration capacity of CLI, which has been extended to as deep as 15 mm. In vivo pseudotumor study further prove the huge potential of this enhancement strategy for Cerenkov luminescence imaging in living animal studies.
BackgroundTo compare the results of external beam radiotherapy in combination with 3D- computed tomography (CT)-implanted interstitial high dose rate brachytherapy (ERT/3D-HDR-BT) versus conventional external beam radiotherapy (ERT) for the treatment of stage T2b nasopharyngeal carcinoma (NPC).MethodsForty NPC patients diagnosed with stage T2b NPC were treated with ERT/3D-HDR-BT under local anesthesia. These patients received a mean dose of 60 Gy, followed by 12-20 Gy administered by 3D-HDR-BT. Another 101 patients diagnosed with non-metastatic T2b NPC received a mean dose of 68 Gy by ERT alone during the same period.ResultsPatients treated with ERT/3D-HDR-BT versus ERT alone exhibited an improvement in their 5-y local failure-free survival rate (97.5% vs. 80.2%, P = 0.012) and disease-free survival rate (92.5% vs. 73.3%, P = 0.014). Using multivariate analysis, administration of 3D-HDR-BT was found to be favorable for local control (P = 0.046) and was statistically significant for disease-free survival (P = 0.021). The incidence rate of acute and chronic complications between the two groups was also compared.ConclusionsIt is possible that the treatment modality enhances local control due to improved conformal dose distributions and the escalated radiation dose applied.
Detection of different classes of atherosclerotic plaques is important for early intervention of coronary artery diseases. However, previous methods focused either on the detection of a specific class of coronary plaques or on the distinction between plaques and normal arteries, neglecting the classification of different classes of plaques. Therefore, we proposed an automatic multi-class coronary atherosclerosis plaque detection and classification framework. Firstly, we retrieved the transverse cross sections along centerlines from the computed tomography angiography. Secondly, we extracted the region of interests based on coarse segmentation. Thirdly, we extracted a random radius symmetry (RRS) feature vector, which incorporates multiple descriptions into a random strategy and greatly augments the training data. Finally, we fed the RRS feature vector into the multi-class coronary plaque classifier. In experiments, we compared our proposed framework with other methods on the cross sections of Rotterdam Coronary Datasets, including 729 non-calcified plaques, 511 calcified plaques, and 546 mixed plaques. Our RRS with support vector machine outperforms the intensity feature vector and the random forest classifier, with the average precision of 92.6 ± 1.9% and average recall of 94.3 ± 2.1%. The proposed framework provides a computer-aided diagnostic method for multi-class plaque detection and classification. Graphical abstract Diagram of the proposed automatic multi-class coronary atherosclerosis plaque detection and classification framework. ᅟ.
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