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Study design Retrospective study. Purpose This study aims to semiquantitatively evaluate the standardized uptake value (SUV) of 99mTc-methylene diphosphonate (MDP) radionuclide tracer in the normal vertebrae of breast cancer patients using an integrated single-photon emission computed tomography (SPECT)/computed tomography (CT) scanner. Overview of literature Molecular imaging techniques using gamma cameras and stand-alone SPECT have traditionally been utilized to evaluate metastatic bone diseases. However, these methods lack quantitative analysis capabilities, impeding accurate uptake characterization. Methods A total of 30 randomly selected female breast cancer patients were enrolled in this study. The SUV mean (SUVmean) and SUV maximum (SUVmax) values for 286 normal vertebrae at the thoracic and lumbar levels were calculated based on the patients' body weight (BW), body surface area (BSA), and lean body mass (LBM). Additionally, 106 degenerative joint disease (DJD) lesions of the spine were also characterized, and both their BW SUVmean and SUVmax values were obtained. A receiver operating characteristic (ROC) curve analysis was then performed to determine the cutoff value of SUV for differentiating DJD from normal vertebrae. Results The mean±standard deviations for the SUVmean and SUVmax in the normal vertebrae displayed a relatively wide variability: 3.92±0.27 and 6.51±0.72 for BW, 1.05±0.07 and 1.75±0.17 for BSA, and 2.70±0.19 and 4.50±0.44 for LBM, respectively. Generally, the SUVmean had a lower coefficient of variation than the SUVmax. For DJD, the mean±standard deviation for the BW SUVmean and SUVmax was 5.26±3.24 and 7.50±4.34, respectively. Based on the ROC curve, no optimal cutoff value was found to differentiate DJD from normal vertebrae. Conclusions In this study, the SUV of 99mTc-MDP was successfully determined using SPECT/CT. This research provides an approach that could potentially aid in the clinical quantification of radionuclide uptake in normal vertebrae for the management of breast cancer patients.

Mind-body techniques, including Guided Imagery (GI) or Progressive Muscle Relaxation (PMR), may effectively manage bloating. The current study aimed to develop and validate (psychometric and psychological responses) audio-based GI and PMR techniques for bloating. Audio scripts were first developed from literature reviews and in-depth interviews of participants with bloating diagnosed based on the Rome IV criteria. Scripts were validated using psychometric (content & face validity index) and physiological approaches (brain event-related potentials & heart rate variability). 45/63 participants completed the in-depth interview, and ‘balloon’ emerged as the synonymous imagery description for bloating, of which inflation correlated with a painful sensation. The final tools consisted of narrated audio scripts in the background of a validated choice of music. Overall, content and face validity index for PMR and GI ranged from 0.92 - 1.00. For ERP and HRV, 17/20 participants were analysed. For ERP, there was significant difference between GI and PMR for alpha waves (p=0.029), delta waves (p=0.029) and between PMR and control for delta waves (p=0.014). For HRV, both GI and PMR exhibited similar autonomic responses over controls (overall p

Purpose The aim of this study was to investigate the potential of the synergetic triple therapeutic combination encompassing bismuth oxide nanoparticles (BiONPs), cisplatin (Cis), and high dose rate (HDR) brachytherapy with Ir-192 source in breast cancer and normal fibroblast cell line. Methods In vitro models of breast cancer cell lines (MCF-7, MDA-MB-231) and normal fibroblast cell line (NIH/3T3) were employed. Cellular localization and cytotoxicity studies were conducted prior to inspection on the radiosensitization effects and generation of reactive oxygen species (ROS) on three proposed radiosensitizers: BiONPs, Cis, and BiONPs-Cis combination (BC). The optimal, non-cytotoxic concentration of BiONPs (0.5 mM) and the 25% inhibitory concentration of Cis (1.30 µM) were applied. The radiosensitization effects were evaluated by using a 0.38 MeV Iridium-192 HDR brachytherapy source over a prescribed dose range of 0 Gy to 4 Gy. Results The cellular localization of BiONPs was visualized by light microscopy and accumulation of the BiONPs within the vicinity of the nuclear membrane was observed. Quantification of the sensitization enhancement ratio extrapolated from the survival curves indicates radiosensitization effects for MCF-7 and MDA-MB-231 when treated with BiONPs, Cis, and BC. However, NIH/3T3 cells exhibited contradictive behavior as it only reacted towards the BC combination. Nonetheless, the MCF-7 cell line loaded with BC shows the highest SER of 4.29. ROS production analysis, on the other hand, shows that Cis and BC radiosensitizers generated the highest free radicals in comparison to BiONPs alone. Conclusion A BiONPs-Cis combination was unveiled as a novel approach that offers promising radiosensitization enhancement that will increase the efficiency of tumor control while preserving the normal tissue at a reduced dose. This data is the first precedent to prove the synergetic implication of BiONPs, Cis, and HDR brachytherapy that will be beneficial for future chemoradiotherapy strategies in cancer care.

Background It is unclear if the 99mTc-sodium phytate (99mTc-SP) is as reliable as the gold-standard 99mTc-sulfur colloid (99mTc-SC) for gastric emptying scintigraphy (GES). This study is aimed to compare the emptying rates of both radiotracers in a prospective, randomized cross-over trial and to determine the normative data of a healthy multi-ethnic Asian population. Methods Out of the 44 healthy individuals screened, 31 (14 females; mean age: 28.4 ± 7.0 years) were enrolled and underwent GES using the standardized egg-white meal. All participants were randomly assigned to either 99mTc-SP or 99mTc-SC on the first GES session before crossed over to the other formulation after 2 weeks. Results Both kits achieved the radiochemical purities of > 95%. The median rate (95th upper normative limit) of gastric emptying, reported as total gastric meal retention between 99mTc-SP and 99mTc-SC, was found to be comparable at all measured time points: 0.5 h [85.0% (96.6%) vs. 82.0% (94.0%)], 1 h [70.0% (86.4%) vs. 65.0% (86.6%)], 2 h [31.0% (55.8%) vs. 25.0% (64.4%)], 3 h [7.0% (26.3%) vs. 5.0% (29.9%)], and 4 h [3.0% (10.3%) vs. 2.0% (9.9%)]; P > 0.05. In addition, both radiotracers correlated well (Kendall’s Tau (τ) coefficient = 0.498, P Conclusions 99mTc-SP is a valid radiotracer alternative to 99mTc-SC for routine GES examination. The normative values for both radiotracers have also been determined for the healthy multi-ethnic Asian population. Trial registration This trial was registered retrospectively in the Thai Clinical Trials Registry on May 23rd, 2020 (Identifier: TCTR20200526004; http://www.clinicaltrials.in.th/index.php?tp=regtrials&menu=trialsearch&smenu=fulltext&task=search&task2=view1&id=6296).

Intraoperative sentinel lymph node mapping (SLNM) with methylene blue dye (MBD) tracer has been the recommended method to detect SLN in early-stage breast cancer patients in low-resource settings. However, the use of MBD alone is hampered by the high false-negative rate; thus, it requires coupling with other mapping methods if the appropriate infrastructure and services are available. In this article, we present two prospective cases detailing our initial experience using the gold-standard dual tracer technique (DTT: MBD and 99mTc-nanocolloid radioisotope) in combination with hybrid single-photon emission computed-tomography/computed-tomography (SPECT/CT) preoperative mapping for image-guided SLN biopsy (SLNB). Overall, both studies were successful in identifying the SLNs, which aided in mapping the possible anatomical spread of the disease.

Additional file 1: Table S1. Separate comparison of gastric emptying parameters according to sex subgroups.

Planar scintigraphy with 99mTc-pertechnetate or Meckel scan is the gold standard in the diagnosis of a bleeding Meckel’s diverticulum (MD) for pediatrics. However, several setbacks may occur during the interpretation of a scintigram, especially in cases of an atypical MD presentation. In this report, we highlight the importance of functional and anatomical image co-registration using a hybrid SPECT/CT scanner to precisely localize a MD lesion. An 18-month-old boy presented with severe hematochezia over 4 days with declining hemoglobin levels. He underwent a conventional 60-min dynamic planar imaging of the Meckel scan. Upon review of the Meckel scan, a suspicious increase in the 99mTc-pertechnetate uptake was observed at the right upper quadrant of the abdomen. Due to its atypical location at the right kidney, we could not differentiate between a physiological uptake of the right kidney or an ectopic gastric mucosa. The patient was imaged again using single-photon emission computed tomography (SPECT) and low-dose CT protocol with a hybrid SPECT/CT scanner, and the co-registration of both SPECT and CT images was able to confirm the MD, which was located anterior to the right kidney at the right hepatic flexure region. An exploratory laparotomy was then ensued to remove the bleeding MD. The patient was discharged after 3 days with no complications. In summary, this case illustrates that hybrid imaging modality and co-registration allow for a more definitive diagnosis, as well as a more precise localization of MD.

Delaminated GAFCHROMIC™ EBT3 radiochromic films (RCFs) are specialised dosimeters that are gaining attention due to its many prospective advantages but are not commercially available. The purpose of this study is to fabricate the delaminated EBT3 RCFs, microscopically examine the structural response of the active layer (LiPCDA), and evaluate its dose-response in electron beam radiotherapy. The delaminated EBT3 RCFs were first made by carefully removing one of the two 125 μm polyester substrates using precision forceps. Next, the films were irradiated using a 12 MeV electron beam under full equilibrium conditions. Microstructure analysis via scanning electron microscope (SEM) was employed to look into the effects of radiation polymerisation on the LiPCDA crystals at 3000× magnification. To characterise the dose-response, the delaminated EBT3 RCFs’ optical density were analysed in Red-channel across a dose range of up to 5 Gy. The resulting calibration curve was then compared with the standard EBT3 RCFs’ curve for performance evaluation. Images from SEM revealed that the irradiated EBT3 RCF possesses a higher density of longer LiPCDA crystals (mode: ∼8.00 μm) compared to the non-irradiated EBT3 RCF (mode: ∼4.00 μm). The delaminated EBT3 RCFs, nonetheless, was found to produce a combined standard uncertainty of 6.62 %, which is inferior to its standard counterpart (3.62 %) and also the radiotherapy’s tolerance level (± 5 %). In sum, this study had successfully demonstrated the effects of radiation polymerisation on the active layer. However, the delamination process introduced a significant amount of uncertainty towards the dose-response. More efforts into delamination techniques and better dosimetry analysis are required to improve its usability in radiotherapy.

This paper aims to assess the dose-response characteristics of delaminated GAFCHROMIC™ EBT3 films for radiotherapy beams. Delaminated EBT3 films were produced by peeling off the top polyester substrate of original EBT3 using surgical precision forceps. The films were irradiated to 500 cGy with photon beams of 6 MV and 10 MV, while proton and 192Ir exposures were conducted at nominal energies of 150 MeV and 0.38 MeV respectively. Digitisations were made using a flatbed scanner in Red-channel for optimum sensitivity. Analyses of data fitting, reading reproducibility, film integrity and energy dependency were then implemented for comparison with original EBT3 films. Results of R2 in each curve suggested that the selected non-linear function appropriately fits the data with low reduced chi-square. However, the delaminated films experience integrity degradation of up to 13% due to active layer distress, affecting the reading reproducibility with values extending to 1.0%. Plus, the mean relative response ratio of energy dependency for delaminated EBT3 in photon irradiations was observed at 0.97, which is inferior to their original counterpart. In summary, the delaminated EBT3 yields comparable dose-response behaviour despite integrity deterioration. It is important to factor film delamination uncertainties into existing uncertainty budget as it is instrumental in reading dose-response deviations. Accurate evaluation together with reliable fabrication processes could make delaminated EBT3 attractive in specific applications including α-particles dosimetry and ultraviolet radiation monitoring.

Proper dosimetry settings are crucial in radiotherapy to ensure accurate radiation dose delivery. This work evaluated scanning parameters as affecting factors in reading the dose-response of EBT2 and EBT3 radiochromic films (RCFs) irradiated with clinical photon and electron beams. The RCFs were digitised using Epson® Expression® 10000XL flatbed scanner and image analyses of net optical density (netOD) were conducted using five scanning parameters i.e. film type, resolution, image bit depth, colour to grayscale transformation and image inversion. The results showed that increasing spatial resolution and deepening colour depth did not improve film sensitivity, while grayscale scanning caused sensitivity reduction below than that detected in the Red-channel. It is also evident that invert and colour negative film type selection negated netOD values, hence unsuitable for scanning RCFs. In conclusion, choosing appropriate scanning parameters are important to maintain preciseness and reproducibility in films dosimetry.