Magnetic Resonance-Guided High-Intensity-Focused Ultrasound for Palliation of Painful Skeletal Metastases: A Pilot Study

BACKGROUND

Bone is one of the most common sites of metastases, with bone metastases-related pain representing a significant source of morbidity among patients with cancer. Magnetic resonance-guided focused ultrasound is a noninvasive, outpatient modality with the potential for treating painful bone metastases. The aim of this study is to report our initial experience with magnetic resonance-guided focused ultrasound in the treatment of bone metastases and our preliminary analysis of urinary cytokine levels after therapy.

METHODS

This was a single-center pilot study of 10 patients with metastatic cancer to investigate the feasibility of magnetic resonance-guided focused ultrasound for primary pain control in device-accessible skeletal metastases. Treatments were performed on a clinical magnetic resonance-guided focused ultrasound system using a volumetric ablation technique. Primary efficacy was assessed using Brief Pain Inventory scores and morphine equivalent daily dose intake at 3 time points: before, day 14, and day 30 after the magnetic resonance-guided focused ultrasound treatment. Urine cytokines were measured 3 days before treatment and 2 days after the treatment.

RESULTS

Of the 10 patients, 8 were followed up 14 days and 6 were followed up 30 days after the treatment. At day 14, 3 patients (37.5%) exhibited partial pain response and 4 patients (50%) exhibited an indeterminate response, and at day 30 after the treatment, 5 patients (83%) exhibited partial pain response. No treatment-related adverse events were recorded. Of the urine cytokines measured, only Transforming growth factor alpha (TGFα) demonstrated an overall decrease, with a trend toward statistical significance ( P = .078).

CONCLUSION

Our study corroborates magnetic resonance-guided focused ultrasound as a feasible and safe modality as a primary, palliative treatment for painful bone metastases and contributes to the limited body of literature using magnetic resonance-guided focused ultrasound for this clinical indication.

Does L/M Cone Opponency Disappear in Human Periphery?

We have assessed the optimal cone contrast sensitivity across eccentricity in human vision of the two cone-opponent mechanisms [L/M or red-green, and S/(L + M) or blue-yellow] and the luminance mechanism. We have used a novel stimulus, termed a ‘sinring’, that is a radially modulated sine-wave arc, Gaussian enveloped in both angular and radial directions. This stimulus overcomes the problem inherent in Gabor stimuli of confounding stimulus spatial frequency, size, and eccentricity and so allows contrast sensitivity to be tracked accurately into the periphery. Our results show that L/M cone opponency declines steeply across the human periphery and becomes behaviourally absent by 25–30 deg (in the nasal field). This result suggests that any L/M cone-opponent neurons found in primate peripheral retina beyond this limit are unlikely to be significant for colour contrast detection measured behaviourally.

The mechanism study of efficient degradation of hydrophobic nonylphenol in solution by a chemical-free technology of sonophotolysis

Nonylphenol is a hydrophobic endocrine disrupting compound, which can inhibit the growth of sewage bacteria in biological processes. This study investigated the degradation of 4-n-nonylphenol (NP) in water by a chemical-free technology of sonophotolysis with emphasis on the impacts of several important parameters, including light intensity, solution pH, two commonly seen inorganic ions (i.e. NO3(-) and HCO3(-)), and principally on the examination of degradation mechanisms. It was found that, solution pH could significantly influence both NP degradation efficiency and the synergistic effect of sonophotolytic process, where higher synergistic effect was obtained at more acidic condition. In addition, the presence of NO3(-) accelerated NP degradation by both acting as a photosensitizer and providing NO2˙ radicals, while HCO3(-) had little effect on NP degradation. Identification of intermediates of NP degradation indicated that NP sonophotolysis was mainly initiated by the formation of hydroxy-NP, and a new intermediate di-hydroxy-NP was identified for the first time ever in this study. Through thermodynamic analysis, results indicated that both ortho- and meta-hydroxy-NP species can coexist in the solution but the ortho-4-NBZQ (4-nonyl-benzoquinone) is dominant. In addition, the mechanism of ortho-hydroxy-NP formation was suggested by the addition of HO˙ and H˙ radicals.

Phase I/II study of stereotactic ablative radiotherapy including regional lymph node irradiation for patients with high-risk prostate cancer (SATURN): Early results

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Background: Dose escalation using five-fraction stereotactic ablative radiotherapy (SABR) is gaining popularity in the treatment of prostate cancer. This has not been extensively tested in the context of pelvic radiation for high-risk groups. The objectives of study are to report early toxicity and quality of life outcomes in patients following 5-fraction prostate and pelvic radiation. Methods: A phase I/II study was performed where high-risk prostate cancer patients (T3a-3b or Gleason score ≥ 8 or PSA > 20ng/ml) received 40Gy to prostate and 25Gy to pelvis and seminal vesicles in 5 weekly fractions, on a gantry-based platform. A 3mm planning target volume margin to the prostate and a 6mm margin to the lymph nodes was applied. Image guidance was performed using gold seed fiducials and cone beam computerized tomography. Androgen deprivation therapy (ADT) was used for 12-18 months. Common Terminology Criteria for Adverse Events version 3.0 was used to assess toxicities at 3- and 6-months. Quality of life data (QOL) was captured using EPIC questionnaire. A minimally clinically important change (MCIC) definition was triggered if the EPIC QOL score decreases > 0.5 SD, where SD is the standard deviation of baseline scores. Results: Thirty patients completed the planned treatment with a median follow up of 11.9 months (IQR 8.3, 13.0). The following toxicities were observed: grade 2 genitourinary (GU): 50% at 3 months and 34.5% at 6 months; grade 2 gastrointestinal (GI): 3.3% at 3months and 6.9% at 6 months. No ≥ grade 3 toxicities were observed. Mean (95% Confidence Interval) EPIC urinary QOL scores were 86.6 (81.9-91.3), 87.1(81.4-92.6) and 86.1(80.2-92.0) at baseline, 3 months and 6 months and the bowel scores were 94.1(91.3-97.0), 93.2(89.1-97.2) and 93.2(89.5-96.8), respectively. Proportion of patients experiencing MCIC at 3 months and 6 months were 27.8% and 31.8% for urinary domain, 23.5% and 28.6% for bowel domain; respectively. Conclusions: This gantry-based novel fractionation schedule incorporating pelvic radiation for high-risk prostate cancer in combination with ADT is feasible and well tolerated in the acute setting. Clinical trial information: NCT 01953055.

Predictive parameters of symptomatic haematochezia following 5-fraction gantry-based SABR in prostate cancer

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Background: To identify clinical and dosimetric predictors of high-grade haematochezia (HH) following 5-fraction gantry based stereotactic ablative radiotherapy (SABR). Methods: Data about haematochezia in 258 patients who received 35-40Gy SABR in 5-fractions (weekly or alternate days) as part of sequential phase II prospective trials was retrieved. Haematochezia was graded as per the Fox Chase LENT criteria, ≥ grade 2 rectal bleeding was labeled as HH. Patients needing steroid suppositories, 4% formalin or 1-2 sessions of argon plasma coagulation (APC) were graded as grade 2 haematochezia. If a patient required >2 sessions of APC, blood transfusion or a course of hyperbaric oxygen, this was grade 3 and development of visceral fistula was grade 4. Various dosimetric and clinical factors were analyzed using univariate and multivariate (MVA) analyses. Receiver-operating characteristic (ROC) curve analysis and recursive partitioning analysis (RPA) were used to determine clinically valid cut-off points and risk groups, respectively. Results: Median follow-up was 29.7 months (IQR 20.6, 61.7). HH was observed in 19.4%. Median time to develop HH was 11.7 months (IQR 9.0, 15.2). Resolution occurred a median of 6.7 months (IQR 5.7, 12.4) later; 3% was prevalent at last follow-up. At two years, cumulative HH was 4.9%, 27.2% and 42.1% in patients who received 35Gy to prostate (4mm planning target volume-PTV margin), 40Gy to prostate (5mm PTV margin) and 40Gy to prostate/seminal vesicles (5mm PTV margin), respectively ( p-value< 0.0001). In the ROC analysis, volume of rectum receiving radiation dose of 38Gy (V38) was a strong predictor of HH with an AUC of 0.65. In MVA, rectal V38 (≥2.0cc; p-value<0.0001, OR 4.9); use of anti-coagulants (p-value<0.0002, OR 14.9) and presence of hemorrhoids (p-value<0.006, OR 3.2) were the strongest predictors. In RPA, rectal V38<2.0cc and use of anticoagulants orrectal V38 ≥2.0cc plus one other risk factor resulted in a HH risk>30%. Conclusions: Rectal V38 and two clinical factors were strong predictors of high-grade haematochezia following 5-fraction SABR. Planning constraints should aim to keep the rectal V38 below 2.0cc.

Highly stable bimetallic Au–Cu supported on Al2O3 for selective CO oxidation in H2-rich gas: effects of Cu/Au atomic ratio and sensitive influence of particle size

The effects of Au/Cu atomic ratio and thermal pretreatment on the catalytic performance of Au_xCu_y/Al₂O₃ for PROX were studied. The reduced Au_xCu_y/Al₂O₃ catalysts display higher catalytic activity and stability than the calcined catalysts.

Applying artificial intelligence technology to support decision-making in nursing: A case study in Taiwan

This study applied artificial intelligence to help nurses address problems and receive instructions through information technology. Nurses make diagnoses according to professional knowledge, clinical experience, and even instinct. Without comprehensive knowledge and thinking, diagnostic accuracy can be compromised and decisions may be delayed. We used a back-propagation neural network and other tools for data mining and statistical analysis. We further compared the prediction accuracy of the previous methods with an adaptive-network-based fuzzy inference system and the back-propagation neural network, identifying differences in the questions and in nurse satisfaction levels before and after using the nursing information system. This study investigated the use of artificial intelligence to generate nursing diagnoses. The percentage of agreement between diagnoses suggested by the information system and those made by nurses was as much as 87 percent. When patients are hospitalized, we can calculate the probability of various nursing diagnoses based on certain characteristics.

Computed Tomography Evaluation of Density Following Stereotactic Body Radiation Therapy of Nonspine Bone Metastases

INTRODUCTION

Stereotactic body radiation therapy allows for the precise delivery of high-dose radiation to disease sites and is becoming increasingly used to treat nonspine bone metastases. Previous studies have shown that remineralization of lytic bone metastases follows after conventional radiotherapy. The objective of this study was to investigate changes in bone density in nonspine bone metastases following stereotactic body radiation therapy.

METHODS

A retrospective review was conducted for all patients treated with stereotactic body radiation therapy to nonspine bone metastases between May 2011 and April 2014. A minimum of 1 pretreatment and 1 posttreatment computed tomography scan was required. An independent musculoskeletal radiologist contoured the lesions on the most representative computed tomography slices. Density was measured in Hounsfield units and analyzed using pretreatment and posttreatment ratios.

RESULTS

Forty sites were treated (55% lytic, 30% sclerotic, and 15% mixed). The median follow-up duration was 7 months. Lytic osseous metastases from renal cell carcinoma progressed during initial follow-up imaging and then returned to baseline. Of 9 lytic lesions not from renal cell carcinoma, 6 showed an immediate increase in density and 2 remained stable. Six of 7 sclerotic lesions from prostate cancer showed decreased density throughout all follow-ups.

CONCLUSION

Stereotactic body radiation therapy is efficacious in the remineralization of lytic and demineralization of sclerotic nonspine bone metastases.

Stereotactic body radiotherapy for the treatment of medically inoperable primary renal cell carcinoma: Current evidence and future directions

The incidence of renal cell carcinoma (RCC) is steadily rising due to an aging population and more frequent imaging of the abdomen for other medical conditions. While surgery remains the standard of care treatment for localized disease, many patients are unfit due to their advanced age and medical comorbidities. In these patients, an active surveillance strategy or ablative therapies, including radiofrequency/microwave ablation or cryotherapy, can be offered. Such options have limitations particularly with fast growing, or larger tumors. A promising ablative therapy option to consider is stereo-tactic body radiotherapy (SBRT). SBRT refers to high dose, focally ablative radiation delivered in a short time (3-5 fractions), and is safe and effective in many other cancer sites, including lung, liver and spine. SBRT offers potential advantages in the primary kidney cancer setting due to its ablative dosing (overcoming the notion of "radio-resistance"), short treatment duration (important in an elderly population), low toxicity profile (enabling SBRT to treat larger RCCs than other ablative modalities), and non-invasiveness. To date, there is limited long-term prospective data on the outcomes of SBRT in primary RCC. However, early evidence is intriguing with respect to excellent local control and low toxicity; however, most studies vary in terms of technique and radiation dosing used. Well-designed prospective cohort studies with clearly defined and standardized techniques, dosing, follow-up, and integration of quality of life outcomes will be essential to further establish the role of SBRT in management of inoperable, localized RCC.