Predictive Value of Day of Treatment SPECT/CT Radiomics in Lobar Y90 Radioembolization of Hepatocellular Carcinoma: A Pilot Study

PURPOSE/OBJECTIVE(S)

Transarterial Radioembolization (TARE) with Yttrium-90 (Y90) microspheres is a well-tolerated liver-directed therapy for patients with inoperable hepatocellular carcinoma (HCC). Y90 TARE uses pretreatment and post-treatment single photon emission computed tomography (SPECT)/CT for assessment of microsphere biodistribution within tumor. Patients who develop disease progression (PD) after lobar TARE have poor overall survival (OS). Conventional radiography can require several months follow-up to assess tumor response per modified RECIST (mRECIST), resulting in treatment delays for patients with PD. Predictive models capable of identifying patients at high risk for PD could prompt close surveillance and rapid initiation of salvage therapies, enhancing disease control (DC). Predictive models in various cancers have incorporated radiomics, an analytic technique that extracts digital patterns from medical imaging. We hypothesized that radiomics of immediate post-treatment SPECT/CT can predict objective response (OR) to Y90 TARE.

MATERIALS/METHODS

A total of 38 lobar TARE treatments were assessed retrospectively. For all treatments, the prescribed dose was 120 Gy. SPECT/CT obtained immediately after TARE underwent radiomics analysis. A total of 75 features related to gray-level (GL) co-occurrence matrices (COM), dependency matrices (DM), run length matrices (RLM), zone size matrices (ZSM), and neighborhood difference matrices (NDM) were examined and balanced between cohorts with and without OR by aid of Gaussian noise up-sampling. Top features were chosen for a weighted k-nearest neighbors (KNN) classifier based on rank as determined by the RELIEF-F algorithm. Performance of the developed classifier was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

Most patients (76%) were Child-Pugh A cirrhotic, while Barcelona Clinic Liver Cancer (BCLC) stage was evenly distributed A to C. On radiographic review, 22 treatments (58%) achieved OR. The selected top features consisted of two from CT (GLNDM-based coarseness; GLDM-based small dependence low gray level emphasis) and two from SPECT (GLNDM-based coarseness; GLZSM-based zone entropy). The weighted KNN classifier built using the selected features demonstrated a relatively strong power for predicting OR, with a ROC area under curve (AUC) of 0.83.

CONCLUSION

In lobar TARE Y90 of inoperable HCC, a predictive model using texture features extracted from day of treatment SPECT/CT distinguished responders from non-responders with high accuracy. Limitations of this study include its retrospective nature and the absence of toxicity analysis. These findings suggest that predictive modeling incorporating SPECT/CT radiomics could enhance the therapeutic ratio for vulnerable HCC patients and merits further investigation in prospective clinical trials of Y90 TARE.

Developing Bioactive Dental Resins for Restorative Dentistry

Despite its reputation as the most widely used restorative dental material currently, resin-based materials have acknowledged shortcomings. As most systematic survival studies of resin composites and dental adhesives indicate, secondary caries is the foremost reason for resin-based restoration failure and life span reduction. In subjects with high caries risk, the microbial community dominated by acidogenic and acid-tolerant bacteria triggers acid-induced deterioration of the bonding interface and/or bulk material and mineral loss around the restorations. In addition, resin-based materials undergo biodegradation in the oral cavity. As a result, the past decades have seen exponential growth in developing restorative dental materials for antimicrobial applications addressing secondary caries prevention and progression. Currently, the main challenge of bioactive resin development is the identification of efficient and safe anticaries agents that are detrimental free to final material properties and show satisfactory long-term performance and favorable clinical translation. This review centers on the continuous efforts to formulate novel bioactive resins employing 1 or multiple agents to enhance the antibiofilm efficacy or achieve multiple functionalities, such as remineralization and antimicrobial activity antidegradation. We present a comprehensive synthesis of the constraints and challenges encountered in the formulation process, the clinical performance-related prerequisites, the materials' intended applicability, and the current advancements in clinical implementation. Moreover, we identify crucial vulnerabilities that arise during the development of dental materials, including particle aggregation, alterations in color, susceptibility to hydrolysis, and loss of physicomechanical core properties of the targeted materials.

Patterns of Recurrence Following Radiation and ADT for Pathologic Lymph Node Positive Prostate Cancer: A Multi-Institutional Study

PURPOSE/OBJECTIVE(S)

Retrospective studies have suggested that post-operative radiation therapy (RT) can reduce the risk of cause-specific mortality in men with pathologic nodal involvement (pN1) after radical prostatectomy (RP). We evaluated prognostic factors and patterns of recurrence in patients who received post-operative RT +/- androgen deprivation therapy (ADT) for pN1 disease in a multicentric cohort of 4 academic centers.

MATERIALS/METHODS

Data from patients with pN1 prostate cancer after RP who subsequently received RT with short term (< = 6 mo) or long term (>6 mo) ADT were obtained from 4 academic institutions. Patterns of recurrence, biochemical progression free survival (bPFS) and distant metastasis free survival (DMFS) were evaluated.

RESULTS

A total of 270 patients with a median follow-up of 48 months were included. Gleason grade group (GG) 2 was present in 20 patients (7.5%), GG 3 in 81 (30%), GG4 in 36 (13.5%), GG5 in 130 (49%) patients. 256 (95%) patients had extracapsular extension, 70% had seminal vesicle invasion, 59% had positive surgical margins, and 66% had a detectable post-operative PSA. The number of positive nodes at surgery were 1 in 59%, 2 in 19% and >2 in 22% of patients. Of the 83 patients that had pre-RT imaging, 46 (55%) had a PET scan (PSMA, or fluciclovine); 25 (30%) of those had lymph nodes detected on imaging prior to RT. Median time from RP to RT was 6 mo (IQR 4.5-9.1 mo). 96% received radiation to both the prostate bed (median dose 68.4Gy) and pelvic lymph nodes (median dose 46Gy). ADT was prescribed short-term (20%) or long-term (68%), while 26 (10%) received no ADT, and 7 (3%) had an unknown duration. Biochemical failure (bF) was observed in 29% of men, with 5% having pelvic nodal failure and 11.5% having distant metastases (majority in bones, followed by paraaortic nodes) at last follow up. Of 59 patients who had normal baseline testosterone levels, 37% recovered their testosterone by last follow-up. The 4-year bRFS was 72% for all patients and was 83% for those with a pre-RT PSA of <0.1 ng/mL, 76% for PSA 0.1-<0.5 ng/mL, 60% for PSA 0.5-2 ng/mL, and 35% for PSA >2 ng/mL. On multivariable analysis, maximum pre-RT PSA ≥0.5 (0.5 to 2.0 vs <0.1 HR = 3.19; >2.0 vs <0.1 HR = 9.00), use of LTADT (HR = 0.47), and percent pN1 (HR = 1.03) were significantly associated with bF. Pre-RT PSA >2 (HR = 4.10), use of LT ADT (HR = 0.33) and percent pN1 (HR = 1.03) were also significantly associated with DM.

CONCLUSION

In pN1 patients, pelvic RT and ADT at low PSA levels is associated with improved oncologic outcomes compared to treatment at higher levels, suggesting that PSA may have prognostic value for pN1 prostate cancer.

Extended Field Radiosurgery of Spinal Metastases with MRI-Guided Adaptive Planning: A Dosimetric Study

PURPOSE/OBJECTIVE(S)

Spinal metastases occur in ∼40% of cancer patients. Stereotactic body radiotherapy (SBRT) precisely delivers high doses of RT to enhance local control and reduce chronic pain. Eligibility for spine SBRT can depend on number of spine vertebrae involved. For example, RTOG 0631 was limited to two contiguous levels due to concerns about spinal cord (SC) tolerance when aligning to long targets in the mobile spine. The purpose of this study was to determine whether adaptive replanning on an MRI-Linear Accelerator could permit SBRT of longer spinal segments.

MATERIALS/METHODS

We randomly selected ten patients treated in the abdomen on a 0.35T MRI-Linac with MRI including L2-T8. For each patient, their simulation MRI was used to generate six distinct plans starting at 2 spinal levels incrementing to 7 spinal levels. Coverage was 90% at 16 Gy to the entire vertebrae including processes and TG-101 constraints were used for SC and other nearby organs at risk (OAR). Each plan was then rigidly fused in 6-dimensions to a treatment MRI obtained on another day (non-adaptive) and evaluated. An adaptive plan was then generated for each non-adaptive plan. Target coverage between non-adaptive and adaptive techniques was compared using paired t tests. McNemar's tests were used to compare proportions of dose objective failures for OAR between sets.

RESULTS

The target-coverage and number of patients meeting V10 Gy <0.35 and Dose max <14 Gy are shown in the table below with respective p-values. Statistically significant p-values (<0.05) were obtained for all criteria analyzed, especially above 4 vertebral body (VB) levels.

CONCLUSION

This dosimetric analysis suggests that adaptive replanning using a hybrid MR/Linac platform has the potential to safely extend spine SRS beyond the currently accepted practice of 2-3 consecutive VB levels. Future directions include applying this innovative approach in a clinical trial.

Toxicity Analysis of a Modified Prostate Bed CTV Based on PSMA-PET Patterns of Failure

PURPOSE/OBJECTIVE(S)

After radical prostatectomy (RP), about 20-50% of prostate cancer patients experience biochemical failure, and many can be cured with salvage radiotherapy (sRT). Adding androgen deprivation and pelvic lymph node (PLN) RT to sRT decreases risk of disease progression at the cost of increased toxicity. PSMA PET patterns of local failure after RP show failures outside the RTOG prostate bed CTV (RTOG_CTV) occurring postero-laterally and inferiorly, while in much of the covered bladder local failures are not seen. A modified CTV (m_CTV) encompassing all sites of observed local failures and less of the bladder would potentially reduce dose to the bladder but increase dose to rectum. Herein, we compared sRT plans using RTOG_CTV vs. m_CTV and assessed predicted genitourinary (GU) and gastrointestinal adverse events (AEs).

MATERIALS/METHODS

Volumes for RTOG_CTV, m_CTV, PLN CTV, and OARs were retrospectively contoured on planning CT scans of 28 post-RP patients. Plans were generated for each RTOG_CTV and m_CTV. Doses to prostate bed PTV (CTV + 8mm expansion, 6mm posteriorly) and PLN CTV were 68 Gy and 52.7 Gy, respectively, all in in 34 fractions. Dose-volume histogram (DVH) data for bladder, rectum, and bowel of each plan were extracted. Normal Tissue Complication Probability (NTCP) curves were generated using Lyman-Kutcher-Burman model to predict risk of late G≥3 GU AEs, early GU urgency, leakage, frequency, nocturia, late GI bleed, and late G≥3 GI AEs. Data were compared using 2 sample t-test and Wilcox signed rank test. Correlation of bladder volume and differences in DVH and NTCP data between plans was assessed using Pearson coefficient.

RESULTS

The m_CTV and RTOG_CTV had a median volume of 70.56cc (IQR 59.72-82.17cc) and 132.14cc (IQR 109.33-155.84cc), respectively. Use of m_CTVs resulted in mean absolute decrease of 20.22% and 17.94% in bladder V65 Gy and V40 Gy, respectively (p<0.01 for both), without differences in rectum V65 Gy (p = 0.44), rectum V40 Gy (p = 0.11), or bowel V45 Gy (p = 0.29). Per NTCP curves, m_CTV plans had mean absolute decrease of 24.89% in predicted late G≥3 GU AEs (p<0.01). For predicted early GU AEs, there were mean absolute decreases ranging from 4.85 to 10.21% (p<0.01 for all). Predicted late GI bleed (p = 0.98) and late G≥3 GI AEs (p = 0.99) were not significantly different between plans. When assessed as a continuous variable, smaller bladder volumes had strong correlation with more benefit from m_CTV in bladder V65 Gy (r = -0.71, p<0.01) and moderate correlation with less early GU AEs (r -0.59 to -0.56, p<0.01 for all). There was no correlation with bladder V40 Gy (p = 0.27) or late G≥3 GU AEs (p = 0.14).

CONCLUSION

The m_CTV plans had significantly less dose to the bladder, no increased dose to the rectum and significantly lower predicted rates of early and late GU toxicity. Using a m_CTV encompassing observed local failures from PSMA PET could improve the therapeutic ratio for patients undergoing sRT. Further clinical validation is warranted.

Dose-Volume Parameters to the Urinary Tract Sub-Volumes and Predictors of Genitourinary Acute Toxicity in a Phase 2 Clinical Trial Assessing MRI-Guided Prostate Boost for Localized Prostate Cancer - The Miami BlastM Trial

PURPOSE/OBJECTIVE(S)

The relationship between radiotherapy dose to the sub-volumes of the genitourinary (GU) tract and GU toxicity is poorly understood, particularly in prostate cancer patients treated with an intraprostatic dominant lesion (IDL) boost. While the use of IDL boost improves outcomes, it results in higher doses to GU structures and potentially increased toxicity. We investigated the association between dose-volume histogram (DVH) parameters for urinary tract sub-volumes and GU toxicity in the context of IDL boost in patients enrolled in the Miami BlastM Trial.

MATERIALS/METHODS

DVH data were assessed for patients enrolled in the Miami BlastM, a randomized phase 2 trial (NCT20140627) evaluating upfront versus integrated IDL boost. IDL GTV boost consisted of either 12-14 Gy administered on day 1 or integrated boost of 2.4 Gy per fraction (91.2 Gy total, 98.5 Gy 2.0 Equiv), with the prostate receiving 76 Gy in 38 fractions. Bladder trigone (BTg) and urethra sub-volumes were contoured retrospectively on planning CT scans. GU toxicity was assessed using Common Toxicity Criteria for Adverse Events (CTCAE) version 4 and International Prostate Symptom Score (IPSS). DVHs of the bladder, BTg, bladder minus BTg, prostatic urethra, and bulbomembranous urethra were examined. The primary composite endpoint was CTCAE GU acute toxicity grade (G) ≥2 and/or IPSS increase of ≥10 from baseline. Secondary endpoints were GU acute toxicity G≥2, GU late toxicity G≥2, and IPSS increase of ≥10 from baseline. Univariable and multivariable logistic regression analyses were performed.

RESULTS

A total of 129 patients treated between February 2015 and January 2022 were eligible for analysis. One hundred and one (78%) patients developed either GU acute toxicity G≥2 (68%) and/or an IPSS increase of ≥10 from baseline (30%). Less than 2% of patients developed GU toxicity G≥3. BTg V30 Gy was significantly associated with IPSS increase ≥10 (p = 0.046). The bulbomembranous urethral maximum dose was significantly associated with GU acute toxicity G≥2 and GU late toxicity G≥2 (p <0.05 for both). Average maximum and mean urethral doses were 88.9 and 81.5 Gy, respectively. The BTg maximum dose, V20 Gy, V30 Gy, and V40 Gy were not significantly associated with the primary composite endpoint (p = 0.56, 0.75, 0.89, 0.82, respectively). On multivariable analysis, a higher bulbomembranous urethral maximum dose was significantly associated with GU acute toxicity G≥2 and/or IPSS increase of ≥10 from baseline (p = 0.019).

CONCLUSION

Our data suggest a dose-effect relationship between maximum doses to the bulbomembranous urethra and GU toxicity. A better understanding of RT-related changes to specific sub-volumes of the urethra and strategies to mitigate urethral dose could enhance the therapeutic ratio in prostate cancer patients treated with MRI-guided IDL boost.

Disfrute a través de una propuesta de descansos activos en educación infantil

La siguiente propuesta muestra un estudio que pretendió comprobar cuál es la influencia que tienen los descansos activos en el disfrute del alumnado de Educación Infantil, siendo este un elemento de la motivación. Además, se evaluó la existencia de diferencias en el disfrute en función del sexo del alumnado. Para ello, se llevó a cabo una metodología basada en los descansos activos durante diez días, en los cuales se recogieron las impresiones del alumnado a través de un test que se pasaba tras la actividad sedentaria, y, de igual forma, tras los descansos activos. Igualmente, se recogieron las impresiones por parte del profesorado a través de una entrevista realizada el último día del estudio. La muestra tomada para este trabajo constaba de 22 sujetos de una clase del primer curso del segundo ciclo de Educación Infantil (3 años), siendo estos 12 niñas y 10 niños. Finalmente, los resultados permitieron concluir que los descansos activos aumentan el disfrute del alumnado, sin que se den diferencias de acuerdo con la variable sexo. 

Epigenetic control of the EWS‑FLI1 promoter in Ewing's sarcoma

Ewing sarcoma (ES) is a primary bone marrow tumor that very rarely develops in extra-osseous tissues, such as lung. The hallmark of ES tumors is a translocation between chromosomes 11 and 22, resulting in a fusion protein, commonly referred to as EWS-FLI1. The epigenetic profile (histone acetylation and methylation enrichment of the promoter region) that may regulate the expression of the aberrant transcription factor EWS-FLI1, remains poorly studied and understood. Knowledge of epigenetic patterns associated with covalent histone modification and expression of enzymes associated with this process, can contribute to the understanding of the molecular basis of the disease, as well as to the identification of possible molecular targets involved in expression of the EWS-FLI1 gene, so that therapeutic strategies may be improved in the future. In the present study, the transcriptional activation and repression of the EWS-FLI1 fusion gene in ES was accompanied by selective deposition of histone markers on its promoter. The EWS-FLI1 fusion gene was evaluated in two patients with ES using conventional cytogenetic, fluorescence in situ hybridization and nested PCR assays, which revealed that the aberrant expression of the EWS-FLI1 gene is accompanied by enrichment of H3K4Me3, H3K9ac and H3K27ac at the promoter region.

Nutritional value of high-fat oat groats fed to weaned pigs

Oat groats with high-fat (HFOG) content for weaned pigs were evaluated. The HFOG contained 95 g fat, 159 g crude protein and 5.4 g of apparently digestible lysine per kilogram DM. Weaned pigs (8.5 kg) were fed diets containing 0, 150, 300 or 450 g HFOG kg-1 DM for 4 wk. No difference in overall average daily gain, feed intake or gain-to-feed ratio was observed between treatments. In conclusion, HFOG can replace a mixture of wheat, canola oil and soybean meal (84:7:9) in diets for nursery pigs. Key words: Weaned pig, oat groats, nutritional value, digestibility, growth

Fenton's oxidation of food processing wastewater components. Kinetic modeling of protocatechuic acid degradation

The oxidation of protocatechuic acid (PA), a typical phenol-type compound present in food processing wastewater, has been carried out by means of Fenton's reagent. Both the H2O2 and Fe(II) initial concentrations increase the PA degradation rate. Temperature also enhances the PA conversion when raised from 283 to 313 K, a further increase to 323 K results in a lower PA removal. Increasing the PA initial concentration leads to a decrease of conversion values but an opposite effect in terms of removal rate. pH values in the range 3-4 resulted in the total inhibition of the oxidation process. Similar PA depletion rates were experienced regardless of the oxidation state of the catalyst (ferrous or ferric iron). Additionally, an attempt based on the classic Fenton's chemistry plus some other stages accounting for the Fe(II) regeneration from Fe(III) and the inefficient H2O2 decomposition was conducted to model the process.

Air bag-induced corneal flap folds after laser in situ keratomileusis

PURPOSE

We describe a case of air bag-induced ocular trauma resulting in folds in the corneal flap 3 weeks after laser in situ keratomileusis.

METHODS

Case report. Three weeks after laser in situ keratomileusis, a 20-year-old man was involved in a motor vehicle accident and sustained blunt trauma to the right eye, which caused corneal flap folds, corneal edema, anterior chamber cellular reaction, and Berlin retinal edema.

RESULTS

Six weeks after laser in situ keratomileusis, persistent flap folds necessitated re-operation with lifting of the flap and repositioning. One week after the procedure, the visual acuity improved to 20/20-2, and the folds had cleared.

CONCLUSION

Trauma after laser in situ keratomileusis may produce folds in the corneal flap. With persistence of these folds, management by lifting and repositioning the corneal flap may be necessary to permit recovery of visual acuity.

Acute effects of soft drink intake on calcium and phosphate metabolism in immature and adult rats

OBJECTIVE

To test the acute effects of the intake of a phosphoric acid containing soft drink on acid-base balance and on calcium and phosphate metabolism.

MATERIAL AND METHODS

We studied 14 young adult male Sprague-Dawley rats aged 90 days, and 14 immature animals aged 30 days. Half of the animals in each group were randomly assigned to receive either tap water (controls), or Coca-Cola ad libitum for seven days. After this period, the rats were individually placed in metabolic cages to collect 24 hours urine, and they were exsanguinated by aortic puncture. Immediately, pH and ionized calcium were measured in whole blood. Creatinine, phosphate and total calcium were determined in the urine and plasma. Plasma levels of PTH, 1 alpha, 25 (OH)2 D3 and 25 OH D3 were measured by IRMA and RIA commercial kits.

RESULTS

The animals receiving the soft drink, both adults and immature, developed significant hypercalciuria and hyperphosphaturia. In immature animals, the plasma pH dropped from 7.45 +/- 0.04 to 7.33 +/- 0.02 (p < 0.05) but did not change in adult animals. Ionized calcium dropped significantly from 1.06 +/- 0.04 to 0.80 +/- 0.06 meq/L (p < 0.05) in immature animals but not in the adult animals. Only immature rats developed significant reduction of 1 alpha, 25 (OH)2 D3 and 25 OH D3, whereas only the adult rats developed significant hyperparathyroidism. Immature animals showed more severe derangement of calcium and phosphate metabolism related to soft drink intake.

[The health care system reform in The Netherlands]

In the sixties, The Netherlands advanced from a voluntary health insurance system, that had an incomplete covering and was unfair, towards a still partial obligatory and solidary insurance system. The insurance paid the hospitals and specialists per action and there was a great rise in cost of the system. A committee, presided by W Dekker, proposed a reform to reduce costs and increase equity. It abolished the difference between private and obligatory insurance systems (that covered 60% of the population) and made possible the competence between both types of insurance. It also created a negotiation margin between insurance companies and providers and replaced the payment per action by more efficient resource allowances. The debate originated by the reform hindered its full application. Meanwhile, the government took steps to reduce costs. Social and private insurance systems continue to exist. This article summarizes the special context of Dutch health care system problems.

Comparison of three keratometry instruments

We compared the reliability of measurements of three keratometers and keratometry readings from a corneal topography system to determine if they were as accurate as the "gold standard" Javal-Schiotz keratometer. Same-day measurement of the steepest and flattest powers of the central 3 mm of the corneas of 200 eyes (100 patients) revealed no statistically significant difference in reliability between the newer keratometers and the Javal-Schiotz. In addition, the newer machines are more convenient and efficient in some clinical settings.

Drinking behavior of children in Santiago, Chile

Eighty per cent of the 9-year-old children studied had consumed alcohol, usually a beverage that was sweet and of low alcohol content; 28% drank once a week, 23% twice a week and 9% every day.