Outcomes Specific to Spinal Metastases with Paraspinal Disease Extension Following Spine Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

Spinal metastases with paraspinal disease (PD) extension are known to have worse outcomes following stereotactic body radiotherapy (SBRT). Characteristics of the PD itself have not been investigated to determine the impact on outcomes such as local control, which is the purpose of this study.

MATERIALS/METHODS

We retrospectively reviewed those patients who had SBRT for spinal metastases with PD disease, identified from a prospectively maintained database. Spinal metastases previously irradiated or surgical resected were excluded. The extent of PD was classified as involving the rib, neuroforamina, and muscle invasion. The gross tumor volume of PD (GTV_PD) and the clinical target volume of PD (CTV_PD) were segregated from the bony compartments based on the treatment plan contours. The outcomes of interest included the cumulative risk of local failure (LF), re-irradiation rates (ReRT), and overall survival (OS). LF and ReRT were estimated for each treated sites using the competing risk model (death as the competing risk), while OS was evaluated per patient using the Kaplan Meier method.

RESULTS

A total of 86 patients with 96 spinal metastases sites with PD were included. Of the 96 treated sites, 65% (62/96), 29% (28/96) and 6% (6/96) of PD spanned 1, 2, and 3 vertebral levels respectively. The median follow-up was 12.4months (range: 0.6-100months). The 6- and 12-month OS for the cohort was 81% and 51%, respectively. 33/86 (38%) patients had radioresistant cancer (gastrointestinal, renal cell carcinoma, thyroid, sarcoma, or melanoma). Involvement of rib, neuroforamina and muscle invasion were observed in 39% (37/96), 65% (62/96) and 21% (20/96) of the treated sites, respectively. Epidural disease was present in 57% (55/96) of treated sites. The median GTV_PD volume was 7cc (range: 0.3-114cc), and the median CTV_PD volume was 24cc (range: 0.4-248cc). The prescribed doses were 24 Gy/2 fractions (fx) (80%), 28 Gy/2 fx (10%) and 30 Gy/4 fx (10%). There were 84 treated sites with at least one post-treatment MRI available for LF assessment. The crude LF risk was 32% (27/84), and the 6- and 12-month cumulative LF rates were 12% and 28%, respectively. There was a trend towards an increased risk of LF when PD involved the rib (35% vs 24% at 1 year respectively, P = 0.07) and muscle (67% vs 20% at 1 year respectively; P = 0.06), but no difference in LF for neuroforamina involvement (26% vs 34% at 1 year respectively, P = 0.5). There were no differences in LF based on cancer radioresistance (P = 0.6), GTV_PD volume (P = 0.3) or CTV_PD volume (P = 0.4). Of the 96 treated sites, 14% (14/96) were re-irradiated (9 with repeat SBRT and 5 with conventional EBRT) at a median of 15 months (range: 4.7-59 months) post initial SBRT. The cumulative incidence of ReRT at 6- and 12-months were 1.2% and 7.3%, respectively.

CONCLUSION

PD involving adjacent rib and muscle may be associated with worse LF following SBRT. Further expansion of the cohort and dosimetric analyses are ongoing.

Predictors of Tumor Dynamics during a 6-Week Course of Chemoradiotherapy for Glioblastoma

PURPOSE/OBJECTIVE(S)

Our prior imaging studies have shown geometrically meaningful inter-fraction tumor dynamics specific to glioblastoma (GBM). We aim to identify predictors associated with tumor dynamics during a 6-week course of concurrent chemoradiotherapy (CRT) for GBM.

MATERIALS/METHODS

Patients enrolled in a prospective serial magnetic resonance imaging (MRI) study were reviewed. All patients were treated with 54-60 Gy in 30 fractions. The gross tumor volume (GTV) included the surgical cavity and T1c enhanced residual tumor; clinical tumor volume (CTV) included GTV with a 15mm isotropic expansion, respecting anatomical boundaries; planning target volume (PTV) was 4mm expansion. MRIs were obtained at RT planning (F0), fraction 10 (F10), and fraction 20 (F20). Tumor dynamic metrics (relative to F0) assessed included the GTV volume (Vrel), Hausdorff distance (dH) and migration distance (dM). dH is the average distance between two datasets in metric space. dM is the maximum linear displacement of the GTV in any direction. Factors to be determined associated with tumor dynamics included: age, sex, corpus callosum (CC) involvement, extent of surgery (gross total resection (GTR), subtotal resection (STR) or biopsy alone (Bx)), MGMT methylation and IDH mutation status.

RESULTS

A total of 129 patients were reviewed. Median GTV was 20.9cc at F0, 17.6cc at F10 (Vrel 0.85), and 16.1cc at F20 (Vrel 0.78). Patients without CC involvement had more marked GTV volume reduction: Vrel 0.82 vs 1.02 with CC involvement at F10 (P = 0.05), and Vrel 0.77 vs 0.88 with CC involvement at F20 (P = 0.03). Patients with GTR (vs STR vs Bx) had more marked GTV volume reduction across all time points: Vrel 0.78, 0.85 and 1.07 respectively at F10 (P = 0.001), and Vrel 0.69, 0.80, 1.04 respectively at F20 (P = 0.001). The median dH was 8.1mm at F10 and 9.2mm at F20. Patients with CC involvement (vs without CC involvement) had a larger dH: 54% vs 25% had dH>10mm respectively at F10 (P = 0.03), and 73% vs 28% had dH>10mm respectively at F20 (P<0.005). Patients with a GTR had smaller dH at both F10 (P = 0.02) and F20 (P = 0.006). At F20, 20%, 47% and 37% of patients with GTR, STR and Bx had dH>10mm (P = 0.04). The median dM were 4.7mm at F10 and 4.7mm at F20. Patients with CC involvement (vs without CC involvement) had larger dM: 41% vs 12% had dM >10mm respectively at F10 (P = 0.01), and 45% vs 9% had dM >10mm respectively at F20 (P<0.001). Patients with GTR had smaller dM at F10 (P = 0.03) and F20 (P0.002). At F20, 0%, 25% and 19% of patients with GTR, STR and Bx had dM>10mm (P = 0.002). Age, sex, MGMT methylation and IDH mutation status were not associated with Vrel, dH and dM at F10 and F20.

CONCLUSION

We identified CC involvement and extent of surgery to be associated with tumor dynamics at F10 and F20 over the course of CRT for GBM. This offers opportunities to better select patients who may benefit from earlier/ more frequent RT replan/ adaptation to ensure adequate tumor coverage, or to reduce RT toxicities.

Splenectomy Does Not Increase Early Morbidity in Patients Undergoing Total Gastrectomy: A Case-Control Study with Propensity Score Analysis

AIM

In gastric cancer (GC), D2 lymph node dissection is, alongside negative-margins gastrectomy, of paramount importance. There is a debate between Western and Eastern scientific communities concerning the risk-benefit balance with respect to splenectomy, as Western countries are inclined to perform spleen-preserving gastrectomy due to an increased risk for postoperative complications. In Eastern countries (such as Japan) this is not the case. Our study aimed to determine whether or not spleen-sacrificing total gastrectomy for GC was associated with a higher rate of early postoperative morbidity or mortality.

METHOD

We performed a retrospective case-control study in which we included patients who underwent total gastrectomy with D2 lymphadenectomy for GC (stages I-III) with curative intent, in a single high-volume tertiary oncologic centre. We divided the cases into two groups: spleenpreserving (SP) and spleen-sacrificing (SS) and evaluated the early complications rate following surgery. Afterwards, we performed propensity score matching (PSM) and analysis of the two groups. Results: We included 74 patients, 29 in the SS group and 45 in the SP group. Fifteen cases (20.2%) developed early postoperative complications and the complication rate was 53% (n=8) in the SS group and 46% (n=7) in the SP group. The overall 30-day mortality rate was 2.7%. Conclusions: Splenectomy is not associated with increased early morbidity following total gastrectomy with D2 lymphadenectomy if performed by an experienced surgeon.

Patient-Reported Urinary and Bowel Quality of Life Outcomes Following External Beam Radiotherapy with or without High-Dose-Rate Brachytherapy Boost: Post-Hoc Analyses of TROG 03.04 (RADAR)

PURPOSE/OBJECTIVE(S)

One of the concerns with combining external beam radiotherapy (EBRT) with a high dose rate brachytherapy boost (HDRBT) for prostate cancer is increased toxicity. We aimed to evaluate long-term urinary and bowel quality of life (QoL) outcomes following EBRT vs EBRT + HDRBT using data from the TROG 03.04 trial.

MATERIALS/METHODS

Men who had dose-escalated EBRT (74 Gy) or EBRT (46 Gy) + HDRBT (19.5 Gy in 3 fractions) were included in this exploratory analysis. QoL outcomes were prospectively collected using the EORTC-QLQ-PR25 at baseline, end of radiotherapy, 12, 18, 24, 36, 60 months, and annually up to 10 years. QoL score was normalized to 0-100 with higher scores representing worse symptom burden. Minimal clinically important differences (MCIDs) were defined as differences in the respective QoL scores ≥0.5 standard deviations of the baseline QoL score. Mixed models for repeated measures were used to evaluate longitudinal changes in the QoL score between EBRT and EBRT + HDRBT arms. Logistic regression was used to evaluate differences in proportion of men with 2xMCID between EBRT and EBRT + HDRBT arms at each time point. Age, baseline QoL score, ECOG performance status, and duration of androgen deprivation therapy use (6 vs. 18 months) were adjusted for in all analyses.

RESULTS

Four hundred ninety-seven men were included in this study: 260 (52%) had EBRT and 237 (48%) had EBRT + HDRBT. The median baseline urinary QoL scores were 12.5 (IQR 4.2-19.0) and 8.3 (IQR 4.2-20.8) for men in EBRT and EBRT + HDRBT arms respectively (P = 0.5). Within the first 24 months, men in the EBRT + HDRBT arm had a slower rate of urinary QoL score resolution compared to men in the EBRT arm (P<0.001). At 12, 18, 24, and 36 months, men who had EBRT + HDRBT were 2.4 times (95% CI = 1.4-4.0; P<0.001), 3.1 times (95% CI = 1.8-5.1; P<0.001), 2.8 times (95% CI = 1.7-4.7; P<0.001), and 2.5 times (95% CI = 1.4-4.5; P = 0.002) more likely to have 2xMCID in urinary QoL scores compared to men who had EBRT alone. Beyond 24 months, there were no significant differences in the rate of urinary QoL score resolution between arms, and beyond 36 months there were no significant differences in the proportion with 2xMCID between arms. The median baseline bowel QoL score was 0 in both arms. There were no differences in the rate of bowel QoL score recovery over time between arms. Men who had EBRT + HDRBT were less likely to have 2xMCID in bowel QoL score in the immediate post-radiotherapy period (OR = 0.66; 95% CI = 0.45-0.97; P = 0.03) and at 60 months (OR = 0.51; 95% CI = 0.33-0.80; P = 0.003) compared to men who had EBRT.

CONCLUSION

EBRT + HDRBT is associated with disturbances in urinary QoL that are of greater magnitude compared to EBRT alone within the first 36 months of treatment, but the differences resolved after 36 months. EBRT + HDRBT is associated with less disturbances in bowel QoL immediately after treatment and at 60 months compared to EBRT alone.

Dosimetric Predictors of Toxicities and Quality of Life Following Two-Fraction Stereotactic Body Radiotherapy for Prostate Cancer

PURPOSE/OBJECTIVE(S)

There is emerging interest in two-fraction stereotactic body radiotherapy (2#SBRT) for localized prostate cancer. However, there is limited data to guide organs at risk (OAR) dose constraints in 2#SBRT. We aim to identify dosimetric predictors of toxicities and quality of life (QoL) using real life patient data from two prospective 2#SBRT trials.

MATERIALS/METHODS

We included 60 patients who had 2#SBRT in the 2STAR (NCT02031328) and 2SMART (NCT03588819) phase 2 trials. The prescribed dose was 26Gy to the prostate +/- focal boost of 32Gy to the dominant intraprostatic lesions. Toxicities and QoL data were prospectively collected using CTCAEv4 and EPIC26 questionnaires. For QoL, we reported the minimal clinical important changes (MCIC), defined as changes in QoL score of >0.5 standard deviation from baseline QoL score. We evaluated the bladder, urethra, rectum, and penile bulb dosimetry (urethra dosimetry only available in 30 patients in 2SMART trial). Some of the dosimetric parameters were log-transformed to normalize the distribution. Cox regression was used to identify dosimetric predictors for acute and late grade ≥2 GU toxicities. Logistic regression was used to identify dosimetric predictors for late MCIC in urinary, bowel and sexual QoL domains. Backward stepwise selection was used to identify significant dosimetric parameters. For GU toxicities and urinary QoL, three additional clinical factors (age, prostate volume and IPSS) were included in the final model as confounding factors. Receiver operating characteristics curve was used to identify cut-off for significant dosimetric parameters.

RESULTS

The median follow-up for the cohort was 56 months (range: 39-78 months). The cumulative acute and late grade ³2 GU toxicities were 62% (37/60) and 57% (34/60) respectively. No bladder or urethra dosimetric parameter was associated with acute grade ≥2 GU toxicities. Bladder D0.5cc was significant predictor of late grade ≥2 GU toxicities in univariate model (P = 0.05), but not in multivariate model. Baseline IPSS score was the single strongest predictor for late grade ≥2 GU toxicities (HR = 1.9; 95% CI = 1.1-3.4; P = 0.03). For late QoL outcomes, there were 36% (21/58), 28% (16/58), and 29% (17/58) of patients with MCIC in urinary, bowel and sexual QoL domains respectively. Bladder V10Gy was associated with late urinary MCIC in multivariate model after adjusting for clinical confounders (HR = 2.6, 95% CI = 1.1-6.6; P = 0.04). 48% (14/29) and 24% (7/29) of patients with bladder V10Gy>13.9% and V10Gy≤13.9% respectively had late urinary MCIC. No rectum and penile bulb dosimetry parameters was identified to be associated with late bowel or sexual QoL.

CONCLUSION

Using real life patient data from prospective clinical trials with medium term follow-up, we identified statistically significant bladder dosimetry parameter predictive of late urinary QoL. This finding could be useful to guide OAR dose constraints in prostate 2#SBRT trials.

Evaluation of Changes in Circulating Cell-Free DNA as an Early Predictor of Response to Chemoradiation in Rectal Cancer-A Pilot Study

Background and Objectives: The objective of this study was to investigate quantitative changes in cell-free DNA (cfDNA) found in the bloodstream of patients with locally advanced rectal cancer who received neoadjuvant long-course chemoradiation, assuming a change in DNA fragments release during therapeutic stress. Materials and Methods: This was a prospective observational study that involved 49 patients who had three distinct pathologies requiring neoadjuvant chemoradiation: 18 patients with breast cancer, 18 patients with cervical cancer, and 13 patients with rectal cancer. Both breast cancer and cervical cancer patients were used as a control groups. Breast cancer patients were used as a control group as irradiation targeted healthy tissue after the tumor resection (R0), while cervical cancer patients were used as a control group to evaluate the effect of chemoradiation regarding cfDNA in a different setting (squamous cell carcinomas) and a different tumor burden. Rectal cancer patients were the study group, and were prospectively evaluated for a correlation between fragmentation of cfDNA and late response to chemoradiation. Blood samples were collected before the initiation of treatment and after the fifth radiation dose delivery. cfDNA was quantified in peripheral blood and compared with the patients' clinicopathological characteristics and tumor volume. Conclusion: Thirteen patients with locally advanced rectal cancer (T3/T4/N+/M0) were included in the study, and all of them had their samples analyzed. Eight were male (61.54%) and five were female (38.46%), with an average age of 70.85 years. Most of the patients had cT3 (53.85%) or cT4 (46.15%) tumors, and 92.31% had positive lymph nodes (N2-3). Of the thirteen patients, only six underwent surgery, and one of them achieved a pathological complete response (pCR). The mean size of the tumor was 122.60 mm3 [35.33-662.60 mm3]. No significant correlation was found between cfDNA, tumor volume, and tumor regression grade. cfDNA does not seem to predict response to neoadjuvant chemoradiotherapy and it is not correlated to tumor volume or tumor regression grade.

Predictive and Prognostic Role of Neutrophil to Lymphocyte Ratio in Rectal Cancer: A Case Control Study with Propensity Score Analysis

Background: Neutrophil to lymphocyte ratio (NLR) is promoted as a marker reflecting the antitumoral inflammatory response. Herein, we aim to assess whether NLR at the time of diagnosis can predict response to neoadjuvant therapy and long-term survival in a matched cohort of rectal cancer patients. Methods: This is a case control study on rectal cancer patients who underwent standard oncological treatment and had NLR sampled at each stage. ROC curve was used to establish the cut off value of NLR at diagnosis. Two groups (high and low NLR) were compared. Kaplan Meier overall and disease-free survival (DFS) analysis was done comparatively between two groups of patients: low and high NLR. Pearson and Log Rank tests were used to establish statistical significance. Propensity score matching (PSM) was performed, and all variables were compared again on the matched subgroups. Results: One hundred patients were included and 54 were compared again after PSM. NLR at diagnosis did not correlate with tumor regression grade (p=0.77). High NLR at diagnosis (NLR 2.58) was not found to be significantly associated with worse overall survival (p=0.096) or DFS (p=0.128). Similar results were achieved after PSM, except when stage III subgroups were compared, where higher NLR was associated with worse DFS (p=0.04), while results for OS were borderline (p=0.05). Conclusions: Overall, a pretherapeutic high NLR ( 2.58) was not found to predict survival or response do neoadjuvant therapy in patients with rectal cancer. However, a higher NLR may be associated with worse outcomes in advanced colorectal cancer.

Effects of acidified blanching water and pectinase enzyme pretreatments on physicochemical properties and antioxidant capacity of Carica papaya juice

The high pectin content in papaya (Carica papaya) causes the juice extraction to be difficult and results in a low yield. This study aims to determine the effect of acidified blanching water and pectinase enzyme pretreatments on the yield, physicochemical properties, and antioxidant activities of the papaya juice. For acidified blanching treatment, papaya cubes (3 cm³ ) were blanched in water containing 0%, 0.5%, 1.5%, and 2.5% w/v citric acid at 95℃ for 2 min. For enzyme treatment, a pectinase enzyme (10, 20, and 30 ppm) was added to the homogenous papaya puree and incubated at 45℃ (200 rpm) for 60 min. The enzyme reaction was stopped by pasteurization at 74℃ for 2 min. The puree was filtered, and the juice was pasteurized at 74℃ for 7 min. All pretreated papaya juice were analyzed for physicochemical properties (color, clarity, viscosity, pH, total soluble solids [TSSs], total carotenoid content, total phenolic content [TPC], and total flavonoid content [TFC]), and antioxidant activities (2,2-diphenyl-1-picrylhydrazyl [DPPH] and ferric reducing antioxidant power [FRAP] assay). Both pretreatments improved the clarity of papaya juice, and was significantly greater after pretreatment with pectinase enzyme. The TPC and antioxidant activities of papaya juice were conserved and maintained by acidified blanching at 1.5% (w/v) citric acid. Increased concentrations of pectinase enzyme significantly reduced the TPC and total carotenoid content. Pretreatment with pectinase enzyme up to 20 ppm does not significantly reduce the TFC and antioxidant activities. Acidified blanching and pectinase enzyme pretreatments have an impact on extraction of papaya fruit juice while retaining the nutritional composition of the juice. PRACTICAL APPLICATION: Papaya (Carica papaya) is a fruit with great nutritional values but is highly perishable and prone to postharvest loss. Juice has become a more cost-effective and convenient option for preserving the fruit. However, since papaya is a pectin-rich fruit, the extraction of juice using mechanical pressing is difficult due to the bonding of juice to the pulp in the form of a jellied mass, which results in juice with low yield. Using acidified blanching and pectinase enzyme to clarify the juice not only increases the yield but also retains the nutrient composition of the juice.

Evolving Practice Pattern of Palliative Radiation Therapy for Bone Metastases from Lung Cancer in Australia

AIMS

Radiation therapy is an effective treatment for bone metastases. Single-fraction conformal radiation therapy (SF-CRT) is equally effective as multifraction radiation therapy for the management of uncomplicated bone metastases. There has been a rapid development of advanced radiation therapy techniques (ART) in radiation oncology. We evaluated the changing pattern of SF-CRT and ART use for the management of bone metastases in lung cancer.

MATERIALS AND METHODS

This was a state-wide population-based cohort of lung cancer patients from Victoria, Australia, who received radiation therapy for bone metastases between 2012 and 2017. The primary outcomes were proportion of radiation therapy courses using: SF-CRT and ART. We identified a subcohort in which radiation therapy was delivered at the end of life (EOL), i.e. within 30 days of death. The Cochran-Armitage test for trend was used to evaluate the change in pattern of SF-CRT and ART use over time. Multivariable analyses were used to identify factors associated with the primary outcomes.

RESULTS

Of the 4335 courses of radiation therapy for bone metastases in lung cancer, 20% were SF-CRT - increasing from 19% in 2012 to 26% in 2017 (P-trend = 0.004). In multivariate analyses, treatment to the rib, shoulder, hip or extremities, and treatment in public institutions were independently associated with SF-CRT use, but the effect of year of radiation therapy was no longer significant. Five per cent of radiation therapy was delivered using ART, increasing markedly from 2016 onwards (P-trend < 0.001). In multivariate analyses, treatment in private institutions and more recent years of treatment were independently associated with the use of ART. There were 587 courses of radiation therapy delivered at the EOL, with SF-CRT more commonly used closer to death - 53%, 29% and 25% of radiation therapy within 7 days, 8-14 days and 15-30 days of death, respectively.

CONCLUSION

SF-CRT continued to be underutilised for bone metastases in lung cancer in Australia, including at the EOL. We observed an increase in ART use for bone metastases from 2016, which occurred contemporaneously with changes in government funding.

Hybrid organic PVDF-inorganic M-rGO-TiO2 (M = Ag, Pt) nanocomposites for multifunctional volatile organic compound sensing and photocatalytic degradation-H2 production

This work focused on the development of a hybrid organic-inorganic TiO2 nanocomposite, which demonstrates the first ever report on harmful volatile organic compound (VOC) sensing and photocatalytic degradation-H2 production. The sensing and photocatalytic properties are enhanced by the synergetic effects of well-structured TiO2 nanotubes, metal nanoparticles and reduced graphene oxide loading for enhanced light absorption and charge-transfer kinetics. Hybridization of a functionalized TiO2 nanocomposite with a polyvinylidene fluoride (PVDF) matrix induced strong cross-linking networks between the inorganic-organic components, which promote mechanical reinforcement-flexibility and highly porous asymmetric structures. The developed solution processable nanocomposite has immense potential to remedy the global environmental and energy issues by producing clean water/air and energy from organic compound waste.

Formation of hybrid structures: copper oxide nanocrystals templated on ultralong copper nanowires for open network sensing at room temperature

A facile large-scale synthesis approach for producing intrinsically p-type nanowires with uniform coverage of nanocrystals to form a highly interconnected porous nanowire network is of great demand for p-type sensing. Here, we have demonstrated synthesis of a very high aspect ratio (10(2)-10(5)) open network of interconnected hybrid nanocrystals-nanowire copper and copper oxide nanomaterials. The copper nanowire scaffold is employed to realize a porous and highly interconnected network of hybrid metal-metal oxide nanocrystal-nanowire structures. The structural and composition tunability of the hybrid nanomaterials is demonstrated. The hybrid copper-copper oxide nanowires exhibit enhanced gas/light sensing properties without any operating temperature. This may be attributed to enhanced medium diffusion due to the porous network of highly interconnected nanocrystal-nanowire structures.