Standard Fractionation Research Articles

RADT-26. RADIATION FRACTIONATION IN THE MANAGEMENT OF ELDERLY PATIENTS WITH GLIOBLASTOMA BY AGE

Abstract Multiple studies have investigated hypofractionated radiation (HFX) for elderly patients with glioblastoma (GBM), using varying age cut-offs. This leads to uncertainty about who benefits most from a hypofractionated course. This study examines the use of and outcomes with HFX, between two commonly used cut offs to define elderly GBM: 65 versus 70 years old. In this retrospective review, 309 patients diagnosed with GBM who were treated with radiation at a single academic institution were included. The Kaplan-Meier method was used to analyze overall survival. A Chi-square test was conducted to compare the use of SFX and HFX and the median survival between those 65-69 versus 70-74 years old. Patients aged 70-74 were more likely to receive HFX radiation compared to those aged 65-69 (80.00% vs. 42.65%, p=0.0002). Median survival for the entire cohort was 12 months. Among those 65-69 years old, SFX was associated with a significantly higher median survival compared to HFX (14 months vs. 7 months, HR 2.00, 95% CI 1.16 – 3.46, p=0.03). This was also true for those 70-74 years old, (18 months vs. 4 months, HR 4.50, 95% CI 1.84 – 11.01, p=0.03). We demonstrate a decrease in the use of SFX in patients 65 years or older, and that that standard fractionation is associated with longer survival in older patients with GBM. This suggests that in a well selected population, SFX should be considered even among elderly patients. Additional work is needed to determine whether these findings are causal or due to patient selection. Performance status and MGMT methylations status, for instance, should guide clinical decision making. Such results highlight the importance of further studies to fine tune radiation dose and fractionation elderly patients with GBM.

RADT-49. IMPACT OF SHORT COURSE RADIOTHERAPY IN REDUCING LYMPHOPENIA IN PATIENTS WITH GLIOBLASTOMA (SAGA STUDY)

Abstract INTRODUCTION Lymphopenia attributed to postoperative chemoradiotherapy (CRT) can accelerate tumor recurrence and contribute to poor prognosis in GBM. We hypothesize that short course (1-2 weeks) CRT can mitigate lymphopenia compared to standard course and may provide immune benefits for future combination therapy. METHODS GBM patients were randomized on a multi-site phase II study comparing short course (35Gy/5Fx or 40Gy/10Fx depending on target volume) (Arm A) versus standard dose fractionation (60Gy/30Fx or 40Gy/15Fx, Arm B). All patients received concurrent and adjuvant temozolomide (TMZ). This unplanned interim analysis evaluates changes of absolute lymphocyte count (ALC), CD4 and CD8 prospectively at 3-timepoints: baseline (prior to CRT), end of CRT, and 1-month post-CRT. RESULTS To date, 72 patients enrolled (34 Arm A, 38 Arm B). Median age 66 (35-86), ECOG 0-2. Patients characteristics as followed in Arm A vs. Arm B, respectively: female 47% vs. 42%, MGMT promotor methylated 31% vs. 34%, steroid use 46% vs. 45%, ALC 1310 cells/mm3 (330 –9730) vs. 1480 (750 –7750), CD4 531 cells/mm3 (86 –1368) vs. 662 (318 –1671), and CD8 151 cells/mm3 (56 –940) vs. 272 (68 –875). Lymphocytes data were collected in 49 patients (21 Arm A, 28 Arm B). There were signficantly fewer reductions of ALC, CD4 and CD8 in Arm A. Median ALC changes were 95% and 99% of baseline (Arm A) vs 52% and 61% of baseline (Arm B) at the end of CRT and 1-month post-CRT, respectively (p<0.01). Median CD4 changes 93% and 96% of baseline (Arm A) vs 51% and 49% (Arm B), and median CD8 changes 97% and 98% of baseline (Arm A) vs 57% and 71% (Arm B) at the end of CRT and 1-month post-CRT, respectively (p<0.05). CONCLUSIONS This interim analysis suggests that short course RT could reduce treatment-related lymphopenia and immune suppression compared to standard RT, thus could be potentially beneficial to combine with immunotherapy.

Breast cancer radiobiology: The renaissance of whole breast radiation fractionation (Review).

Breast cancer radiotherapy has evolved significantly, driven by decades of research into fractionation schedules aimed at optimizing treatment efficacy and minimizing toxicity. Initial trials such as NSABP B-06 and EBCTCG meta-analyses established the benefits of adjuvant whole-breast irradiation in reducing local recurrence and improving survival rates. The linear-quadratic (LQ) model provided a framework to understand tissue response to radiation, highlighting the importance of the α/β ratio in determining fractionation sensitivity. The present scoping review aimed to identify and describe hypofractionation regimens for whole breast radiotherapy and evaluate dose differences using the LQ model across proposed α/β ratios. A comprehensive PubMed search for clinical trials published since 2010 on hypo-fractionated regimens was performed. Studies discussing α/β ratios for breast cancer have been also searched. Data on dose, fractions and α/β ratios were collected, and biologically effective dose (BED) and equivalent dose in 2 Gy fractions were calculated. The coefficient of variation for BED varied with α/β ratios, showing the lowest variability for an α/β ratio of ~3 without tumor repopulation and increased with repopulation (BED-kT; k is a constant that depends on the repopulation rate of the tumor, and T is the total treatment time in days). Significant differences in BED variances were observed across α/β ratios (F-statistic 219.6, P<0.0001). START trials (P, A, and B) established α/β ratios of 3-4 Gy for breast cancer and normal tissues, confirming that hypofractionation is as effective as standard fractionation with potentially fewer late toxicities. Subsequent trials, such as FAST and FAST-Forward, demonstrated that ultra-hypofractionation is equivalent in tumor compared with conventional regimens. Further research is needed to gain a stronger understanding of radiobiological properties of breast cancer cells. Advances in radiotherapy technologies and the integration of biomarkers, radiomics and genomics are transforming treatment, moving towards precision medicine.

Radiation therapy in the hypofractionation mode on the Halcyon elite linear accelerator: the first experience of St. Petersburg city clinical oncology dispensary

Stereotactic radiation therapy in the hypofractionation mode is a method in which high doses of ionizing radiation (more than 3 Gy per fraction) are delivered in a small number of fractions (from 2 to 5). Treatment and the process of preparation for it are carried out using special fixing devices, dosimetric planning techniques of high conformity, with control of the treatment position using x-ray imaging. which makes it possible to ensure the required irradiation accuracy. The advantages are a shorter course of treatment compared to standard fractionation, a high biologically effective dose, a reduced effect of tumor repopulation, greater efficiency under hypoxic conditions, and satisfactory results when irradiating radioresistant tumors. The article presents clinical cases of the use of hypofractionation modes on the Halcyon elite linear accelerator.

Hypofractionated versus standard fractionation radiotherapy for merkel cell carcinoma

Purpose/Objective(s)Merkel cell carcinoma (MCC) radiation treatment has historically consisted of standard 1.8–2 Gy fractions treated daily over 4–6 weeks. Hypofractionated treatment regimens have demonstrated tumor control and toxicity equivalence to standard fractionation regimens for common cutaneous malignancies such as basal cell and squamous cell carcinomas. Herein we report the outcomes of hypofractionated versus standard fractionation radiotherapy for MCC at our institution.Materials/MethodsThe study involved a retrospective review of MCC patients treated with radiotherapy. Treatment characteristics and patient outcomes, including acute toxicities, disease recurrence and survival data were collected. The cumulative incidence of local and distant failures was estimated, with death as a competing risk.ResultsA total of 29 treatment courses for 24 patients were included, of which 13 involved standard fractionation with curative intent, 10 involved hypofractionated radiotherapy with curative intent, and 6 involved single fraction (8 Gy) palliative radiation. Half the patients were treated to a head/neck site. A subset of patients treated adjuvantly with curative intent included 8 standard fractionation and 8 hypofractionated radiotherapy patients. No statistically significant differences in local and/or distant failure or overall survival was observed between the patient groups.ConclusionHypofractionated radiotherapy for MCC was associated with similar treatment outcomes relative to standard fractionation. In our limited patient sample, hypofractionated radiation treatment achieved similar results with similar toxicity and fewer treatments. Further analysis of a larger patient population with longer follow up is needed to confirm treatment tolerability and efficacy.

Comparative long-term oncological outcomes of intraoperative radiotherapy vs. whole-breast irradiation in early breast cancer: a single institute study.

Intraoperative radiation therapy (IORT) and whole breast irradiation (WBI) are both effective adjuvant radiotherapy methods for ductal carcinoma in situ (DCIS) or early-stage breast cancer (BC) patients undergoing breast-conserving surgery (BCS). We aim to evaluate the long-term oncological efficacy and refine patient selection criteria based on our findings. Female patients who underwent either IORT or WBI from January 2016 to December 2019, with a minimum follow-up of 12 months were collected. IORT was administered as a single fraction of 20 Gray (Gy) to the lumpectomy cavity using the Axxent electronic brachytherapy system, while WBI consisted of a standard fractionation of 50 Gy in 25 fractions, along with a reduced boost of 10 Gy. The clinicopathologic characteristics and oncological outcomes were retrospectively analyzed. A total of 247 patients were enrolled, comprising 164 with BC and 83 with DCIS. Among them, 112 underwent IORT, and 135 received WBI after BCS. The median age was 62.2 years, with median tumor sizes of 1.5cm for BC and 1.2cm for DCIS. At a median follow-up of 64.6 months, IORT demonstrated 11 locoregional recurrences (LRR), 1 metastasis, and 1 death, compared to 4 LRR, 5 metastases, and 2 deaths in the WBI group. WBI yielded significantly higher locoregional control (97.0% vs. 90.2%, p = 0.033), although metastasis-free (96.3% vs. 99.1%, p = 0.166) and overall survival rates (98.4% vs. 99%, p = 0.688) did not differ. The LRR rate was significantly higher in the IORT group among the DCIS or BC patients (p = 0.043). The hazard ratio for locoregional recurrence significantly increased in estrogen-receptor-negative (ER-) patients in both univariate analysis (HR = 4.98, 95% CI = 1.76-14.09, p = 0.002) and multivariate analysis (HR = 40.88, 95% CI = 1.29-1297.84, p = 0.035). Additionally, IORT was associated with increased LRR in the multivariate analysis (HR = 4.71, 95% CI = 1.16-19.06, p = 0.030). At a long-term follow-up, the LRR rate was higher in the BCS followed by IORT, without significant differences in metastasis-free or overall survival rates. Our data confirmed the importance of exclusion ER- patients for IORT.

Highly enriched carbon and oxygen isotopes in carbonate-derived CO2 at Gale crater, Mars

Carbonate minerals are of particular interest in paleoenvironmental research as they are an integral part of the carbon and water cycles, both of which are relevant to habitability. Given that these cycles are less constrained on Mars than they are on Earth, the identification of carbonates has been a point of emphasis for rover missions. Here, we present carbon (δ13C) and oxygen (δ18O) isotope data from four carbonates encountered by the Curiosity rover within the Gale crater. The carbon isotope values range from 72 ± 2‰ to 110 ± 3‰ Vienna Pee Dee Belemnite while the oxygen isotope values span from 59 ± 4‰ to 91 ± 4‰ Vienna Standard Mean Ocean Water (1 SE uncertainties). Notably, these values are isotopically heavy (13C- and 18O-enriched) relative to nearly every other Martian material. The extreme isotopic difference between the carbonates and other carbon- and oxygen-rich reservoirs on Mars cannot be reconciled by standard equilibrium carbonate-CO2 fractionation, thus requiring an alternative process during or prior to carbonate formation. This paper explores two processes capable of contributing to the isotopic enrichments: 1) evaporative-driven Rayleigh distillation and 2) kinetic isotope effects related to cryogenic precipitation. In isolation, each process cannot reproduce the observed carbonate isotope values; however, a combination of these processes represents the most likely source for the extreme isotopic enrichments.

Effect of consolidation radiation therapy on treatment outcomes of early-stage favorable Hodgkin lymphoma

Background. Early (stage I–II) classical Hodgkin lymphoma is a highly treatable malignant neoplasm. For many years, the standard treatment of early Hodgkin lymphoma has been combination therapy: polychemotherapy with subsequent consolidating radiation therapy. Aim. To retrospectively evaluate the results of treatment of stage I–II classical Hodgkin lymphoma in a favorable prognosis group using monotherapy and combination therapy (chemotherapy followed by consolidating radiotherapy). Materials and methods. The study included 58 patients aged 19–81 years (median age 36 years) diagnosed with stage I–II classical Hodgkin lymphoma with favorable prognosis; 23 (39.7 %) patients were men, 35 (60.3 %) were women. Depending on the treatment received, the patients were divided into two groups: 40 (69 %) patients received ABVD polychemotherapy, and 18 (31 %) patients received polychemotherapy followed by consolidating radiation therapy to the initial lesion zones with standard fractionation regimen (total dose 30 Gy). The Kaplan–Mayer method was used to evaluate overall, progression-free, recurrence-free, and event-free survival. Odds ratios and their 95 % confidence intervals were also calculated. The statistical significance of differences in survival was assessed using the log-rank test. The level of statistical significance was 0.05. Statistical data processing was carried out using the IBM SPSS Statistics 27 software and Microsoft Excel. Results. According to the results of our study, while in the total patient group a clear numerical advantage in survival (overall, progression-free, relapse-free and event-free survival) was observed in the combination therapy group compared to chemotherapy group (5.5, 13.2, 9.2 and 23.9 %, respectively), no preferred tactics were identified in the total patient group. However, considering a subgroup of patients with mediastinum involved in the tumor process, a statistically significant advantage of combined treatment over single-mode chemotherapy was determined for 2-year event-free survival (92.9 ± 6.9 % vs. 62.5 ± 9.9 %, respectively, p = 0.046). The risk of an adverse event is reduced by &gt;80 % (odds ratio 0.197; 95 % confidence interval 0.036–0.977) when using consolidating radiation therapy after chemotherapy.

The JWST EXCELS survey: too much, too young, too fast? Ultra-massive quiescent galaxies at 3 &amp;lt; z &amp;lt; 5

ABSTRACT We report ultra-deep, medium-resolution spectroscopic observations for four quiescent galaxies with log$_{10}(M_*/\mathrm{M_\odot })\gt 11$ at $3 \lt z \lt 5$. These data were obtained with JWST NIRSpec as part of the Early eXtragalactic Continuum and Emission Line Science (EXCELS) survey, which we introduce in this work. The first two galaxies are newly selected from PRIMER UDS imaging, both at $z=4.62$ and separated by 860 pkpc on the sky, within a larger structure for which we confirm several other members. Both formed at $z\simeq 8-10$. These systems could plausibly merge by the present day to produce a local massive elliptical galaxy. The other two ultra-massive quiescent galaxies are previously known at $z=3.99$ and 3.19, with the latter (ZF-UDS-7329) having been the subject of debate as potentially too old and too massive to be accommodated by the $\Lambda$-CDM halo-mass function. Both exhibit high stellar metallicities, and for ZF-UDS-7329 we are able to measure the $\alpha -$enhancement, obtaining [Mg/Fe] = $0.42^{+0.19}_{-0.17}$. We finally evaluate whether these four galaxies are consistent with the $\Lambda$-CDM halo-mass function using an extreme value statistics approach. We find that the $z=4.62$ objects and the $z=3.19$ object are unlikely within our area under the assumption of standard stellar fractions ($f_*\simeq 0.1-0.2$). However, these objects roughly align with the most massive galaxies expected under the assumption of 100 per cent conversion of baryons to stars ($f_*$=1). Our results suggest extreme galaxy formation physics during the first billion years, but no conflict with $\Lambda$-CDM cosmology.

Evaluation of acute, repeated dose 28-day and 13-week oral toxicity and genotoxicity of a standardized fraction (HemoHIM) from Angelica gigas, Cnidium officinale, and Paeonia lactiflora

Evaluation of acute, repeated dose 28-day and 13-week oral toxicity and genotoxicity of a standardized fraction (HemoHIM) from Angelica gigas, Cnidium officinale, and Paeonia lactiflora

HYPCON trial: A phase II randomized study evaluating hypofractionated versus conventional adjuvant radiation therapy in head and neck malignancies.

143 Background: Hypofractionated RT has been established as standard of care at many cancer sites but there is limited data on use of hypofractionated RT for head and neck carcinomas (HNC). The HYPCON trial (CTRI/2023/02/049804) tested to reduce 10 fractions of PORT by delivery of hypofractionated PORT. Methods: Patients of HNC after radical surgery, with intermediate risk factors, were randomized based on site, T and N stage to either standard fractionation arm A (60Gy/30 fractions/6 weeks) or hypofractionated arm B (50Gy/20 fractions/4 weeks) in a 1:2 manner. The minimum sample size for the study was estimated based on a non-inferiority trial design as 120 considering a 10% clinical effectiveness margin and 5% attrition. Treatment allocation was done based on T stage, N stage &amp; HNC subsite. Target delineation included tumour bed with adequate margins (CTV_P) and microscopic lymph nodal (CTV_N) basin at risk. Organ delineation included all DARS. A double arc swallowing-sparing IMRT was used in both arms. The primary endpoint was locoregional control (LRC) at 1 year. Compliance, RT time (RTT), overall treatment time (OTT), progression-free survival (PFS) and overall survival (OS) were calculated in all patients. Acute &amp; late toxicities were recorded as per RTOG scale. Results: 135 patients were enrolled, 45 in Arm A &amp; 90 in Arm B. Majority of patients (96.9%) had oral cavity primary. Most of patients 74.8 % had early-stage disease. Compliance to PORT was 91.1% in Arm A versus 100% in Arm B. Median RTT for Arm A was 43 days (25-73 days) and 28 days (25-43 days) for Arm B (p&lt;0.0001). Median OTT in Arm A was 91 days (70-126 days) and 77 days (57-119 days) in Arm B (p&lt;0.0001). Median follow-up was 12.7 (2.73-23.87) months. One year, LRC was 72.9% vs 91.6% (p=0.007); PFS was 70.6% vs 90.5% (p=0.009) and OS was 88.7% vs 94.5% (p 0.02) Arm A versus Arm B respectively. Grade 3 or higher acute toxicity was seen in 39% in Arm A and 31.1% in Arm B (p=0.374). Grade 3 or higher late toxicity events were noted in 29.2% and 32.2% in arms A and B respectively (p= 0.671). Conclusions: Hypofractionated PORT reduced RTT &amp; OTT and was associated with improved treatment compliance, treatment outcomes (LRC, PFS, OS), and similar acute and late toxicity profile. This is the first study to demonstrate the superiority of hypofractionated compared to conventional PORT delivery for HNC. Clinical trial information: CTRI/2023/02/049804 .

Conditional Risk and Predictive Factors Associated With Late Toxicity in Patients With Prostate Cancer Treated With External Beam Radiation Therapy Alone in the Randomized Trial RTOG 0126

The objective of this study was to characterize the conditional risk of developing grade 2+ urinary or gastrointestinal (GI) toxicity for patients treated with external beam radiation therapy in Radiation Therapy Oncology Group 0126. A secondary objective was to analyze baseline patient and treatment characteristics and determine their relevance in predicting toxicity both at the time of trial enrollment and at later points of follow-up. One thousand five hundred thirty-two patients with localized prostate cancer were enrolled between March 2002 and August 2008, of whom 1499 were eligible and included in data analysis with a median follow-up of 8.4 years (range, 0.02-13 years). Patients were treated with either 3-dimensional conformal radiation therapy or intensity-modulated radiation therapy according to institutional practice without the addition of androgen deprivation and randomized to receive either standard-dose radiation therapy of 70.2 Gy or dose-escalated radiation therapy of 79.2 Gy of radiation therapy to the prostate only with standard fractionation. Univariate and multivariate analyses were performed to determine whether initial factors were predictive of late toxicity at the time of treatment and at later time points. As patients proceed further from completion of radiation therapy without the development of toxicity, the subsequent risk of both grade 2+ genitourinary (GU) and GI toxicity decreases with time. At the time of enrollment, the risk of developing grade 2+ toxicity over the next 5 years was 9.57% and 17.89%, respectively. After 5 years of toxicity-free survival, the risk of developing grade 2+ GU or GI toxicity in the subsequent 5 years was 3.02% and 1.54%, respectively. Baseline treatment and patient-related factors predicted late toxicity both at trial enrollment and after 2 years of toxicity-free survivorship. Baseline urinary dysfunction and dose-escalated radiation therapy were associated with increased late GU toxicity. Acute GI toxicity and dose-escalated radiation therapy were associated with increased risk of late GI toxicity. Treatment with intensity-modulated radiation therapy was associated with reduced risk of either toxicity. The conditional risk of grade 2+ toxicities decreases as patients proceed further from treatment, with most toxicities occurring in the first few years after treatment completion. Baseline patient and treatment characteristics remain relevant at both enrollment and later time points.

Xevinapant with radiation and concurrent carboplatin and paclitaxel in patients ineligible for cisplatin with locoregionally advanced squamous cell carcinoma of the head and neck (EXtRaCT study).

TPS6126 Background: Locoregionally advanced (LA) head and neck cancer (HNC) patients undergoing chemoradiotherapy (CRT) who are ineligible for cisplatin have comparatively poor outcomes, with only ~40% alive at 5 years. There is an urgent unmet need to improve survival in these vulnerable patients with no standard therapeutic approach. Xevinapant, an oral inhibitor of XIAP and cIAP1/2, sensitizes cancer cells to apoptosis. Randomized phase II results in patients eligible for cisplatin combining xevinapant with CRT showed improved locoregional control, manageable toxicity, and promising survival outcomes. (Sun et al. Lancet Oncol. 2020) The current trial aims to extend these benefits to patients ineligible for cisplatin using xevinapant with carboplatin-paclitaxel-based CRT, hypothesizing safety and tolerability in this high-risk group. Methods: This phase I dose escalation/expansion study investigates xevinapant combined with carboplatin and paclitaxel to treat LA HNC in patients ineligible for cisplatin. Key eligibility includes previously untreated LA HNC and specific cisplatin ineligibility criteria, including &gt;=70yo with moderate to severe comorbidity or vulnerability (Geriatric-8 score ≤ 14 and/or CARG score ≥ 30%) or &lt;70yo with severe comorbidity and/or vulnerability, or &gt;=18yo with an absolute contraindication to cisplatin. The treatment regimen comprises escalating doses of oral xevinapant (50-200 mg daily) on days 1-14 of a 21-day cycle for 3 cycles concurrent with CRT and 3 cycles adjuvant, weekly carboplatin AUC 1.5 IV, and paclitaxel 30 mg/m2 IV for 7 doses, and radiotherapy to 70 Gy in standard 2Gy fractions over 7 weeks with primary endpoint of tolerability and recommended phase 2 dose. A Bayesian-modified toxicity probability interval design will identify the maximum tolerated dose (MTD), targeting a 25% dose-limiting toxicity rate, with a sample size of 24 patients in dose-finding. 18 additional patients will be enrolled in the dose-expansion cohort at the MTD, totaling 42 patients. Secondary objectives include safety, response, progression-free, overall survival, and locoregional and distant control. Exploratory aims: in-clinic geriatric evaluations (Katz ADL, Lawton iADL, MMSE), QoL surveys, symptom tracking via smartphone, and wearable-derived steps and sarcopenia assessment. Recruitment began 02/2024. Clinical trial information: NCT06110195 .

Meta-Analysis of 5-Fraction Preoperative Radiotherapy for Soft Tissue Sarcoma.

Studies investigating preoperative 5-fraction radiation therapy (RT) for soft tissue sarcoma (STS) are limited. We performed a meta-analysis to determine the efficacy and safety of this treatment paradigm. This study-level meta-analysis was conducted using Bayesian methods. Statistical estimation for risk of outcome rates was conducted by posterior mean and 95% highest posterior density (HPD) intervals. Studies with 2-year local control (LC) and description of major wound complications (MWC) per the CAN-NCIC-SR2 study were included and served as the primary endpoints. Secondary endpoints included rates of acute and late toxicity. A total of 10 studies were identified and 7 met the inclusion criteria. Subgroup analyses were performed for ≥30 Gy vs <30 Gy. A total of 209 patients from 7 studies were included. Five studies used ≥30 Gy (n=144), and 2 studies <30 Gy (n=64). Median follow-up was 29 months (range: 21 to 57mo). Primary tumor location was lower extremity in 68% and upper extremity in 22%. Most tumors were intermediate or high grade (95%, 160/169), and 50% (79/158) were >10cm. The two-year LC for the entire cohort was 96.9%, and the rate of MWC was 30.6%. There was a trend toward improved LC with ≥ 30 Gy (95% HPD: 0.95 to 0.99 vs 0.84 to 0.99). There was no difference in MWC (95% HPD: 0.18 to 0.42 vs 0.17 to 0.55) or late toxicity between the groups. Preoperative 5-fraction RT for STS demonstrates excellent 2-year LC with MWC and toxicity similar to standard fractionation preoperative RT. Multi-institutional trials with a universal RT protocol are warranted.

Effect of Milk Sources on Whey Protein and Fractions of Casein

Aim: Milk from Cow, Buffalo and goat was used for the study of isolation and fractionation of casein and whey proteins. Buffalo and goat milk were subjected to physicochemical attribute studies and a detailed protein profile namely total protein, casein fractions α-, β- and κ casein and whey protein were separated by urea fractionation method. The aim of this study was to compare various casein fractions isolated from cows, Buffalo and Goat milk. The method of separating casein into its fractions is based on the solubility of the individual components in urea the solution. The separation of casein fractions was carried out in dissolving molar concentration of urea and the yield of fractions and total protein percentages were calculated. Buffalo and goat milk have comparatively higher total protein and whey protein content as compared to cow milk. Maximum whey proteins found in goat milk (20.58%) whereas cow milk had the lowest whey protein (19.29%). Among casein fractions, α fraction (16.64%) was found maximum in Buffalo milk followed by cow (14.92%) and goat milk (5.42%). The goat milk showed the highest level of β casein (17.81%) whereas, the lowest concentration of β casein was found in cow milk (9.38%). Study Design: A significant contribution to the total milk production of India comes from buffalo milk and goat milk. Despite that, Buffalo milk and goat milk are not being utilized for many products because of difference in composition of different species milk and their inherent problems associated in the production of products. Place and Duration of Study: Karnataka Veterinary Animal and Fisheries Sciences University (KVAFSU), Dairy Science College, Hebbal, Bangalore Karnataka, India Materials: The Goat milk samples were collected from Sinchana Goat and Sheep farm, Marenahalli village (Bengaluru Rural Dist) and Buffalo milk was obtained from Country Delight Pvt. Ltd., J. P. Nagar, Bengaluru, Karnataka. Cow milk used in this investigation was collected from SEDP, Dairy Science College, Hebbal, Bengalore.. All the glassware used was soaked in chromic acid solution, repeatedly washed with water, rinsed with distilled water and dried before use. For microbiological analysis dried test tubes, conical flasks, pipettes were cotton plugged and sterilized in a hot air oven. The chemicals and reagents used in this study were mainly of analytical grade procured from Prince Laboratory Company Pvt. Limited, Bangalore. The protein molecular weight markers used for the electrophoretic study were procured from Bangalore Genei Pvt. Ltd. Methodology: Standard urea fractionation method adopted by Hipp et al was used for isolation and fractionation of caseins. Skim milk was prepared by subjecting whole milk for centrifugation, the skim milk obtained was acidified using 1 % hydrochloric acid at 200 C to obtain casein precipitate. Obtained whole casein was dissolved in 3.3 M urea at pH 7.5 and adjusted to pH 4.6 which precipitates the bulk of α casein and leaving k-caseins into soluble filtrates. Again the supernatant was adjusted to pH 4.9 diluted to 1.0 M urea and warmed to 300 C precipitating the β-caeisn. Further, addition of ammonium sulphate was used to isolate k-casein from the precipitate. Results: The sources of protein had a significant influence on the total casein, casein fractions and whey protein content of different species. The highest quantity of total caseins (34.30g/l) and whey protein (8.87 g/l) were observed in buffalo milk followed by cow (28.52 g/l) and lowest was observed in goat milk (28.45 g/l). Total protein, casein and whey protein contents were greatly affected by the source of milk. Conclusion: The significant effect of source of milk on total protein, casein, its fractions and their yield was observed. highest yield of casein (54.31%) was observed in cow milk than buffalo milk (48.95 %) and lower yield was found in goat milk. Amongst the three species, highest per cent of β casein was noted in goat milk (54.05 %) followed by buffalo (36.03%) and cow milk (34.14%). Recommendation: Rasagulla will be consumed universally by all age groups globally. Thus, the consumption of Rasagulla helps in providing overall nutritional requirements. However, the study has been conducted on a pilot scale. Moreover, commercial production may necessitate huge cost on enzymatic modification of proteins and separation peptides for value addition.

Abstract PO5-14-02: Diagnostic leukapheresis to increase CTC detection rate in breast cancer patients after 5 years of adjuvant endocrine treatment

Abstract Purpose: Patients with early hormone receptor positive, HER2 negative breast cancer have a risk of recurrence for up to 20 years after the initial diagnosis and is therefore treated with adjuvant endocrine treatment (ET) for 5 to 10 years. As a result there is a large proportion of patients that overtreated, hence, an urgent need for better biomarkers to guide treatment decisions. In previous research, it was shown that circulating tumor cells (CTCs) are detected in 5% of patient after 5 years of adjuvant treatment and that this indicated a 13-fold higher risk of recurrence, with a median lead time of 2.8 years. However, the sensitivity and specificity of the test were moderate. This could be caused by stochastic variation, given the low numbers of CTCs detected in 7.5 ml peripheral blood. We hypothesized that increasing the screening volume, increases the test statistics. Methods: In this study, we investigated whether increasing the screening volume by diagnostic leukapheresis (DLA) can increase the detection rate of CTCs (CellSearch platform). With DLA, 5 liters of peripheral blood was screened, which in previous studies had shown to increase the CTC-yield per ml by 25-fold. To this end, we included early hormone receptor positive, HER2 negative breast cancer patients that were treated with ET for 4.5-5.5 years with no signs of disease recurrence. We compared the number of detected CTCs in the standard fraction of 7,5 mL peripheral blood (PB), to buffy coat (30 ml), to DLA sample (200 × 109 white blood cells (WBC), equal to 25-50 mL PB) and to DLA after WBC depletion. Results: Thirty two hormone receptor positive/HER2 negative breast cancer patients were included in this study after a median duration of ET of 60 months, of which 3 (9%) patients completed ET according to clinical guidelines and the remaining patients were still on treatment. Twenty eight patients (88%) had 1-3 positive lymph nodes at diagnosis, and 3 patients had 4-9 positive lymph nodes. The Clinical Treatment Score at 5 years (CTS5 score) was intermediate or high in 75%, and unknown in 19%, indicating a recurrence risk of &amp;gt;5% at years 5-10 after diagnosis. In none of the included patients, CTCs were detected in 7,5 ml PB, nor in any of the other tested blood volumes. To date, 2 patients have been diagnosed with overt metastatic disease during follow-up. DLA was well tolerated and did not cause adverse events. Conclusions: We conclude that DLA was unable to increase the detection rate of CTCs in hormone receptor positive, HER2 negative patients with early breast cancer being on treatment for a median duration of 5 years. Additional circulating tumor DNA analyses are planned. Citation Format: Noortje Verschoor, Jaco Kraan, Johanna Zuetenhorst, Mijntje Vastbinder, Jan Drooger, Stefan Sleijfer, Saskia M Wilting, John WM Martens, Agnes Jager. Diagnostic leukapheresis to increase CTC detection rate in breast cancer patients after 5 years of adjuvant endocrine treatment [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-14-02.

Abstract 3181: Immune modulatory activity of radio-sensitizing gold nanoparticle

Abstract Radiation therapy (RT) is frequently used in the neoadjuvant setting in borderline resectable and some resectable pancreatic ductal adenocarcinoma (PDAC) and in the definitive setting in locally advanced PDACs which is third leading cause of cancer associated death. Higher doses of RT improve overall treatment outcomes but increasing the dose significantly above 50Gy in standard 2Gy fractions risks profound gastrointestinal (GI) toxicity. Additionally, genotoxic stress such as RT, can induce CXCL12 secretion by cancer associated fibroblast (CAFs) and overexpression of CXC motif chemokine receptor 4 (CXCR4) in cancer cells. CXCL12-CXCR4 downstream signaling results in immune suppression and consequent enhanced tumor growth and metastasis and poor prognosis in PDAC. To overcome these clinical challenges, we have developed multimodal gold nanoparticle constructs (GNPs) by functionalizing the CXCR4 antagonists to (i) bind to CXCR4 and mediate GNP internalization, (ii) abolish the feedback immune inhibitory signals mediated by CXCR4 overexpression, and (iii) enhance therapeutic benefit of radiation. To achieve these multimodal activities, we have covalently attached the CXCR4 antagonist, AMD070, to thiol-terminated polyethylene glycol (PEG) to synthesize AMD-PEG which was then conjugated with GNPs to produce AMD-PEG-GNP. In our experiment AMD-PEG-GNP has successfully inhibited CXCL12-CXCR4 downstream signalling such as reduction of ERK phosphorylation in PDAC cells. To analyze the radiosensitization role of GNP nanoconjugates, PDAC cells were incubated with AMD-PEG, PEG-GNP and AMD-PEG-GNPs for 4 hours and then treated with increasing doses of radiated, from 1-4Gy. AMD-PEG-GNP demonstrated a systematic enhancement on reactive oxygen species (ROS) production and downregulation of a colony formation. Collectively, the results from in vitro study with PDAC cells confirm that the nanoconjugate with AMD070 enhances radio-cytotoxicity and impair CXCL12-CXCR4 downstream signaling. Hence AMD-PEG-GNP has strong merit to enhance radiation dose locally and simultaneously restrict RT induced immunosuppression in PDAC. Citation Format: Tanmay Kulkarni, Shamit Dutta, Hazel Parent, Karington Perry, Yuri Mackeyev, Santanu Bhattacharya. Immune modulatory activity of radio-sensitizing gold nanoparticle [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3181.

The Role of Postoperative Radiotherapy in the Management of Dermatofibrosarcoma Protuberans: A Multidisciplinary Systematic Review.

Background: Dermatofibrosarcoma protuberans (DFSP) is a superficial soft tissue sarcoma, and surgical excision is the first-line treatment. The aim of this systematic review is to provide an update about the current indications and clinical results regarding the use of postoperative radiotherapy in DSFP, considering both adjuvant and salvage setting. Methods: We conducted a systematic literature review using the main scientific database, including Cochrane library, Scopus, and PubMed, for any relevant article about the topic, and we considered all available papers without any time restriction. Results: Twenty-two papers, published between 1989 and 2023, were retrieved and considered eligible for inclusion in this review. Regarding the fractionation schedules, most authors reported using standard fractionation (2 Gy/die) with a wide total dose ranging from 50 to 70 Gy. The local control after postoperative radiotherapy was excellent (75-100%), with a median follow-up time of 69 months. Conclusions: After the primary surgical management of DFSP, postoperative radiotherapy may either be considered as adjuvant treatment (presence of risk factors, i.e., close margins, recurrent tumours, aggressive histological subtypes) or as salvage treatment (positive margins) and should be assessed within the frame of multidisciplinary evaluation.

Growth Inhibition of Standardized Amine Fraction From Clinacanthus nutans on Mice Xenograft Model for Human Cervical Cancer

Introduction: Cervical cancer continue to be a leading cause of cancer-related death for women. The current anticancer drugs remain inefficient due to the lack of specificity to inhibit the cancer cells growth. Plant-based drugs with potent anticancer should add to the efforts in finding drugs with lesser side effects but great potential to increase survival. Hence, this study sought to determine the tumour growth inhibition of standardized fraction (SF1) from Clinacanthus nutans as a potential alternative treatment for cervical cancer. Methods: SF1 was isolated from a series of bioassay-guided fractionation of C.nutans leaves. Female nude mice were xenografted with human cervical cancer cell line, SiHa, subcutaneously. When the tumour volume reached 100mm3, SF1 was intraperitoneally injected once daily for 28 days. Body weight and tumour volume were recorded every 3 days. Tumour and liver were fixed for hematoxylin and eosin staining and immunohistochemistry using caspase-3 antibody. Blood was collected by cardiac puncture for assessment of liver enzymes level, AST and ALT. Results: SF1 has a great tumour inhibition with more than 50% inhibition rate compared to the negative control group (DMSO). ALT and AST levels in SF1-treated mice were maintained in normal ranges compared to the positive control group, cisplatin indicating no sign of toxicities. SF1-treated group revealed no indication of liver toxicity. The number of tumour mitosis was reduced and caspase-3, a critical mediator of apoptosis was overexpressed in SF1-treated group. Conclusion: SF1 demonstrated potent anticancer activity by inhibiting the tumour growth with less toxic effects, suggesting a promising candidate for preventing cancer progression.

Carotid Blowout after Standard Fractionation Re-irradiation: The Ohio State University Experience

Carotid Blowout after Standard Fractionation Re-irradiation: The Ohio State University Experience