Start Of Radiotherapy Research Articles

Role of consolidative thoracic and prophylactic cranial radiation in extensive stage small cell lung cancer in chemo-immunotherapy era

IntroductionThe role of consolidative thoracic and prophylactic brain radiation for extensive stage small cell lung cancer patients is controversial. We investigated the factors associated with the use of any radiation therapy (RT) and whether RT has a benefit to overall survival (OS) in patients receiving any systemic therapy and whether this benefit is the same if Chemotherapy (CT) or chemo-immunotherapy (CT-IO) is used. Material/MethodsThe NCDB database was queried from years 2017–2019. Patients receiving systemic therapy- STX (CT or CT-IO) had to have at least 6 months of follow-up and have no brain metastases at diagnosis. All RT patients had to receive upfront systemic therapy, be treated 2–6 months from diagnosis, and if treated to the brain received 25 Gy in 10 fractions only. Multi-variable analyses (MVA) were used to determine factors associated with OS and selection for any radiation. Propensity matching for factors affecting OS were used to generate Kaplan-Meier OS curves. Log-rank tests were used to determine differences in Kaplan Meier survival curves for the effects of RT on OS. ResultsThe total number of patients receiving RT/STX or STX alone as well as their median follow-up (months) were (890, 17.0 mn) and (6898, 14.0mn). The median time to the start of STX and RT were 22.9 days and 152 days, respectively. MVA noted that RT had a greater effect on OS (Thorax, Brain, Both Brain/Thorax – HRs = 0.80, 0.77, 0.70) than other interventions including IO (HR 0.87) and palliative care without RT (HR 1.06). Selection for radiation depended significantly upon factors affecting OS (HR) including lack of liver metastases, females, age and Charlson co-morbidity index, but did not depend upon insurance status, race, or county income/high school graduation rates. Propensity-score matched OS curves noted the same significant effects of RT on OS in those receiving CT +/- IO, CT-IO, and CT alone with HRs of 0.68/0.68/0.68 for thoracic RT, 0.72/0.72/0.70 for brain RT, and 0.60/0.60/0.60 for brain/thoracic RT, respectively. ConclusionsThe patient with extensive stage small cell lung cancer who reach candidacy and receive RT may have a significant improvement in OS compared to the patients treated only with CT or CT-IO. Combined thoracic and prophylactic brain RT seems to be better than either one alone. The impact of radiation whether given to one or two sites may be more beneficial than immunotherapy added to chemotherapy.

Computed tomography patterns and clinical outcomes of radiation pneumonitis in non-small-cell lung cancer patients.

Radiation pneumonitis (RP) is not an uncommon complication in lung cancer patients undergoing radiation therapy (RT) and symptomatic RP can affect their quality of life. To investigate the CT findings of RP in non-small cell lung cancer (NSCLC) patients and their relationship with clinical outcomes. We reviewed data from 240 NSCLC patients who underwent RT between 2014 and 2022. CT findings of RP were evaluated for parenchymal abnormalities and distribution, which were then classified into three patterns: localized pneumonia (LP), cryptogenic organizing pneumonia (COP), and acute interstitial pneumonia (AIP). Clinical outcomes of RP were evaluated based on Common Terminology Criteria for Adverse Events (CTCAE) grade. Of the 153 patients, 135 developed RP. The most common pattern was LP (n = 78), followed by COP (n = 30) and AIP (n = 25). Among the three CT patterns, CTCAE grade and days between the start of RT and the onset of RP (RT-RP days) were statistically significantly different (p < 0.05). The patients with AIP patterns exhibited higher CTCAE grade, and fewer RT-RP days compared to those with non-AIP patterns (p < 0.05). In these patients, lung-to-lung metastasis and underlying interstitial lung abnormality were observed more frequently (p < 0.05). Underlying pulmonary fibrosis, the AIP pattern, and higher CT extent scores were more frequently observed in higher CTCAE grade group (p < 0.001). In multiple regression analysis, age, bilateral distribution, RT-RP days, and CT extent score ≥3 were independent predicting factors for higher CTCAE grade. RP in NSCLC patients can be classified into LP, COP, and AIP patterns and they exhibit different severities in clinical outcomes.

Postprostatectomy Radiotherapy Timing and Long-Term Health-Related Quality of Life

The association between radiotherapy (RT) timing after radical prostatectomy and long-term patient-reported health-related quality of life (HRQOL) in men with prostate cancer is unknown. To measure long-term HRQOL in men with prostate cancer up to 15 years after prostatectomy with or without RT and examine whether early vs late postprostatectomy RT is associated with differences in sexual, urinary, and bowel HRQOL. A prospective, multicenter, longitudinal cohort analysis using HRQOL data from the PROST-QA (2003-2006) and RP2 consortium (2010-2013) studies was conducted. Men with localized prostate cancer undergoing radical prostatectomy were included. Data were analyzed between May 8, 2023, and March 1, 2024. The study was conducted in 12 high-volume academic medical centers in the US. Men were stratified based on receipt and timing of postprostatectomy RT: prostatectomy only, early RT (<12 months), and late RT (≥12 months). Longitudinal sexual, incontinence, urinary irritation, bowel, and hormonal/vitality HRQOL were measured via the Expanded Prostate Cancer Index Composite at baseline; months 2, 6, and 12; and annually thereafter. Treatment groups were compared using multivariable linear mixed-effects models of change in longitudinal domain scores. Pad use for incontinence was measured longitudinally among men receiving postprostatectomy RT. A total of 1203 men were included in the study: prostatectomy only (n = 1082), early RT (n = 57), and late RT (n = 64). Median age for the entire cohort was 60.5 (range, 38.8-79.7) years, and 1075 men (92.0%) were White. Median follow-up was 85.6 (IQR, 35.8-117.2) months. Compared with men receiving prostatectomy alone, those receiving postprostatectomy RT had significantly greater decreases in sexual, incontinence, and urinary irritation HRQOL. However, timing of postprostatectomy RT, specifically early vs late, was not associated with a long-term decrease in any HRQOL domain. There was evidence of improved recovery of sexual, continence, and urinary irritation scores among men receiving early RT compared with those receiving late RT after prostatectomy. Before the start of postprostatectomy RT, 39.3% of men in the early RT cohort and 73.4% of men in the late RT cohort were pad-free. By the sixth visit post-RT, 67.4% in the early RT cohort and 47.6% in the late RT cohort were pad-free. In this multicenter, prospective analysis, postprostatectomy RT appeared to be negatively associated with long-term HRQOL across all domains. However, receipt of early vs late postprostatectomy RT may result in similar long-term HRQOL outcomes.

The impact of cancer patient pathway on timing of radiotherapy and survival: a cohort study in glioblastoma patients.

Glioblastoma (GBM) is an aggressive brain tumor in which primary therapy is standardized and consists of surgery, radiotherapy (RT), and chemotherapy. However, the optimal time from surgery to start of RT is unknown. A high-grade glioma cancer patient pathway (CPP) was implemented in Norway in 2015 to avoid non-medical delays and regional disparity, and to optimize information flow to patients. This study investigated how CPP affected time to RT after surgery and overall survival. This study included consecutive GBM patients diagnosed in South-Eastern Norway Regional Health Authority from 2006 to 2019 and treated with RT. The pre CPP implementation group constituted patients diagnosed 2006-2014, and the post CPP implementation group constituted patients diagnosed 2016-2019. We evaluated timing of RT and survival in relation to CPP implementation. A total of 1212 patients with GBM were included. CPP implementation was associated with significantly better outcomes (p < 0.001). Median overall survival was 12.9 months. The odds of receiving RT within four weeks after surgery were significantly higher post CPP implementation (p < 0.001). We found no difference in survival dependent on timing of RT below 4, 4-6 or more than 6 weeks (p = 0.349). Prognostic factors for better outcomes in adjusted analyses were female sex (p = 0.005), younger age (p < 0.001), solitary tumors (p = 0.008), gross total resection (p < 0.001), and higher RT dose (p < 0.001). CPP implementation significantly reduced time to start of postoperative RT. Survival was significantly longer in the period after the CPP implementation, however, timing of postoperative RT relative to time of surgery did not impact survival.

Evaluating a hypofractionated radiotherapy schedule for prostate cancer at an institution in South Africa

Background: Hypofractionated radiotherapy (HFRT) in the treatment of prostate cancer (PCa) has logistical and cost advantages, especially in a resource constrained setting. Studies have demonstrated equivalent efficacy with HFRT schedules using Intensity Modulated Radiation Therapy (IMRT) as treatment modality. However, higher rates of acute and late gastrointestinal (GI) and genitourinary (GU) toxicity have been reported when compared to conventionally fractionated radiotherapy (CFRT). In this study, we evaluate the efficacy and toxicity rates of a HFRT schedule using 3D conformal radiotherapy (RT) as treatment modality.Aim: With this study, we aim to describe the safety and outcomes of a definitive HFRT schedule used for localised PCa. We hypothesise that there is no difference in the biochemical relapse rate and incidence rates of normal tissue toxicities between patients receiving CFRT and HFRT schedules.Setting: This RT schedule was used at Tygerberg Academic Hospital in South Africa for the treatment of localised prostate cancer.Methods: This is a retrospective study in which the records of patients diagnosed with localised PCa were reviewed. Patients were treated with either CFRT regimen to a total of 74Gy in 37 daily fractions for 5 days a week or a HFRT regimen to a total of 65Gy in 26 daily fractions for 4 days per week.Results: In all, 116 patients were included in the study with a median follow-up of 57.2 months from the start of RT. No statistically significant differences in overall survival (OS) and biochemical relapse-free survival were found between the two schedules. A significant difference in acute GI toxicity was observed, with a higher incidence noted in the HFRT schedule. No significant differences were observed in late GI toxicity or in early and late GU toxicities.Conclusion: This study observes a hypofractionated regimen using three-dimensional conformal radiation therapy (3DCRT) with similar efficacy and RT-related toxicities to CFRT.Contribution: The HFRT schedule used in this study could be useful in hospitals with limited access to resources.

Double Dissociation of Cognitive Varies under Unilateral Radiation Exposure on the Hippocampus

Although the key position of the hippocampus (HP) in memory processes is not in doubt, the specifics of its participation in cognitive processes are far from being established. At the same time, the role of the HP in differentiating the novelty of impressions is often discussed in the context of adult HP neurogenesis. Radiation exposure to the HP, which inhibits the processes of neurogenesis, can serve as a model for studying this relationship. A homogeneous sample of 28 patients with meningiomas of the chiasmal-sellar area adjacent to the HP was studied. 15 patients were diagnosed with a left-sided location of the tumor and 13 patients with a right-sided one. The two groups were comparable in terms of demographic, clinical and morphometric characteristics. In order to stop the growth of the tumor, the patients underwent radiation therapy (RT), in which the HP on the side of the pathological process was forced to receive a dose comparable to the dose in the tumor. The study using the original technique was carried out before the start of RT, immediately after its completion, 6 and 12 months after the end of RT. Data were obtained on earlier changes in memory characteristics mediated by the right hippocampal region, but at the same time — more pronounced long-term cognitive consequences of ionizing effects on the HP of the left hemisphere.

The predictive value of hematological inflammatory markers for severe oral mucositis in patients with nasopharyngeal carcinoma during intensity-modulated radiation therapy: A retrospective cohort study

BackgroundThis study aims to investigate the predictive value of the circulating blood cell count, including neutro-philto-lymphocyte ratio (NLR), platelet-to-lymphocyte (PLR), and thesystemic inflammation index (SII) for the development of severe oral mucositis (SOM) induced by radiation in patients undergoing radiotherapy for nasopharyngeal carcinoma (NPC). MethodsIn this retrospective study, 142 NPC patients were screened, and based on mucositis toxicity grade, they were categorized into two groups: SOM and nonSOM. Peripheral blood cell counts were conducted prior to Intensity-Modulated Radiation Therapy (IMRT). Associations between blood cell count, NLR, PLR, SII, and SOM occurrence were examined. ResultsRevealed elevated NLR and SII levels, along with reduced lymphocyte (LYM), eosinophil (EOS), and basophil (BAS) in patients with SOM. LYM, EOS, BAS, NLR, and SII were effective predictors of the severity of radiation-induced oral mucositis (RIOM) in NPC patients. ConclusionsThe occurrence of SOM was strongly linked to the hematological status at the start of Radiation Therapy (RT). Integrating BAS count and NLR into comprehensive risk prediction models could prove valuable for predicting SOM in NPC patients.

QOL-50. THE ROLE OF TUMOR SIZE IN COGNITIVE FUNCTIONING AMONG SURVIVORS TREATED FOR MEDULLOBLASTOMA

Abstract BACKGROUND Medical and treatment variables, including presence of post-operative cerebellar mutism syndrome (CMS), shunt placement, craniospinal radiation, and total radiotherapy (RT) dose, have been evaluated as potential risk factors for adverse cognitive effects among pediatric patients diagnosed and treated for medulloblastoma. Larger brain tumor size is associated with increased risk of medical complications, but cognitive risk of larger tumor size remains unknown. METHODS Cognitive scores were examined for 40 participants diagnosed and treated for medulloblastoma. The age-appropriate Wechsler Intelligence Scale was administered at the start of RT and up to 10 years post-RT (M=4.96, SD=3.78). A total of 162 evaluations were examined across participants. Linear mixed models examined change in Wechsler Index scores over time since RT based on tumor size, which was dichotomized at the median diameter (small ≤4.6cm versus large &amp;gt;4.6cm), covarying for maternal education, total RT dose, and presence of CMS. RESULTS Patients (72.5% male) were diagnosed with medulloblastoma and began RT at a mean age of 8.89 years. Groups did not differ on demographic or medical variables with the exception of presence/absence of CMS, with a higher proportion of patients diagnosed with CMS having large-size tumors (40%) versus small-size tumors (5%). Tumor size did not predict change in IQ, working memory, or processing speed performance over time since RT after accounting for covariates. CMS was associated with significant decline in processing speed (p&amp;lt;.001) and IQ over time (p&amp;lt;.05); RT dose was associated with significant working memory and IQ decline (both p&amp;lt;.05); and maternal education was associated with decline in processing speed, working memory, and IQ (all p&amp;lt;.05). CONCLUSIONS While tumor size may be associated with treatment intensity and other medical risk factors, CMS and RT dose significantly increase cognitive risk, independent of tumor size. Lower socioeconomic status also increases cognitive risk post-RT, which may illuminate pathways for prevention and intervention efforts.

LMIC-01. SURVIVAL AND PROGNOSTIC FACTORS IN CHILDHOOD MEDULLOBLASTOMA SINGLE TERTIARY CENTER EXPERIENCE FROM KING FAHAD MEDICAL CITY KFMC SAUDI ARABIA

Abstract BACKGROUND Medulloblastoma (MB) is the most common childhood malignant brain tumor treated with intensive multimodalities therapy including Surgery, Craniospinal Radiation, and chemotherapy. Our study aims to document the clinical courses, prognostic factors, and survival outcomes in Saudi children above three years with Medulloblastoma treated in King Fahad Medical City KFMC. METHODS Retrospective analysis of MB patients diagnosed between January 2009 to January 2022 All patients received Risk-adapted Radiation therapy followed by maintenance chemotherapy,3 patients progressed and died after surgery and were excluded from analysis. RESULTS We identified 145 MB patients 65.5 % were male. median age at Diagnosis 7.00 years (range3-14 years), Age less than 5 years did not have a worse outcome in our cohort. Classic histology was predominant (80%), 42.1% of patients had metastatic disease at presentation; the Median time to start radiation therapy after surgery was 35 days. 51.7% were treated as High-Risk HR MB and Average Risk AR MB 48.3%. 65 cases having molecular testing for MB molecular subgroups. 6 patients 4.1% developed a second malignancy with a median time of 6 years post diagnosis. Multivariate survival analysis showed that progression-free survival was significantly reduced by the extent of surgical resection (P=0.021) and Metastatic MB at diagnosis(P=0.014). At Median follow-up of 7 years, Progression-free survival PFS and overall survival OS for the whole cohort were 72.4% and 71.7% respectively. PFS for AR MB and HR MB was 81.4% and 64.0% respectively. PFS analysis based on molecular subgroup: WNT subgroup 92.3%, SHH 69.2%, Group 4:57.7%:and group 3: 46.2%. CONCLUSIONS Our study is the largest analysis of childhood MB treatment outcomes in Saudi Arabia Defining the poor prognostic factor for these patients and will form the baseline for future pediatric Neuro-Oncology studies in KFMC, which may help to improve the outcome of childhood MB in Saudi Arabia.

Geriatric assessment with management for older patients with cancer receiving radiotherapy: a cluster-randomised controlled pilot study

BackgroundGeriatric assessment and management (GAM) improve outcomes in older patients with cancer treated with surgery or chemotherapy. It is unclear whether GAM may provide better function and quality of life (QoL), or be cost-effective, in a radiotherapy (RT) setting.MethodsIn this Norwegian cluster-randomised controlled pilot study, we assessed the impact of a GAM intervention involving specialist and primary health services. It was initiated in-hospital at the start of RT by assessing somatic and mental health, function, and social situation, followed by individually adapted management plans and systematic follow-up in the municipalities until 8 weeks after the end of RT, managed by municipal nurses as patients’ care coordinators. Thirty-two municipal/city districts were 1:1 randomised to intervention or conventional care. Patients with cancer ≥ 65 years, referred for RT, were enrolled irrespective of cancer type, treatment intent, and frailty status, and followed the allocation of their residential district. The primary outcome was physical function measured by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (QLQ-C30). Secondary outcomes were overall quality of life (QoL), physical performance, use and costs of health services. Analyses followed the intention-to-treat principle. Study registration at ClinicalTrials.gov ID NCT03881137.ResultsWe included 178 patients, 89 in each group with comparable age (mean 74.1), sex (female 38.2%), and Edmonton Frail Scale scores (mean 3.4 [scale 0–17], scores 0–3 [fit] in 57%). More intervention patients received curative RT (76.4 vs 61.8%), had higher irradiation doses (mean 54.1 vs 45.5 Gy), and longer lasting RT (mean 4.4 vs 3.6 weeks). The primary outcome was completed by 91% (intervention) vs 88% (control) of patients. No significant differences between groups on predefined outcomes were observed. GAM costs represented 3% of health service costs for the intervention group during the study period.ConclusionsIn this heterogeneous cohort of older patients receiving RT, the majority was fit. We found no impact of the intervention on patient-centred outcomes or the cost of health services. Targeting a more homogeneous group of only pre-frail and frail patients is strongly recommended in future studies needed to clarify the role and organisation of GAM in RT settings.

Induction chemotherapy effects on very advanced (T3/T4) human papillomavirus-related oropharyngeal cancer for participation in hypoxia-directed major de-escalation (30 Gy) definitive treatment trial.

6076 Background: De-escalation trials in human papillomavirus associated oropharyngeal carcinoma (HPV+ OPC) often exclude patients with very locally advanced disease. We previously demonstrated in a Phase II study that for patients with T1-T2 HPV+OPC that de-escalation to 30Gy of definitive chemoradiation based on lack of hypoxia on 18F-FMISO (fluoromisonidazole) PET (ROC Study) is associated with excellent outcomes (JNCI 2021; JCO 2024). Here, we hypothesized that induction chemotherapy (ICT) could be used in locally advanced (T3-T4) HPV+OPC to down-stage patients and make them eligible for de-escalation and simultaneously improve tumor hypoxia. Methods: We conducted a pilot study in HPV+ OPC patients with AJCC v7 T3-T4 and/or large volume N2b-N2c-N3 disease (i.e. pts ineligible for ROC Study (NCT03323563)). ICT – carboplatin (AUC2), paclitaxel (90 mg/m2), and cetuximab (250 mg/m2 after 400 mg/m2 loading dose) weekly for 6 weeks. To be eligible for de-escalation (ROC), after ICT, patients needed to be down-staged (&lt;=T2). 18F-FMISO PET scan done prior to ICT, after ICT, and, if eligible for ROC study, about 2 weeks after start of radiation therapy. If an 18F-FMISO PET scan showed no hypoxia at any time point, no further scans necessary and patients received 30Gy of radiation therapy with 2 cycles of chemotherapy concurrently. Primary outcome is 2-year local control rate in 20 evaluable patients (description only in this pilot study). This abstract reports only on the outcomes of the ICT portion of the study. Results: 20 patients were accrued 3/2023-12/2023. Median age - 70 years old (46-88); Male – 95%; ECOG PS 0 – 80%. Tumor stage – T3 (70%); T4a (30%); N2b (70%); N2c (30%). All 20 patients had pretreatment hypoxia by 18F-FMISO. Of the 17 evaluable patients post ICT, 14 (82%) had no hypoxia on post ICT scan (other 3 still receiving ICT). Of 3 patients with hypoxia after ICT, 2 had resolution 2 weeks into radiotherapy, and 1 patient is still pending intra-treatment scan. All 17 evaluable patients had a significant enough of a response anatomically to allow treatment on the ROC Study. All patients to date were able to receive 2 cycles of cisplatin (100 mg/m2) without dose or treatment adjustment. Conclusions: Preliminary results suggest that ICT can allow more advanced tumors (T3/T4), that are typically excluded from de-escalation studies, to be de-escalated and may eliminate tumor hypoxia in a large proportion of cases, but a larger study is needed to confirm these results. Further followup of outcomes (2 year local control rate) is still needed. Clinical trial information: NCT05491512 .

Explainable Machine Learning Model to Predict Overall Survival in Patients Treated With Palliative Radiotherapy for Bone Metastases.

The estimation of prognosis and life expectancy is critical in the care of patients with advanced cancer. To aid clinical decision making, we build a prognostic strategy combining a machine learning (ML) model with explainable artificial intelligence to predict 1-year survival after palliative radiotherapy (RT) for bone metastasis. Data collected in the multicentric PRAIS trial were extracted for 574 eligible adults diagnosed with metastatic cancer. The primary end point was the overall survival (OS) at 1 year (1-year OS) after the start of RT. Candidate covariate predictors consisted of 13 clinical and tumor-related pre-RT patient characteristics, seven dosimetric and treatment-related variables, and 45 pre-RT laboratory variables. ML models were developed and internally validated using the Python package. The effectiveness of each model was evaluated in terms of discrimination. A Shapley Additive Explanations (SHAP) explainability analysis to infer the global and local feature importance and to understand the reasons for correct and misclassified predictions was performed. The best-performing model for the classification of 1-year OS was the extreme gradient boosting algorithm, with AUC and F1-score values equal to 0.805 and 0.802, respectively. The SHAP technique revealed that higher chance of 1-year survival is associated with low values of interleukin-8, higher values of hemoglobin and lymphocyte count, and the nonuse of steroids. An explainable ML approach can provide a reliable prediction of 1-year survival after RT in patients with advanced cancer. The implementation of SHAP analysis provides an intelligible explanation of individualized risk prediction, enabling oncologists to identify the best strategy for patient stratification and treatment selection.

Combined modality for localized gastric diffuse large B-cell lymphoma: Long-term outcomes of 50 patients.

7079 Background: R-CHOP is the primary treatment for gastric diffuse large B-cell lymphoma (GDLBCL); for localized disease, the role of consolidative radiation therapy (RT) after chemotherapy remains underexplored. This study focuses on localized GDLBCL undergoing a combined modality therapy of R-CHOP followed by gastric RT, comparing outcomes between those receiving short-course (3-4 cycles) and full-course (6 cycles) R-CHOP. Methods: A retrospective analysis identified 50 consecutive PGDLBCL pts treated with R-CHOP followed by RT between 1/2000-1/2021. Baseline characteristics and follow-up data were collected. Lugano PET criteria and endoscopy (EGD) assessed overall response rate. Kaplan-Meier and univariable cox regression models estimated overall survival (OS) and (PFS). Results: Of the 50 pts with localized (Stage I-II) disease, 34 (68%) received 3-4 cycles of R-CHOP and 16 (32%) received 6 cycles. Pre-RT disease evaluation varied, with 36 (72%) undergoing EGD and PET, 4 (8%) EGD and CT, and 6 (12%) PET alone. One pt (3%) exhibited active DLBCL post 3-4 cycle R-CHOP, while 5 (31%) did so after 6 cycles (p=0.1). Median time from last R-CHOP dose to RT start date was 1.2 months with a median 3060 cGy delivered dose for both groups (range 2340-3060 in the 3-4 cycle group, 3000-4500 in the 6-cycle group). Median follow-up time from RT end is 58 months. No in-field failures occurred post-complete response (CR); however, 1 pt did not achieve a CR following R-CHOP and RT, progressing in the stomach and subsequently at new, out-of-field (OOF) sites. 3 pts had OOF progression without relapses in the stomach in a median time of 21 months. Low-grade lymphoma in the stomach post-DLBCL CR was observed in 2 pts, 3 and 22 months from RT end, with 1 OOF marginal zone lymphoma 2 years-post RT. OS and PFS did not significantly differ between the 3-4 and 6 cycle groups (96-month OS 70% vs. 86%, p=0.8; 96-month PFS 76% vs. 86%, p=0.7). OS and DLBCL PFS were analyzed for pts with evidence of residual DLBCL pre-RT compared to those without evidence of disease after R-CHOP. The 24-month DLBCL PFS was 92% in the CR group and 67% for those with incomplete response (p=0.14), with 92% and 67% 24-month survival probability (p=0.11). On univariate analysis, pre-RT evidence of active DLBCL by PET and/or EGD, pre-RT PET FDG uptake, and achieving CR on first-post-RT imaging were not statistically significant for DLBCL PFS. Conclusions: Recognizing the limitations of a retrospective study, our study documents the effectiveness of short-course R-CHOP followed by RT in localized GDLBCL, with similar outcomes to the full 6-cycle regimen. Excellent disease control was observed, with few instances of DLBCL or low-grade lymphoma relapse. Further analysis will include a cohort receiving R-CHOP alone without consolidative RT. This analysis aims to contribute to the evolving standard of care for GDLBCL, providing insights for future treatment strategies.

Potential Single Nucleotide Polymorphisms markers for radiation dermatitis in head and neck cancer patients: ameta-analysis.

To identify potential Single Nucleotide Polymorphisms (SNPs) of susceptibility for the development of acute radiation dermatitis in head and neck cancer patients, and also to verify the association between SNPs and the severity of RD. This systematic review was reported according to the PRISMA guideline. The proportion meta-analysis was performed to identify the prevalence of genetic markers by geographical region and radiation dermatitis severity. The meta-analysis was performed to verify the association between genetic markers and RD severity. The certainty of the evidence was assessed by GRADE. Thirteen studies were included. The most prevalent SNPs were XRCC3 (rs861639) (36%), TGFβ1 (rs1800469) (35%), and RAD51 (rs1801321) (34%). There are prevalence studies in Europe and Asia, with asimilar prevalence for all SNPs (29-40%). The prevalence was higher in patients who developed radiation dermatitis ≤2 for any subtype of genes (75-76%). No SNP showed astatistically significant association with very low certainty of evidence. The most prevalent SNPs may be predictors of acute RD. The analysis of SNP before starting radiation therapy may be apromising method to predict the risk of developing radiation dermatitis and allow radiosensitive patients to have acustomized treatment. This current review provides new research directions.

Earlier Radiation Is Associated with Improved 1-Year Survival After Metastatic Spine Tumor Surgery

ObjectivesIn patients undergoing metastatic spine surgery, we sought to: 1) report time to postoperative radiation therapy (RT), 2) describe the predictive factors of time to postoperative RT, and 3) determine if earlier postoperative RT is associated with improved local recurrence (LR) and overall survival (OS). MethodsA single-center, retrospective cohort study was undertaken of all patients undergoing spine surgery for extradural metastatic disease and receiving RT within 3-months postoperatively between 02/2010-01/2021. Time to postoperative RT was dichotomized at <1month vs. 1-3months. The primary outcomes were LR, OS, and 1-year survival. Secondary outcomes were wound complication, Karnofsky Performance Scale (KPS), and Modified McCormick Scale (MMS). Regression analyses controlled for age, BMI, tumor size, preoperative RT, preoperative/postoperative chemotherapy, and type of RT. ResultsOf 76 patients undergoing spinal metastasis surgery and receiving postoperative RT within 3-months, 34(44.7%) received RT within 1month and 42(55.2%) within 1-3months. Patients with larger tumor size (β=-3.58,95%CI=-6.59,-0.57,p=0.021) or new neurological deficits (β=-16.21,95%CI=-32.21,-0.210,p=0.047) had a shorter time to RT. No significant association was found between time to RT and LR or OS on multivariable logistic/Cox regression. However, patients who received RT between 1-3month had a lower odd of 1-year survival compared to those receiving RT within 1month (OR=0.18,95%CI=0.04-0.74,p=0.022). Receiving RT within 1month vs. 1-3month was not associated with wound complications (7.1% vs. 2.9%,p=0.556)(OR=4.40,95%CI=0.40-118.0,p=0.266) or KPS/MMS. ConclusionsSpine surgeons, oncologists, and radiation oncologists should make every effort to start RT within 1 month to improve 1-year survival after metastatic spine tumor surgery.

Association Between Time From Surgery to Radiation Therapy and Multimodality Treatment Outcomes in HPV+ Head and Neck Cancer: A Multi-Institutional Cohort Experience

Oropharyngeal squamous cell cancers (OPSCCs) are traditionally managed with surgery and, if indicated, adjuvant radiation therapy (RT) with or without chemotherapy. NCCN recommends keeping the time from surgery to the start of RT (TSRT) within 6 weeks to avoid possibly compromising patient outcomes. HPV+ OPSCCs behave more favorably than HPV- OPSCCs. We hypothesized that TSRT beyond 6 weeks may not portend poorer outcomes for the former. We identified nonmetastatic, high-risk HPV+ OPSCCs treated with multimodal therapy at 2 institutions. Prolonged TSRT was defined as >6 weeks and was evaluated for association with recurrence-free survival (RFS). Radiation treatment time (RTT; time from the first to the last day of RT), total treatment package time (TTPT; time from surgery to the end of adjuvant treatments), de-escalated RT (dose ≤56 Gy), concurrent chemotherapy, smoking history, and treatment institution were evaluated as possible confounders. In total, 96 patients were included. The median follow-up time was 62 months (4-123 months); 69 patients underwent transoral robotic surgeries, and 27 received open surgeries. The median postoperative RT dose was 60 Gy (50-70.8 Gy). The median TSRT, RTT, and TTPT were 38 days (11-208), 43 days (26-56 days), and 81 days (40-255 days), respectively. Ten patients failed treatment at a median of 8 months (4-64 months). Two locoregional and 4 distant failures occurred in the group without prolonged TSRT, whereas 2 locoregional and 2 distant failures were recorded in the prolonged TSRT group. Prolonged TTPT, de-escalated RT, chemotherapy, smoking history, and treatment institution were not associated with treatment failure. RTT was dropped from our analyses as no events appeared in the prolonged RTT group, and no reliable hazard ratio could be computed. TSRT > 6 weeks was not significantly associated with inferior outcomes in the postoperative management of HPV+ OPSCCs. Longer TSRT may facilitate better recovery from surgical toxicity, as needed, without compromising oncologic outcomes. The TSRT goal for these cancers should be investigated in future studies.

Overall Survival after Radiotherapy for Brain Metastases According to ECOG Status-A Prospective Study of 294 NSCLC Patients.

Up to 40% of non-smallcell lung cancer (NSCLC) patients develop brain metastases (BMs). The potential benefits of radiotherapy (RT) in patients with poor performance status (PS) are questionable, with considerable risk for futile treatment. We analyzed overall survival after initial radiotherapy in NSCLC patients with BMs, focusing on the relationship between PS and survival after RT. This study reports a prospective observational study including consecutive 294 NSCLC patients with first-time BMs. Overall survival (OS) was calculated from the start of RT to death or last follow-up (1 June 2023). Overall, in the 294 included patients (median age 69 years), the median OS was 4.6 months; 2.5 months after WBRT (n = 141), and 7.5 months after SRT (n = 153). After WBRT, mOS was equally poor for patients with ECOG 2 (1.9 months) and ECOG 3-4 (1.2 months). After SRT, mOS for patients with ECOG 2 was 4.1 months; for ECOG 3 patients, mOS was 4 1.6 months. For NSCLC patients with ECOG 2 diagnosed with BMs who are not candidates for surgery or SRT, WBRT should be questioned due to short survival.

Profiling of swallowing function in head and neck cancer patients prior to radiation therapy-Findings from a tertiary hospital in South India

PurposeHead and neck cancer (HNC) patients often face difficulties with swallowing, which can be due to the cancer itself or the treatment modalities like radiation therapy. The presentation of HNC can vary between developing and developed countries due to socioeconomic factors. The current study aimed to profile the swallowing function of HNC patients before starting radiation therapy in a tertiary hospital in India. MethodThis cross-sectional observational study examined patients with HNC who were scheduled for radiation therapy. The Functional Oral Intake Scale (FOIS) and Karnofsky Performance Status Scale were used to assess the patients’ swallowing status and functional abilities, respectively. The study also evaluated the relationship between swallowing function and clinical-demographic factors. ResultsOur assessment of 162 HNC patients found that the cancer site significantly affects swallowing. Although 92% of patients had an oral diet, 64% made dietary modifications. Patients with non-oral intake had either oral or pharyngeal cancer, and over 80% of oral cancer patients and 60% of those with pharyngeal cancer had already made changes to their diet. Patients with laryngeal cancer had a better oral intake, with 58% reporting no swallowing issues. ConclusionPatients with HNC scheduled for radiation therapy may experience varying degrees of swallowing difficulty. Early intervention and teaching of safe swallowing strategies are crucial to prepare for the potential worsening of swallowing difficulties resulting from the treatment. Advanced tumor stages and oral/pharyngeal cancers increase the risk of significant swallowing issues.

Abstract 1128: Association between gut microbial change and acute gastrointestinal toxicity in patients with prostate cancer undergoing definitive radiation therapy

Abstract Purpose: This prospective cohort study investigated the association between gut microbial changes and acute gastrointestinal toxicities in prostate cancer patients undergoing definitive radiation therapy (RT). Methods: Seventy-nine fecal samples were analyzed. Stool samples were collected at the following timepoints: pre-RT (prRT), 2 weeks after the start of RT (RT-2w), 5 weeks after the start of RT (RT-5w), 1 month after completion of RT (poRT-1m), and 3 months after completion of RT (poRT-3m). We computed the microbial community polarization index (MCPI) as an indicator of RT-induced dysbiosis. Results: Patients experiencing toxicity had lower alpha diversity, especially at RT-2w (P=0.037) and RT-5w (P=0.003). Compared to patients without toxicity, the MCPI in those experiencing toxicities was significantly elevated (P=0.019). In terms of predicted metabolic pathways, we found linearly decreasing pathways including carbon fixation pathways in prokaryotes (P=0.035) and the bacterial secretion system (P=0.005), in patients who experienced toxicities. Conclusions: We showed RT-induced dysbiosis among patients who experienced toxicities. Reduced diversity and elevated RT-related MCPI could be helpfully used for developing individualized RT approaches. Citation Format: Bum-Sup Jang, Dong Soo Lee. Association between gut microbial change and acute gastrointestinal toxicity in patients with prostate cancer undergoing definitive radiation therapy [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 1128.

Abstract 2745: Sequential tracking of PD-L1 expression on circulating epithelial tumor cells (CETCs) in men with primary non-metastatic prostate cancer

Abstract Background: Radiotherapy (RT) is an essential component of multimodality therapy in the primary or postoperative treatment of prostate cancer with curative intent by preventing local recurrence and distant metastases, indicating its impact on residual occult tumor, such as circulating tumor cells. Immunogenic changes in cancer cells induced by RT can lead to adaptive up-regulation of PD-L1 expression. As immune checkpoint inhibition plays an increasingly important role in prostate cancer, radiogenic PD-L1 upregulation may be of therapeutic importance. The aim of this study was to determine PD-L1 status on CETCs before and during RT. Methods: Peripheral blood samples were collected from 52 primary non-metastatic prostate cancer patients. CETCs were enumerated and analyzed for PDL-L1 expression prior to (baseline), 3 and 6 weeks after the start of RT using fluorescence scanning microscopy. Results: PD-L1 expression was detectable in CETCs and localized in the membrane and/or cytoplasm. We found a correlation between PD-L1 status in CETCs and aggressiveness of cancer disease prior to RT. The frequency of PD-L1 positive CETCs depended on the grading and Gleason score of the primary tumor. Patients with a high Gleason score and G3 tumors had significantly more PD-L1 positive CETCs compared to patients with a low Gleason Score and G1 tumors. Moreover, patients in stage I/II had significantly less PD-L1 positive CETCs compared to patients in stage III/IV (mean 54.25 vs. mean 69.65; p&amp;lt;0.05). A higher number of PD-L1 positive CETCs were detected in patients who had radical prostatectomy before start of RT than in those who had no surgical intervention (mean 66.24 vs. mean 47.46; p&amp;lt;0.01). Interestingly, the fraction of PD-L1 positive CETCs decreased significantly during RT only in patients with G3 tumors and a high Gleason Score. Conclusion: Our results indicated that PD-L1 in CETCs is closely related to the aggressiveness of the primary tumor and may be a co-factor associated with the progression of prostate cancer. PD-1/PD-L1 blockade combined with RT represents a novel and promising treatment strategy that could contribute to improve the treatment efficacy of prostate cancer. Citation Format: Dorothea Schott, Monika Pizon, Ulrich Pachmann, Katharina Pachmann, Matthias Mäurer. Sequential tracking of PD-L1 expression on circulating epithelial tumor cells (CETCs) in men with primary non-metastatic prostate cancer [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 2745.