Small-cell carcinoma of the bladder (SCCB) is a rare, aggressive neuroendocrine malignancy associated with early metastasis and poor survival. Due to its rarity, optimal management is not well defined and is generally extrapolated from small-cell lung cancer treatment paradigms. We report a rare case of SCCB with synchronous high-grade prostate adenocarcinoma managed with a bladder-preserving multimodal approach. An 82-year-old man presented with hematuria and urinary retention, who was diagnosed with limited-stage SCCB following transurethral resection of bladder tumor (TURBT). He received neoadjuvant cisplatin and etoposide, but definitive therapy was significantly delayed due to severe necrotizing perineal infection with fistula formation requiring multiple surgical interventions. During this period, he was also diagnosed with high-risk prostate adenocarcinoma (Gleason 4 + 5 = 9, prostate-specific antigen (PSA) > 100 ng/mL, with normal PSA range less than or equal to 4 ng/mL) and was initiated on androgen deprivation therapy. After recovery and surgical repair of a large inguinal hernia (that would have hindered external beam radiation therapy planning), he underwent definitive bladder-preserving radiotherapy using simultaneous integrated boost volumetric modulated arc therapy (VMAT), delivering 60 Gy in 20 fractions to the prostate and proximal seminal vesicles, 55 Gy in 20 fractions to the whole bladder, and 44 Gy in 20 fractions to the elective pelvic lymph nodes. Treatment was well tolerated with minimal toxicity. Follow-up cystoscopy and imaging demonstrated a complete response in both malignancies. More than three years after treatment, the patient remains without evidence of disease, with a low PSA and no evidence of local, distant, or intracranial recurrence on serial brain magnetic resonance imaging (MRI) studies. This case demonstrates that durable long-term disease control in SCCB may be achievable with individualized bladder-preserving multimodal therapy, even in the setting of significant treatment delays, severe intercurrent complications, and synchronous high-grade prostate cancer. It also highlights the feasibility of simultaneous integrated pelvic radiotherapy for dual malignancies and supports MRI surveillance as a reasonable alternative to prophylactic cranial irradiation in carefully selected patients with SCCB.

Primary pulmonary non-Hodgkin lymphoma (PPL) is a rare malignancy most commonly presented as indolent marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) or bronchus-associated lymphoid tissue (BALT). Aggressive subtypes of PPL, such as diffuse large B-cell lymphoma (DLBCL), occur less frequently. Diagnosis and workup require tissue biopsy, immunophenotyping, and cross-sectional imaging, often supplemented by positron emission tomography (PET)/computed tomography (CT) for staging and treatment planning. Radiation therapy or radiotherapy (RT) is a cornerstone in managing localized, indolent PPL, offering durable local control with minimal toxicity. Modern involved-site RT (ISRT) techniques deliver radiation in conventional fractionation schedules, precisely targeting pulmonary lesions while sparing surrounding lung and mediastinal structures. RT can be used alone for early-stage disease or following systemic therapy for residual or refractory lesions. The cases in this report highlight the importance of histology-driven, individualized treatment planning and the pivotal role of RT in achieving optimal outcomes in this rare malignancy.

Primary bone lymphoma (PBL) is a rare extranodal hematologic malignancy that can pose significant diagnostic challenges. Patients commonly present with localized pain, swelling, pathological fracture, or neurological deficits, and the disease may mimic infection, degenerative conditions, trauma, or metastatic carcinoma. Lesions can arise in any skeletal site, underscoring the importance of interdisciplinary awareness among orthopedics, neurosurgery, dentistry, and oncology. Histologically, diffuse large B-cell lymphoma is the most frequently encountered subtype, with certain molecular features carrying important prognostic implications. Accurate diagnosis depends on adequate tissue sampling, immunophenotyping, and staging with positron emission tomography/computed tomography, and repeat or open biopsy may be required in select cases. Management is typically optimized with combined chemo-immunotherapy, most commonly rituximab-based regimens, with or without consolidative radiotherapy to improve local control and symptom relief. Surgical intervention is generally reserved for diagnostic purposes or skeletal stabilization. We report two cases of elderly patients, one Middle Eastern male and one White female, with stage IE PBL involving the sacrum and iliac crest, respectively. Both patients were treated with systemic therapy followed by salvage involved-site radiotherapy, achieving durable local disease control and symptom resolution. Early recognition of PBL enables effective multimodal treatment and favorable clinical outcomes. This case series highlights the diagnostic complexity of PBL, emphasizes the role of radiotherapy in management, and underscores the need for standardized treatment approaches to optimize care for this rare lymphoma subtype.

419 Background: A third of patients with biochemical recurrence after radiation (RT) have intraprostatic radiorecurrence (IPR) on PSMA PET/CT. Patients with IPR have worse metastasis-free survival - a surrogate for progression to lethal prostate cancer (PCa). We previously reported the results from our F-SHARP clinical trial that demonstrated salvage reirradiation using focal dose-escalated high dose rate (HDR) brachytherapy is safe and effective. Here, we examine the Decipher score to determine if it could be a tool to risk stratify patients with IPR. Methods: F-SHARP (NCT03312972) is a multi-institutional phase I/II trial of focal dose-escalated salvage HDR for IPR. Patients were recruited from 2017-2023 at 3 centers. Eligibility criteria included a history of localized PCa treated with any form of definitive RT and biopsy-proven IPR with no regional or distant metastasis. Of the 62 participants, 37 consented for the biomarker correlative study and 31 (50%) had sample data passing quality control for Decipher analysis (Veracyte, San Diego, CA). De-identified data from 146,940 patients tested (2016-2024) with the Decipher prostate genomic classifier were retrieved from the GRID registry (NCT02609269) and used to create a matched cohort based on NCCN risk at diagnosis. Univariable Cox proportional hazards models were used to compare oncologic, CTCAE v4.03 toxicity, and EPIC-26 hrQoL events by Decipher risk group. Results: The biomarker cohort had similar baseline characteristics to the overall trial cohort. 30% received ADT with initial RT (73% external beam, 27% LDR brachytherapy). At recurrence, 71% had high Decipher risk (median score 0.67) as compared to only 35% (median score 0.48) in the matched GRID cases (n=130,760). Median time from initial RT to enrollment in Decipher low (<0.45) was 16.9 years, compared to 8.0 and 7.4 years in the intermediate (0.45-0.6) and high (>0.6) score patients. Median follow up was 32.3 months. Decipher score was not associated with toxicity or quality of life post-HDR (all p>0.05). As depicted in the table, higher Decipher score was associated with an increased risk of biochemical progression-free survival (bFS; p=0.03), local recurrence-free survival (LRFS; p=0.04), and radiographic progression-free survival (rPFS; p=0.01). At 3 years, bPFS was 43% vs. 75%, LRFS was 58% vs. 100%, and rPFS was 42% vs. 100% for Decipher high vs. lower risk (<0.6). Conclusions: Salvage reirradiation is a growing indication for RT in PCa. This is the first use of genomic risk stratification in this setting. Nearly a third of patients with IPR have a lower Decipher risk score, and our data suggest especially favorable outcomes with salvage HDR. Future studies to determine how Decipher risk stratification can be used to tailor further treatment intensification with systemic therapy for those most at risk of reirradiation failure are warranted. Clinical trial information: NCT03312972 . Endpoint Hazard Ratio per 0.1 unit (95% CI) bPFS 1.70 (1.05-2.75) LRFS 2.30 (1.02-5.18) rPFS 2.47 (1.23-4.97)

The United States Veterans Affairs (VA) Health Care System has a strong history of conducting impactful oncology randomized clinical trials (RCTs). We developed a phase II/III RCT to test the use of metastasis-directed therapy in Veterans with oligometastatic prostate cancer (OMPC)—the first VA RCT in OMPC that leverages novel imaging and advanced radiotherapy techniques. To accomplish this, we developed a clinical trial network to conduct the study. In this manuscript, we describe several challenges we encountered in study development/conduct and our strategies to address them, with the goal of helping investigators establish robust study networks to conduct clinical trials. In the study start-up, we encountered challenges in timely site activation, and leveraged project management to maximize efficiency. Additionally, there were several changes in the clinical paradigms in imaging and treatment that led to protocol amendments to ensure maximum equipoise, recruitment, and impact of the study. Specifically, we amended the trial to add de novo OMPC patients (from initially only recurrent OMPC) and expanded the study to allow up to 10 metastases (from initially five). Finally, in order to maintain local study team engagement, we developed initiatives to maximize collaboration and add value to the overall clinical program through study participation.

The treatment landscape for localized and regional prostate cancer includes active surveillance, radiation therapy (RT), and radical prostatectomy (RP). Population-based studies comparing RP to radiation reveal conflicting results due to methodological flaws. This systematic review and pooled analysis of studies aim to compare cause-specific survival (CSS), overall survival (OS), disease-free survival (DFS) and toxicity outcomes, comparing RP to RT in the management of prostate cancer. This systematic review search included the PubMed, Embase, and Cochrane libraries according to the PRISMA statement with the inception of each database up to June 24, 2023. Randomized phase 2 or 3 clinical trials that compared RP to RT in prostate cancer were included. The forest plot for the Odds ratio (OR) was plotted using the Mantel-Haenszel method, and the Z test was used to assess significance. A fixed effects model was used for meta-analysis. The search yielded seven completed randomized clinical trials and four ongoing trials. The majority of complete trials had low to intermediate-risk patient populations. OR for OS was 1.00 with 95% CI, 0.71-1.41 (P-value: 0.98), CSS OR was 0.99 with 95% CI, 0.45-2.18 (P-value 0.11), OR for DFS was 1.26 with 95% CI, 0.89-1.78 (P-value 0.19) when comparing RP to RT. The rate of distant metastatic disease was 2.3% in the RP versus 2.9% in the RT at 10 years. The rate of second malignant neoplasms was 4.5% in the RP compared to 4.2% in the RT arm at 10 years. RP caused more urinary symptoms, with a predominance of the need for urinary pads and a higher incidence of sexual dysfunction, and RT caused a higher incidence of bowel symptoms, such as blood in stools and fecal incontinence. This study provides evidence that the treatment-related outcomes are similar in patients with low to intermediate-risk prostate cancer when comparing RP to RT. Multidisciplinary treatment approaches and factoring patients' values and preferences should form the cornerstone of the ideal treatment option for each patient with localized prostate cancer. Patients with prostate cancer have an equal chance of being cancer-free and alive at 10 years with either RP or RT. In terms of side effects, RP causes more urine leakage and loss of erections, whereas RT tends to cause more bowel side effects, such as blood in stools and fecal leakage.

Cone-beam computed tomography (CBCT) is a noninvasive x-ray imaging technique with multiple clinical applications (orthopedics, dentistry, radiation therapy, etc.). These systems can provide sub-millimeter resolution in images of high diagnostic quality with short scanning times. However, CBCT scans require subjecting the patient with a sufficient radiation dose to obtain a high-quality image. Although relatively low, some clinical applications such as image guidance in radiotherapy (IGRT) require obtaining CBCT daily. This repeated exposure to x-ray radiation outside the treatment volume can have detrimental effects and may increase the lifetime risk of a secondary malignancy in younger patients. Hence, there is a clinical need to reduce CBCT imaging dose. However, images produced with a reduced dose often have greater noise and artifacts which deteriorate CBCT image quality, reducing their clinical efficacy. Deep learning-based methods have become a popular choice showing impressive performance for noise reduction in low-dose CBCT. The success of these methods critically depends on the availability of paired images for training which is a major obstacle for most applications. Recently, the Noise2Inverse method was designed specifically for denoising computed tomography (CT) data without requiring paired noisy and clean images. While the Noise2Inverse method was shown to reduce noise in challenging real-world experimental datasets, it processes 3D-CT volumes as individual 2D images. In this work, we extend the Noise2Inverse method to work directly with 3D-CBCT volumes requiring the use of high-end HPC resources. We compare the results between a 2D and 3D UNet++ model utilizing the ICASSP-2024 3D Low Dose CBCT Grand Challenge dataset with CBCT data corresponding to two dose levels, clinical and low-dose. Experimental results show that both 2D and 3D models can significantly reduce the noise in CBCT increasing the SSIM up to 148.05% compared to the low-dose FDK reconstruction. Furthermore, the 3D model improves the SSIM by 0.26% and 1.46% for clinical- and low-dose, respectively, over the 2D model.

Purpose: Molecular imaging better identifies anatomic regions of metastatic spread of prostate cancer compared with conventional imaging, resulting in para-aortic (PA) nodal metastases being increasingly identified. Consequently, some radiation oncologists electively treat the PA lymph node region in patients with gross or high risk of PA nodal involvement. The anatomic locations of at-risk PA lymph nodes for prostate cancer are unknown. Our objective was to use molecular imaging to develop guidelines for the optimal delineation of the PA clinical target volume (CTV) in patients with prostate cancer. Methods and Materials: We conducted a multi-institutional retrospective cohort study of patients with prostate cancer undergoing 18F-fluciclovine or 18F-DCFPyL prostate-specific membrane antigen positron emission tomography (PET)/computed tomography (CT). Images of patients with PET-positive PA nodes were imported into the treatment planning system, avid nodes were contoured, and measurements were taken in relation to anatomic landmarks. A contouring guideline that encompassed the location of >= 95% of PET-positive PA nodes was created using descriptive statistics and then validated in an independent data set. Results: Five hundred fifty-nine patients had molecular PET/CT imaging in the development data set (78% 18F-fluciclovine, 22% prostate-specific membrane antigen). Seventy-six patients (14%) had evidence of PA nodal metastasis. We determined that expanding the CTV to 1.8 cm left of the aorta, 1.4 cm right of the inferior vena cava (IVC), 7 mm posterior to the aorta/ IVC or to the vertebral body, and superiorly to the T11/T12 vertebral interface, with the anterior border 4 mm anterior to the aorta/IVC and inferior border at the bifurcation of the aorta/IVC, resulted in coverage of >= 95% of PET-positive PA nodes. When the guideline was used in the independent validation data set (246 patients with molecular PET/CT imaging, of whom 31 had PA nodal metastasis), 97% of nodes were encompassed, thereby validating our guideline. Conclusions: We used molecular PET/CT imaging to determine the anatomic locations of PA metastases to develop contouring guidelines for creating a prostate cancer PA CTV. Although the optimal patient selection and clinical benefits of PA radiation therapy remain uncertain, our results will aid in delineating the optimal target when PA radiation therapy is pursued. Published by Elsevier Inc.

Cranial neuropathy can result from pathology affecting the nerve fibers at any point and requires imaging of the entire course of the nerve from its nucleus to the end organ in order to identify a cause. MRI with and without intravenous contrast is often the modality of choice with CT playing a complementary role. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Objective Surgical resection is standard treatment for pleomorphic adenoma (PA) of the parotid gland. A small number (2–5%) of these tumors recur. Recurrence usually necessitates reoperation, which is technically challenging and puts the facial nerve (FN) at risk. The aim of this study is to characterize the recurrent parotid PA population and compare outcomes after surgery for singly recurrent and multiply recurrent tumors. Methods This study was a retrospective chart review of patients at a single tertiary care academic medical center who underwent operations for recurrent PA of the parotid gland between 2007 and 2020. Demographic data, details of surgical interventions, pre- and postoperative FN function, and recurrence rates were studied. These factors were compared between patients with singly and multiply recurrent tumors. Results Thirty-eight patients met criteria: 4 patients presented for primary PA and subsequently recurred, 26 with a first recurrence, 7 with a second recurrence, and 1 with a fourth recurrence. Multiply recurrent PAs were more likely to require at least partial nerve sacrifice at the time of reoperation ( P = 0.0092). Significantly worse long-term FN outcomes were seen following surgery for multiply recurrent PA ( P = 0.008). There was no significant difference between the rate of re-recurrence following first revision surgery vs second-fourth revision surgery. Time to reoperation was significantly shorter between the first and second revision surgery than between the primary surgery and first revision ( P = 0.0017). Conclusion Surgery for recurrent PA incurs high risk to the FN, and this risk appears to increase in the setting of multiple recurrences.

The purpose of the present study was to present a single institution experience with intraoperative radiation therapy (IORT) for patients with head and neck cancer (HNC). The present study included all patients with HNC treated consecutively with IORT at Loyola University Medical Center between January 2014 and December 2018. Charts were reviewed for patient and tumor characteristics, IORT technical details, IORT-induced adverse events and treatment outcomes. The study included 23 eligible patients. Median patient age was 66 years (range, 34-91 years). Tumor sites included the parotid gland (43%), lymph nodes (43%), oral tongue (9%) and ear (4%). A total of 48% of patients received IORT upfront with or without postoperative adjuvant external beam radiation therapy (EBRT), whereas 52% received salvage IORT after local tumor recurrence. The median prescribed IORT dose was 7.5 Gy (range, 5-14 Gy) in a single fraction prescribed to 5 mm depth with flat applicators (median diameter, 5 cm). A total of 92% of patients did not experience wound healing complications. One patient (4%) developed postoperative acute thromboembolic stroke and a second patient (4%) experienced protracted wound healing. At a median follow up of 36 months (range, 2-81 months), overall survival was 52%. In addition, 48% of patients were reported to have no evidence of disease, and although two had died of unrelated causes, 13% of patients were alive with disease and 39% died with the disease. The local-regional recurrence rate was 39% (median time to local recurrence, 11 months; range, 1-34 months), the rate of distant metastasis was 35% (median time to distant metastasis, 16 months; range, 4-40 months), and 21% of patients had both local-regional recurrence and distant metastases. The percentages of local-regional recurrence and distant metastases among patients receiving salvage IORT were 58 and 50% respectively, compared with 18 and 18% respectively in those receiving upfront IORT with or without adjuvant EBRT. In the present single institution retrospective study, it was concluded that IORT for patients with locally advanced and recurrent HNC was a safe treatment modality, with tumor control comparable to historical IORT data. Larger prospective studies are needed to further assess the utility of IORT in the management of locally advanced and recurrent HNC.

months (31.3-60.6 months), 22 biochemical failures have been observed for a 4-yr bNED survival of 84.4% (95%CI: 77.9-90.9%).On UVA, bNED-survival after sRT was significantly more likely for patients with VUA-only lesions (VUA-only vs others, HR=0.307, 95%CI: 0.120-0.784,p=0.014) and with smaller lesions (for every cc, HR: 1.071, 95%CI: 1.025-1.119,p=0.002).These associations remained significant (p< 0.01) on multivariate analysis as well.For patients with VUA-only disease or with lesions smaller than 0.5cc, 4-yr bNED survival rates were 90.7% (95%CI: 83.4-98.0%)and 90.6% (95%CI: 83.9-97.3%),respectively.The 46 patients with both favorable features had a 4-yr bNED rate of 94.6% (95%CI: 87.3-100%).Conclusion: These data support local restaging with DCE-MRI before sRT in the setting of a biochemical failure after RP.Patients with VUA-only and/or small volume lesions have an excellent outcome after dose-escalated sRT.

PURPOSE:Currently, calculations of proton range in proton therapy patients are based on a conversion of CT Hounsfield units of patient tissues into proton relative stopping power. Uncertainties in this conversion necessitate larger proximal and distal planned target volume margins. Proton CT can potentially reduce these uncertainties by directly measuring proton stopping power. We aim to demonstrate proton CT imaging with complex porcine samples, to analyze in detail three-dimensional regions of interest, and to compare proton stopping powers directly measured by proton CT to those determined from x-ray CT scans.METHODS:We have used a prototype proton imaging system with single proton tracking to acquire proton radiography and proton CT images of a sample of porcine pectoral girdle and ribs, and a pig's head. We also acquired close in time x-ray CT scans of the same samples and compared proton stopping power measurements from the two modalities. In the case of the pig's head, we obtained x-ray CT scans from two different scanners and compared results from high-dose and low-dose settings.RESULTS:Comparing our reconstructed proton CT images with images derived from x-ray CT scans, we find agreement within 1% to 2% for soft tissues and discrepancies of up to 6% for compact bone. We also observed large discrepancies, up to 40%, for cavitated regions with mixed content of air, soft tissue, and bone, such as sinus cavities or tympanic bullae.CONCLUSIONS:Our images and findings from a clinically realistic proton CT scanner demonstrate the potential for proton CT to be used for low-dose treatment planning with reduced margins.

Very low dose ionizing radiation (LDR) may have paradoxically beneficial effects via an adaptive response. This adaptive response can mitigate against the potential adverse effects of high-dose radiation therapy and chemotherapy. In this study we aimed to:1.identify the specific molecular details behind the adaptive response to LDR and2.integrate the LDR adaptive response into clinical practice. Our aim was to determine how low dose radiation modifies genetic expression in both healthy and tumor tissue. To determine this, a human clinical trial (n=8) was conducted in 2018 to ascertain the biological effects of integrating 0.1Gy of LDR into standard radiotherapy (2Gy fractions) over the first two weeks of radiation treatment for epidermoid skin cancers. RNA was obtained from skin biopsies and processed for genetic expression using Affymetrix Human gene chips Clarion-D (138K genes). 8 patients with squamous skin cancer, were studied according to the experimental design showed in Figure 1. Biopsy samples were collected and total RNA preparation (100 ng), labeled cRNA synthesis, hybridization, scanning, and image analysis were performed. Changes in biological response were measured using Affymetrix microarrays. Experiments 17F1 and 17F2 were performed in duplicate, and experiments 18F3 and 18F4 were performed in triplicate. Pathway analysis was performed using the Affymetrix Transcriptome Analysis Console software and the Wikipaths database. Comparisons were performed as noted in Table 1. The difference in gene expression in healthy tissues due to LDR exposure is quite low (only 325 genes, mostly downregulated) as noted in Figures 2A and 3A and Tables 2 and 3. The 20 most important biological processes enriched are shown in Figure 4 and include Senescence and Autophagy in malignant cells, and the Genotoxicity Pathway (both downregulated). The difference in gene expression in tumor tissue due to LDR exposure is significantly more pronounced (5,651 genes, mostly upregulated) as noted in Figures 2C and 3C. The 20 most important biological processes enriched are shown in Figures 5 and 6 and Tables 4-6, and include the Allograft rejection pathway in skin cancer (upregulated). Our results suggest that very low doses of radiation (0.1Gy) have a narrow effect on gene expression when applied in the healthy peritumoral area. Down regulated genes predominate, and DNA repair mechanisms are stimulated by the first low dose in healthy tissue.

Radiation therapy (RT) is often necessary for the treatment of head and neck cancers. Osteoradionecrosis (ORN) is a rare, but potentially serious complication of RT. RT leads to the destruction of vasculature in radiated tissue causing hypoxia and tissue necrosis. ORN can occur in any bone, but bones with naturally poor blood supply appear to be more susceptible. Bones of the skull base are susceptible, with ORN occurring in the anterior, central, and lateral skull base. Risk factors include cancer type and location, radiation dose, and a variety of patient factors. Patients often present with pain, bleeding, and foul odor and are typically found to have exposed and necrotic bone. Treatment options vary depending on the severity, but typically include pentoxifylline and vitamin E as well as surgical debridement, with less evidence supporting hyperbaric oxygen therapy. Recognition and prompt treatment of ORN will allow for improved patient outcomes.

Purpose: Our peer-review program previously consisted of weekly chart rounds performed before the end of the first week of treatment. In order to perform peer review before the start of treatment when possible, we implemented daily prospective contouring and planning rounds (CPR). Methods and materials: At the time of computed tomography simulation, patients were categorized by the treating physician into 5 treatment groups based on urgency and complexity (ie, standard, urgent, palliative nonemergent, emergent, and special procedures). A scoring system was developed to record the outcome of case presentations, and the results of the CPR case presentations were compared with the time period 2.5 years before CPR implementation, for which peer review was performed retrospectively. Results: CPR was implemented on October 1, 2015, and a total of 4759 patients presented for care through May 31, 2018. The majority were in the standard care path (n = 3154; 66.3%). Among the remainder of the charts, 358 (7.5%), 430 (9.0%), and 179 (3.8%) cases were in the urgent, nonemergent palliative, and emergent care paths, respectively. The remaining patients were in the special procedures group, representing brachytherapy and stereotactic radiosurgery. A total of 125 patients (2.6%) required major changes and were re-presented after the suggested modifications, 102 patients (2.1%) had minor recommendations that did not require a repeat presentation, and 247 cases (5.2%) had minor documentation-related recommendations that did not require editing of the contours. In the 2.5 years before the implementation, records of a total of 1623 patients were reviewed, and only 9 patients (0.6%) had minor recommendation for change. The remainder was noted as complete agreement. Conclusions: Contouring and planning rounds were successfully implemented at our clinic. Pretreatment and, most often, preplanning review of contours and directives allows for a more detailed review and changes to be made early on in the treatment planning process. When compared with historical case presentations, the CPR method made our peer review more thorough and improved standardization. (C) 2019 The Authors. Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.

75 Background: Patients with adverse pathologic features (≥pT3 disease or positive margins) at the time of radical prostatectomy (RP) have higher biochemical recurrence (BR). Adjuvant radiotherapy (ART) reduces BR, but has potential toxicities. Also, studies suggest Black men are more likely to have aggressive prostate cancer. Our objective was to identify whether black men undergoing RP are more likely to have adverse pathologic features (APF) that lead to an indication for ART. Methods: We conducted a retrospective cohort study of men with cT1-4 Nx/0 Mx/0 prostate adenocarcinoma in the National Cancer Database who underwent RP. Race was divided into 3 groups (Caucasian, Black, Other). Chi-square tests and analysis of variance (ANOVA) tests were used to compare clinical and socioeconomic covariates between race groups. Univariate (UVA) and multivariable analysis (MVA) were performed using logistic regression (LR) to identify covariates predicting for APF. LR was performed to identify the impact of race on pT3 disease and positive margins. Results: A total of 313,013 patients diagnosed between 2004-2014 and undergoing RP were included. 256,315 (85%) were Caucasian, 33,725 (11%) were Black, and 12,973 (4%) were Other race. Fewer Black men had Gleason group 1 (33% vs. 41%) but more had Gleason group 2 disease (46% vs. 38%, p < 0.001). Black men more frequently had PSA ≥10 ng/ml (18% vs. 16%, p < 0.001) and ≥cT2b disease (18% vs. 14%, p < 0.001). On UVA, Black men were more likely to have APF (Odds Ratio [OR] 1.18; 95% Confidence Interval [CI] 1.15-1.21; [p < 0.001]). On MVA, black race was independently associated with having APF (OR 1.21; 95% CI 1.18-1.24; p < 0.001). Black men were more likely to have positive margins (OR 1.26; 95% CI 1.22-1.29; p < 0.001) but less likely to have ≥pT3 disease (OR 0.77; 95% CI 0.74-0.79; p < 0.001). Conclusions: Independent of socioeconomic and clinical factors, Black men undergoing RP are more likely to have APF, increasing the risk of BR in this group, and more frequently creating an indication for ART. This appears to be more due to positive margins than locally advanced tumor. The underlying cause of this disparity warrants further exploration.

Template-based matching algorithms are currently being considered for markerless motion tracking of lung tumors. These algorithms use tumor templates derived from the planning CT scan, and track the motion of the tumor on single energy fluoroscopic images obtained at the time of treatment. In cases where bone may obstruct the view of the tumor, dual energy fluoroscopy may be used to enhance soft tissue contrast. The goal of this study is to predict which tumors will have a high degree of accuracy for markerless motion tracking based on radiomic features obtained from the planning CT scan, using peak-to-sidelobe ratio (PSR) as a surrogate of tracking accuracy. In this study, CT imaging data of 8 lung cancer patients were obtained and analyzed through the open source IBEX program to generate 2,287 radiomic features. Agglomerative hierarchical clustering was used to narrow down these features into 145 clusters comprised of the highest correlation to PSR. The features among the clusters with the least inter-correlation were then chosen to limit redundancy in the data. The results of this study demonstrated a number of radiomic features that are positively correlated to PSR. The features with the highest degree of correlation included complexity, orientation and range. This approach may be used to determine patients for whom markerless motion tracking would be beneficial.

Purpose: Bladder-preserving curative radiation therapy (RT) has been established as an excellent treatment option for select patients with muscle-invasive bladder cancer (MIBC). However, some clinicians have concerns that good outcomes are only achievable at high-volume facilities (HVFs) and academic centers (ACs), questioning successful reproducibility of curative RT at smaller centers. This study sought to determine whether treatment at ACs or HVFs was associated with better overall survival (OS) than treatment at nonacademic centers or lower-volume facilities. Methods and Materials: We performed a retrospective cohort study of National Cancer Database patients (nZ2763) with cT2 to cT4 N0 M0 transitional cell MIBC who received curative RT (60-70 Gy) with or without concurrent chemotherapy. Cox proportional hazards models were used to estimate the instantaneous hazard of death as a function of univariate and multivariate patient characteristics and clinical measures. Results: Univariate analysis showed that academic facility type was significantly associated with improved OS (hazard ratio [HR], 0.88; 95% confidence interval [CI] 0.79-0.98; P = .02) whereas higher case volume was not associated with improved survival (HR, 0.97; 95% CI 0.92-1.01; P = .15). Multivariate analysis showed no differences in OS for treatment at ACs versus nonacademic centers (HR, 0.94; 95% CI 0.84-1.06; P = .31) or HVFs versus lower-volume facilities (HR, 0.99; 95% CI 0.94-1.04; P = .60). The 2-year OS rate was 54.5% (95% CI 52.5%-56.4%), and the 5-year OS rate was 54.5% (95% CI 52.5%-56.4%), and the 5-year OS rate was 28.9% (95% CI 27.0%-30.8%). Conclusions: Although some providers are cautious about offering curative RT at all centers, this large hospital-based study suggests that facility type and volume are not significantly associated with OS for patients undergoing curative RT after we account for other clinically relevant risk factors. The results of this study demonstrate that curative RT in the treatment of MIBC may be considered for patients regardless of facility type or volume. (C) 2017 Elsevier Inc. All rights reserved.