Disease and toxicity outcomes for a modern cohort of patients with squamous cell carcinoma of cutaneous origin involving the parotid gland: Comparison of volumetric modulated arc therapy and pencil beam scanning proton therapy.

OBJECTIVES: We sought to describe outcomes for locally advanced cutaneous squamous cell carcinoma (SCC) involving the parotid treated with volumetric modulated arc therapy (VMAT) versus pencil beam scanning proton beam therapy (PBT). MATERIALS AND METHODS: Patients were gathered from 2016 to 2022 from 5 sites of a large academic RT department; included patients were treated with RT and had parotid involvement by: direct extension of a cutaneous primary, parotid regional spread from a previously or contemporaneously resected but geographically separate cutaneous primary, or else primary parotid SCC (with a cutaneous primary ostensibly occult). Acute toxicities were provider-reported (CTCAE v5.0) and graded at each on treatment visit. Statistical analyses were conducted. RESULTS: Median follow-up was 12.9 months (1.3 - 72.8); 67 patients were included. Positive margins/extranodal extension were present in 34 cases; gross disease in 17. RT types: 39 (58.2 %) VMAT and 28 (41.8 %) PBT. Concurrent systemic therapy was delivered in 10 (14.9 %) patients. There were 17 treatment failures (25.4 %), median time of 168 days. Pathologically positive neck nodes were associated with locoregional recurrence (p = 0.015). Oral cavity, pharyngeal constrictor, and contralateral parotid doses were all significantly lower for PBT. Median weight change was -3.8 kg (-14.1 - 5.1) for VMAT and -3 kg (-16.8 - 3) for PBT (p = 0.013). Lower rates of ≥ grade 1 xerostomia (p = 0.002) and ≥ grade 1 dysguesia (p < 0.001) were demonstrated with PBT. CONCLUSIONS: Cutaneous SCC involving the parotid can be an aggressive clinical entity despite modern multimodal therapy. PBT offers significantly lower dose to organs at risk compared to VMAT, which seemingly yields diminished acute toxicities.

A Longitudinal Metagenomic Comparative Analysis of Oral Microbiome Shifts in Patients Receiving Proton Radiation versus Photon Radiation for Head and Neck Cancer.

Introduction: Due to the radiation-sparing effects on salivary gland acini, changes in the composition of the oral microbiome may be a driver for improved outcomes in patients receiving proton radiation, with potentially worse outcomes in patients exposed to photon radiation therapy. To date, a head-to-head comparison of oral microbiome changes at a metagenomic level with longitudinal sampling has yet to be performed in these patient cohorts. Methods and Materials: To comparatively analyze oral microbiome shifts during head and neck radiation therapy, a prospective pilot cohort study was performed at the Maryland Proton Treatment Center and the University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center. A longitudinal metagenomic comparative analysis of oral microbiome shifts was performed at three time points (pre-radiation, during radiation, and immediately post-radiation). Head and neck cancer patients receiving proton radiation (n = 4) were compared to photon radiation (n = 4). Additional control groups included healthy age- and sex-matched controls (n = 5), head and neck cancer patients who never received radiation therapy (n = 8), and patients with oral inflammatory disease (n = 3). Results: Photon therapy patients presented with lower microbial alpha diversity at all timepoints, and there was a trend towards reduced species richness as compared with proton therapy. Healthy controls and proton patients exhibited overall higher and similar diversity. A more dysbiotic state was observed in patients receiving photon therapy as compared to proton therapy, in which oral microbial homeostasis was maintained. Mucositis was observed in 3/4 photon patients and was not observed in any proton patients during radiation therapy. The bacterial de novo pyrimidine biosynthesis pathway and the nitrate reduction V pathway were comparatively higher following photon exposure. These functional changes in bacterial metabolism may suggest that photon exposure produces a more permissive environment for the proliferation of pathogenic bacteria. Conclusion: Oral microbiome dysbiosis in patients receiving photon radiation may be associated with increased mucositis occurrence. Proton radiation therapy for head and neck cancer demonstrates a safer side effect profile in terms of oral complications, oral microbiome dysbiosis, and functional metabolic status.

Is noncoplanar plan more robust to inter-fractional variations than coplanar plan in treating bilateral HN tumors with pencil-beam scanning proton beams?

PURPOSE: Noncoplanar plans (NCPs) are commonly used for proton treatment of bilateral head and neck (HN) malignancies. NCP requires additional verification setup imaging between beams to correct residual errors of robotic couch motion, which increases imaging dose and total treatment time. This study compared the quality and robustness of NCPs with those of coplanar plans (CPs). METHODS AND MATERIALS: Under an IRB-approved study, CPs were created retrospectively for 10 bilateral HN patients previously treated with NCPs maintaining identical beam geometry of the original plan but excluding couch rotations. Plan robustness to the inter-fractional variation (IV) of both plans was evaluated through the Dose Volume Histograms (DVH) of weekly quality assurance CT (QACT) sets (39 total). In addition, delivery efficiency for both plans was compared using total treatment time (TTT) and beam-on time (BOT). RESULTS: No significant differences in plan quality were observed in terms of clinical target volume (CTV) coverage (D95) or organ-at-risk (OAR) doses (p > 0.4 for all CTVs and OARs). No significant advantage of NCPs in the robustness to IV was found over CP, either. Changes in D95 of QA plans showed a linear correlation (slope = 1.006, R2  > 0.99) between NCP and CP for three CTV data points (CTV1, CTV2, and CTV3) in each QA plan (117 data points for 39 QA plans). NCPs showed significantly higher beam delivery time than CPs for TTT (539 ± 50 vs. 897 ± 142 s; p < 0.001); however, no significant differences were observed for BOT. CONCLUSION: NCPs are not more robust to IV than CPs when treating bilateral HN tumors with pencil-beam scanning proton beams. CPs showed plan quality and robustness similar to NCPs while reduced treatment time (∼6 min). This suggests that CPs may be a more efficient planning technique for bilateral HN cancer proton therapy.

Proton beam stereotactic body radiotherapy and hypofractionated therapy with pencil beam scanning is safe and effective for advanced hepatocellular carcinoma and intrahepatic cholangiocarcinoma: A single center experience.

Background: Proton beam therapy (PBT) is a non-surgical treatment that spares adjacent tissues compared to photon radiation and useful for Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). We present a single center experience in HCC and iCCA treated with Pencil Beam Scanning (PBS) PBT. Methods: Forty-four consecutive patients (22 patients in each group) receiving PBT were included and reviewed. PBT was delivered with hypofractionated or stereotactic body radiation therapy (SBRT) using PBS. Tumor size was approximated by clinical target volume (CTV). Outcomes were evaluated with Kaplan-Meier and liver toxicity was determined by MELD-Na and albumin-bilirubin (ALBI) grade. Results: Median follow up was 38.7 months, fourteen (35%) had multifocal disease and median CTV was 232.5cc. Four (9%) and 40 (91%) patients received SBRT and hypofractionated radiation, respectively. Two year overall survival was statistically higher for HCC (entire group: 68.9% months [95% CI: 61.3 - 76.3%]; iCCA: 49.8% [95% CI: 38.5% - 61.1%]; HCC: 89.4% [95% CI: 82.3 - 96.5%]; P <0.005). There was no statistical difference in progression-free survival or freedom from local failure. Biologically Equivalent Dose (BED) was greater than or equal to 80.5Gy in 37 (84%) patients. All iCCA patients had stable or improved ALBI grade following treatment. ALBI grade was stable in 83% of HCC patients and average MELD-Na score remained stable. Tumor size, pretreatment liver function, and total radiation dose were not associated with liver toxicity. Conclusions: PBT for unresectable HCC and iCCA is safe and effective, even for large and multifocal tumors. Liver function was preserved even in those with baseline cirrhosis in this advanced population with large tumors.

Post-treatment PET/CT for p16-positive oropharynx cancer treated with definitive proton therapy.

Objectives: Given emerging data suggesting that uncertainty in the relative biologic effectiveness at the distal end of the Bragg peak results in increased mucosal injury in patients with oropharynx cancer receiving adjuvant proton therapy, we evaluated the results of post-treatment positron emission tomography-computed tomography (PET/CT) in patients with p16-positive oropharynx cancer (p16+OPC) treated with definitive intensity-modulated proton therapy (IMPT). Material and Methods: A retrospective cohort study of patients with p16+OPC treated with definitive IMPT between 2016 and 2022 was performed at a single institution. Patients with PET/CT scans within 6 months following completion of IMPT were included in the study. Positive post-treatment scans were defined by a maximum standard uptake values (SUVmax) >4.0 or a <65% reduction in SUVmax in either the primary tumor or lymph node. The Fisher's exact test was used to evaluate factors associated with positive post-treatment PET/ CT values. Results: Sixty-two patients were included for analysis. Median follow-up was 21 months (range: 3-71 months) with a median time to post-treatment PET/CT of 3 months (range: 2-6 months). Median post-treatment SUVmax of the primary disease and nodal disease was 0 (mean: 0.8, range: 0-7.7) and 0 (mean: 0.7, range: 0-9.5), respectively. Median post-treatment percent reduction in SUVmax for the primary site and lymph node was 100% (mean: 94%, range: 31.3-100%) and 100% (mean: 89%, range: 23-100%), respectively. Eleven patients had a positive post-treatment PET/CT with one biopsy-proven recurrence. Negative and positive predictive values (NPV and PPV) were 98% and 9.1%, respectively. There were no factors associated with positive post-treatment PET/CT. Conclusion: Similar to patients treated with photon-based radiation therapy, post-treatment PET/CT has a high NPV for patients with p16+OPC treated with definitive proton therapy and should be used to guide patient management. Additional patients and more events are needed to confirm the PPV of a post-treatment PET/CT in this favorable patient cohort.

Conditional Risks of Biochemical Failure and Prostate Cancer-Specific Death in Patients Undergoing External Beam Radiotherapy: A Secondary Analysis of 2 Randomized Clinical Trials.

Importance: As patients achieve years of survival after treatment for prostate cancer, the risk of biochemical failure (BF) or prostate cancer-specific death (PCSD) may evolve over time, with clinical relevance to both patients and clinicians. Objective: To determine conditional BF-free survival, PSCD, and overall survival estimates for patients with low- or intermediate-risk prostate cancer enrolled in the Radiation Therapy Oncology Group (RTOG) 0126 and RTOG 0415 clinical trials. A secondary objective was to determine whether prognostic factors at diagnosis remain relevant at later points in follow-up. Design, Setting, and Participants: A pooled secondary analysis of patients treated with external-beam radiotherapy alone and enrolled in the prospective randomized clinical trials RTOG 0126 and RTOG 0415 was performed. Patients included for analysis were enrolled between March 2002 and December 2009 with a median follow-up of 6.9 years. Overall survival was calculated using the Kaplan-Meier method at various survivorship time points. Cumulative incidence was used to calculate BF rates using the Phoenix definition, as well as PCSD. Risk factors such as Gleason score, tumor (T) stage, prostate-specific antigen level, and the equivalent dose in 2 Gy fractions of prescribed dose were analyzed at different time points using multivariable Cox proportional hazards modeling. Data were analyzed from November 2021 to February 2023. Main Outcomes and Measures: Conditional risks of BF and PCSD after completion of external-beam radiotherapy. Results: A total of 2591 patients (median [IQR] age, 69 [63-73] years) were included in the study with a mean (range) PSA level of 7.1 (4.7-8.9) ng/mL, 1334 patients (51.5%) with a Gleason score 6 disease, and 1706 patients (65.8%) with T1 disease. Rates of BF from time of treatment were 1.63% (95% CI, 1.20%-2.18%) at 1 year, 7.04% (95% CI, 6.09%-8.08%) at 3 years, 12.54% (95% CI, 11.28%-13.88%) at 5 years, and 22.32% (95% CI, 20.46%-24.24%) at 8 years. For patients surviving 1, 3, and 5 years without BF, the rates of BF in the next 5 years were 14.20% (95% CI, 12.80%-15.66%), 17.19% (95% CI, 15.34%-19.14%), and 18.85% (95% CI, 16.21%-21.64%), respectively. At the initial time point, the rate of PCSD in the next 5 years was 0.66% (95% CI, 0.39%-1.04%). For patients who achieved 1, 3, 5, and 8 years of survivorship, the rates of PCSD in the next 5 years were 1.16% (95% CI, 0.77-1.67) at 1 year, 2.42% (95% CI, 1.74%-3.27%) at 3 years, 2.88% (95% CI, 2.01%-3.99%) at 5 years, and 3.49% (95% CI, 0.98%-8.73%) at 8 years. Conclusions and Relevance: In this secondary analysis of 2 randomized clinical trials of patients undergoing external beam radiotherapy for prostate cancer, the conditional risks of BF and death from prostate cancer increased with time for patients with low- and intermediate-risk prostate cancer treated with radiotherapy alone. These results could inform optimal trial design and may be helpful information for patients evaluated in follow-up. Trial Registration: ClinicalTrials.gov Identifier: NCT00033631; NCT00331773.

Regionalization of Head and Neck Oncology Tumor Boards: Perspectives of Collaborating Physicians.

Objectives: To survey academic and community physician preferences regarding the virtual multidisciplinary tumor board (MTB) for further improvement and expansion. Study Design: This anonymous 14-question survey was sent to individuals that participated in the head and neck virtual MTBs. The survey was sent via email beginning August 3, 2021, through October 5, 2021. Setting: The University of Maryland Medical Center and regional practices in the state of Maryland. Methods: Survey responses were recorded and presented as percentages. Subset analysis was performed to obtain frequency distributions by facility and provider type. Results: There were 50 survey responses obtained with a response rate of 56%. Survey participants included 11 surgeons (22%), 19 radiation oncologists (38%), and 8 medical oncologists (16%), amongst others. More than 96% of participants found the virtual MTB to be useful when discussing complex cases and impactful to future patient care. A majority of respondents perceived a reduction in time to adjuvant care (64%). Community and academic physician responses strongly agreed that the virtual MTB improved communication (82% vs 73%), provided patient-specific information for cancer care (82% vs 73%), and improved access to other specialties (66% vs 64%). Academic physicians, more so than community physicians, strongly agreed that the virtual MTB improves access to clinical trial enrollment (64% vs 29%) and can be useful in obtaining CME (64% vs 55%). Conclusion: Academic and community physicians view the virtual MTB favorably. This platform can be adapted regionally and further expanded to improve communication between physicians and improve multidisciplinary care for patients.

Gross tumor volume margin and local control in p16-positive oropharynx cancer patients treated with intensity modulated proton therapy.

BACKGROUND: To determine if the extent of high-dose gross tumor volume (GTV) to clinical target volume (CTV) expansion is associated with local control in patients with p16-positive oropharynx cancer (p16+ OPC) treated with definitive intensity modulated proton therapy (IMPT). METHODS: We performed a retrospective analysis of patients with p16+ OPC treated with IMPT at a single institution between 2016 and 2021. Patients with a pre-treatment PET-CT and restaging PET-CT within 4 months following completion of IMPT were analyzed. RESULTS: Sixty patients were included for analysis with a median follow-up of 17 months. The median GTV to CTV expansion was 5 mm (IQR: 2 mm). Thirty-three percent of patients (20 of 60) did not have a GTV to CTV expansion. There was one local failure within the expansion group (3%). CONCLUSION: Excellent local control was achieved using IMPT for p16+ OPC independent of GTV expansion. IMPT with minimal target expansions represent a potential harm-minimization technique for p16-positive oropharynx cancer.

How many brain metastases can be treated with stereotactic radiosurgery before the radiation dose delivered to normal brain tissue rivals that associated with standard whole brain radiotherapy?

INTRODUCTION: Clinical trial data comparing outcomes after administration of stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT) to patients with brain metastases (BM) suggest that SRS better preserves cognitive function and quality of life without negatively impacting overall survival. Here, we estimate the maximum number of BM that can be treated using single and multi-session SRS while limiting the dose of radiation delivered to normal brain tissue to that associated with WBRT. METHODS: Multiple-tumor SRS was simulated using a Monte Carlo - type approach and a pre-calculated dose kernel method. Tumors with diameters ≤36 mm were randomly placed throughout the contoured brain parenchyma until the brain mean dose reached 3 Gy, equivalent to the radiation dose delivered during a single fraction of a standard course of WBRT (a total dose of 30 Gy in 10 daily fractions of 3 Gy). Distribution of tumor sizes, dose coverage, selectivity, normalization, and maximum dose data used in the simulations were based on institutional clinical metastases data. RESULTS: The mean number of tumors treated, mean volume of healthy brain tissue receiving > 12 Gy (V12) per tumor, and total tumor volume treated using mixed tumor size distributions were 12.7 ± 4.2, 2.2 cc, and 12.9 cc, respectively. Thus, we estimate that treating 12-13 tumors per day over 10 days would deliver the dose of radiation to healthy brain tissue typically associated with a standard course of WBRT. CONCLUSION: Although in clinical practice, treatment with SRS is often limited to patients with ≤15 BM, our findings suggest that many more lesions could be targeted while still minimizing the negative impacts on quality of life and neurocognition often associated with WBRT. Results from this in silico analysis require clinical validation.

Racial Analysis of Clinical and Biochemical Outcomes in Patients With Prostate Cancer Treated With Low-Dose-Rate Brachytherapy.

PURPOSE: Black men in the United States experience significantly higher incidence of and mortality from prostate cancer (PCa) than non-Black men. The cause of this disparity is multifactorial, though inequitable access to curative radiation modalities, including low-dose-rate (LDR) brachytherapy, may contribute. Despite this, there are few analyses evaluating the potential of different radiation therapies to mitigate outcome disparities. Therefore, we examined the clinical outcomes of Black and non-Black patients treated with definitive LDR brachytherapy for PCa. METHODS: Data were collected for all patients treated with definitive LDR brachytherapy between 2005 and 2018 on a retrospective institutional review board approved protocol. Pearson χ2 analysis was used to assess demographic and cancer differences between Black and non-Black cohorts. Freedom from biochemical failure (FFBF) was calculated using Kaplan-Meier analysis. Univariate and multivariate analyses were used to identify factors predictive of biochemical failure. RESULTS: One hundred and sixty-seven patients were included in the analysis (Black: n = 81; 48.5%) with a median follow-up of 88.4 months. Black patients were from lower income communities (P < .01), had greater social vulnerability (P < .01), and had a longer interval between diagnosis and treatment (P = .011). Overall cumulative FFBF was 92.3% (95% confidence interval [CI], 87.8%-96.8%) at 5 years and 87.7% (95% CI, 82.0%-93.4%) at 7 years. There was no significant difference in FFBF in Black and non-Black patients (P = .114) and Black race was not independently predictive of failure (hazard ratio, 1.51; 95% CI, 0.56-4.01; P = .42). Overall survival was comparable between racial groups (P = .972). Only nadir prostate-specific antigen was significantly associated with biochemical failure on multivariate (hazard ratio, 3.57; 95% CI, 02.44-5.22; P < .001). CONCLUSIONS: Black men treated with LDR brachytherapy achieved similar FFBF to their non-Black counterparts despite poorer socioeconomic status. This suggests that PCa treatment with brachytherapy may eliminate some disparities in clinical outcomes.

Functional Imaging of Liver Cancer (FLIC): Study protocol of a phase 2 trial of 18F-DCFPyL PET/CT imaging for patients with hepatocellular carcinoma.

BACKGROUND: While prostate specific membrane antigen (PSMA) is overexpressed in high-grade prostate cancers, it is also expressed in tumor neovasculature and other malignancies, including hepatocellular carcinoma (HCC). Importantly, no functional imaging for HCC is clinically available, making diagnosis and surveillance following local therapies particularly challenging. 18F-DCFPyL binds with high affinity to PSMA yet clears rapidly from the blood pool. PET imaging with 18F-DCFPyL may represent a new tool for staging, surveillance and assessment of treatment response in HCC. The purpose of this Functional Imaging Liver Cancer (FLIC) trial is to assess the ability of 18F-DCFPyL-PET/CT to detect sites of HCC. METHODS: This is a phase II multi-site prospective imaging trial with a plan to enroll 50 subjects with suspected HCC on standard of care CT or MRI and eligible for standard local treatment. Participants will undergo a baseline 18F-DCFPyL-PET/CT, prior to therapy. Subjects will also be scanned with 18F-FDG-PET/CT within 2 weeks of 18F-DCFPyL-PET/CT. Participants will undergo histopathologic assessment and standard of care local treatment for HCC within a multidisciplinary team context. Participants with histopathologic confirmation of HCC and a positive baseline 18F-DCFPyL-PET/CT will undergo a post-treatment 18F-DCFPyL-PET/CT during the first routine follow-up, typically within 4-8 weeks. Subjects with negative baseline 18F-DCFPyL-PET/CT will not be re-scanned after treatment but will remain in follow-up. Participants will be followed for 5-years to assess for progression-free-survival. The primary endpoint is the positive predictive value of 18F-DCFPyL-PET for HCC as confirmed by histopathology. Secondary endpoints include comparison of 18F-DCFPyL-PET/CT with CT, MRI, and 18F-FDG-PET/CT, and evaluation of the value of 18F-DCFPyL-PET/CT in assessing treatment response following local treatment. Exploratory endpoints include next generation sequencing of tumors, and analysis of extracellular vesicles to identify biomarkers associated with response to therapy. DISCUSSION: This is a prospective imaging trial designed to evaluate whether PSMA-PET/CT imaging with 18F-DCFPyL can detect tumor sites, assess local treatment response in HCC patients, and to eventually determine whether PSMA-PET/CT could improve outcomes of patients with HCC receiving standard of care local therapy. Importantly, this trial may help determine whether PSMA-selective radiopharmaceutical therapies may be beneficial for patients with HCC. CLINICAL TRIAL REGISTRATION: NIH IND#133631. Submission date: 04-07-2021. Safe-to-proceed letter issued by FDA: 05.07.2021. NIH IRB #00080. ClinicalTrials.gov Identifier NCT05009979. Date of Registry: 08-18-2021. Protocol version date: 01-07-2022.

Evaluation of intrafraction couch shifts for proton treatment delivery in head-and-neck cancer patients: Toward optimal imaging frequency.

PURPOSE: Treatment planning for head-and-neck (H&N) cancer, in particular oropharynx, nasopharynx, and paranasal sinus cases, at our center requires noncoplanar proton beams due to the complexity of the anatomy and target location. Targeting accuracy for all beams is carefully evaluated by using image guidance before delivering proton beam therapy (PBT). In this study, we analyzed couch shifts to evaluate whether imaging is required before delivering each field with different couch angles. METHODS: After the Institutional Review Board approval, a retrospective analysis was performed on data from 28 H&N patients treated with PBT. Each plan was made with two-to-three noncoplanar and two-to-three coplanar fields. Cone-beam computed tomography and orthogonal kilovoltage (kV) images were acquired for setup and before delivering each field, respectively. The Cartesian (longitudinal, vertical, and lateral) and angular (pitch and roll) shifts for each field were recorded from the treatment summary on the first two fractions and every subsequent fifth fraction. A net magnitude of the three-dimensional (3D) shift in Cartesian coordinates was calculated, and a 3D vector was created from the 6 degrees of freedom coordinates for transforming couch shifts in the system coordinate to the beam's-eye view. RESULTS: A total of 3219 Cartesian and 2146 angular shift values were recorded for 28 patients. Of the Cartesian shifts, 2069 were zero (64.3%), and 1150 (35.7%) were nonzero (range, -7 to 11 mm). Of the angular shifts, 1034 (48.2%) were zero, and 1112 (51.8%) were nonzero (range, -3.0° to 3.2°). For 17 patients, the couch shifts increased toward the end of the treatment course. We also found that patients with higher body mass index (BMI) presented increased net couch shifts (p < 0.001). With BMI < 27, all overall net shift averages were <2 mm, and overall maximum net shifts were <6 mm. CONCLUSIONS: These results confirm the need for orthogonal kV imaging before delivering each field of H&N PBT at our center, where a couch rotation is involved.

Genomic biomarkers to guide precision radiotherapy in prostate cancer.

Our ability to prognosticate the clinical course of patients with cancer has historically been limited to clinical, histopathological, and radiographic features. It has long been clear however, that these data alone do not adequately capture the heterogeneity and breadth of disease trajectories experienced by patients. The advent of efficient genomic sequencing has led to a revolution in cancer care as we try to understand and personalize treatment specific to patient clinico-genomic phenotypes. Within prostate cancer, emerging evidence suggests that tumor genomics (e.g., DNA, RNA, and epigenetics) can be utilized to inform clinical decision making. In addition to providing discriminatory information about prognosis, it is likely tumor genomics also hold a key in predicting response to oncologic therapies which could be used to further tailor treatment recommendations. Herein we review select literature surrounding the use of tumor genomics within the management of prostate cancer, specifically leaning toward analytically validated and clinically tested genomic biomarkers utilized in radiotherapy and/or adjunctive therapies given with radiotherapy.

Radiation Therapy and Malignant Fistulae of Anorectal Cancers.

PURPOSE: Although fistulization is a well-studied late toxic effect of radiation therapy (RT), anorectal cancers (ARCs) can present with malignant fistulae (MF) and negatively affect quality of life. The effect of RT, often combined with concurrent chemotherapy, on MF needs systematic analysis, because practitioners are concerned that RT may exacerbate MF. We reviewed our institutional series evaluating the hypothesis that RT worsens MF. METHODS AND MATERIALS: A single-institutional retrospective analysis of patients with ARC receiving RT from 2006 to 2019 was performed. These patients were screened for MF. Any MF resected before RT and RT not directed at the site of MF were excluded. Effects were assessed by review of available follow-up documentation and imaging. RESULTS: A total of 639 patients with ARC were reviewed, and 47 had MF (7.4%). With a median follow-up of 22 months (range, 2-133 months), RT improved MF in 17 of 29 evaluable patients (59%), with 9 of 29 (31.0%) having resolution. The median time to improvement was 50 days (range, 25-117 days); the median duration of improvement was 161 days (range, 0-1941 days). Malignant fistulae persisted in 12 of 29 patients (41%), with persistent local disease in all cases; in 2 cases, MF worsened concomitant with local progression. CONCLUSIONS: In all, 7.4% of patients with ARC presented with MF. Radiation therapy led to improvement or resolution in more than half of evaluable patients. Persistence or worsening of MF was only observed in patients with refractory or progressive local disease. Based on our findings, MF is not a contraindication to RT and may be considered as an independent indication for palliative RT.

Administering Docetaxel for Metastatic Hormone-Sensitive Prostate Cancer 1-6 Days Compared to More Than 14 Days after the Start of LHRH Agonist Is Associated with Better Clinical Outcomes Due to Androgen Flare.

Docetaxel, when given at the beginning of androgen deprivation therapy (ADT) for patients with metastatic hormone-sensitive prostate cancer (MHSPC), results in significantly longer overall survival than ADT alone. We aimed to investigate if the delivery of the first dose of docetaxel during the testosterone flare associated with LHRH initiation results in better clinical outcomes, as testosterone induces mitosis of prostate cancer cells, and docetaxel specifically targets cells in mitosis. We analyzed data from the CHAARTED trial which randomized MHSPC patients to ADT alone or ADT plus docetaxel. We included only patients treated with LHRH agonist and docetaxel (n = 379). The only cutoff that resulted in differences in treatment outcomes was between patients who started docetaxel 1-6 days (n = 18) compared to more than 14 days from LHRH initiation (n = 297). Actuarial median overall survival was 72 versus 57 months (p = 0.2); progression-free survival was 49 versus 17 months (p = 0.06), and freedom from castrate-resistant prostate cancer was 51 versus 18 months (p = 0.04) for patients who started docetaxel 1-6 days compared to more than 14 days from LHRH initiation, respectively. Administering docetaxel 1-6 days from the initiation of LHRH agonist for patients with MHSPC could be associated with improved clinical outcomes.

Impact of the Novel Coronavirus 2019 (COVID-19) Pandemic on Head and Neck Cancer Care.

OBJECTIVE: The study aimed to assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on head and neck oncologic care at a tertiary care facility. STUDY DESIGN: This was a cross-sectional study conducted between March 18, 2020, and May 20, 2020. The primary planned outcome was the rate of treatment modifications during the study period. Secondary outcome measures were tumor conference volume, operative volume, and outpatient patient procedure and clinic volumes. SETTING: This single-center study was conducted at a tertiary care academic hospital in a large metropolitan area. METHODS: The study included a consecutive sample of adult subjects who were presented at a head and neck interdepartmental tumor conference during the study period. Patients were compared to historical controls based on review of operative data, outpatient procedures, and clinic volumes. RESULTS: In total, 117 patients were presented during the review period in 2020, compared to 69 in 2019. There was an 8.4% treatment modification rate among cases presented at the tumor conference. There was a 61.3% (347 from 898) reduction in outpatient clinic visits and a 63.4% (84 from 230) reduction in procedural volume compared to the prior year. Similarly, the operative volume decreased by 27.0% (224 from 307) compared to the previous year. CONCLUSION: Restrictions related to the COVID-19 pandemic resulted in limited treatment modifications. Transition to virtual tumor board format observed an increase in case presentations. While there were reductions in operative volume, there was a larger proportion of surgical cases for malignancy, reflecting the prioritization of oncologic care during the pandemic.

Executive Summary of Clinical and Technical Guidelines for Esophageal Cancer Proton Beam Therapy From the Particle Therapy Co-Operative Group Thoracic and Gastrointestinal Subcommittees.

Radiation therapy (RT) is an integral component of potentially curative management of esophageal cancer (EC). However, RT can cause significant acute and late morbidity due to excess radiation exposure to nearby critical organs, especially the heart and lungs. Sparing these organs from both low and high radiation dose has been demonstrated to achieve clinically meaningful reductions in toxicity and may improve long-term survival. Accruing dosimetry and clinical evidence support the consideration of proton beam therapy (PBT) for the management of EC. There are critical treatment planning and delivery uncertainties that should be considered when treating EC with PBT, especially as there may be substantial motion-related interplay effects. The Particle Therapy Co-operative Group Thoracic and Gastrointestinal Subcommittees jointly developed guidelines regarding patient selection, treatment planning, clinical trials, and future directions of PBT for EC.

High-risk, recurrent and oligometastatic prostate cancer: recent developments on the role of radiation.

PURPOSE OF REVIEW: Although a standard of care in the treatment of organ-confined prostate cancer, use of radiation for treatment in the high-risk, metastatic and salvage settings is evolving rapidly. RECENT FINDINGS: Recent clinical trials have explored the role of increased treatment for high-risk disease with the addition of adjuvant chemotherapy and expanded the role of radiation in settings previously reserved for systemic therapy. Addition of adjuvant chemotherapy for high-risk prostate cancer is controversial and recent evidence is discussed that continues to refine the patient population for further evaluation. Evidence recently published demonstrates that for patients with low burden metastatic disease and those with oligometastatic disease may have a survival benefit with radiation treatment to all sites of known disease. Finally, reirradiation after prior radiotherapy-based treatment offers a potential salvage option for patients with locally recurrent prostate cancer. SUMMARY: As treatment paradigms evolve for prostate cancer, recent evidence continues to demonstrate benefit for the use of local therapy, both in patients with organ-confined disease and, more increasingly, in those with limited metastatic or locally recurrent disease. Further work is needed to identify subgroups of patients who may benefit from available treatment escalation approaches.

Selection of Mediastinal Lymphoma Patients for Proton Therapy Within the Proton Collaborative Group Registry: Concordance With the ILROG Guidelines.

PURPOSE: As patients with mediastinal lymphoma are typically young with curable disease, advanced radiation techniques such as proton therapy are often considered to minimize subacute and late toxicity. However, it is unclear which mediastinal lymphoma patients are treated with proton therapy. Within a prospective, multi-institutional proton registry, we characterized mediastinal lymphoma patients treated with proton therapy and assessed concordance with consensus recommendations published in 2018 by the International Lymphoma Radiation Oncology Group (ILROG). METHODS: Eligible patients included those with lymphoma of the mediastinum treated exclusively with proton therapy for whom digital imaging and communications in medicine (DICOM) treatment data were available for review. Given the challenge with reliably visualizing the left mainstem coronary artery, the inferior-most aspect of the left pulmonary artery (PA) was used as a surrogate. Extent of disease was characterized as upper mediastinum (above level of left PA), middle mediastinum (below left PA but at or above level of T8), or low mediastinum (below T8). RESULTS: Between November 2012 and April 2019, 56 patients were treated and met inclusion criteria. Patients treated with proton therapy were young (median, 24 y; range: 12 to 88), with over half being female (55%). Patients were most commonly treated at initial diagnosis (86%) and had Hodgkin lymphoma (79%). Most patients (96%) had mediastinal disease that extended down to the level of the heart: 48% had middle and 48% had low mediastinal involvement. Nearly all patients (96%) met the ILROG consensus recommendations: 95% had lower mediastinal disease, 46% were young females, and 9% were heavily pretreated. Heart (mean) and lung dose (mean, V5, V20) were significantly associated with lowest extent of mediastinal disease. CONCLUSIONS: Mediastinal lymphoma patients treated with proton therapy are typically young with lower mediastinal involvement. Within a prospective, multi-institutional proton registry, nearly all treated patients fit the ILROG consensus recommendations regarding which mediastinal lymphoma patients may most benefit from proton therapy.