Faculty Bibliography

PURPOSE/OBJECTIVE:Historically, toxicity concerns have existed in patients with large prostate glands treated with radiation therapy, particularly brachytherapy. There are questions whether this risk extends to stereotactic body radiation therapy (SBRT). In this retrospective review, we examine clinical outcomes of patients with prostate glands ≥100 cc treated curatively with SBRT. METHODS AND MATERIALS/METHODS:We retrospectively analyzed a large institutional database to identify patients with histologically confirmed localized prostate cancer in glands ≥100 cc, who were treated with definitive-robotic SBRT. Prostate volume (PV) was determined by treatment planning magnetic resonance imaging. Toxicity was measured using Common Terminology Criteria for Adverse Events, version 5.0. Many patients received the Expanded Prostate Cancer Index Composite Quality of Life questionnaires. Minimum follow-up (FU) was 2 years. RESULTS:Seventy-one patients were identified with PV ≥100 cc. Most had grade group (GG) 1 or 2 (41% and 37%, respectively) disease. All patients received a total dose of 3500 to 3625 cGy in 5 fractions. A minority (27%) received androgen deprivation therapy (ADT), which was used for gland size downsizing in only 10% of cases. Nearly half (45%) were taking GU medications for urinary dysfunction before RT. Median toxicity FU was 4.0 years. Two-year rates of grade 1+ genitourinary (GU), grade 1+ gastrointestinal (GI), and grade 2+ GU toxicity were 43.5%, 15.9%, and 30.4%, respectively. Total grade 3 GU toxicities were very limited (2.8%). There were no grade 3 GI toxicities. On logistic regression analysis, pretreatment use of GU medications was significantly associated with increased rate of grade 2+ GU toxicity (odds ratio, 3.19; P = .024). Furthermore, PV (analyzed as a continuous variable) did not have an effect on toxicity, quality of life, or oncologic outcomes. CONCLUSIONS:With early FU, ultra large prostate glands do not portend increased risk of high-grade toxicity after SBRT but likely carry an elevated risk of low-grade GU toxicity.

PURPOSE/OBJECTIVE:Locoregionally recurrent head and neck cancer is a complex clinical scenario that often requires multimodality treatment. These patients have often previously received definitive treatment with a combination of surgery, radiation therapy, and systemic therapy, which can make further management difficult. A second isolated locoregional failure is rare and clinicians are faced with a challenge to optimize disease control while minimizing treatment-related toxicity. METHODS AND MATERIALS/METHODS:In this report, we present the diagnosis, management, and outcomes of a patient with an isolated locoregional recurrence who was previously treated with two courses of radiation. The patient was treated with a second course of reirradiation using interstitial brachytherapy as well as a discussion regarding patient selection and optimal management for recurrent head and neck cancer. RESULTS:Repeat reirradiation using interstitial HDR-brachytherapy with the use of an alloderm spacer was successfully delivered to the patient for an in-field right neck nodal recurrence. He received a total EQD2/BED dose of 127.70/153.24 Gy. At 1-year followup, the patient was without evidence of recurrent disease or new significant side effects. CONCLUSION/CONCLUSIONS:Recurrent head and neck cancer should be managed with a multidisciplinary approach given the complex clinical scenario. Reirradiation is a commonly used salvage measure for recurrent head and neck cancer that requires careful planning and patient selection due to prior treatment-related effects and dose constraints. We reported a case of a second course of reirradiation using interstitial HDR-brachytherapy for locoregionally recurrent head and neck cancer and showed no recurrence of disease or worsening long term side effects at 1 year.

OBJECTIVE:The purpose of this study is to compare oncologic and functional outcomes of men with unilateral, localized PCa treated with stereotactic body radiotherapy (SBRT) versus focal cryoablation (FC). METHODS:Patients from our IRB-approved PCa database who underwent FC or SBRT and were eligible for both treatments were included. Patients with less than 1 year of follow-up or prior PCa treatment were excluded. The primary outcome was treatment failure, defined as salvage treatment or a Gleason group (GG) of ≥ 2 on post-treatment biopsy. Biochemical recurrence (BCR) was evaluated with Phoenix. Functional outcomes were based on EPIC surveys. Complications were categorized with the CTCAE 5.0. Outcomes were compared using descriptive statistics, univariate analyses, and Kaplan-Meier curve for failure-free survival (FFS) and BCR-free survival. P < 0.05 was significant. RESULTS:68 FC and 51 SBRT patients with a median age of 68 years (48-86) and a median follow-up time of 84 (70-101) months were included in this analysis. There was no difference in tumor risk (p = 0.47), GG (p = 0.20), or PSA (p = 0.70) among the two cohorts at baseline. At 7-year follow-up, no difference in FFS was found between the two cohorts (p = 0.70); however, significantly more FC patients had BCR (p < 0.001). At 48 months, no differences existed in urinary or bowel function; however, SBRT patients had significantly worse sexual function (p = 0.032). CONCLUSION/CONCLUSIONS:FC and SBRT are associated with similar oncologic and functional outcomes 7-year post-treatment. These results underscore the utility of FC and SBRT for the management of unilateral low-to-intermediate-risk PCa.

OBJECTIVE:To review quality-of-life (QoL) metrics between patients who underwent definitive stereotactic body radiotherapy (SBRT) versus active surveillance (AS) for management of low- to intermediate-risk prostate cancer (PCa). METHODS:A prospectively maintained PCa database was reviewed containing results of patient-reported QoL surveys. Patients with localized disease who chose AS or SBRT and completed at least one survey within four years of treatment were included. Patients who received salvage therapy were excluded. Survey results were compared across time using mixed-effects repeated measures analysis of covariance models that adjusted for factors significant in univariate analysis. A group x time interaction effect was examined to compare rate of change over time between AS and SBRT. P < 0.05 was significant. RESULTS:148 AS and 161 SBRT patients were included. Significantly more SBRT patients had intermediate-risk disease (p < 0.0001). AS had significantly worse sexual function compared to SBRT across time. While not significant, bowel function scores were lower for SBRT patients across time points. SBRT patients had significantly lower anxiety than AS patients at 24 months (p < 0.011) and 36 months (p < 0.010). Urinary function though worse in SBRT patients at 12 months in EPIC, was not significantly different in both groups across time points. CONCLUSION/CONCLUSIONS:SBRT patients have excellent QoL compared to AS with regard to anxiety post treatment. Though SBRT patients initially have worse urinary and bowel function than AS, scores were eventually similar in both cohorts by 48 months. SBRT patients have significantly worse sexual function post treatment. This study may help facilitate counseling in patients choosing PCa treatment.

PURPOSE/OBJECTIVES/OBJECTIVE:We report on our early experience of our prospective multi-center phase I dose escalation study of single fraction stereotactic partial breast irradiation (S-PBI) for early stage breast cancer after partial mastectomy using a robotic stereotactic radiation system. MATERIALS/METHODS/METHODS:Thirty women with in situ or invasive breast cancer stage 0, I, or II with tumor size < 3 cm, treated with lumpectomy were enrolled to this phase 1 single fraction S-PBI dose escalation trial. Women received either 22.5 Gy, 26.5Gy, or 30 Gy in a single fraction using a robotic stereotactic radiation system.  The primary outcome was to reach tumoricidal dose of 30Gy in single fraction to the lumpectomy cavity without exceeding the maximum tolerated dose (MTD). Secondary outcomes were to determine dose-limiting toxicity (DLT) and cosmesis.  Tertiary goals were ipsilateral breast recurrence rate, distant disease-free interval, recurrence-free survival, and overall survival. RESULTS:From 6/2016 to 1/2021, 11, 8, and 10 patients were treated to doses of 22.5Gy, 26.5Gy, or 30Gy in a single fraction, respectively, with median follow-up being 47.9, 25.1, and 16.2 months. No patients experienced acute (<90 days) grade 3 or higher treatment-related toxicity and MTD was not reached. There were two delayed grade 3 toxicities. Four patients (13.8%) developed fat necrosis across all three cohorts, which compares favorably with results from other PBI trials. No dose cohort had a statistically significant cosmetic detriment from baseline to 12 months or 24 months follow-up by patient- or physician-reported global cosmetic scores. There were no reports of disease recurrence. CONCLUSION/CONCLUSIONS:This phase 1 trial demonstrates that S-PBI can be used to safely escalate dose to 30Gy in single fraction with low toxicity and without detriment in cosmesis relative to baseline.

BACKGROUND:Historically, IBD has been thought to increase the underlying risk of radiation related toxicity in the treatment of prostate cancer. In the modern era, contemporary radiation planning and delivery may mitigate radiation-related toxicity in this theoretically high-risk cohort. This is the first manuscript to report clinical outcomes for men diagnosed with prostate cancer and underlying IBD curatively treated with stereotactic body radiation therapy (SBRT). METHODS:A large institutional database of patients (n = 4245) treated with SBRT for adenocarcinoma of the prostate was interrogated to identify patients who were diagnosed with underlying IBD prior to treatment. All patients were treated with SBRT over five treatment fractions using a robotic radiosurgical platform and fiducial tracking. Baseline IBD characteristics including IBD subtype, pre-SBRT IBD medications, and EPIC bowel questionnaires were reviewed for the IBD cohort. Acute and late toxicity was evaluated using the CTCAE version 5.0. RESULTS:A total of 31 patients were identified who had underlying IBD prior to SBRT for the curative treatment of prostate cancer. The majority (n = 18) were diagnosed with ulcerative colitis and were being treated with local steroid suppositories for IBD. No biochemical relapses were observed in the IBD cohort with early follow up. High-grade acute and late toxicities were rare (n = 1, grade 3 proctitis) with a median time to any GI toxicity of 22 months. Hemorrhoidal flare was the most common low-grade toxicity observed (n = 3). CONCLUSION/CONCLUSIONS:To date, this is one of the largest groups of patients with IBD treated safely and effectively with radiation for prostate cancer and the only review of patients treated with SBRT. Caution is warranted when delivering therapeutic radiation to patients with IBD, however modern radiation techniques appear to have mitigated the risk of GI side effects.

Background and Purpose: Fiducial marker placement is required in patients undergoing robotic-based Stereotactic Body Radiotherapy (SBRT) or image-guided radiation therapy (IGRT) for prostate cancer. Many patients take antiplatelet or anticoagulant medication due to other medical comorbidities. They are often required to temporarily discontinue these medications prior to invasive medical procedures as they are prone to bleed. Some patients are unable to discontinue therapy due to an elevated risk of thromboembolic events. The purpose of this study is to report this institution's experience placing fiducial markers in prostate cancer patients who are on chronic antiplatelet or anticoagulant medication. Materials and Methods: From August 2015-March 2019 57 patients on chronic antiplatelet or anticoagulation therapy who were not cleared to stop these medications underwent transrectal ultrasound guided (TRUS) fiducial marker placement for SBRT/IGRT. All patients were monitored by a registered nurse during the procedure for prolonged bleeding that required staff to hold pressure to the area with a 4 × 4 gauze until it resolved. All patients were also called the following day to assess for ongoing bleeding events. Treatment planning CT scan confirmed the ideal geometry of the marker placement. Results: All 57 patients on antiplatelet or anticoagulant medication who underwent fiducial marker placement were discharged home the same day of the procedure. Four patients experienced persistent bleeding that required a nurse to hold prolonged pressure to the area. No patient experienced significant bleeding the following day or any untoward cardiovascular event. Conclusions: This series suggests the use of antiplatelet or anticoagulant medication is not an absolute contraindication to fiducial marker placement in patients undergoing SBRT or IGRT for prostate cancer. These patients should be closely monitored after the procedure for bleeding complications. Practitioners may consider the patient's medical comorbidities, risk factors for thromboembolism, and overall functional status as there is no standardized protocol for discontinuing anticoagulant or antiplatelet therapy for fiducial marker placement.