Faculty Bibliography

Purpose/UNASSIGNED:Whole gland cryoablation is a guideline-approved definitive treatment for localized prostate cancer, and is being explored for partial gland ablation. However, there is limited data regarding management of cryoablation failures. Stereotactic body radiation therapy (SBRT) is a well-established method of primary treatment for prostate cancer. Here we review salvage SBRT after cryoablation failures. Methods and Materials/UNASSIGNED:A large database of patients treated with definitive SBRT was interrogated to identify those who underwent primary cryoablation. All patients were determined to have progressive disease based on a rising prostate specific antigen and/or postcryoablation biopsy. All patients were treated with SBRT over 5 treatment fractions using a robotic radiosurgical platform. Baseline cryoablation characteristics and pre- and posttreatment Expanded Prostate Cancer Index Composite questionnaires were analyzed. Acute and late toxicity was evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0. Cancer outcomes after salvage SBRT were stratified by disease and treatment characteristics. Results/UNASSIGNED:A total of 51 patients were identified who underwent cryoablation followed by salvage SBRT. The majority (47%) were found to have intermediate-risk disease at the time of SBRT salvage and most commonly were treated with 3500 cGy in 5 fractions to the prostate and seminal vesicles. Only 1 grade 3+ toxicity was identified. Patient-reported quality of life metrics after SBRT salvage followed prior patterns observed in the de novo SBRT setting. With a median follow-up of 40 months, 76% of the cohort demonstrated disease control. Median time to prostate cancer recurrence was 57.5 months, and recurrence was predominantly seen in patients with underlying high-risk disease. Conclusions/UNASSIGNED:This is the largest cohort of patients treated with any radiation therapy salvage after cryoablation and the first institution to report SBRT as a modality of salvage. Salvage SBRT after cryoablation results in low rates of high-grade toxicity, acceptable changes in patient-reported quality of life, and durable rates of long-term oncologic control.

BACKGROUND:The use of treatment planning prostate MRI for Stereotactic Body Radiation Therapy (SBRT) is largely a standard, yet not all patients can receive MRI for a variety of clinical reasons. Thus, we aim to investigate the safety of patients who received CT alone based SBRT planning for the definitive treatment of localized prostate cancer. METHODS:Our study analyzed 3410 patients with localized prostate cancer who were treated with SBRT at a single academic institution between 2006 and 2020. Acute and late toxicity was evaluated using the Common Terminology Criteria for Adverse Events version 5.0. Expanded Prostate Cancer Index Composite (EPIC) questionnaires evaluated QOL and PSA nadir was evaluated to detect biochemical failures. RESULTS:A total of 162 patients (4.75%) received CT alone for treatment planning. The CT alone group was older relative to the MRI group (69.9 vs 67.2, p < 0.001) and had higher risk and grade disease (p < 0.001). Additionally, the CT group exhibited a trend in larger CTVs (82.56 cc vs 76.90 cc; p = 0.055), lower total radiation doses (p = 0.048), and more frequent pelvic nodal radiation versus the MRI group (p < 0.001). There were only two reported cases of Grade 3 + toxicity within the CT alone group. Quality of life data within the CT alone group revealed declines in urinary and bowel scores at one month with return to baseline at subsequent follow up. Early biochemical failure data at median time of 2.3 years revealed five failures by Phoenix definition. CONCLUSIONS:While clinical differences existed between the MRI and CT alone group, we observed tolerable toxicity profiles in the CT alone cohort, which was further supported by EPIC questionnaire data. The overall clinical outcomes appear comparable in patients unable to receive MRI for their SBRT treatment plan with early clinical follow up.

INTRODUCTION/BACKGROUND:Stereotactic radiosurgery is a well-established treatment option in the management of brain metastases. Multiple prognostic scores for prediction of survival following radiotherapy exist, but are not disease-specific or validated for radiosurgery in women with primary pelvic gynecologic malignancies metastatic to the brain. The aim of the present study is to evaluate the feasibility, safety, outcomes, and impact of established prognostic scores. METHODS:We retrospectively identified 52 patients treated with radiotherapy for brain metastases between 2008 and 2021. Stereotactic radiosurgery was utilized in 31 patients for an overall number of 75 lesions; the remaining 21 patients received whole-brain radiotherapy. Kaplan-Meier survival analysis and the log-rank test were used to calculate and compare survival curves and univariate and multivariate Cox regression to assess the influence of cofactors on recurrence, local control, and prognosis. RESULTS:With a median follow-up of 10.7 months, overall survival rates post radiosurgery were 65.3%, 51.3%, and 27.7% for 1, 2, and 5 years, respectively, which were significantly higher than post whole-brain radiotherapy (p=0.049). Five local failures (6.7%) were detected, resulting in 1 and 2 year local cerebral control rates of 97.4% and 94.0%, respectively. Univariate factors for prediction of superior overall survival were high performance status (p=0.030) and application of three prognostic scores, especially the Recursive Partitioning Analysis score (p=0.028). Uni- and multivariate analysis revealed that extracranial progression prior to radiosurgery was significant for inferior overall survival (p<0.0001). Radionecrosis was diagnosed in five women (16%); long-term neurotoxicity was significantly worse after whole-brain radiotherapy compared with radiosurgery (p=0.023). CONCLUSION/CONCLUSIONS:Stereotactic radiosurgery for brain metastases from pelvic gynecologic malignancies appears to be safe and well tolerated, achieving promising local cerebral control. Prognostic scores were shown to be transferable and radiosurgery should be recommended as primary intracranial treatment, especially in women with no prior extracranial progression and Recursive Partitioning Analysis class I.

Purpose/UNASSIGNED:Proton beam radiotherapy (PBT) has been used for the definitive treatment of localized prostate cancer with low rates of high-grade toxicity and excellent patient-reported quality-of-life metrics. Technological advances such as pencil beam scanning (PBS), Monte Carlo dose calculations, and polyethylene glycol gel rectal spacers have optimized prostate proton therapy. Here, we report the early clinical outcomes of patients treated for localized prostate cancer using modern PBS-PBT with hydrogel rectal spacing and fiducial tracking without the use of endorectal balloons. Materials and Methods/UNASSIGNED:This is a single institutional review of consecutive patients treated with histologically confirmed localized prostate cancer. Prior to treatment, all patients underwent placement of fiducials into the prostate and insertion of a hydrogel rectal spacer. Patients were typically given a prescription dose of 7920 cGy at 180 cGy per fraction using a Monte Carlo dose calculation algorithm. Acute and late toxicity were evaluated using the Common Terminology Criteria for Adverse Events (CTCAE), version 5. Biochemical failure was defined using the Phoenix definition. Results/UNASSIGNED:From July 2018 to April 2020, 33 patients were treated (median age, 75 years). No severe acute toxicities were observed. The most common acute toxicity was urinary frequency. With a median follow-up of 18 months, there were no high-grade genitourinary late toxicities; however, one grade 3 gastrointestinal toxicity was observed. Late erectile dysfunction was common. One treatment failure was observed at 21 months in a patient treated for high-risk prostate cancer. Conclusion/UNASSIGNED:Early clinical outcomes of patients treated with PBS-PBT using Monte Carlo-based planning, fiducial placement, and rectal spacers sans endorectal balloons demonstrate minimal treatment-related toxicity with good oncologic outcomes. Rectal spacer stabilization without the use of endorectal balloons is feasible for the use of PBS-PBT.

In this review we outline the current evidence for the use of hydrogel rectal spacers in the treatment paradigm for prostate cancer with external beam radiation therapy. We review their development, summarize clinical evidence, risk of adverse events, best practices for placement, treatment planning considerations and finally we outline a framework and rationale for the utilization of rectal spacers when treating unfavorable risk prostate cancer with dose escalated Stereotactic Body Radiation Therapy (SBRT).

Endometrial cancer is a common malignancy in elderly women that are more likely to suffer from limiting medical comorbidities. Given this narrower therapeutic ratio, we aimed to assess the oncologic outcomes and toxicity in the adjuvant setting. Out of a cohort of 975 women, seventy patients aged ≥ 80 years, treated with curative postoperative radiotherapy (RT) for endometrial cancer between 2005 and 2021, were identified. Outcomes were assessed using Kaplan-Meier-analysis and comorbidities using the Charlson Comorbidity Index and G8 geriatric score. The overall survival at 1-, 2- and 5-years was 94.4%, 82.6%, and 67.6%, respectively, with significant correlation to G8 score. At 1- and 5-years, the local control rates were 89.5% and 89.5% and distant control rates were 86.3% and 66.9%, respectively. Severe (≥grade 3) acute toxicity was rare with gastrointestinal (2.9%), genitourinary (1.4%), and vaginal disorders (1.4%). Univariate analysis significantly revealed inferior overall survival with lower RT dose, G8 score, hemoglobin levels and obesity, while higher grading, lymphangiosis, RT dose decrease and the omission of chemotherapy reduced distant control. Despite older age and additional comorbidities, elderly patients tolerated curative treatment well. The vast majority completed treatment as planned with very low rates of acute severe side-effects. RT offers durable local control; however, late distant failure remains an issue.

PURPOSE/OBJECTIVE(S): Historically, caution has been warranted when irradiating large target volumes particularly those in close proximity to organs at risk. Prior literature has demonstrated an increased incidence of GI and GU toxicity when men with large prostates were treated with conventionally fractionated radiation therapy. However, there is very limited data regarding the clinical outcomes when SBRT is used as a definitive treatment modality. We explore the long term oncologic, toxicity, and patient reported outcomes of men treated with definitive SBRT with ultra-large prostate glands (>= 100 cc.) MATERIALS/METHODS: From 2006 to 2020, a total of 3,393 patients with low and intermediate risk prostate cancer were treated with definitive robotic-SBRT. We performed a retrospective review to identify all patients in this cohort with pre-treatment prostate volumes >= 100 cc. Prostate volume was measured at the time of treatment regardless of ADT incorporation. All patients were treated to a total dose of 35-36.25 Gy in 5 fractions. All patients had a minimum of 2 years follow-up and were given pre- and post-treatment EPIC questionnaires at defined intervals. Biochemical control was assessed using the Phoenix definition. Late toxicity was defined using CTCAE version 5.0 and was characterized as occurring >= 6 months post treatment.
RESULT(S): A total of 67 patients were identified with >= 100 cc prostate glands. Of these, 18 patients received ADT prior to treatment. Overall, the median prostate volume was 139.37 cc (range 100.1 - 227 cc). The D'Amico risk classification was low (n=19) and intermediate (n=48). The median age was 70 years (range 54 - 87 years) and the median pretreatment PSA was 8.7 ng/ml. The mean pre-treatment EPIC bowel and urinary scores were 87.8 and 79.7, respectively. One-month following SBRT, mean EPIC bowel and urinary scores worsened to 83.6 and 76.5, respectively. Three months following SBRT, mean epic bowel and urinary scores continued to decline to 83.2 and 77.1, respectively. However, bowel and bladder symptomatology improved by 1 year to 86.16 and 77.19, and by 2 years improved above baseline to 90.00 and 85.78, respectively. There were no high grade (3+) GI toxicities observed, though one grade 3 urinary retention was identified. Excellent oncologic outcomes were observed with a 5-year median PSA nadir of 0.6 ng/mL and a biochemical relapse free survival (bRFS) of 100% at 5 years.
CONCLUSION(S): SBRT has been demonstrated to be oncologically effective with minimal toxicity, and has become a more ubiquitous radiation option in men with localized prostate cancer. Although there is a historical reticence for treatment of men with large glands, we report excellent clinical outcomes. Five-year bRFS was 100% and grade 3+ urinary toxicity was 2%. Although EPIC scores transiently dropped at 1 and 3 months following SBRT, resolution was seen by 1 year following treatment. The use of SBRT for the treatment of localized prostate cancer in men with ultra-large prostate gland is feasible with minimal toxicity.
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PURPOSE/OBJECTIVE(S): Definitive chemoradiation is standard-of-care treatment for locally advanced inoperable non-small cell lung cancer (NSCLC). However, some patients refuse radiation therapy (RT) and this information is captured in the National Cancer Database (NC

BACKGROUND/UNASSIGNED:Vaginal cancer is a rare disease for which prospective randomized trials do not exist. We aimed to assess survival outcomes, patterns of recurrence, prognostic factors, and toxicity in the curative treatment using image-guided radiotherapy (RT). METHODS/UNASSIGNED:In this retrospective review, we identified 53 patients who were treated at a single center with external beam radiotherapy and brachytherapy with or without concomitant chemotherapy from 2000 to 2021. RESULTS/UNASSIGNED:= 0.027). Minimal toxicity was observed with no patients having documentation of high-grade toxicity (CTCAE grade 3+). CONCLUSION/UNASSIGNED:In treatment of vaginal cancer, high-dose RT in combination with brachytherapy is well tolerated and results in effective local control rates, which significantly improve with an EQD2(α/β=10) ⩾65 Gy. Multivariate analyses revealed concomitant chemotherapy was a positive prognostic factor for overall and progression-free survival.