Faculty Bibliography

Purpose: Advancements in breast radiation therapy offer innumerable benefits to patients and the health care system. Despite promising outcomes, clinicians remain hesitant about long-term side effects and disease control with accelerated partial breast radiation therapy (APBI). Herein, we review the long-term outcomes of patients with early-stage breast cancer treated with adjuvant stereotactic partial breast irradiation (SAPBI). Methods and Materials: This retrospective study examined outcomes of patients who received diagnoses of early-stage breast cancer treated with adjuvant robotic SAPBI. All patients were eligible for standard ABPI and underwent lumpectomy, followed by fiducial placement in preparation for SAPBI. Using fiducial and respiratory tracking to maintain a precise dose distribution throughout the course of treatment, patients received 30 Gy in 5 fractions on consecutive days. Follow-up occurred at routine intervals to evaluate disease control, toxicity, and cosmesis. Toxicity and cosmesis were characterized using the Common Terminology Criteria for Adverse Events version 5.0 and Harvard Cosmesis Scale, respectively.
Result(s): Patients (N = 50) were a median age of 68.5 years at the time of treatment. The median tumor size was 7.2 mm, 60% had an invasive cell type, and 90% were estrogen receptor positive, progesterone receptor positive, or both. Patients (n = 49) were followed for a median of 4.68 years for disease control and 1.25 years for cosmesis and toxicity. One patient experienced local recurrence, 1 patient experienced grade 3+ late toxicity, and 44 patients demonstrated excellent cosmesis.
Conclusion(s): To our knowledge, this is the largest retrospective analysis with the longest follow-up time for disease control among patients with early breast cancer treated with robotic SAPBI. With follow-up time for cosmesis and toxicity comparable to that of previous studies, results of the present cohort advance our understanding of the excellent disease control, excellent cosmesis, and limited toxicity that can be achieved by treating select patients with early-stage breast cancer with robotic SAPBI.
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INTRODUCTION/UNASSIGNED:Brain metastases are the most common intracranial tumor diagnosed in adults. In patients treated with stereotactic radiosurgery, the incidence of post-treatment radionecrosis appears to be rising, which has been attributed to improved patient survival as well as novel systemic treatments. The impacts of concomitant immunotherapy and the interval between diagnosis and treatment on patient outcomes are unclear. METHODS/UNASSIGNED:This single institution, retrospective study consisted of patients who received single or multi-fraction stereotactic radiosurgery for intact brain metastases. Exclusion criteria included neurosurgical resection prior to treatment and treatment of non-malignant histologies or primary central nervous system malignancies. A univariate screen was implemented to determine which factors were associated with radionecrosis. The chi-square test or Fisher's exact test was used to compare the two groups for categorical variables, and the two-sample t-test or Mann-Whitney test was used for continuous data. Those factors that appeared to be associated with radionecrosis on univariate analyses were included in a multivariable model. Univariable and multivariable Cox proportional hazards models were used to assess potential predictors of time to local failure and time to regional failure. RESULTS/UNASSIGNED:A total of 107 evaluable patients with a total of 256 individual brain metastases were identified. The majority of metastases were non-small cell lung cancer (58.98%), followed by breast cancer (16.02%). Multivariable analyses demonstrated increased risk of radionecrosis with increasing MRI maximum axial dimension (OR 1.10, p=0.0123) and a history of previous whole brain radiation therapy (OR 3.48, p=0.0243). Receipt of stereotactic radiosurgery with concurrent immunotherapy was associated with a decreased risk of local failure (HR 0.31, p=0.0159). Time interval between diagnostic MRI and first treatment, time interval between CT simulation and first treatment, and concurrent immunotherapy had no impact on incidence of radionecrosis or regional failure. DISCUSSION/UNASSIGNED:An optimal time interval between diagnosis and treatment for intact brain metastases that minimizes radionecrosis and maximizes local and regional control could not be identified. Concurrent immunotherapy does not appear to increase the risk of radionecrosis and may improve local control. These data further support the safety and synergistic efficacy of stereotactic radiosurgery with concurrent immunotherapy.

[This corrects the article DOI: 10.3389/fonc.2023.1132777.].

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.

PURPOSE/OBJECTIVE(S): Stereotactic Body Radiation Therapy (SBRT) is a standard therapeutic option for men with prostate adenocarcinoma. The median age of prostate cancer in the US is 66 but patients as young as 35 have been reported. Many younger patients will have surgery rather than SBRT for localized prostate cancer but some will be treated with SBRT. There is a paucity of data on the outcomes of this younger subset. This study reports outcomes on patients younger than 50 treated with SBRT at a single institution and compares outcomes to older patients. MATERIALS/METHODS: Between April 2006 and December 2020, 3626 patients with prostate cancer were treated with inhomogeneous-dosed SBRT using a robotic linear accelerator and followed at an academic institution. 3173 (87.51%) of patients were treated with a median dose of 3500cGY (3500-3625) delivered over 5 consecutive fractions prescribed to the 83-85% isodose line, and the remaining 453 (12.49%) other patients receiving a median dose of 4500cGY (4500-5400) to the pelvis in conventional fractionation followed by a 3 fraction SBRT boost of 2100 cGY (1950-2100) over 3 consecutive fractions. Androgen deprivation Therapy (ADT) was prescribed in 865 (23.86%) of these cases. The mean age was 67.3 years old. 47 patients were younger than 50 years old (mean age 46.6). 3,579 patients were 50 or older. Patients were divided into prognostic D'Amico risk groups with 44.68%, 48.94%, 6.38% of patients falling in the low, intermediate, and high-risk stratifications in the younger cohort and 24.76%, 56.83%, 18.41% in the older cohort respectively. Pretreatment PSA was 1.72 - 43.2 (median: 5.4) in the younger group and 0.3 - 661 (median: 6.5) in the older group. In the younger group, Gleason scores were 6 in 48.94%, 7 in 46.81%, and 8-10 in 4.25%. 44 younger patients were treated with SBRT alone. 3 patients also received supplemental external beam radiation (median dose 4500cGY) and 5 patients (10.6%) received Androgen Deprivation Therapy (ADT) as part of their treatment regimen. In the older group, Gleason scores were 6 in 30.57%, 7 in 54.06%, and 8-10 in 15.37%. 3129 were treated with SBRT alone. 450 patients also received supplemental external beam radiation (median dose 4500cGY) and 860 patients (24.03%) received Androgen Deprivation Therapy (ADT) as part of their treatment regimen.
RESULT(S): At 64.8 months (range 7 months - 177 months) the 5-year biochemical relapse free survival was 98% in younger patients compared to 99% in older patients using the Phoenix definition of biochemical failure. The 5-year median post treatment PSA was 0.15 in the younger patients and 0.20 in the older patients. There were no significant differences in biochemical relapse free survival between the groups.
CONCLUSION(S): This represents the largest series evaluating outcomes in very young patients treated with definitive SBRT for prostate cancer. With 5-year follow up, SBRT is an effective treatment for this younger subset of patients. Continued follow up will be required to see if these results remain durable.
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