Pectoralis Muscle Dosimetry and Posttreatment Rehabilitation Utilization for Patients With Early-Stage Breast Cancer.

PURPOSE: Up to 50% of women treated for localized breast cancer will experience some degree of arm or shoulder morbidity. Although radiation is thought to contribute to this morbidity, the mechanism remains unclear. Prior studies have shown biologic and radiographic changes in the pectoralis muscles after radiation. This study thus aimed to investigate the relationship between radiation to the pectoralis muscles and referrals for rehabilitation services posttreatment for arm and shoulder morbidity. METHODS AND MATERIALS: A retrospective 1:1 matched case-control study was conducted for patients with breast cancer who were and were not referred for breast or shoulder rehabilitation services between 2014 and 2019 at a single academic institution. Patients were included if they had a lumpectomy and adjuvant radiation. Patients who underwent an axillary lymph node dissection were excluded. Cohorts were matched based on age, axillary surgery, and use of radiation boost. Muscle doses were converted to equivalent dose in 2 Gy fractions assuming an α:ß ratio of 2.5 and were compared between the 2 groups. RESULTS: In our cohort of 50 patients of a median age 60 years (interquartile range, 53-68 years), 36 patients (72%) underwent a sentinel lymph node biopsy in addition to a lumpectomy. Although pectoralis muscle doses were generally higher in those receiving rehabilitation services, this was not statistically significant. Pectoralis major V20-40 Gy reached borderline significance, as did pectoralis major mean dose (17.69 vs 20.89 Gy; P = .06). CONCLUSIONS: In this limited cohort of patients, we could not definitively conclude a relationship between pectoralis muscle doses and use of rehabilitation services. Given the borderline significant findings, this should be further investigated in a larger cohort.

Quality rectal hydrogel placement allows for gel-enabled dose-escalated EBRT (GEDE-EBRT) without rectal interference in prostate cancer.

Multiple trials have shown that dose-escalation of radiation for prostate cancer provides a biochemical progression-free survival benefit (bPFS); however, rectal constraints are often limiting. In this dosimetric study, we hypothesized that a well-placed rectal hydrogel (RH) would permit improved dose-escalation and target coverage. We selected patients with good-quality RH and created plans with and without RH, prescribing 70 Gy in 28 fractions to the prostate and proximal seminal vesicles (PSV), and a peripheral zone (PZ) boost to 84 Gy, 98 Gy, or 112 Gy. We then compared plans with and without RH, prescribing a 112 Gy boost to 1 to 2 cm simulated dominant intraprostatic lesions (DIL). In the 18 plans created with a PZ boost, the PTV_boost D95% was higher in RH plans compared to non-RH plans (median 98.5 Gy vs 75.53 Gy, p < 0.01). The PSV planning target volume (PTV_PSV) D95% was also marginally higher with RH (71.87 Gy vs 71.04 Gy, p < 0.01). All rectal metrics were improved with RH. For the 32 plans created for simulated DILs treated to 112 Gy, the PTV_boost coverage (median D95% 112.48 Gy vs 102.63 Gy, p < 0.01) and rectal metrics were improved with RH. Four non-RH plans with at least a 4 mm rectal-PTV_boost gap achieved D95% > 98% of the prescription dose for the PTV_boost. Our study showed that placement of a high-quality RH allowed for GEDE-EBRT up to 112 Gy in 28 fractions (EQD2 160 Gy with α/ß = 2.5). This concept should be tested prospectively, particularly to assess for increases in nonrectal toxicities.

Cannabis Use in Patients Seen in an Academic Radiation Oncology Department.

PURPOSE: Cannabis use rates are increasing in the United States. Patients with cancer use cannabis for many reasons, even without high-quality supporting data. This study sought to characterize cannabis use among patients seen in radiation oncology in a state that has legalized adult nonmedical use cannabis and to identify key cannabis-related educational topics. METHODS AND MATERIALS: Cannabis history was documented by providers using a structured template at patient visits in an academic radiation oncology practice October 2020 to November 2021. Cannabis use data, including recency/frequency of use, reason, and mode of administration, were summarized, and logistic regression was used to explore associations between patient and disease characteristics and recent cannabis use. A multivariable model employed stepwise variable selection using the Akaike Information Criterion. RESULTS: Of 3143 patients total, 91 (2.9%) declined to answer cannabis use questions, and 343 (10.9%) endorsed recent use (≤1 month ago), 235 (7.5%) noted nonrecent use (>1 month ago), and 2474 (78.7%) denied history of cannabis use. In multivariable analyses, those ≥50 years old (odds ratio [OR], 0.409; 95% confidence interval [CI], 0.294-0.568; P < .001) or with history of prior courses of radiation (OR, 0.748; 95% CI, 0.572-0.979; P = .034) were less likely, and those with a mental health diagnosis not related to substance use (OR, 1.533; 95% CI, 1.171-2.005; P = .002) or who smoked tobacco (OR, 3.003; 95% CI, 2.098-4.299; P < .001) were more likely to endorse recent cannabis use. Patients reported pain, insomnia, and anxiety as the most common reasons for use. Smoking was the most common mode of administration. CONCLUSIONS: Patients are willing to discuss cannabis use with providers and reported recent cannabis use for a variety of reasons. Younger patients new to oncologic care and those with a history of mental illness or tobacco smoking may benefit most from discussions about cannabis given higher rates of cannabis use in these groups.

Changes in pectoralis major stiffness and thickness following radiotherapy for breast cancer: A 12-month follow-up case series.

Radiotherapy (RT) is a common and often essential treatment for breast cancer, but has been associated with pectoralis major (PM) muscle fibrosis and atrophy. In an initial prospective evaluation, we assessed muscle stiffness and muscle thickness of the sternocostal and clavicular regions of the PM with ultrasound shear wave elastography and B-mode imaging. Changes in PM muscle stiffness and thickness following RT can be detected within the first twelve months of RT completion. These parameters may potentially be useful for screening of patients who would benefit from post-RT physical therapy. Further studies with larger sample sizes that include patients who receive nodal radiation are necessary to confirm these findings.

Novel Body Composition Predictors of Outcome in Patients With Angiosarcoma of the Breast: A Preliminary Study.

OBJECTIVE: The aim of the study was to determine abdominal and breast adipose tissue parameters on 18-fluorodeoxyglucose positron emission tomography/computed tomography (CT) that may serve as outcome predictors in breast angiosarcoma patients. MATERIALS: Women with breast angiosarcoma (n = 13) who underwent 18-fluorodeoxyglucose positron emission tomography/CT were identified. A control group was selected (n = 25). Abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) were assessed on unenhanced computed tomographies. Breast adipose tissue (BAT) volumes of the uninvolved breast were quantified. Metabolic activity of VAT, SAT, and BAT was calculated (standardized uptake value [SUV]). RESULTS: Breast angiosarcoma patients had higher metabolic activity of VAT compared with controls (SUV 0.93 ± 0.39 vs 0.64 ± 0.11, P = 0.044). Within the patient group, there were 6 deaths (46.2%). Patients who died had higher SAT activity (SUV 0.52 ± 0.24 vs 0.29 ± 0.06, P = 0.027) and higher BAT metabolic activity (SUV 0.48 ± 0.20 vs 0.27 ± 0.11, P = 0.045) compared with nondeceased patients. CONCLUSIONS: Patients with breast angiosarcoma have higher metabolic activity of VAT. Higher abdominal SAT and higher BAT metabolic activity of the uninvolved breast might predict mortality.