Christina Small

Image Guided Cervical Brachytherapy: 2014 Survey of the American Brachytherapy Society

PURPOSE To provide an update of the 2007 American brachytherapy survey on image-based brachytherapy, which showed that in the setting of treatment planning for gynecologic brachytherapy, although computed tomography (CT) was often used for treatment planning, most brachytherapists used point A for dose specification. METHODS AND MATERIALS A 45-question electronic survey on cervical cancer brachytherapy practice patterns was sent to all American Brachytherapy Society members and additional radiation oncologists and physicists based in the United States between January and September 2014. Responses from the 2007 survey and the present survey were compared using the χ(2) test. RESULTS There were 370 respondents. Of those, only respondents, not in training, who treat more than 1 cervical cancer patient per year and practice in the United States, were included in the analysis (219). For dose specification to the target (cervix and tumor), 95% always use CT, and 34% always use MRI. However, 46% use point A only for dose specification to the target. There was a lot of variation in parameters used for dose evaluation of target volume and normal tissues. Compared with the 2007 survey, use of MRI has increased from 2% to 34% (P<.0001) for dose specification to the target. Use of volume-based dose delineation to the target has increased from 14% to 52% (P<.0001). CONCLUSION Although use of image-based brachytherapy has increased in the United States since the 2007 survey, there is room for further growth, particularly with the use of MRI. This increase may be in part due to educational initiatives. However, there is still significant heterogeneity in brachytherapy practice in the United States, and future efforts should be geared toward standardizing treatment.

A Survey Study of Pregnant Women and Healthcare Practitioners Assessing the Knowledge of Attitudes and Practices of Hepatitis B Management at a Teaching Hospital in Kumasi, Ghana, West Africa

Hepatitis B virus (HBV) infection is a major global health problem, with sub-Saharan Africa (SSA), including West Africa, bearing a large proportion of cases. Mother-to-child and early childhood horizontal transmission, the most common mechanisms of disease spread in West Africa, lead to a high rate of chronic infection. Although these transmission mechanisms are preventable through vaccine and hepatitis B immunoglobulin, they are not routinely used due to limited resources. Antiviral therapy in pregnant women who are HBV positive is another option to reduce transmission. We conducted a survey study of pregnant women and clinicians at a teaching hospital in West Africa to determine the knowledge base about HBV and willingness to implement measures to reduce HBV transmission. Pregnant women had limited knowledge about HBV and the common transmission mechanisms. Clinicians identified cost and time as the major barriers to implementation of HBV prevention measures. Both pregnant women and clinicians were largely willing to implement and use measures, including antivirals, to help reduce HBV transmission.

Adjuvant Radiotherapy Use by US Radiation Oncologists After Radical Cystectomy for Muscle-invasive Bladder Cancer

AIMS Historic trials suggested significant toxicity with adjuvant radiotherapy (ART) after radical cystectomy for muscle-invasive bladder cancer (MIBC). However, recent trials have found improved locoregional control and the 2016 National Comprehensive Cancer Network (NCCN) guidelines recommend ART consideration for select patients at high risk of local recurrence. ART practice patterns among US radiation oncologists are unknown and we carried out a survey to explore current trends. MATERIALS AND METHODS We conducted a survey of US radiation oncologists regarding the management of patients with cT2-3N0M0 transitional cell MIBC. Responses were reported using descriptive statistics. Chi-square and univariate logistic regression of clinical and demographic covariates were conducted, followed by multivariable logistic regression analysis to identify factors predicting for ART use. RESULTS In total, 277 radiation oncologists completed our survey. Nearly half (46%) have used ART for MIBC at least once in the past. In ART users, indications for ART include gross residual disease (93%), positive margins (92%), pathological nodal involvement (64%), pT3 or T4 disease (46%), lymphovascular invasion (16%) and high-grade disease (13%). On univariate logistic regression, ART use was associated with the number of years in practice (P=0.04), pre-cystectomy radiation oncology consultation (P=0.004), primarily treating MIBC patients fit for cystectomy (P=0.01) and intensity-modulated radiotherapy use (P=0.01). On multivariable logistic regression analysis, routine pre-cystectomy radiation oncology consultation (odds ratio 1.91, 95% confidence interval 1.04-3.51; P=0.04) and intensity-modulated radiotherapy use (odds ratio 2.77, 95% confidence interval 1.48-5.22; P=0.002) remained associated with ART use. CONCLUSIONS ART use is controversial in bladder cancer, yet unexpectedly has commonly been used among US radiation oncologists treating patients with MIBC after radical cystectomy. NRG-GU001 was a randomised trial in the US randomizing patients with high-risk pathological findings for observation or ART after cystectomy. However, due to poor accrual it recently closed and thus it will be up to other international trials to clarify the role of ART and identify patients benefiting form this adjuvant therapy.

Local control dependence on consecutive vs. nonconsecutive fractionation in lung stereotactic body radiation therapy

BACKGROUND Recent reports demonstrate impaired tumor re-oxygenation 24-48h after stereotactic body radiation therapy (SBRT), suggesting that non-consecutive treatment delivery may be advantageous. To test this hypothesis clinically, we compared local control in patients treated in consecutive daily fractions vs. nonconsecutive fractions. METHODS We retrospectively reviewed 107 lung SBRT patients (117 tumors) treated for T1-T2N0 NSCLC with LINAC based SBRT (50 or 60Gy/5fractions). Patients were characterized as having been treated in consecutive daily fractions vs. in non-consecutive fractions. Local control, survival and toxicity end points (CTCAE V4.0) were compared. Propensity score matching and Cox regression analyses were performed in order to determine the effect of fractionation on local control. RESULTS With a median follow up of 23.7months, 3-year local control was superior at 93.3% vs. 63.6% in the non-consecutive and consecutive group, respectively (p=0.001). Multivariate analysis and propensity score matching showed that consecutive fractionation was an independent predictor of local failure. Overall survival trended toward improvement in the non-consecutive group, but this was not statistically significant (p=0.188). Development of any grade 2 toxicity was not significantly different between the two groups (p=0.75). CONCLUSION Five-fraction SBRT delivered over non-consecutive days imparts superior LC and similar toxicity compared to consecutive fractionation. These results should be validated in independent datasets and in a prospective fashion.

Predictors of Distant Failure After Stereotactic Body Radiation Therapy for Stages I to IIA Non–Small-Cell Lung Cancer

Purpose: The use of stereotactic body radiation therapy (SBRT) has emerged as an effective treatment modality for patients with early‐stage non–small‐cell lung cancer (NSCLC), with excellent local control rates. Despite this, there is a predominant pattern of distant failure. We sought to identify factors that help predict which patients with stages I to IIA NSCLC treated with SBRT are at highest risk of distant failure, so that we may utilize these factors in the future to help determine which patients may benefit from the addition of systemic therapies. Patients and Methods: We retrospectively reviewed 292 patients treated with SBRT for early stage NSCLC from 2006 to 2016 at 2 institutions. Patients were classified by T stage, tumor size, location and histology, pretreatment positron emission tomography/computed tomography (PET/CT) standardized uptake value (SUV), smoking status, and age. The primary endpoint of the study was distant failure. We aimed to analyze if patient characteristics could be identified that predicted for distant failure through the use of competing risk analysis. Results: The median follow‐up was 21.9 months. The median dose of radiation and fractionation delivered was 50 Gy (range, 45‐65 Gy) in 5 fractions (range, 3‐13 fractions). The median patient age was 72.8 years (interquartile range, 65.4‐79.7 years). The 2‐year distant failure was 22.0%, and overall survival at 2 years was found to be 61.0%. For every 1‐year increase in patient age, the hazard of distant failure at any given time was 3% lower (hazard ratio, 0.97; 95% confidence interval, 0.94‐0.99; P = .04). None of the remaining characteristics emerged as significant risk factors for distant failure on univariable or multivariable analysis. Conclusions: Overall, our cohort had distant failure and survival rates comparable with what has been described in the literature. Although we were unable to identify factors outside of age that correlated to risk of distant failure, this topic warrants further investigation, as distant failure is the primary pattern of failure with SBRT when used as the primary management for early‐stage NSCLC. Additional molecular studies are needed to further inform on the role of systemic therapy in patients with early‐stage NSCLC to improve clinical outcomes.