Annual Meeting of the American Radium Society (ARS)

Patients without insurance were less than half as likely to receive MIS and more than twice as likely to receive EBRT compared with patients with private insurance in our national cohort. Our findings suggest that with expanding access to private insurance under the Affordable Care Act, there may be significant shifts in the selection of treatment modality for men with prostate cancer in the United States.

Greater intraprostatic heterogeneity was associated with late grade 2+ GU toxicity. Given the high correlation of prostate volume with toxicity, SBRT dose parameters should be individualized and risk-adapted based on normalized prostate volumes, including a V50 not to exceed 9% of the prostate. The urethra is an important organ at risk, and the 42-Gy dose-volume should be limited to 2 mL, while bladder dose-volumes appear to be poor predictors of GU grade 2+ toxicity.

In this young patient population, no definitive treatment was selected in 22.5% of men with LR disease. For those with HR disease, 25.5% did not undergo active treatment, indicating that these men appear to be receiving less aggressive therapy than recommended by NCCN guidelines. In addition, African-American race is also associated with a decreased likelihood for receipt of definitive therapy.

Patients tolerated proton therapy in this randomized trial well, with excellent QoL scores, persistent low IPSS, and no grade ≥ 3 AEs in either arm. Thus far, there is no apparent clinical difference in outcomes with hypofractionated proton beam therapy compared to standard fractionation.

This study demonstrates that even though most MRI-identified GTVs are located in close proximity to critical structures, dose escalation is achievable without exceeding rectal constraints in all cases, and bladder constraints in the majority of cases. These variations are in cases with small bladders encompassed in the CTV and are not associated with increased acute toxicity.

Radiotherapy improves both local and locoregional control in patients with desmoplastic melanoma of the head and neck, regardless of margin status.

HIV+ patients with HNC have inferior oncologic and functional outcomes compared to HIV− patients. HPV positivity and smoking did not have a statistically significant impact on clinical outcomes. Innovative treatment modalities and approaches with better efficacy and less morbidity need to be developed for this growing patient population.

Following radiotherapy +/− chemotherapy for HPV+ oropharynx cancer, there is a low risk of disease recurrence or late grade ≥ 3 toxicity. As most events occur within 6 months of treatment completion, it may be reasonable to reduce the intensity of follow-up appointments to an every-6-month basis beyond this window.

Delays to adjuvant RT > 60 days increased mortality by 17% to 35% compared to patients treated earlier. Current efforts should be focused on timely delivery of care, and further investigation into factors associated with delays is necessary.

When corrected for comorbid conditions in this patient cohort, CaP patients with less than 10% %LN+ have almost 14 years before their disease becomes incurable. Progressively larger %LN+ yields smaller windows of such time. Above 50% LN+, the inflection point is only about 4 years. While better therapies for pN+ CaP must be defined, this patient cadre is not homogenous and should be stratified by %LN+ in future clinical trials.

Under current Medicare-allowable reimbursements, the cost of proton therapy relative to the cost of other therapeutic options is highly dependent on the number of radiotherapy fractions delivered. Ultimately, the cost of proton therapy will need to be weighed against tumor control probabilities, as well as the economic and quality of life benefits associated with reduced normal tissue exposure.

The presence of cN3 disease, ENE, and > 3 lymph nodes at lymphadenectomy and the presence of pT4 disease at penile surgery were associated with increased risk of early RR, while adjuvant chemotherapy decreased RR. Since RR portends a dismal prognosis with few salvage options, men with these adverse factors should be considered for adjuvant therapy, including radiation therapy, to reduce RR.

In this population-based analysis, IMRT use was significantly associated with improved overall survival and reduced cardiac mortality in patients with esophageal cancer.

Primary hepatic malignancies that are not amenable to surgical resection portend a poor prognosis, despite available treatment options. Though RILD is rare following SBRT, this study demonstrates a risk, despite close adherence to standard dose and volume constraints. Further analysis of this prospective study will seek to elicit patient parameters that may increase susceptibility to toxicities, such as RILD.

In our analysis of 458 patients with resected pancreatic cancer and adjuvant therapy, elevated preoperative CA 19.9 and no adjuvant RT were associated with increased risk of LRF. LRF was associated with poor OS. As such, RT should be considered as an adjunctive LR treatment modality for patients undergoing pancreatic cancer resection.

Metformin was demonstrated to increase ROS levels, cytotoxicity, and radiosensitization in A549 and MCF-7 cancer cells under oxic, hypoxic, glucose-full, and glucose-free conditions. Normal MCF-10A cells did not show increased toxicity with metformin. The preferential metformin-induced increase in ROS levels found in cancer cells, particularly hypoxic cells, may provide some explanation for the therapeutic benefit seen in diabetic patients taking metformin while undergoing cancer treatment.

This is the first prospective imaging study to objectively document normal-tissue toxicity in patients treated with hypofractionation breast RT using ultrasonography tissue characterization. Contrary to the criticism, patients receiving hypofractionation RT recovered better and experienced less late toxicity at the 1-year follow-up.

Reports of sexual changes in women after cancer treatment are highest in patients receiving pelvic radiation, particularly brachytherapy. Rates of sexual changes are higher than expected in patients receiving radiation elsewhere and/or chemotherapy alone. These findings support the need for both adequate patient counseling prior to treatment and support for late-effect management afterwards.

We determined several patient and treatment-specific characteristics that predicted for treatment incident events. Children were more susceptible to incident alerts, possibly related to increased staff vigilance or more frequent use of complex modalities. Patients with head and neck tumors, greater number of fractions, treatment on protocol, and use of IMRT also predicted for incidents.

Our study suggests that while young age may be a poor prognostic factor for breast cancer, there is no evidence that these patients have better outcomes with mastectomy over BCT, supporting the continued use of BCT.

Targeted combinatorial therapy with XRT is necessary to overcome adaptive radioresistance. RPPA is a powerful proteomic platform, suggesting alterations in energy metabolism following XRT that are targetable by inhibition of the enzyme glutaminase. Further in vivo experiments with glutaminase inhibition and xenograft models to assess combinatorial efficacy with radiation are warranted.

Patient-level DDR pathway profiling revealed distinct clusters. Individual DDR pathways and a composite biomarker showed strong prognostic performance with the long-term outcomes of metastatic progression and OS, which may be useful for risk stratification of high-risk prostate cancer patients aged < 70 years.

Outcomes for women with breast cancer aged ≤ 40 years undergoing BCT and M have improved significantly over time, likely reflecting the advent of improved local and systemic therapies. In addition, for women treated after 2000, BCT appears to be safe and equivalent to M at 10 years in terms of FFLR, OS, and RFS.

Our analysis of this single-institution population of women with left-sided breast cancer treated to the whole breast demonstrates that differing radiation treatment techniques have statistically significant impacts on dosimetric parameters of the heart, left ventricle, and LAD.

CPM with TER resulted in a complication in 25% of patients, half of which occurred within 6 months of surgery. However, adjuvant chemotherapy or radiotherapy was delayed by acute complications in only 3% after CPM. Delayed complication rates were higher on the therapeutic side, possibly due to effects of radiotherapy. These data may better inform patients considering bilateral mastectomies with TER.

While all three comorbidity indices correlated significantly with OS in women with early-stage EC, AACCI was the only independent predictor of OS and should be considered for evaluating comorbidity in future endometrial cancer patients.

Sandwich chemotherapy and radiation therapy is a tolerable treatment modality for patients with high-risk endometrial cancer. Rates of hematologic toxicities are acceptable, and nonhematologic toxicities are uncommon. Further enrollment of patients is underway to determine efficacy.

Aside from the known benefits of IGBT, MRI-based planning allows for assessment of tumor regression and prognosticates patients, as shown in the present study. If these findings are replicated in prospective trials, alternative methods, such as dose escalation and surgical salvage, should be considered to offset poor prognoses.

External beam radiotherapy during an era after IMRT has become widespread is associated with improved HRQOL measures among prostate cancer patients compared with the era prior to IMRT dissemination.

Tumor size appears to be a significant prognostic factor for brain recurrence in patients with limited-stage SCLC after PCI. Further investigation is warranted to in order to best individualize treatment for limited-stage SCLC patients with large tumors.