Annual Meeting of the American Radium Society (ARS)

Median survival of multifocal GBM is incredibly short, even compared with the already short median survival of single-lesion GBM. The majority of our patients had biopsy alone, likely due to the nature of multifocal GBM. This most likely contributes to a worse MS.

Our results establish that WBRT + SRS produces leukoencephalopathy at a much higher rate than SRS alone. Surprisingly, an SRS integral dose of over only 3 J predicts for leukoencephalopathy in patients treated with SRS alone. Our data define a dosimetric threshold at which radiation-induced leukoencephalopathy is likely to occur following SRS. As the survival of patients with CNS metastases increases and as the neurotoxicity of chemotherapeutic and targeted agents becomes established, the threshold of 3 J may influence the therapeutic management of patients with multiple brain metastases.

The use of antiepileptic HDACi drugs during RT for GBM did not significantly improve outcomes or RT response in this retrospective analysis. Further study of the concomitant use of HDACis and TMZ is necessary to elucidate clinically relevant results.

SRS appears to be a reasonable treatment option for focally persistent or recurrent PCNSL in select patients, especially in the setting of focal neurologic deficits. As a radiosensitive entity, all PCNSL lesions had a substantial volumetric reduction with at least 14 Gy, and all patients with a focal neurologic deficit at treatment experienced symptomatic improvement with SRS. Further investigation should be completed regarding the benefits of SRS for focally appearing PCNSL as a potential way to avoid neurotoxicity and improve symptoms in selected patients.

SRS is both safe and efficacious for PTN. Additionally, prior to treatment, PTN patients who characterize their facial pain as dull and not exacerbated by daily activities are more likely to receive therapeutic benefit, with a mean response time of 1 month.

FSRT and SRS in treatment for acoustic neuromas had similar outcomes and toxicity at our institution. Both modalities appear to be successful at providing high tumor control with acceptable toxicities in the noninvasive treatment of acoustic neuromas.

Adjuvant RT was delivered to a minority of CNC patients after either GTR or STR in this national database, though patients were more likely to receive RT after STR. Long-term OS was excellent for all subgroups, and there was no clear evidence of resection extent or adjuvant RT influencing survival outcomes. Since our database is subject to selection bias and limited by a lack of information regarding local recurrence, salvage therapies, exact extent of STR, and RT technique, further research is needed to validate our findings.

Our study showed that patients with primary malignant meningioma had better outcomes after maximal resection followed by postoperative radiation. In contrast, transformed meningiomas demonstrated more aggressive behavior, with lower median survival despite RT. Further multi-institutional or randomized studies are required to evaluate the effectiveness of postoperative RT to determine the best approach to managing these tumors.

Patients who undergo surgery after chemoradiotherapy demonstrate improved survival; however, this may be related to underlying comorbidities that preclude surgery. IMRT appears to be a reasonable treatment option that may reduce complications from radiotherapy. Careful attention should be given to heart dose during treatment planning.

Several radiographic texture features from the pre-RT CT scan were identified as potential predictors of pCR in rectal cancer patients after neoadjuvant chemoradiation therapy. Future work will focus on validating these features in a larger dataset.

We discerned no significant improvements with the addition of radiation therapy in these patients with resected pancreatic adenocarcinoma treated with modern adjuvant chemotherapy, but statistical power was limited. The eventual results of the ongoing Radiation Therapy Oncology Group (RTOG) study RTOG 0848 will provide definitive data regarding the appropriate role for radiation in the era of modern adjuvant chemotherapy.

Novel mutations were identified in the majority of patients, including mutations within a number of genes that have the potential to influence KRAS-mediated signaling, as well as other prominent signaling pathways. These results could potentially serve to identify targets for novel chemotherapeutic agents and guide personalized, combinatorial therapy in appropriately selected patients.

The majority of cases exhibited increased enhancement on portal venous phase following treatment with TACE, demonstrating the importance of surveillance with proper multiphase imaging to assess for recurrence, especially in light of a decrease in arterial phase enhancement following treatment.

90Y radioembolization is an effective treatment for CRCLMs in extending local control for liver-dominant metastatic disease. However, KRAS-mutant tumors may be more radioresistant to treatment.

There was no HPV oncogene expression in our patient cohort, which corresponds with a low-to-no prevalence of esophageal HPV infection in a population of patients in the United States. However, further studies including a larger patient cohort with pretreatment tissue analysis would still be helpful in determining the true prevalence of HPV in esophageal cancer. Patients who are treated with trimodality therapy experienced a high rate of pathologic response.

Pathologic outcomes after neoadjuvant chemoradiation for esophageal cancer were similar between patients treated at an academic center and community setting, although patients treated in the community tended to be older than patients treated at our academic center. These results will need to be validated with a larger dataset. The pCR rate after neoadjuvant chemoradiation at our institution was 21%, consistent with published data.

This is the first report about a Chinese population with prostate cancer treated with carbon ion therapy. Our primary data showed that carbon ion therapy was well tolerated, and the immediate effect was encouraging. Long-term follow-up is needed for the analysis of final treatment responses and toxicities.

Patients with HGPC at diagnosis have high rates of early disease recurrence, though mortality at 5 years remains low. Following RP without systemic therapy, high primary GS and initial post-RP PSA were independently associated with worse FFF outcomes.

Both benign and malignant cases had outcomes dependent upon the location and extent of surgical resection. In malignant cases that are not amenable to surgery, radiation offers a survival benefit. Given the cohort in this analysis, selection bias likely plays a significant role. Further study is required to define the optimal management of IPNB.

We observed a wide range of RSs among elderly ESBC patients in the NCDB. Further research is needed to determine if gene expression assays are capable of risk-stratifying within this population, as a means for directing adjuvant RT recommendations after BCS. Should this be proven, our findings would suggest that ODX-directed decision-making is theoretically cost-effective at a conservative willingness-to-pay threshold of $50,000/QALY.

Compared with prior literature, our study shows comparable rates of survival with a decreased rate of radiation-induced toxicity.

Sinonasal neuroendocrine tumors are a challenging group of diseases to manage, due to their rarity and heterogeneous natural histories. New multimodality strategies need to be explored to potentially enhance outcomes, especially in non-ONB histologies.

Although the majority of oropharyngeal cancer survivors enjoy functional recovery in early survivorship, almost 10% suffer severe, late deterioration of swallowing abilities. Delayed lower cranial neuropathies often precipitate late-RAD.

Sparing the ipsilateral lung of at least a finite functional unit per 1 L of the ipsilateral lung is a predictor of the development of radiation pneumonitis. This represents a new dosimetric measure in plan evaluation and correlates significantly with the development of toxicity in patients with malignant pleural mesothelioma receiving radiation to the ipsilateral lung. This factor might be a more effective and useful parameter in these challenging cases.

In stage III NSCLC patients treated with definitive radiation, increased frequency of PET-CT scan surveillance did not result in decreased time to detection of locoregional or distant recurrence or improved survival. If validated, further investigation is warranted to elucidate the benefit, if any, of NSCLC posttreatment surveillance with PET-CT scan.

In our patient population, strict adherence to lung dose constraints during IMRT resulted in improved outcomes without fatal toxicity.

Our institutional experience confirmed that SBRT to primary NSCLC is well tolerated and provides excellent LC, regardless of tumor size or histology. Tumor density did not appear to have a significant effect on PTC, but denser tumors were more likely to have poorer outcomes, likely owing to associated larger tumor burden.

We did not find an association of SUVmax with recurrences or death; however, the sample size was relatively small, and the power to detect differences was low. These findings will be further evaluated in a larger multicenter study in the future.

Despite developments in surgery, perioperative management, and radiotherapy, the prognosis for MPM patients has not improved over the past four decades. In this SEER study of 14,228 patients over 36 years, cancer-directed surgery was associated with better survival in MPM, independent of other prognostic factors. These data support the role of surgery-based therapy as the cornerstone of treatment for this challenging disease.

Prognostic factors that were significantly associated with survival on both UV and MV analyses were used to construct a valid scoring system that can be used to predict survival of NSCLC patients. The score can be used for trial stratification or for choosing patients specifically for high-risk trials. Optimally, this score will be helpful when counseling patients and designing future trials.