Repeat Stereotactic Radiosurgery for Locally Recurrent Brain Metastases.

PURPOSE/OBJECTIVES: The outcomes of repeat stereotactic radiosurgery (SRS) after failure of previous SRS are not well established. We report our overall experience using SRS for the retreatment of locally recurrent brain metastases. METHODS: Patients with brain metastases diagnosed between 2003 and 2015 who underwent repeat SRS for local tumor progression following prior SRS were identified. Rates of local control, radiation necrosis, and overall survival were analyzed. Factors affecting local failure and radiation necrosis were assessed by chi-square test. RESULTS: Twenty-four lesions in 22 patients underwent repeat SRS in a single fraction. Median age was 59 years. The median SRS-1 dose was 18 Gy, and the median SRS-2 dose was 15.5 Gy. The median SRS-1 target volume was 2.25 cm3, and the median SRS-2 target volume was 3.30 cm3. The median follow-up from SRS-2 was 8.8 months. The actuarial local controls for SRS-2 were 94.1% and 61.1% at 6 and 12 months, respectively. The incidences of actuarial radiation necrosis were 9.2% and 9.2% at 6 and 12 months, respectively. Volume of tumor >4 cm3 correlated with increased risk of local failure (P = 0.006) with no local failures recorded with volumes ≤4 cm3. SRS-2 dose, cumulative SRS dose, receipt of whole brain radiotherapy, and use of SRS-2 as boost after surgery did not correlate with local failure or radiation necrosis. Median overall survival after SRS-2 was 8.78 months. CONCLUSION: Repeat SRS is feasible for select patients, particularly for those with tumor volume ≤4 cm3. Further evaluation is needed to establish the most appropriate treatment doses and volumes for this approach.

Locally advanced pancreatic cancer. Looking beyond traditional chemotherapy and radiation.

About a third of all pancreatic cancer is found to be locally advanced at the time of diagnosis, where the tumor is inoperable but remains localized to the pancreas and regional lymphatics. Sadly, this remains a universally deadly disease with progression to distant disease being the predominant mode of failure and average survival under one year. Optimal treatment of these patients continues to be an area of controversy, with chemotherapy alone being the treatment preference in Europe, and chemotherapy followed by chemoradiation in selected patients, preferred in the USA. The aim of this paper is to summarize the key abstracts presented at the 2013 ASCO Annual Meeting that address evolving approaches to the management of locally advanced pancreatic cancer. The late breaking abstract (#LBA4003) provided additional European data showing non-superiority of chemoradiation compared to chemotherapy in locally advanced pancreatic cancer patients without distant progression following 4 months of chemotherapy. Another late breaking abstract, (#LBA4004), unfortunately showed a promising new complement to gemcitabine and capecitabine using immunotherapy in the form of a T-helper vaccine did not translate to improved survival in the phase III setting.

Correlation of near infrared absorption and diffuse reflectance spectroscopy scattering with tissue neovascularization and collagen concentration in a diabetic rat wound healing model.

The objective of this paper was to correlate optical changes of tissue during wound healing measured by near infrared (NIR) and diffuse reflectance spectroscopy (DRS) with histologic changes in an animal model. Amplitude and phase of scattered light were obtained in a diabetic rat and control model and biopsies were taken for blood vessel ingrowth and collagen concentration. NIR absorption coefficient correlated with blood vessel ingrowth over time, in both the control and diabetic animals. DRS data correlated with collagen concentration. Previous publications by this group documented only the NIR changes during the wound healing process but this is the first reported correlation with histology data. The ability to correlate DRS scattering with collagen concentration during healing is another important and novel finding. This technology may play an important role clinically in assessing the efficacy of wound healing agents in diabetics.