Plaque brachytherapy is an effective eye and vision-sparing method to treat patients with intraocular tumors. Practitioners are encouraged to use ABS-OOTF guidelines to enhance their practice.

Despite a time-dependent deterioration in the success rate of GKS for medically intractable TN, the authors' study showed that > 50% of patients can be expected to have a good outcome based on their scoring system, with approximately 33% having an ideal outcome (pain free with no need for medications). Long-term data, as those presented here, are important when counseling patients on their treatment options.

Bleomycin (BLM) hydrolase catalyzes the inactivation of the antitumor drug BLM and is believed to protect normal and malignant cells from BLM toxicity. The normal physiological function of BLM hydrolase is not known. We now provide evidence for its membership in the cysteine proteinase family. BLM hydrolase was purified to homogeneity from rabbit lungs, and a partial amino acid sequence was determined from a tryptic digest peptide. On the basis of this sequence a 36-mer oligonucleotide was synthesized. The 36-mer oligonucleotide probe hybridized to a single mRNA species of 2.5 kb from several species and was used to isolate an 832-bp cDNA insert from a lambda gt11 rabbit liver cDNA library. This insert encoded the tryptic digest peptide previously identified in rabbit lung BLM hydrolase by amino acid sequencing. Analysis of the predicted amino acid sequence coded by the 832-bp BLM hydrolase cDNA fragment indicated no significant homology with any currently known proteins except for a 15 amino acid portion, which displayed remarkable homology with the active site of cysteine proteinases. Within this active-site region, 10 of the amino acid residues of papain and 9 of aleurain, cathepsin H, and cathepsin L were identical with those of rabbit liver BLM hydrolase. The catalytic cysteine of thiol proteinases was also conserved in BLM hydrolase, and cysteine proteinase specific inhibitors, such as E-64, were found to be potent inhibitors of BLM hydrolase activity. Furthermore, bleomycin hydrolase exhibited cathepsin H like enzymatic activity. Bleomycin hydrolase had, however, no significant cathepsin B or L activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful retreatment of patients in whom the initial GKS treatment fails is feasible. Patients who respond initially may be at a higher risk of retreatment-related complications. There appears to be a dose-response relationship for both pain control and development of new side effects. It is important to counsel and treat patients individually based on this dose-response relationship.

Given the potential morbidity of whole brain radiation therapy (WBRT), there has been an increasing trend to defer WBRT and deliver Gamma Knife stereotactic radiosurgery (GKS) to cerebral metastatic lesions. We analyzed our experience delivering GKS to the tumor cavity following surgical resection of brain metastases and compared our results to patients receiving WBRT after surgical resection of a metastatic lesion. We performed a retrospective review of patients undergoing surgical resection of at least one brain metastasis between December 1999 and December 2008. Both univariate and multivariate Cox proportional hazards regression were utilized to analyze the influence of various prognostic factors on survival. Twenty-five patients had a metastatic lesion resected followed by adjuvant GKS to the resection cavity while another 18 had surgical resection followed by WBRT. Aside from a disparity in gender distribution (72% of GKS patients were female while women only constituted 28% of the WBRT group), no significant differences existed between groups. The median survival for patients receiving GKS was 15.00 months as compared to 6.81 months among those receiving WBRT (P = 0.08). Univariate Cox regression analysis identified the number of metastases (HR 1.65, 95% CI 1.07-2.54, P = 0.02) and regional recurrence (RR 5.23, 95% CI 1.78-15.38, P = 0.003) as poor prognostic factors. Multivariate regression analysis showed that regional recurrence (HR 5.17, 95% CI 1.69-15.78, P = 0.004) was again strongly associated with worse survival. Although limited by the retrospective nature of our study and lack of some clinical measures, patients undergoing GKS to the resection cavity had a trend towards longer median survival.

No abstract

Though the 4 mm Gamma Knife helmet is used routinely, there is disagreement in the Gamma Knife users community on the value of the 4 mm helmet relative output factor. A range of relative output factors is used, and this variation may impair observations of dose response and optimization of prescribed dose. To study this variation, measurements were performed using the following radiation detectors: silicon diode, diamond detector, radiographic film, radiochromic film, and TLD cubes. To facilitate positioning of the silicon diode and diamond detector, a three-dimensional translation micrometer was used to iteratively determine the position of maximum detector response. Positioning of the films and TLDs was accomplished by manufacturing custom holders for each technique. Results from all five measurement techniques indicate that the 4 mm helmet relative output factor is 0.868 +/- 0.014. Within the experimental uncertainties, this value is in good agreement with results obtained by other investigators using diverse techniques.

The risk of isolated local recurrence in patients with T3pN0 breast cancer and negative margins is moderately low and similar to T2pN0 patients. These results suggest that routine use of postoperative chest wall and nodal irradiation in all T3pN0 patients may not be required.