Inactivation of Escherichia coli O157:H7 on Orange Fruit Surfaces and in Juice Using Photocatalysis and High Hydrostatic Pressure.

Nonpasteurized orange juice is manufactured by squeezing juice from fruit without peel removal. Fruit surfaces may carry pathogenic microorganisms that can contaminate squeezed juice. Titanium dioxide-UVC photocatalysis (TUVP), a nonthermal technique capable of microbial inactivation via generation of hydroxyl radicals, was used to decontaminate orange surfaces. Levels of spot-inoculated Escherichia coli O157:H7 (initial level of 7.0 log CFU/cm(2)) on oranges (12 cm(2)) were reduced by 4.3 log CFU/ml when treated with TUVP (17.2 mW/cm(2)). Reductions of 1.5, 3.9, and 3.6 log CFU/ml were achieved using tap water, chlorine (200 ppm), and UVC alone (23.7 mW/cm(2)), respectively. E. coli O157:H7 in juice from TUVP (17.2 mW/cm(2))-treated oranges was reduced by 1.7 log CFU/ml. After orange juice was treated with high hydrostatic pressure (HHP) at 400 MPa for 1 min without any prior fruit surface disinfection, the level of E. coli O157:H7 was reduced by 2.4 log CFU/ml. However, the E. coli O157:H7 level in juice was reduced by 4.7 log CFU/ml (to lower than the detection limit) when TUVP treatment of oranges was followed by HHP treatment of juice, indicating a synergistic inactivation effect. The inactivation kinetics of E. coli O157:H7 on orange surfaces followed a biphasic model. HHP treatment did not affect the pH, °Brix, or color of juice. However, the ascorbic acid concentration and pectinmethylesterase activity were reduced by 35.1 and 34.7%, respectively.

Long term follow-up results of external beam radiotherapy as primary treatment for retinoblastoma.

The authors reviewed their experiences of external beam radiotherapy (EBR) as an initial treatment in retinoblastoma patients to determine its long-term effect on subsequent tumor control and complications. A total of 32 eyes in 25 patients that underwent EBR for retinoblastoma were reviewed retrospectively. The patients consisted of 21 boys and 4 girls of median age at treatment of 7.1 months. Radiation doses ranged from 35 to 59.4 Gy. The 10-yr ocular and patient survivals were 75.4% and 92.3%, respectively. Nine of the 32 eyes progressed; 7 of these were enucleated and 2 were salvaged by focal treatment. According to the Reese-Ellsworth classification, 4 of 5 eyes of Group II, 13 of 16 Group III eyes, 2 of 4 Group IV eyes, and 5 of 7 Group V eyes were retained, and of the 32 eyes, 13 had visual acuity better than 20/200. Eleven patients experienced a radiation-induced complication. No patient developed a second malignancy during follow-up. Despite the limited number of patients enrolled, EBR may provide a mean of preserving eyeball and vision for some advanced lesions.

Robotic system-based fractionated stereotactic radiotherapy in locally recurrent nasopharyngeal carcinoma.

PURPOSE: We reviewed survival, local control, and toxicity in patients with locally recurrent nasopharyngeal carcinoma (NPC) who had been treated with fractionated stereotactic radiotherapy (FSRT). MATERIALS AND METHODS: Between June 2002 and March 2008, we retrospectively reviewed 35 patients with locally recurrent NPC treated using FSRT with CyberKnife. Gross tumor volumes ranged from 2.6 to 64.0 ml (median, 7.9 ml). Radiation doses were prescribed at the isodose line (75-84% of the maximum dose; median, 80%). The prescribed dose of FSRT ranged from 24 to 45 Gy (median, 33 Gy) in three or five fractions. RESULTS: The overall survival (OS) rate, local failure-free survival (LFFS) rate, and disease progression-free survival (DPFS) rate at 5 years were 60%, 79%, and 74%, respectively. Twenty-three patients achieved complete response after FSRT. Only T stage at recurrence was an independent prognostic factor for OS and DPFS. Five patients exhibited severe late toxicity (Grade 4 or 5). CONCLUSIONS: With regard to OS and LFFS, our study provided favorable outcomes. The incidence of severe late toxicities was acceptable in our study. FSRT would be considered as the alternative treatment of choice in re-irradiation for locally recurrent NPC.

Stereotactic body radiation therapy boost in locally advanced pancreatic cancer.

PURPOSE: To investigate the clinical application of a stereotactic body radiation therapy (SBRT) boost in locally advanced pancreatic cancer patients with a focus on local efficacy and toxicity. METHODS AND MATERIALS: We retrospectively reviewed 30 patients with locally advanced and nonmetastatic pancreatic cancer who had been treated between 2004 and 2006. Follow-up duration ranged from 4 to 41 months (median, 14.5 months). A total dose of 40 Gy was delivered in 20 fractions using a conventional three-field technique, and then a single fraction of 14, 15, 16, or 17 Gy SBRT was administered as a boost without a break. Twenty-one patients received chemotherapy. Overall and local progression-free survival were calculated and prognostic factors were evaluated. RESULTS: One-year overall survival and local progression-free survival rates were 60.0% and 70.2%, respectively. One patient (3%) developed Grade 4 toxicity. Carbohydrate antigen 19-9 response was found to be an independent prognostic factor for survival. CONCLUSIONS: Our findings indicate that a SBRT boost provides a safe means of increasing radiation dose. Based on the results of this study, we recommend that a well controlled Phase II study be conducted on locally advanced pancreatic cancer.

Stereotactic body radiation therapy in patients with pelvic recurrence from rectal carcinoma.

OBJECTIVE: To investigate the clinical applications of stereotactic body radiation therapy (SBRT) using the CyberKnife system for pelvic recurrence from rectal cancer with a focus on survival and toxicity. METHODS: Between 2002 and 2006, 23 patients with recurrent rectal cancer were treated with SBRT at our institution. The median follow-up was 31 months. Sites of recurrence were pre-sacral in seven patients and the pelvic wall in 16. SBRT doses ranged from 30 to 51 Gy (median 39 Gy) and were delivered in three fractions. Response to treatment was assessed by computed tomography. Overall and local progression-free survival and toxicities were recorded. RESULTS: Four-year overall survival and local control rates were 24.9 and 74.3%, respectively. No prognostic factor was found to affect patient survival or local progression. One patient developed a severe radiation-related toxicity, but recovered completely after treatment. CONCLUSIONS: SBRT for pelvic recurrence was found to be comparable with other modalities with respect to overall survival and complication rates. Further studies are needed to confirm these preliminary results.