RESUMO
PURPOSE: We conducted an investigation to evaluate the robustness of different proton therapy delivery technique for treatment of prostate cancer. Three commonly used delivery techniques; intensity modulated, double-scattered, and single field uniform dose delivery was investigated for one field verses two field daily fraction. METHOD: Computer tomography (CT) for a patient was deformed based on acquired daily MVCTs obtained during the course of treatment by a Tomotherapy unit. The deformed CTs were used for proton planning retrorespectively using intensity modulated (IMPT), double-scattered (DSPT), and single field uniform dose (SFUD) delivery technique. The plans were evaluated for single-field versus two-field per fraction for each technique. The plans robustness was evaluated for each technique by comparing the maximum dose to rectum, bladder, prostate and CTV as well as the minimum dose to prostate and CTV. In addition, 95% coverage to prostate and CTV compared for each plan. RESULTS: The average and STD for deformed prostate volume was 22.4 ±0.5 (1s) for the course of treatment. On average the maximum dose delivered to rectum and bladder with single-field verses two-field IMPT were higher by 2.5%. With same respect, the single-field verses two-field for DSPT were 0.5% higher for rectum but the same for bladder. Single-field SFUD delivered 1% higher dose to both rectum and bladder compare to two-field delivery. Table 1 summarizes the results. CONCLUSION: Single-field IMPT delivered higher dose to rectum, bladder, prostate, and CTV than any other technique. But two-file IMPT delivered most homogenous and consistent dose to prostate and CTV with much lower dose to rectum and bladder compare to DSPT and SFUD. With same respect two-field SFUD delivery produced better dose coverage to prostate and CTV compare to DSPT. The two-field IMPT with conjunction of daily cone beam CT can be considered a better dose delivery technique.
RESUMO
This preliminary study was designed in a trial to delineate the size of the problem of ochratoxicosis and its relation to genesis of lesions mounting to end stage renal disease (ESRD) or urothelial tumors in Egypt. This study comprised five groups of patients having renal diseases of different presentations; they are: patients with (ESRD) under conservative medical treatment (group 1), patients with (ESRD) under treatment with regular hemodialysis (group 2), renal allograft recipients (group 3), patients with nephrotic syndrome (group 4) and patients with urothelial tumors (group 5). In addition, two reference groups: potential related donors for renal transplantation (group 6) and healthy control with negative family history of renal disease (group 7). For all groups, laboratory, radiological and histopathological evaluation of kidney status were carried out coupled with determination of ochratoxin A level in serum, in urine and in biopsy specimens of patients with urothelial tumors. High ochratoxin serum levels were found in patients with ESRD (groups 1 and 2) (P < 0.01), higher serum levels were detected in the group without dialysis (group 1) in comparison with the reference groups possibly due to ochratoxin. A clearance by dialysis. Ochratoxin A was detected in serum and urine of renal transplant recipients (group 3) (P < 0.01) and especially higher levels were found in patients with nephrotic syndrome (group 4) (P < 0.001). For the group with urothelial tumor (group 5), positive serum, urine and tissue biopsy specimens for ochratoxin levels were found (P < 0.01). The results could lead to the conclusion that ochratoxin A could be correlated to the genesis of renal disease leading to (ESRD) or causing urothelial cancer. A thorough and in depth study of the problem of ochratoxicosis and renal disease causation in Egypt is now recommended.
