Assessment of radiation dose for surrounding organs and persons approaching implanted patients upon brachytherapy of prostate cancer with Iridium-192.

To assess a proper dose for radiation therapy fitting the typical physical characteristics of male Korean bodies, a mathematical phantom was prepared based on standard Korean male measurements. Upon brachytherapy of prostate cancer by implanting 192Ir into the prostate gland (the source organ), the absorbed dose of the prostate gland and surrounding organs and the expected dose of people within the vicinity were assessed. 192Ir, which has been the radionuclide of choice for prostate cancer brachytherapy, was selected for the simulation. It was assumed that 1 Ci of initial radioactivity would be administered. As a result, 1.28E-02 Gy/Ci was exhibited in the prostate gland of the source organ, and the dose to which persons within the vicinity were exposed was exhibited to be 9.19E-06 Sv at a distance of 30 cm from the front.

Paired-organ and other selected absorbed fraction for the Korean Reference Adult Male model.

The authors have developed a mathematical model for calculating internal radionuclide dosimetry for the Korean Reference Adult Male, and have also derived paired-organ and other selected inter-organ photon-specific absorbed fractions for this model. Each lung, kidney and adrenal gland was set as a separate source region even though each of them shares an identical physiological function with their complementary half. The thyroid gland was also set as a source region. Specific absorbed fractions (SAFs) were then derived by selecting 10 photon energies from 0.02 to 4.0 MeV inclusive. For this purpose the Monte Carlo methodology was used, and the derived SAF was compared with the resulting value of MIRD Pamphlet No. 5 and ORNL TM-8381, both of which were derived on the basis of the ICRP-23 reference man. The comparison showed that MIRD No. 5 and ORNL TM-8381 resulted in a higher absorbed fraction, but the phantom created on the basis of the Korean reference man led to a higher SAF. The weight of the organs of the phantom, and the size and location of the trunk seem to account for the differences. The energy-dependent differences in the SAFs are considered to be related to the distance between the source and target regions, the composition of the intervening tissues, and the photon energies and mean free paths. Also, as a result of deriving SAFs after setting each separate lung, kidney and adrenal gland as a source region, it was found that, although they are of the same physiological function, each individual organ serves as a source region on its own. Differences were noted in SAFs exerted on the source and target organs in accordance with the location of the organs, that is, whether they were located to the left or right of the source organs. The SAF derived in this study can be used for a more accurate internal radionuclide dosimetry for Koreans and other Orientals whose physiology, lifestyle and dietary habits are similar to those of Koreans.

Risk factors for pancreatitis in patients with anomalous union of pancreatobiliary duct.

BACKGROUND/AIMS: The clinical features of pancreatitis in patients with an anomalous union of the pancreatobiliary duct (AUPBD) are unclear. This study analyzed the clinical features, pathogenic mechanisms, risk factors, and clinical courses after treatment in AUPBD patients. METHODOLOGY: The medical records and cholangiopancreatograms of 58 patients with AUPBD and a choledochal cyst diagnosed between 1982 and 2001 were retrospectively reviewed. RESULTS: Sixteen (27.6%) out of the 58 AUPBD patients experienced pancreatitis. The incidence of pancreatitis was significantly higher in those patients with a long (>21mm) and wide (>5mm) common channel, a wide diameter of the proximal pancreatic duct (>2.5mm), the presence of a filling defect in the common channel, and the presence of a pancreatic duct anomaly (p<0.05). A bile duct diversion from the pancreatic duct by a choledochal cyst excision prevented the recurrence of pancreatitis in most cases. A duodenopancreatectomy was required in some cases. CONCLUSIONS: The morphological characteristics of the common channel and pancreatic duct contribute to the development pancreatitis in AUPBD patients and bile reflux into the pancreatic duct might be the main mechanism of pancreatitis in these patients.

Transurethral needle ablation for chronic nonbacterial prostatitis.

OBJECTIVE: To investigate the efficacy of transurethral needle ablation (TUNA) of the prostate for treating chronic nonbacterial prostatitis unresponsive to conservative therapies. PATIENTS AND METHODS: Forty-two patients (mean age 38.5 years, range 25-52) with nonbacterial prostatitis in whom clinical management was unsuccessful in relieving the symptoms or signs of prostatitis were treated using TUNA. All patients had a high leukocyte count (> 15 per high-power field) in expressed prostatic secretions (EPS) with no bacterial growth in either urine or prostatic secretion cultures. Before TUNA all patients were evaluated using a symptom score, satisfaction score (quality of life) and an examination of prostatic secretions. All patients were reassessed using the same variables 1 and 3 months after TUNA. Of the 42 patients, 10 had their semen analysed before and 3 months after treatment. RESULTS: The mean (sd) symptom and satisfaction scores improved significantly, from 11.02 (2.90) to 5.00 (2.61) and from 4.84 (0.57) to 1.26 (1.18), respectively, 3 months after TUNA (both P < 0.05). Of the 42 patients, 30 (71%) had normal EPS results within 3 months of TUNA. Also, of 37 patients with high leukocyte counts (> 100 per high-power field) before TUNA, 26 (70%) had normal EPS results within 3 months afterward, and 29 (78%) had a satisfaction score of < 3 points. CONCLUSIONS: TUNA may be a possible treatment option for patients with chronic nonbacterial prostatitis that is unresponsive to conservative therapies. A long-term follow-up and randomized studies are needed to confirm the efficacy of the TUNA against intractable chronic prostatitis.