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International audience; Purpose To characterize stray radiation around the target volume in scanning proton therapy and study the performance of active neutron monitors. Methods Working Group 9 of the European Radiation Dosimetry Group (EURADOS WG9-Radiation protection in medicine) carried out a large measurement campaign at the Trento Centro di Protonterapia (Trento, Italy) in order to determine the neutron spectra near the patient using two extended-range Bonner sphere spectrometry (BSS) systems. In addition, the work focused on acknowledging the performance of different commercial active dosimetry systems when measuring neutron ambient dose equivalents, H∗(10), at several positions inside (8 positions) and outside (3 positions) the treatment room. Detectors included three TEPCs-tissue equivalent proportional counters (Hawk type from Far West Technology, Inc.) and six rem-counters (WENDI-II, LB 6411, RadEye™ NL, a regular and an extended-range NM2B). Meanwhile, the photon component of stray radiation was deduced from the low-lineal energy transfer part of TEPC spectra or measured using a Thermo Scientific™ FH-40G survey meter. Experiments involved a water tank phantom (60 × 30 × 30 cm3) representing the patient that was uniformly irradiated using a 3 mm spot diameter proton pencil beam with 10 cm modulation width, 19.95 cm distal beam range, and 10 × 10 cm2 field size. Results Neutron spectrometry around the target volume showed two main components at the thermal and fast energy ranges. The study also revealed the large dependence of the energy distribution of neutrons, and consequently of out-of-field doses, on the primary beam direction (directional emission of intranuclear cascade neutrons) and energy (spectral composition of secondary neutrons). In addition, neutron mapping within the facility was conducted and showed the highest H∗(10) value of ∼51 μSvGy-1; this was measured at 1.15 m along the beam axis. H∗(10) values significantly decreased with distance and angular position with respect to beam axis falling below 2 nSv Gy-1 at the entrance of the maze, at the door outside the room and below detection limit in the gantry control room, and at an adjacent room (

Measurement of stray neutron radiation within a proton therapy facility

Primary cholangiocarcinoma (PCC) accounts for cca 9% of all carcinomas of the liver and biliary system. Its prognosis of always unfavourable and treatment is difficult.In 25 pigs strain BU PCC was induced chemically with the aim to test the action of regional chemotherapy on the tumor tissue. For treatment 5-fluorouracil, 5-fluoro-2-deoxyuridine, mitomycin C and doxorubicin was used either as monotherapy or in combinations. During chemotherapy a significant reduction of the tumour or fibrotization occurred, as compared with animals not receiving treatment. The median of survival was prolonged from 51.3 to 210.3 days.Regional chemotherapy is a significant constituent of oncological treatment of PCC. Complications of treatment are negligible and the rest for further treatment are encouraging.

The inhibition of H+/K(+)-ATPase (proton pump) of gastric parietal cells by substituted benzimidazoles represents a new therapeutic approach in conditions connected with hypersecretion of hydrochloric acid. Pantoprazol is the newest member of this group of drugs. Monotherapy of duodenal ulcer with pantoprazole or ranitidine was evaluated in terms of healing rate, tolerance and compliance.A double-blind, parallel-group comparing study (double dummy technique) of treatment florid duodenal ulcer (diameter 5-20 mm) was performed in 95 subjects (age 18-74 years). The active substances were either pantoprazole (40 mg before breakfast-47 subjects) or ranitidine (300 mg before bedtime-48 subjects). The average diameter of the ulcer and subjective complaints before treatment were comparable in both groups. After 2 weeks of pantoprazole therapy 88.5% of ulcers (a) and 87.2% patients (b) were cured, whereas the corresponding values in the ranitidine series amounted to 66% (a) and 62.5% (b) only (p = 0.006 for both (a) and (b)). The rate of healing in relative values of reducing the ulcer size was significantly higher after 2 weeks of pantoprazole therapy (p = 0.026 (a) and 0.0027 (b)). All ulcers healed after 4 weeks of this regimen. The difference between the pantoprazole and ranitidine series after 4 weeks was closely above the 5% level of significance (p = 0.589 for (a) and 0.0588 for (b) respectively). This was due to the low number of patients in both groups at this time interval, particularly in the pantoprazole group. Pain during day-time and regurgitation were observed significantly more frequently after ranitidine therapy. The compliance was very good and practically no adverse effects of pantoprazole therapy were observed.The healing rate of duodenal ulcer with pantoprazole monotherapy (40 mg before breakfast) was significantly higher than with ranitidine (300 mg before bedtime). The compliance of patients and the tolerance of pantoprazole were very good and its administration was not associated with any side-effects.

Pancreatic stones may be treated by endoscopic extraction or by surgery. Extracorporeal shock wave lithotripsy increased possibility of noninvasive steps to their elimination. The aim of this study was to describe our first experience with this method.10 patients (6 men and 4 women) in average age 47 years (between 19 to 72 years) were treated. The lithotriptor MEDILIT with sonographic targeting was used for fragmentation of pancreatic stones. Fragmentation was achieved in 8 patients, in 4 cases we observed spontaneous disappearnace, in 3 cases an endoscopic extraction of fragments was necessary. In one case good fragmentation was observed at control ECRP, but the repeated Wirsungography showed a big pseudocyst which had not been diagnosed at the first examination and surgery was necessary. In 2 cases no fragmentation was achieved and in these cases surgery was also indicated. No serious side effects were observed, nor elevation of amylase values compared with the situation before the shock wave treatment.Extracorporeal shock wave lithotripsy of pancreatic stones revealed good fragmentation and disappearance stone from ductus Wirsungi without serious side effects on clinical course and surrounding soft tissues.

Tumours of the biliary system (NBS) account for as many as 16% of all tumours of the GIT. Early diagnosis is difficult, contemporary treatment is not satisfactory and the prognosis is poor. It seems that one of the few therapeutic perspectives is multimodal treatment. The objective of the present work is to assemble experience with multimodal treatment of NBS.From January 1987 to December 1993 347 patients with NBS were treated, using bilioduodenal endoprostheses (BDE). In 26 patients treatment was supplemented by regional chemotherapy, in 10 by intraluminal radiotherapy, using lr 192. Average periods of survival:BDE 230 days, BDE+regional chemotherapy 662 days. Endoprostheses+intraluminal radiotherapy-survival period 96-293 days. The investigation has not yet been completed, as the majority of patients still survives.Implantation of BDE combined with regional chemotherapy significantly prolongs the life of patients with NBS. It seems that similar results will be obtained also by a combination of BDE and intraluminal radiotherapy. Multimodal treatment of NBS can be nowadays considered the method of choice in the treatment of tumours in this region.

Subjective complaints of patients with tumours of the biliary tree are late, early diagnosis is difficult and frequently impossible, the therapeutic results are unsatisfactory and the prognosis is poor. Surgical intervention is in more than 90% palliative, the tumours are not radiosensitive and their sensitivity to systemically administered cytostatics is low. The perspective of some patients was improved by implantation of bilioduodenal endoprostheses. The objective of the submitted work was to assemble experience with this method in patients with tumours of the upper portions of the biliary tree.Between January 1991 and May 1993 75 patients (42 females and 33 males, aged 48-65 years) with malignancies of the upper and middle part of the biliary tree were treated. Bilioduodenal endoprostheses (BDE) were inserted endoscopically in 70 patients. In 21 of them stenting was combined with regional chemotherapy via an implantable portho catheter. For patients with BDE alone, the median survival time was 18 months, for those with BDE and chemotherapy the median survival was 23 months (p0.01). 5-fluorouracil in monocombination was as potent as in combination with carmustine and/or doxorubicin.Endoscopic implantation of a bilioduodenal endoprosthesis with subsequent regional administration of 5-fluorouracil is an important therapeutic procedure in the treatment of malignant tumours of the upper and middle biliary tree.

Concentrations of CA 19-9, CA 50, CA 195 and DUPAN-2 were followed in serum, bile and pancreatic juice of 65 patients with malignant or benign lesions of CBD and/or pancrease. In sera, significant differences between neoplasias and benign lesions were seen only in patients with tumors in stages III. and IV. In the bile, however, the significant increase of DUPAN-2 and CA 195 were present in all stages of cholangiocarcinoma when compared with benign CBD lesions. In the pancreatic juice, the significant increase on of CA 19-9, CA 50 and DUPAN-2 in patients with pancreatic cancer (stages I-IV) could also be evidenced.

Lithotripsy by shock wave was performed in 12 patients with choledocholithiasis using the authors' own apparatus. The shock wave is created by an electric spark and the concentration is made by a rotational semi-elipsoid. The pressures attained in the second focus are 150 MPa. The focusing of the stones and the setting to the site of maximal pressures is made by means of two X-ray projections. Patients were indicated for the procedure when the method of endoscopic extraction had failed. Before the procedure a nasobiliary drain was inserted and after administration of analgesia on average 520 shocks were applicated. During the procedure no complications were observed. Fragmentation was achieved in 11 patients. Spontaneous release of fragments was recorded in five of the patients and in 6 during the check-up ERCP endoscopic extraction was made.

To evaluate the effect of a combination of intraluminal brachytherapy and metallic stent implantation in the treatment of patients with nonresectable biliary tumors.Thirty-two patients aged 41-80 years with nonresectable biliary malignancies--Klatskin's tumor (n = 17), gallbladder carcinoma (n = 11) and carcinoma of papilla Vateri (n = 4)--were treated with a combination of intraluminal brachytherapy (source Ir192, high-dose radiation regimen, total dose 30 Gy) and metallic stent implantation. Intraluminal brachytherapy and stent insertion (metallic, spiral-Z stent) were performed percutaneously in all patients.The mean survival in patients with Klatskin's tumor was 457 days (range: 64-1186; median: 358 days), in patients with gallbladder carcinoma 237 days (range: 92-609; median: 210 days) and in patients with carcinoma of papilla Vateri 850 days (range: 48-1518; median: 1277 days). The rate of 2-year survival in these groups as 27, 0 and 50%, respectively. The survival time differed significantly at the 5% level. The mean time of stent patency was 418, 220 and 850 days, respectively. No complications related directly to intraluminal brachytherapy were observed.Intraluminal brachytherapy combined with stent implantation is a safe method and appears to prolong survival in inoperable patients with Klatskin's tumor and carcinoma of papilla Vateri compared with nontreated patients in previous studies. In contrast no similar effect should be expected in patients with gallbladder carcinoma.