In vivo assessment of the gastric mucosal tolerance dose after single fraction, small volume irradiation of liver malignancies by computed tomography-guided, high-dose-rate brachytherapy.
OBJECTIVE
The aim of this study was to assess the tolerance dose of gastric mucosa for single-fraction computed tomography (CT)-guided, high-dose-rate (HDR) brachytherapy of liver malignancies.


METHODS
A total of 33 patients treated by CT-guided HDR brachytherapy of liver malignancies in segments II and/or III were included. Dose planning was performed upon a three-dimensional CT data set acquired after percutaneous applicator positioning. All patients received gastric protection post-treatment. For further analysis, the contours of the gastric wall were defined in every CT slice using Brachyvision Software. Dose-volume histograms were calculated for each treatment and correlated with clinical data derived from questionnaires assessing Common Toxicity Criteria (CTC). All patients presenting symptoms of upper GI toxicity were examined endoscopically.


RESULTS
Summarizing all patients the minimum dose applied to 1 ml of the gastric wall (D(1 ml)) ranged from 6.3 to 34.2 Gy; median, 14.3 Gy. Toxicity was present in 18 patients (55%). We found nausea in 16 (69%), emesis in 9 (27%), cramping in 13 (39%), weight loss in 12 (36%), gastritis in 4 (12%), and ulceration in 5 patients (15%). We found a threshold dose D(1 ml) of 11 Gy for general gastric toxicity and 15.5 Gy for gastric ulceration verified by an univariate analysis (p = 0.01).


CONCLUSIONS
For a single fraction, small volume irradiation we found in the upper abdomen a threshold dose D(1 ml) of 15.5 Gy for the clinical endpoint ulceration of the gastric mucosa. This in vivo assessment is in accordance with previously published tolerance data.
Streitparth
Florian
F
Department of Radiology, Charité Medical University Center, Campus Virchow Clinic, Humboldt University, Berlin, Germany.
Pech
Maciej
M
Böhmig
Michael
M
Ruehl
Ricarda
R
Peters
Nils
N
Wieners
Gero
G
Steinberg
Johannes
J
Lopez-Haenninen
Enrique
E
Felix
Roland
R
Wust
Peter
P
Ricke
Jens
J
D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D005260:Female; D005753:Gastric Mucosa / Q000528:radiation effects*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology*; D011836:Radiation Tolerance; D015641:Radiography, Interventional / Q000379:methods; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed