MR Imaging of Endometrial Cancer that Occurs After Radiation Therapy for Cervix Cancer

PURPOSE: We wanted to describe the MR imaging findings of endometrial cancer in patients with a history of prior radiation therapy for cervical cancer (ECRT) and we compare them to the MR imaging findings of patients with spontaneously occurring endometrial cancer (SEC). MATERIALS AND METHODS: Twenty-two patients with endometrial cancer that was diagnosed by operation or endometrial biopsy were included in the study. The patients were divided into two groups according to the presence of past RT for cervical cancer: ECRT (n = 4) and SEC (n = 18). The MR images were retrospectively analyzed by consensus of two experienced radiologists. The MR imaging findings were analyzed by the size, shape and signal intensity of the mass, distension of the uterine cavity, the presence of cervical stenosis and the nature of the fluid collection. RESULTS: For the mass shape, all the ECRT lesions were polypoid masses. However, the SEC patients had 5 polypoid masses and 13 wall thickenings. The maximal diameter, signal intensity and enhancement pattern of the masses were not different between the ECRT and SEC patients. The width of the endometrial cavity varied between 3.9 cm in the ECRT patients and 0.4 cm in the SEC patients (p =0.002). All the ECRT patients had cervical stenosis. However, none of the SEC patients had cervical stenosis. CONCLUSION: MR imaging of ECRT patients demonstrated prominent distension of their uterine cavity and cervical stenosis, which may be the result of radiation fibrosis in the uterus.

Change of Ovary Before and After Radiotherapy in Reproductive Women with Cervix Carcinoma in MR Imaging

PURPOSE: To investigate changes in the ovary revealed by MR imaging before and after radiotherapy in premenopausal patients with cervical carcinoma. MATERIALS AND METHODS: Thirty-three premenopausal patients with cervical carcinoma underwent radiation therapy at an average dosage of 11,279 (external: 5,352; internal: 5,927) cGy. Before and after this therapy, all underwent pelvic MR imaging using a 1.5T MR scanner (GE Medical Systems, Milwaukee, U.S.A.). The average interval of follow-up MR imaging was 7.2 months, and axial T1-weighted and axial and sagittal T2-weighted MR images were obtained. The presence, size number of follicles, and differentiation of the zonal anatomy of the ovary were determined by two radiologists, who reached a consensus. RESULTS: After radiation therapy, all patients ceased menstruation. For ovaries, the detection rates before and after radiation therapy were 94% (62/66) and 39% (26/66) (p<0.05), respectively, and average ovary size was 2.6x1.9x2.2 cm before and 1.7x1.3x1.4 cm after therapy (p<0.05). The average number of ovarian follicles before and after therapy was 5.1 and 3.1, respectively (p<0.05). T2-weighted imaging, demonstrated differentiation of zonal anatomy in 74% of cases (46/62) before radiotheraphy, and 15% (4/26) after (p<0.05). CONCLUSION: Our study has shown that after radiation therapy in premenopausal patients with cervical cancer, detection rates, average size, and the number of ovaries decreased, findings which are similar to those for normal postmenopausal ovary. MR imaging can reveal structural change in ovaries.

Extensive acute lung injury following limited thoracic irradiation: radiologic findings in three patients

The aim of our study was to describe the radiologic findings of extensive acute lung injury associated with limited thoracic irradiation. Limited thoracic irradiation occasionally results in acute lung injury. In this condition, chest radiograph shows diffuse ground-glass appearance in both lungs and thin-section CT scans show diffuse bilateral ground-glass attenuation with traction bronchiectasis, interlobular septal thickening and intralobular smooth linear opacities.

Effect of Holmium-166 Injection into Hepatocellular Carcinomas (SK-HEP1) Heterotransplanted in Mice

PURPOSE: Holmium-166(H0-166) is a potent beta-emitter with a short half-life(26.83 hours) and high betaenergy(1.85MeV), and its necrotic effect on breast carcinoma has been proved. In cases of hepatocellularcarcinoma, Ho-166 can therefore be used for internal radiation therapy. The purpose of this study is to evaluatethe therapeutic effect of Ho-166 on hepatocellular carcinomas and to estimate the required dosage, according totheir size. MATERIALS AND METHODS: Tumor cells of hepatocellular carcinomas(SK-HEP1) were subcutaneouslyheterotransplanted into 71 nude mice and 71 hepatocellular carcinomas less than 2cm in diameter were grown. Ho-166was directly injected into a tumor at a dosage of between 0.5mCi(18.5MBq) and 3.0mCi(11MBq). After initialinjection of Ho-166, tumor uptake and radioactivity were indicated by gamma camera scanning. Hepatocellularcarcinomas in a control group of 20 mice were injected with 0.025ml of normal saline(n=10) and chitosansolution(n=10). Pathologic examination was performed and the necrotic tumor area was measured with an imageanalyzer. RESULTS: All specimens of Ho-166-injected hepatocellular carcinomas showed coagulation necrosisconsistent with radiation effect, while the control group did not show necrosis. As the injected dosage of Ho-166was increased, the necrotic area extended proportionally and the dosage required for total necrosis was calculatedaccording to tumor size. Gamma scintigraphy showed that injected Ho-166 had accumulated within the tumor, withoutthe accumulation of radioactivity in other organs ; the required dosage could be predicted on the basis ofradioactivity count indicated by a gamma camera. CONCLUSION: High-energy beta radiation emitted by Ho-166 can besufficient to kill tumor tissue without associated radiation damage to neighboring organs; intratumoral injectionis thought to be a promising therapeutic approach and a new method for the treatment of hepatocellular carcinoma.

Radiation Fibrosis : Differentiation from True Hilar Mass on Plain Chest Film

PURPOSE: Radiation-induced fibrotic mass might masquerade as a true hilar tumor mass on a plain chest radiograph. We attempted to differentiate radiation fibrosis from a true hilar tumor using only a plain radiograph. MATERIALS AND METHODS: Plain chest radiographs were obtained from seven patients who had developed radiation fibrosis simulating hilar mass after radiation therapy for lung cancer, and from 19 patients with lung cancer, a comparison group, who had not received radiation therapy. They were reviewed for the obliteration of the overlapped mediastinal and hilar anatomical silhouettes by the mass : pulmonary artery, heart or aorta border, and paraspinal line. RESULTS: All seven patients with radiation-induced fibrotic mass(bilateral lesion in twopatients) showed obliteration of all three overlapped anatomical silhouettes of the mediastinum and hilum on chestradiographs. in the comparison group of 19 patients with a true hilar mass, there was, however, no case which demonstrated obliteration of all landmarks. CONCLUSION: Obliteration of all anatomical landmarks at the hilum and mediastinum may be a helpful clue in the differential diagnosis of radiation-induced fibrotic mass from true hilarmass on a plain radiograph, particularly when clinical information on previous radiation therapy is unavailable.