CASE REPORT Annals of Nuclear Medicine Vol. 15, No. 3, 289-291 , 2001 Accumulation of 67Ga citrate in early pregnancy Hiromasa KUROSAKI, Yoshihiro SAITO, Miho KAWASHIMA, Takeshi EBARA, Michitaka YAMAKAWA and Norio MITSUHASHI Department of Radiology and Radiation Oncology, Gunma University School of Medicine A 26-year-old pregnant woman complained of chest pain and dyspnea and was diagnosed with malignant lymphoma of the mediastinum. To determine the stage of malignant lymphoma, tumor scintigraphy with 67Ga citrate was performed. 67Ga scintigraphy revealed an abnormal accumulation in the center of the pelvic cavity. An artificial abortion was performed, and the early pregnancy obtained from the abortion showed a prominent uptake of 67Ga citrate ex vivo 67Ga citrate re-examination, which was performed immediately after the abortion, showed no abnormal accumulation in the pelvic cavity. To our knowledge, this is the first medical report on an aborted tissue investigated ex vivo to determine whether it demonstrated increased uptake of 67Ga citrate. Key words: gallium scintigraphy, pregnancy, placenta, fetal membrane, early pregnancy INTRODUCTION 67Ga citrate scintigraphy is one of the radionuclide type of examinations 67Ga citrate accumulates in the foci of inflammations and tumors, but only a few reports have shown an increased uptake of 67Ga citrate in the placenta. We report here on a case of a pregnant patient with malignant lymphoma, whose aborted fetal tissue showed an increased uptake of 67Ga citrate. CASE REPORT A 26-year-old woman visited her family doctor complain-ing of chest pain and dyspnea. There was an abnormal shadow on the mediastinum in a chest X-ray. Computed tomography of the chest revealed a tumor-like shadow, which seemed to infiltrate into the chest wall (Fig, 1). An operation was performed, but the tumor was unresectable because it had infiltrated into its immediate surroundings. Pathological examination of the open biopsy specimen indicated malignant lymphoma (diffuse large B cell type). The patient was admitted to our department for radiotherapy and was found to be 6 weeks pregnant. Informed consent for artificial abortion and further radiological examinations was obtained. 67Ga citrate (74 MBq) was administered after she had received radiation therapy with a total dose of 14 Gy to the mediastinum mass. At the point when she received 67Ga citrate, she was seven weeks pregnant. 67Ga citrate scintigraphy revealed an abnormal accumulation in the center of the pelvic cavity, but not in the mediastinal mass (Fig. 2). Artificial abortion was performed 5 days after 67Ga citrate injection. The aborted tissue showed a prominent uptake of 67Ga citrate in ex vivo imaging (Fig. 3). In histological research there were no records on infiltration of tumor cells in to fetal tissue. The scanning, which was performed immediately after the abortion, did not show the abnormal accumulation in the pelvic cavity (Fig. 4). The mediastinal tumor disappeared completely after ra- diation therapy with a total dose of 30 Gy, and the patient is now receiving chemotherapy and is in remission. DISCUSSION It has often been reported that there is an increased uptake of 67Ga citrate in the mammary glands during the lactation period.1 There was, however, no report regarding an accumulation of 67Ga citrate in the placenta, except for 2 reports in English medical literature.2,3 To our knowledge, this is the first report where the aborted tissue was investigated ex vivo. Mahon et al. reported that the placenta showed a higher uptake rate than other organs in rabbits.4 According to their report, 113mIn is only one radioligand which indicates a higher uptake rate than 67Ga, and the uptake of radioligand in the placenta is more evident than that in the fetus. It is uncertain at which stage of early pregnancy 67Ga citrate accumulates. Strong uptake was found in the early pregnancy at the 7th week in our case, and in the placenta at the 19 week stage in Newman's report.3 Tyndall et al. reported a marked concentration of 67Ga in uterus in 5-day pregnant rabbits.5 In 7- to 8-day pregnant rabbits 67Ga concentrated in blastocysts and sites of implantation. As gestation progressed, 67Ga increasingly concentrated in placental and mammary tissue. To our knowledge, it is uncertain where 67Ga citrate will concentrate in early pregnancy; the villi, chorion, deciduas, fetal membrane, or fetus. We always consider the possibility of accumulation in the placenta when we perform 67Ga citrate scintigraphy in women of childbearing age. It is important to take anamnesis when 67Ga citrate examination is planned, because the procedure may affect the normal development of the fetus, but in this case artificial abortion was planned before the 67Ga citrate examination was performed. ACKNOWLEDGMENT We gratefully acknowledge the help of Mr. Hidenori Ohtake, Division of Radiology, Gunma University School of Medicine, and thank Dr. Kazuko Abe, Department of Obstetrics and Gynecology, Tatebayashi Kousei Hospital. REFERENCES 1. Larson SM, Schall GL. Gallium-67 concentration in human breast. JAMA 1971; 218: 257. 2. Palestro CJ, Malat J, Collica CJ, Richman AH. Incidental diagnosis of pregnancy on bone and gallium scintigraphy, J Nucl Med 1986; 27: 370-372. 3. Newman RA, Gallagher JG, Clements JP, Krakoff IH. Demonstration of Ga-67 localization in human placenta. J Nucl Med 1978; 19: 504-506. 4. Mahon DF, Subramanian G. McAfee JG. Experimental comparison of radioactive agents for studies of the placenta. J Nucl Med 1973; 14: 651-659. 5. Tyndall RL, Chaskes SJ. Carlton JE, Nelson B, Daniel JC. Gallium-67 distribution in pregnant mammals. J Exp Zoo 1976; 195: 417-424.