Australian and New Zealand Journal of Obstetrics and Gynaecology 2005; 45: 161–164 161 Blackwell Publishing, Ltd. Short Communication Gestational trophoblastic neoplasia treatment Comparison of pulse methotrexate and pulse dactinomycin in the treatment of low-risk gestational trophoblastic neoplasia Mitra Modares GILANI, 1 Fariba YARANDI, 1 Zahra EFTEKHAR, 1 and Parviz HANJANI 2 1 Tehran University of Medical Sciences, Tehran, Iran, 2 Rosenfeld Cancer Center, Abington Memorial Hospital, Pennsylvania, USA. Abstract Methotrexate and dactinomycin are efficient drugs in the treatment of patients with low-risk gestational trophoblastic neoplasia (LRGTN). To compare the effectiveness of these two drugs in LRGTN, 46 patients were randomised to receive weekly intramuscular methotrexate at 30 mg/m 2 (n = 28) or intravenous dactinomycin at 1.25 mg/m 2 every 2 weeks (n = 18). Fourteen patients (50%) in the methotrexate group and 16 patients (89%) in the dactinomycin group achieved complete response. Greater patient convenience and a lower number of required visits make dactin- omycin superior to other alternatives. Key words: β-hCG, dactinomycingestational trophoblastic neoplasia, methotrexate. Introduction Low risk gestational trophoblastic neoplasia (LRGTN) is defined as persistent molar pregnancy with a score lower than six based on the modified World Health Organisation (WHO) prognostic system as adapted by the International Federation of Gynecologists and Obstetrics (FIGO). 1 In 1956, methotrexate was first reported to be useful in the treatment of trophoblastic neoplasia. 2 A few years later, dactinomycin was introduced as an effective treatment in methotrexate- resistant LRGTN cases. 3 Several different chemotherapy regimens have been reported. 4–6 Complete response rates for these various treatment regimens have ranged from 60 to 98%. Dactinomycin has also been used as various chemotherapy regimens for the treatment of LRGTN. In 1980, Petrilli and Morrow reported a trial of pulsed dactinomycin. 7 According to preliminary reports, single dose dactinomycin as the primary therapy for LRGTN patients has produced an excellent remission rate with acceptable toxicity, and is also cost effec- tive and convenient. 8–10 Both methotrexate and dactinomycin continue to be used for LRGTN. However, there is as yet no consensus on a single ‘best’ regimen. The particular agent used to treat LRGTN depends more on local experience with one of the various regimens. The present study was designed to determine whether weekly parenteral methotrexate or pulsed dactinomycin is more effective for the treatment of LRGTN. Methods Between 2001 and 2003, 46 patients with LRGTN were enrolled into these protocols after we obtained the informed consent. Ethically, privacy and confidentiality were observed. The selection of patients for each treatment group was com- pletely randomised and based on an approved protocol by the Medical Ethics Committee at the University of Medical Sciences, Tehran. The diagnosis of gestational trophoblastic neoplasia (GTN) was based on the history of an antecedent molar pregnancy, and/or a plateau or rise in the follow-up β- hCG serum levels, where plateau was defined as less than 10% fall of β-hCG level over three consecutive weeks and rise was defined as significant, more than 20% rise of β-hCG level over the previous values. β-hCG levels were all measured by the immunochemiluminescent assay. Patients with histologically confirmed placental site pseu- dotumour (PSTT), patients who received any prior chemo- therapy for any occurrence of GTN, patients who would not agree to practice effective contraception for the duration of the study, patients with metastatic GTN disease (lung metastases Correspondence: Dr Fariba Yarandi, Department of Gynecological Oncology, Mirza Koochak Khan Hospital, North Villa Street, Tehran, Iran. Email: fariba_yarandi@yahoo.com Received 4 October 2004; accepted 8 November 2004.