I read the recent International Federation of Gynecology and Obstetrics (FIGO) paper on “Cancer in pregnancy: FIGO Best practice advice and narrative review”1 with great interest. The article is a landmark paper on the approach and treatment of cancer in pregnancy. However, I wish to raise concern about an inconsistency in the discussion of sentinel lymph node biopsy (SNB) during pregnancy. This ambiguity could inadvertently lead to misinterpretation by clinicians. In the section on breast cancer, the FIGO guidance explicitly recommends SNB using low-dose technetium-99 m at the preferred tracer because of its proven safety and feasibility.1 In the section on cervical cancer, the article states that “sentinel node mapping may be performed.” This phrasing, by omission, implies that the same approach endorsed for breast cancer should be extrapolated to cervical cancer. The first report on SNB and cervical cancer during pregnancy was with technetium in 2006 and showed it was feasible.2 Until now, there are no safety data supporting the use of technetium in cervical cancer during pregnancy, and its application should therefore be avoided given the potential risk of fetal radiation exposure.3 The rationale for this precaution lies in the fundamental anatomical and radio-physical differences between breast and cervical injection sites. In breast cancer, the injection site is located 25–40 cm from the uterus, and attenuation through thoracic and abdominal soft tissues minimizes fetal exposure. In cervical cancer, by contrast, technetium is injected within centimeters of the fetus, through highly vascularized pelvic tissue with limited shielding. Therefore, tracer leakage into uterine or placental circulation seems realistic. Fetal radiation exposure in this context has never been quantified through in vivo dosimetry, leaving the true dose uncertain and unquantified. Available evidence supports indocyanine green (ICG) as the preferred tracer for pelvic SNB during pregnancy. ICG avoids ionizing radiation entirely and has negligible placental transfer.4, 5 ICG has shown high SNB detection rates in cervical cancer and has been used successfully in a few pregnant patients.4 Blue dye tracers are contraindicated, due to risks of maternal anaphylaxis, methemoglobinemia, serotonin syndrome. The potential fetal risks include teratogenicity, hyperbilirubinemia, hemolytic anemia, and respiratory distress and fetal death. Unfortunately, the authors fail to explicitly mention ICG as the tracer of choice for pelvic procedures, leaving the statement incomplete and potentially misleading.1 In non-pregnant patients with early-stage cervical cancer, SNB has become the standard staging procedure and is incorporated into international guidelines, achieving high sensitivity and reducing the morbidity associated with complete pelvic lymphadenectomy.6 In pregnancy, however, the situation is entirely different. The “Cancer in pregnancy: FIGO Best practice advice and narrative review” explicitly states that “sentinel node resections are considered safe during pregnancy,” yet this assertion is based exclusively on studies in breast cancer and is not supported by any evidence in cervical cancer.1 The guideline further mentions that pelvic lymphadenectomy may be performed up to the mid-second trimester but does not provide a clear recommendation on whether sentinel node biopsy should replace it. This omission creates ambiguity, as the phrasing could be interpreted as implicit support for SNB. In contrast, recent publications emphasize that laparoscopic pelvic lymphadenectomy remains the preferred approach, while sentinel node biopsy is still regarded as experimental during pregnancy.7, 8 Across all major international and national guidelines, there is a consistent absence of endorsement for SNB during pregnancy (Table 1). The American, European, Spanish, Italian, French, Polish, Australian and Japanese guidelines do not provide any statement or recommendation regarding SNB in pregnant patients, limiting nodal assessment to conventional pelvic lymphadenectomy.9-17 Both the European (ESGO/ESTRO/ESP) and the 2026 American National Comprehensive Cancer Network (NCCN) guidelines support SNB only in non-pregnant women with early-stage cervical cancer. For pregnant patients requiring nodal staging, standard lymphadenectomy remains the recommended approach.18, 19 The UK guidelines explicitly discourage SNB during pregnancy due to unproven safety and lack of validated diagnostic accuracy.20 Similarly, a Swedish group recommends to classify the procedure as experimental and advises a pelvic lymphadenectomy.21 The recent ESGO–INCIP22 guidelines maintain this cautious approach, stating that SNB with ICG should only be considered within prospective clinical trials. In conclusion, there is no empirical or guideline-based justification for performing SNB in cervical cancer during pregnancy. Across all major societies, this procedure is either omitted or explicitly discouraged. FIGO appears to stand alone in suggesting the feasibility, a position that remains isolated and unsupported by evidence. The identification of a sentinel node in a pregnant patient does not equate to proven diagnostic accuracy or procedural safety equivalent to that in non-pregnant woman. Furthermore, the FIGO guidance should explicitly state that, in cervical cancer during pregnancy, ICG, is the only acceptable tracer. The use of technetium is inappropriate for cervical cancer in this clinical setting. Until prospective data confirm fetal safety and diagnostic reliability, pelvic lymphadenectomy must remain the standard for nodal assessment in cervical cancer during pregnancy. Any consideration of SNB should occur only within research settings or in exceptional cases, and only after multidisciplinary team discussion, including obstetric and neonatal input. The author has no conflicts of interest to declare. Generative AI was used only for language editing and improving readability. No AI tool was involved in generating scientific content, data analysis, or interpretation. The authors take full responsibility for the accuracy and integrity of the manuscript. No new data were generated for this study; the article is based on previously published literature and data sharing is therefore not applicable.
Wiebren Age Andries Tjalma (Fri,) studied this question.