Department of Plastic Surgery, Herlev and Gentofte Hospital, Copenhagen, Denmark; Department of Clinical Medicine, Copenhagen University, Copenhagen, Denmark.
Department of Clinical Physiology, Nuclear Medicine and PET, Herlev and Gentofte Hospital, Copenhagen, Denmark.
Eur J Surg Oncol. 2021 Sep;47(9):2450-2453. doi: 10.1016/j.ejso.2021.03.241. Epub 2021 Mar 17.
It has been reported that the survival of patients having sentinel node (SN) biopsy for melanoma the day after lymphoscintigraphy using Tc99m-nanocolloid is worse than that of patients having lymphoscintigraphy and SN biopsy on the same day [1,2]. A possible explanation suggested is that overnight migration of the tracer from SNs to 2nd-tier nodes occurs, causing failure to remove true SNs.
The possibility of overnight tracer migration leading to errors in SN-identification was investigated in 12 patients scheduled for lymphoscintigraphy the day before surgery by repeating SPECT-CT imaging the next morning, before their SN biopsy. The aim was to check whether onward migration of colloid from previously-identified SNs had occurred.
No significant migration of Tc99m-nanocolloid occurred overnight in any patient. All nodes reported to be SNs on day 1 imaging were also present and regarded as SNs on day 2 images. No new foci were visualised on day 2, but some that had been identified on day 1 were not seen on day 2.
Since migration of nanocolloid overnight did not occur, this cannot explain the reported survival disadvantage for patients undergoing SN biopsy the day after lymphoscintigraphy. A likely alternative possibility is that inadequate doses of radioisotope were used for next-day procedures, causing the mistaken removal of 2nd-tier nodes instead of true SNs more frequently. Further research is required to explain the reported reduction in survival of patients having next-day SN biopsy procedures, since the possibility has important clinical implications.
据报道，使用 Tc99m-纳米胶体进行淋巴闪烁显像后第二天进行前哨淋巴结 (SN) 活检的患者的生存率比同一天进行淋巴闪烁显像和 SN 活检的患者差[1,2]。提出的一个可能的解释是示踪剂从 SN 向二级节点的夜间迁移导致无法切除真正的 SN。
为了研究示踪剂的夜间迁移是否会导致 SN 识别错误，我们对 12 名计划在手术前一天进行淋巴闪烁显像的患者进行了研究，在进行 SN 活检前的第二天早上重复进行 SPECT-CT 成像。目的是检查胶体是否从先前识别的 SN 中发生了迁移。
在任何患者中，Tc99m-纳米胶体都没有发生明显的夜间迁移。在第 1 天的图像中报告为 SN 的所有节点在第 2 天的图像中也存在并被视为 SN。第 2 天没有观察到新的焦点，但第 1 天已经识别的一些焦点在第 2 天没有观察到。
由于纳米胶体没有发生夜间迁移，因此不能解释报告中进行 SN 活检的患者在淋巴闪烁显像后第二天生存率下降的原因。一个可能的替代可能性是，第二天的程序使用的放射性同位素剂量不足，导致经常错误地切除二级节点而不是真正的 SN。需要进一步的研究来解释报告中第二天进行 SN 活检程序的患者生存率降低的原因，因为这种可能性具有重要的临床意义。
