Radiat Oncol J.  2021 Sep;39(3):193-201. 10.3857/roj.2021.00395.

Single photon emission computed tomography-computed tomography visualization of sentinel lymph nodes for lymph flow guided nodal irradiation in oral tongue cancer

• Novikov SN
• Krzhivitskii PI
• Radgabova ZA
• Kotov MA
• Girshovich MM
• Artemyeva AS
• Melnik YS
• Kanaev SV

• KMID: 2520455
• DOI: http://doi.org/10.3857/roj.2021.00395

Abstract

Purpose
To evaluate correlation of single photon emission computed tomography-computed tomography (SPECT-CT) data on lymph flow (LF) from oral tongue cancer (OC) and the topography of lymph nodes (LN) metastases; to determine the clinical value of lymph flow guided radiotherapy (LFGRT).
Materials and methods
SPECT-CT visualization of LF from the OC lesions was performed after peritumoral injection of 99mTc-phytate in 26 primary patients with clinical stage cT1-2N0M0 disease. We determined the individual drainage (unilateral/bilateral) from the tumor, and localization of sentinel LNs according to the neck levels. Metastases in LNs were verified with histology and a 2-year follow-up.
Results
SPECT-CT detected bilateral LF in 10 (38.5%) of 26 patients; in 16 (61.5%) cases the drainage was unilateral. Histology revealed LNs metastases in three cases; regional recurrences were diagnosed in other four patients. In all seven observations metastases were located at the same site and level as the sentinel LNs. In eight (30.8%) of 26 patients sentinel LNs were visualized unilaterally at levels Ib–IIa; in five cases, unilaterally at levels I–IIa–III. In these patients, LFGRT demonstrated 59%–70% reduction of irradiated volume, and 26%–42% and 51%–70% decrease of the mean dose to the spinal cord and the contralateral parotid gland. In patients with a bilateral drainage the reduction of doses absorbed by the spinal cord and contralateral parotid gland was 19% and 6%, respectively.
Conclusions
Localization of sentinel LNs determined by SPECT-CT corresponds to the localization of metastatic LNs in terms of side and levels.

Keyword

Oral tongue cancer; Sentinel lymph nodes; Lymph flow; Radiotherapy