Pilot Study on the Feasibility of PET/CT Lymphoscintigraphy with ⁸⁹Zr-Nanocolloidal Albumin for Sentinel Node Identification in Oral Cancer Patients

Abstract

With conventional imaging techniques such as planar lymphoscintigraphy and SPECT/CT, preoperative sentinel node (SN) identification can be difficult when the SN is near the primary tumor, as is the case in floor-of-mouth carcinomas. PET/CT lymphoscintigraphy may improve the detection and localization of such SNs. Methods: In this study, the clinical feasibility of PET/ CT lymphoscintigraphy using 89 Zr-nanocolloidal albumin was evaluated in 5 oral cancer patients. PET/CT lymphoscintigraphy was performed after peritumoral injection of 89 Zr-nanocolloidal albumin. The routine SN procedure, including SPECT/CT using 99m Tc-nanocolloidal albumin, was performed on the same patients 7-9 d after the injection of 89 Zr-nanocolloidal albumin. Results: Comparison of radiocolloid distribution on PET/CT and SPECT/CT showed identical drainage patterns. Moreover, PET/ CT was able to identify additional foci near the primary tumor. Conclusion: This pilot PET/CT study on SN detection indicated that lymphoscintigraphy using 89 Zr-nanocolloidal albumin is feasible.Key Words: sentinel node; PET/CT; 89 Zr; Nanocoll; head and neck cancer J Nucl Med 2013; 54:585-589 DOI: 10.2967/jnumed.112.115188Sent inel nodes (SNs) near a primary tumor can be hidden by the high amount of radioactivity at the injection site. In such cases, the resolution of planar lymphoscintigraphy and SPECT/CT is limited (1). For oral cancer, this is especially true for tumors located in the floor of the mouth that drain to lingual lymph nodes or level I lymph nodes (2,3), which may explain the significantly lower sensitivity of the SN procedure for floor-of-mouth tumors than for other sites in the oral cavity (80% vs. 97%) (4).PET provides dynamic 3-dimensional information at a higher spatial resolution and, thus, improves anatomic localization-of particular importance in the complex anatomy of the neck, with its abundant lymph nodes (i.e., about 150 on each side). In addition, improved visualization of lymphatic vessels may result in better differentiation between first-and second-echelon lymph nodes. Therefore, we hypothesized that PET might perform better than g-camera-based techniques.Recently, we developed 89 Zr-nanocolloidal albumin for lymphatic mapping and SN detection using PET/CT. The potential of this tracer was shown preclinically in a rabbit lymphogenic metastasis model (5).The present study aimed to evaluate the feasibility of PET/ CT lymphoscintigraphy using 89 Zr-nanocolloidal albumin in patients with early-stage oral cavity carcinoma and to obtain initial clinical experience in a head-to-head comparison with g-camera-based imaging using 99m Tc-nanocolloidal albumin. MATERIALS AND METHODS PatientsThe study included 5 previously untreated patients with earlystage oral cancer who were scheduled for transoral excision and the SN procedure. Each patient had a clinically negative neck as assessed by ultrasound-guided fine-needle aspiration cytology. Three of the patients had a paramedian floor-of-mouth carcinoma, and 2 had a lateral tongue carcinoma. Th...

Non-invasive mapping of deep-tissue lymph nodes in live animals using a multimodal PET/MRI nanoparticle

“…This approach allows for multimodal SPECT and fluorescence guided resection of draining LNs in both pre- and clinical settings 30,31 . In a related strategy, others have covalently modified the albumin colloid with 89 Zr-DFO (rather than with 99m Tc) for preclinical drainage mapping in rabbits 32 and man 18 , as well as with IRDye800CW for multimodal imaging 33 . Further developments in the radio- and radio-fluorescence guidance are expected in the near future.…”

“…The most interesting translated work has used infrared dyes coupled to the colloid, either covalently (with IRDye800CW) 16 or non-covalently (with indocyanine green) 17 , or PET radiolabelling of the colloidal material 18 . Recently a new 99m Tc dextran preparation ‘Lymphoseek’ was approved for lymphosciintigraphy by the USFDA 19 .…”

First-in-human evaluation of a hybrid modality that allows combined radio- and (near-infrared) fluorescence tracing during surgery

“…Although this procedure can be considered relatively straightforward, e.g. for the identification of SNs in the axilla, for the identification of SNs in the head and neck or in the pelvic area several issues remain to be resolved: i) the complexity of the anatomy and the abundance of delicate anatomical structures that surround the SN may complicate intraoperative SN detection; ii) blue dye is of limited value in these areas and may obscure resection margins [2]; and iii) detection of an SN located in close proximity to the injection site may be hampered due to the high radioactive background signal coming from the injection site [3]. The integrated use of the near-infrared (NIR) dye indocyanine green (ICG) and 99m Tc-nanocolloid in the form of the hybrid tracer ICG-99m Tc-nanocolloid [4] was shown to extend the conventional radioguided technology.…”

Molecular Imaging and Therapy of Merkel Cell Carcinoma

“…New techniques such as SPECT/CT and intraoperative cameras might further increase the sentinel node detection rate and help in complicated cases where primary tumor is close to the drainage site. Recently, there has been interest in combining new radiopharmaceuticals such as Zr-89 nanoalbumin with PET/CT [45]. …”