Development of sentinel lymph node biopsy technique in patients with salivary gland cancer using the IDEAL framework

Distribution of sentinel nodes from parotid tumors-A feasibility study

BACKGROUND

Optimum management of the N0 neck is unresolved in parotid salivary gland cancer. Sentinel node biopsy (SNB) can reliably detect microscopic lymph node metastasis and its´ clinical use is increasing for head and neck tumors. The object of this study was to establish whether the technique is applicable to detect distribution of sentinel nodes for parotid tumors.

MATERIALS AND METHODS

Prosepective observational study in 30 patients with benign or low-grade T1-T2N0 malignant tumors in the parotid gland planned for surgical treatment. Distribution of SN was detected with a preoperative ultrasound-guided peritumoral injection with a technetium-99 (Tc-99 m) laballed tracer followed by a SPECT-CT and intraoperative measurement in the neck and parotidal tissue. In patients with cytologically suspected malignant tumor or highly unclerar cytology, SNB was also performed.

RESULTS

Sentinel nodes (SNs) were detected in 26/30 cases. Out of these, 7 presented with only one SN, whereas multiple sentinel nodes where detected in 19 cases. No SNs were found in neck level 1. SN was detected in level 5 independent of tumor location within the parotid gland. An intraparotidal distribution of SNs was more frequent in larger tumors.

CONCLUSIONS

The use of SN-technique in the planning of surgical treatment of parotid tumors seems feasible. It may be of clinical value for patients with parotid cancer to enable a more accurate staging and to detect occult metastasis in the SNs within the parotid as well as in the neck, enabaling the possibility to surgically remove all positive SNs at primary surgery and with reduced surgical morbidity.

PET- and SPECT-based navigation strategies to advance procedural accuracy in interventional radiology and image-guided surgery

INTRODUCTION

Nuclear medicine has a crucial role in interventional strategies where a combination between the increasing use of targeted radiotracers and intraprocedural detection modalities enable novel, but often complex, targeted procedures in both the fields of interventional radiology and surgery. 3D navigation approaches could assist the interventional radiologist or surgeon in such complex procedures.

EVIDENCE ACQUISITION

This review aimed to provide a comprehensive overview of the current application of computer-assisted navigation strategies based on nuclear imaging to assist in interventional radiology and image-guided surgery. This work starts with a brief overview of the typical navigation workflow from a technical perspective, which is followed by the different clinical applications organized based on their anatomical organ of interest.

EVIDENCE SYNTHESIS

Although many studies have proven the feasibility of PET- and SPECT-based navigation strategies for various clinical applications in both interventional radiology and surgery, the strategies are spread widely in both navigation workflows and clinical indications, evaluated in small patient groups. Hence, no golden standard has yet been established.

CONCLUSIONS

Despite that the clinical outcome is yet to be determined in large patient cohorts, navigation seems to be a promising technology to translate nuclear medicine findings, provided by PET- and SPECT-based molecular imaging, to the intervention and operating room. Interventional Nuclear Medicine (iNM) has an exciting future to come using both PET- and SPECT-based navigation.