Potential role of hybrid positron emission tomography in pre-operative assessment of primary salivary gland carcinomas

Abstract

Objective The added value of hybrid positron emission tomography is increasingly recognised in head and neck cancer. However, its potential role in salivary gland carcinomas has been scarcely investigated. Methods A consecutive cohort of 45 salivary gland carcinoma patients who underwent pre-therapeutic hybrid positron emission tomography and surgical resection was reviewed. This study investigated whether maximum standardised uptake value correlated with tumour phenotype. Results Tumours of high-grade disease on histology (salivary duct carcinoma, carcinoma ex pleomorphic adenoma) had higher maximum standardised uptake value (Kruskal–Wallis test, p = 0.011) than low-grade tumours (adenoid cystic carcinoma and acinic cell carcinoma). Patients with pathologically confirmed node-positive disease had significantly higher maximum standardised uptake value of the primary tumour than patients with pathologically confirmed node-negative disease (Kruskal–Wallis test, p = 0.012). Conclusion Maximum standardised uptake value of the primary tumour may guide clinical decision-making in patients with salivary gland carcinomas, as a high maximum standardised uptake value is associated with high-grade tumour histology and the presence of lymph node metastases. Clinicians may consider more aggressive surgery for these patients.

The protective role of postoperative radiation therapy in low and intermediate grade major salivary gland malignancies: A study of the Canadian Head and Neck Collaborative Research Initiative

“…Treatment of primary salivary gland malignancies usually includes surgical resection followed by postoperative radiation therapy for high‐grade histology and/or advanced‐stage disease 10,12 . For low and intermediate grade disease without pathologic lymph node involvement and with clear resection margins, adjuvant treatment is not routinely offered 13 …”

“…[9][10][11] Treatment of primary salivary gland malignancies usually includes surgical resection followed by postoperative radiation therapy for high-grade histology and/or advanced-stage disease. 10,12 For low and intermediate grade disease without pathologic lymph node involvement and with clear resection margins, adjuvant treatment is not routinely offered. 13 Because tumors of the parotid gland share a close anatomic relationship to the facial nerve, close or even microscopically positive resection margins are often demonstrated upon final pathological examination.…”

MRI-based radiomics for predicting histology in malignant salivary gland tumors: methodology and “proof of principle”

“…The extent of surgery, i.e. partial or total parotidectomy, sacrificing the facial nerve (at least indirectly, based on aggressiveness/ infiltration) and the decision for or against a neck dissection or the probability of postoperative radiotherapy strongly depends on the histopathological findings 28 , 29 . Unfortunately, this information can only be obtained after initial surgery, as open biopsies should be avoided.…”

“…Karimian et al investigated the utilization of FDG-PET-CT to characterize high-grade malignancies in 45 patients and could demonstrate that the tracer uptake positively correlated with the grading 29 . In that study no machine learning model was trained or tested on data, but the correlation between SUV and tumor grade was investigated and the dataset was relatively small and also imbalanced (41 cases including 24 high grade, 9 low grade and 8 intermediate grade).…”