Role of functional imaging in head and neck squamous cell carcinoma: fluorodeoxyglucose positron emission tomography and beyond

Chapter 3 The Role of PET/CT in Squamous Cell Carcinoma of the Head and Neck

Head and neck squamous cell carcinoma is an important cause of cancer morbidity worldwide and has been stratified into human papillomavirus-related and human papillomavirus-unrelated subgroups that affect prognosis and now staging. Conventional anatomical imaging methods are suboptimal for the detection of regional and distant metastases that are important prognosticators associated with poor outcomes. Functional imaging with (F18)-fluorodeoxyglucose-positron emission tomography/computed tomography (PET/CT) is a useful tool in the management of head and neck squamous cell carcinoma, providing complementary physiological and anatomical information. In this article, optimal PET/CT technique will be reviewed and the pretreatment and posttreatment applications of PET/CT will be described. A simplified approach to imaging interpretation, including review of pearls and pitfalls will be discussed. An initial framework for follow-up evaluation will be provided.

The role of changes in maximum standardized uptake value of FDG PET-CT for post-treatment surveillance in patients with head and neck squamous cell carcinoma treated with chemoradiotherapy: preliminary findings

OBJECTIVE

No clear consensus exists regarding the optimal interval and frequency of follow-up positron emission tomography (PET)-CT in patients with head and neck squamous cell carcinoma (HNSCC) treated with chemoradiotherapy (CRT). Here, we sought to clarify whether the changes in the maximum standardized uptake value (ΔSUV_max) may be a valid parameter to help decision-making for surveillance management after CRT.

METHODS

40 patients underwent PET-CT at pre-treatment and 3 months after CRT. Patients were followed by sequential PET-CT for 2 years after CRT. The ΔSUV_max of the primary tumour and the metastatic nodes were calculated between pre-treatment and 3 months after the CRT, and we evaluated the associations between ΔSUV_max and the manifestation of recurrence, time to recurrence and the patient survival.

RESULTS

The ΔSUV_max of the primary tumour was significantly lower for the lesions with recurrence than that for those with non-recurrence for both the primary site and the nodal site (p = 0.007, 0.02). A significant correlation was found between the time to recurrence and the ΔSUV_max of the primary tumour (r = 0.63, p < 0.05). The threshold ΔSUV_max of the primary tumour of 1.04 revealed 76.9% sensitivity and 86.4% specificity for distinguishing recurrence from non-recurrence. The progression-free survival and overall survival of the two patient groups divided by the ΔSUV_max of the primary tumour at 1.04 showed a significant difference (p = 0.003, 0.02). The ΔSUV_max of the metastatic nodes did not show a significant association with recurrence or patient survival.

CONCLUSION

The ΔSUV_max of the primary tumour showed a significant association with recurrence and patient survival. Advances in knowledge: The ΔSUV_max of the primary tumour may be a valid clinical parameter to help decision-making for the surveillance management of patients with HNSCC after CRT.

Prognostic factors and the role of adjuvant radiation therapy in non-melanoma skin cancer of the head and neck

Non-melanoma skin cancer (NMSC) is the most common cancer worldwide. Among the two types of NMSC, basal cell carcinoma (BCC) accounts for approximately 75% to 80% of cases and cutaneous squamous cell carcinoma (cSCC) accounts for 20% to 25% of cases. The majority of lesions are low risk and treated with simple surgical excision, which provides histopathologic information and is associated with high cure rates and acceptable cosmetic and functional outcomes. cSCCs are generally more aggressive than BCCs. NMSC commonly occurs in the sun-exposed head and neck region (80% to 90%). Approximately 5% of patients with NMSC (mainly cSCC) will have clinicopathologic features that predict for an increased risk for local and regional recurrence and, rarely, distant relapse. These features include locally advanced primary disease (stage T3-T4), regional nodal involvement, clinical perineural invasion, recurrent disease following treatment, and immunosuppression. Patients who have these features may warrant review by a multidisciplinary tumor board and might require combined modality treatment involving surgery and adjuvant radiation therapy (RT). This article focuses on our current understanding of the prognostic factors and role of adjuvant RT in high-risk NMSC of the head and neck.

Impact of initial FDG PET/CT in the management plan of patients with locally advanced head and neck cancer

OBJECTIVE

To determine the impact of initial FDG PET/CT staging on clinical stage and the management plan in patients with locally advanced head and neck cancer (LAHNC).

MATERIALS AND METHODS

We retrospectively reviewed the records of 72 consecutive patients (2007-2010) staged with PET/CT and conventional CT with tumours of hypopharynx/larynx (26 patients, 36 %), oral cavity (17 patients, 24 %), oropharynx (16 patients, 22 %), nasopharynx (12 patients, 17 %), and others (2 %). The impact of PET/CT on management plans was considered high when PET/CT changed the planned treatment modality or treatment intent, and intramodality changes were considered as minor changes with low impact.

RESULTS

FDG PET/CT changed the stage in 27 patients and had high impact on the management plan in 12 % of patients (detection of distant metastases in 6 patients and stage II in 2 patients). Intramodality changes were more frequent: FDG PET/CT altered the TNM stage in 18/72 (25 %) of patients, upstaging N stage in 90 % of patients with low impact.

CONCLUSIONS

Initial FDG PET/CT staging not only improves stage but also affects the management plan in LAHNC patients.

The role of FDG PET-CT in the therapeutic evaluation for HNSCC patients

F-18 FDG PET/CT has been widely used to diagnose primary tumors and lymph node metastases and to evaluate the response of head and neck squamous cell carcinoma (HNSCC) to therapy. The advantage of using PET/CT is that this combination allows metabolic information to be precisely overlapped with anatomical information, thereby improving the identification of sites with an abnormal accumulation of F-18 FDG. The role of FDG PET/CT in the therapeutic evaluation (such as in treatment planning, the therapeutic response, and the surveillance and examination of HNSCC patients) is discussed in this manuscript. When evaluating the post-treatment outcome via FDG PET/CT, it is important to exclude the post-treatment inflammation-related increase in glucose metabolism in lymph nodes, salivary gland, muscles, and soft tissues. The influence of inflammation can be eliminated if PET/CT is performed after 12 weeks, by which time post-treatment inflammation subsides. Further, FDG PET/CT affords a high negative predictive value. Based on the results of an FDG PET/CT test, some invasive tests that are performed to detect recurrence can be omitted.

The emerging era of personalized therapy in squamous cell carcinoma of the head and neck

Over the past three decades there has been a move toward organ preservation protocols in the management of locally advanced mucosal head and neck squamous cell carcinomas (LAHNSCC) with combinations of radiotherapy (RT), chemotherapy and, more recently, biological agents. Current standard chemoradiation strategies have reached the upper limits of toxicity. In addition, the traditional one size fits all approach of grouping patients according to traditional clinicopathological features fails to take into account the vast underlying biological heterogeneity of tumors and their host. A number of recent advances such as highly conformal RT, molecular profiling and targeted agents, and improvements in treatment response assessment have set the scene for a fundamental paradigm shift toward greater tailoring of therapy with the aim of improving outcomes and reducing the burden of survivorship. This review focuses on the recognition of the prognostic value of tumor human papillomavirus (HPV) status, the incorporation of biologically targeted therapies and the evolving role of molecular imaging in predicting tumor response and prognosis in the curative management of LAHNSCC.

[Metabolic markers of the head and neck cancers--clinical applications and the biochemical background]

The problem of diagnosis in the field of head and neck region is still valid. Specific diagnosis and precise estimation of the tumor's size with the use of CT and MRI imaging is generally unsatisfactory. The Positron Emission Tomography (PET) supports this process with additional information about the tumor's metabolism. Numerous publications show that PET-CT has a great influence on the evaluation of the size of the tumor, presence of lymph node metastases, choice of treatment and the prognosis of the recurrence. Cancer cells represent a specific metabolic state. These cells intake large quantities of glucose and utilize it in the process of glycolysis. The oxidative phosphorylation is not efficient in the transformed cells and defects in mitochondrial functions are at the heart of malignant cell transformation. Disruption of the oxidative phosphorylation chain has been described in the neoplasms. As a consequence, in cancer the glycolysis is active even in the normoxic environment. This metabolic shift in cell transformation has been described in early XX century and so called Warburg's hypothesis profoundly influenced the present perception of cancer metabolism, positioning what is termed aerobic glycolysis in the mainstream of clinical oncology. Today we know that neoplastic cells differ at the proteomic level. A subset of different proteins such as hexokinase II or HIF are upregulated. These abnormalities might be used as the neoplastic markers.