[Value of 18F fluorodeoxyglucose positron emission tomography in radiotherapy planning of head-neck tumors].

PURPOSE

An individualized radiation treatment planning in patients with head and neck tumors requires an exact definition of tumorspread. Despite of high reliability of methods like computed tomography, sonography or magnetic resonance imaging used in daily routine, the correct diagnosis of lymphonodal tumor infiltration is often not possible. In a prospective trial, we examined whether an additional FDG-PET gives a relevant gain of information for radiation treatment planning.

PATIENTS AND METHODS

We studied data of 34 patients with histologically confirmed squamous cell carcinoma of the head and neck who received a FDG-PET prior to treatment planning additionally to conventional staging procedures. The extent of changes of treatment strategy or target volume due to additional FDG-PET findings were analyzed.

RESULTS

In 9/22 of patients with primary tumors and in 7/12 of patients with recurrent disease, FDG-PET detected additional tumor manifestations. In all cases, changes of treatment strategy or target volume were necessary. Regarding patients with primary tumors, the percentage of treatment modifications was highest in patients with large tumors (T3 and T4) and patients with advanced lymph node involvement (N2 and N3).

CONCLUSIONS

Especially in patients with recurrent disease and patients with advanced tumor stages, FDG-PET is able to give clinically relevant information compared to conventional staging procedures. Therefore, in these group of patients a FDG-PET study prior to radiotherapy planning should be considered.