FDG-PET in radiotherapy treatment planning of advanced head and neck cancer—A prospective clinical analysis

Overall and disease-free survival outcomes of patients receiving intensity-modulated radiation therapy (IMRT) with PET-CT-based planning for cancers of the head and neck

Introduction

Combined modality treatment regimens have provided modest gains in locoregional control rates of cancers of the head and neck (HNC), and intensity-modulated radiation therapy (IMRT) has gained widespread use. The methodology for determining contours of the gross tumour volume (GTV) in the radiation treatment plan is often based on combined anatomic and metabolic data from positron emission tomography–computed tomography (PET-CT). This study aimed to retrospectively evaluate the overall survival and disease-free survival outcomes of patients with HNC who received definitive IMRT with or without chemotherapy, planned with PET-CT.

Materials and Methods

A total of 1,200 patients underwent treatment for HNC during the study period, from 1 January 2002 to 31 December 2010. Of those, 261 cases had evaluable data that met the inclusion criteria for the study. The incidence and timing of locoregional recurrence, distant metastatic disease, new primary malignancies and death were evaluated retrospectively. Overall and disease-free survival (survival to time of first recurrence) were determined by the life table method. Incidence of distance metastatic disease and additional cancers were also studied.

Results

Median follow-up from treatment initiation was 26·4 months (range 1·2–84·7 months). Overall survival and disease-free survival rates were 0·883 and 0·791, respectively, at 1 year; 0·793 and 0·688, respectively, at 2 years; and 0·732 and 0·619, respectively, at 3 years. The cumulative risk of recurrence was 22·6% at 3 years following definitive IMRT and the median time to recurrence was 345 days. There was an overall low incidence of distant metastatic disease (3·07%) and additional cancers (8·05%).

Conclusion

Overall and disease-free survival outcomes of a large cohort of HNC patients treated with definitive IMRT radiotherapy following treatment planning with PET-CT shows a similar high level of disease control and mortality rate as previously published outcome studies of shorter terms and/or smaller numbers of patients.

Use of prechemotherapy positron emission tomography-CT imaging, acquired in the treatment position, to help plan involved nodal radiotherapy for a patient with diffuse large B-cell lymphoma

Fused positron emission tomography/computed tomography (PET-CT) images are increasingly being used to assist radiation oncologists in the definition of treatment volumes for patients with metabolically active tumours. This is the first report in which baseline fluorodeoxyglucose-PET-CT images were acquired in the treatment position in a case of diffuse large B-cell lymphoma and incorporated directly into the radiotherapy treatment planning process. It highlights the potential benefits of using combined 3-D functional and structural imaging for the design of radiation target volumes in patients with aggressive lymphomas that are managed with combined chemo and radiotherapy.