Cinzia Iotti, Presenter: Nothing to Disclose

Nunzia D'Abbiero, Abstract Co-Author: Nothing to Disclose

Giuseppina De Marco, Abstract Co-Author: Nothing to Disclose

Mauro Iori, Abstract Co-Author: Nothing to Disclose

Marta Paiusco, Abstract Co-Author: Nothing to Disclose

Tamara Palmieri, Abstract Co-Author: Nothing to Disclose

Dafne Ramundo, Abstract Co-Author: Nothing to Disclose

Silvana Riccardi, Abstract Co-Author: Nothing to Disclose

Antonino Romeo, Abstract Co-Author: Nothing to Disclose

Annibale Versari, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

The objective of this study is to evaluate the influence of FDG-PET on the H&N-IMRT treatment planning and to provide preliminary data on tumor control and toxicity

From Feb03 to Oct06, 64 pts with H&N cancer underwent FDG-PET scan for IMRT planning. PET data have been used only for high dose volume definition, and every variation of the prophylactic volume has been consequential to changes of the tumor extension and/or staging. The PET images segmentation has been run by the radiation oncologist applying a threshold corresponding to a percentage of the max lesion uptake(42%±3SD). For the GTV contouring the following rules have been used: if FDG-uptake was seen outside the CT volume, the final GTV was the sum of the CT and PET volume; if the CT scan or physical examination revealed more suspected lesions than PET, the CT information was taken to define the size of the radiation field. Every GTV has been expanded of 0.5-1.5 cm to high dose clinical target volume (CTV).

FDG-PET led to a stage migration in 20% of pts.In all cases but 3 it has been an over-staging because of finding of additional node disease. The primary and nodal GTVs have been modified in 15.6% and 29.7% respectively. Partly because of our prudential segmentation rules, GTVs have been mostly increased. The parotid sparing has been done easily in 41 pts because of the exclusion of closest disease. With a median follow-up of 29 mos (6-50) the LR control has been 81%, with the best results in the nasopharynx (91%). Only one relapse occurred in a region excluded from the high dose for PET negativity. An other recurrence has been observed both in the GTV and in adjacent, FDG-negative, lower dose area. If the parotid sparing has been planned, no salivary damage > gr.2 has been observed. No other late toxicity greater than gr.1 has been reported

Our data support the use of FDG-PET in the H&N radiotherapy. However, a more reliable method for tumor segmentation could lead to more substantial change in the radiotherapy approach, in terms of fractionation schemes and/or prophylactic irradiation

In H&N-IMRT, the FDG-PET may improve the target definition and allows a safer healthy tissues avoidance.

Iotti, C, D'Abbiero, N, De Marco, G, Iori, M, Paiusco, M, Palmieri, T, Ramundo, D, Riccardi, S, Romeo, A, Versari, A, et al, , et al, , The Influence of FDG-PET in Head and Neck IMRT Planning and Preliminary Data of Clinical Outcome: The Experience of Reggio Emilia Hospital.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5015423.html