c  lThe purpose of our work is evaluation of the impact of 18FDG-PET/CT on the complex management of locoregionally advanced (T3-4N1-3) head and neck @entity1544 (LAHNSC), and on the target definiton for 3D conformal (3DCRT) and intensity-modulated radiotherapy (IMRT). 18FDG-PET/CT were performed on 185 @entity1 with LAHNSC prior to radiotherapy/chemoradiation in the treatment position between 2006 and 2011. Prior to it 91 @entity1 recieved induction chemotherapy (in 20 cases of these, baseline PET/CT was also available). The independently delineated CT-based gross @entity5 volume (GTVct) and PET/CT based ones (GTVpet) were compared. Impact of PET/CT on the treatment strategy, on @entity5 response evaluation to @entity5835 , on GTV definition furthermore on @entity66 ( @entity66 , @entity13419 ) was analysed. PET/CT revealed 10 @entity135 for 15 @entity1 with carcinoma of unknown primary (CUP) while 3 remained unknown. Second @entity5 were detected in 8 (4.4%), distant @entity3 in 15 (8.2%) cases. The difference between GTVct and GTVpet was significant (p=0.001). In 16 @entity1 (14%) the GTVpet were larger than GTVct due to multifocal manifestations in the laryngo-pharyngeal regions (4 cases) or lymph node @entity3 (12 cases). In the majority of the cases (82 pts, 72%) PET/CT-based conturing resulted in remarkable decrease in the volume (15-20%: 4 cases, 20-50%: 46 cases, >50%: 32 cases). On the basis of the initial and post- @entity5835 PET/CT comparison in 15/20 @entity1 more than 50% volume reduction and in 6/20 cases complete response were achieved. After an average of 6.4 years of follow-up the @entity66 (median: 18.3  2.6 months) and @entity13419 (median: 25.0  4.0 months) exhibited close correlation (p=0.0001) to the GTVpet. In cases with GTVpet <10 cm3 prior to RT, @entity13419 did not reach the median, the mean is 82.1  6.1 months, while in cases with GTVpet 10-40 cm3 the median of the @entity13419 was 28.8  4.9 months (HR = 3.57; 95% CI: 1.5-8.3), and in those with GTVpet >40 cm3 the median @entity13419 was 8.4  0.96 months (HR= 11.48; 95% CI: 5.3-24.9). Our results suggest that 18FDG-PET/CT plays an important role for @entity1 with LAHNSC, by modifying the treatment concept and improving the target definition for selective RT modalities. Volumetric PET/CT-based assessment of the @entity5 response after @entity5835 gives valuable contribution to further therapy planning.

[Role of 18FDG-PET/CT in the management and gross XXXX volume definition for radiotherapy of @entity135 ; single institution experiences based on long-term follow-up].

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity135 :: ('MESH:D006258', 'Disease') :: ['head and neck, 2 lung cancers'] @entity66 :: ('MESH:D004194', 'Disease') :: ['OS', 'overall and disease-specific survival'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'tumors'] @entity13419 :: ('MESH:C535601', 'Disease') :: ['DSS'] @entity5835 :: ('MESH:C566123', 'Disease') :: ['ICT'] @entity1544 :: ('MESH:D018307', 'Disease') :: ['squamous cell cancer'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastasis', 'metastases']
@entity5 :: (MESH:D009369,Disease) :: ['tumor']
