Initial experience of FDG-PET/CT guided IMRT of head-and-neck carcinoma

Correlation between pretreatment FDG-PET biological target volume and anatomical location of failure after radiation therapy for head and neck cancers

“…However, when used together MRI, CT, and PET each can add complimentary data to improve tumor delineation [25]. While most studies examining PET alone based GTVs are usually smaller then their counterpart CT based GTVs, in ∼25% of patients of cases the additional information obtained from PET can increase the GTV compared to CT alone based GTVs [10][11][12][13]15,[26][27][28]. In addition, this number can increase to up to 64% depending on the SUV threshold used [28].…”

“…FDG-PET uptake may be a surrogate for hypoxia and it has been shown to predict treatment response and loco regional failure (LRF) [7][8][9]. In addition, FDG-PET defined tumor volumes have been reported to be smaller than CT defined ones [10][11][12][13][14][15] and several others have suggested PET alone based methods to define the GTV. An examination of the exact site of LRF relative to pre-treatment PET defined target may shed light on the utility of PET as a vehicle to define the GTV.…”

Use of PET and PET/CT for Radiation Therapy Planning: IAEA expert report 2006–2007

“…Use of FDG-PET planning in H&N cancers is complex [100]. The boundaries of primary tumors can differ significantly from one another in the same patient when determined using PET, CT or MRI, making it difficult to decide where exactly to draw the GTV for RT planning.…”

18F-FDG PET/CT Imaging In Oncology

“…18 F-FDG PET/CT alters the initial clinical staging and TNM category of the tumor in 14% to 57% of the patients when compared with CT-based evaluation alone,4445 and has an accuracy of approximately 90% compared with 86% for conventional CT 4647…”

“…In addition, it alters the initial management in 18% to 37% of the patients 4649. The impact of 18 F-FDG PET/CT on radiotherapy planning is especially important: planning is changed in 29% of the patients,50 with an alteration in the gross tumor volume in 57% of the patients 45. It has been reported that the gross tumor volume is statistically significantly larger with 18F-FDG PET/CT–based assessment than with CT-based assessment 5152.…”