Margin on Gross Tumor Volume and Risk of Local Recurrence in Head-and-Neck Cancer

Prospective Assessment of Patterns of Failure After High-Precision Definitive (Chemo)Radiation in Head-and-Neck Squamous Cell Carcinoma

“…Most of the failures were truly in-field in the high-dose region, consistent with previously published data (9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). In large series (Table 4) the predominant pattern of failure after CRT for HNSCC has been in-field within the GTV, with marginal failures ranging from 0% to 25%.…”

“…Recently, FDG-PET/CT has been increasingly used for assessment of extent of disease, with several methods being described for coregistering the PET/CT data with planning CT for radiotherapy planning (29). Another area that lacks consensus is the definition of high-dose CTV for the primary site, with some cooperative groups using anatomic expansion whereas others using volumetric expansion (22). Thus a major limitation of CRT is the presence of interobserver, intraobserver, intermodality, and interdiscipline variation, which can result in inconsistency, rendering interinstitutional comparisons difficult.…”

Impact of Reduced-volume Intensity Modulated Radiation Therapy on Disease Control for Nasopharyngeal Carcinoma

“…Indeed, if subclinical cancer cells deposit outside the imagingbased GTV, the relatively high radiation doses (60-70Gy) surrounding the GTV should be sufficient for treating the subclinical disease [26]. Caudell et al [10] reported that there were no differences in local control between head-and-neck cancer patients treated using GTV to PTV expansions of 4-6 mm and patients treated with expansions of 10-15 mm or even >15 mm. With respect to their in-field failures, a median GTV volumetric expansion of 6mm (range, 0-15mm) was required to contain the contoured recurrence structures.…”

“…However, the use of high-dose radiation in tissues adjacent to the clinical target volumes (CTVs) for the treatment of potentially subclinical disease is controversial [8][9][10]. In particular, increased high-dose treatment volumes inevitably increase the probability of both acute and late adverse effects.…”

Comparison of Methods to Reduce Dose to Swallowing-Related Structures in Head and Neck Cancer

“…Patients with both dosing levels (70 Gy to PTV-HD and 56 Gy to elective PTV [PTV-ED]), simultaneous in 35 fractions, n = 8) and three dosing levels (69.3 Gy to PTV-HD, 59.4 Gy to intermediate PTV, and 54.12 to elective PTV, simultaneous in 33 fractions, n = 7) were included, reflecting institutional practice. Clinical target volumes (CTV) and PTV were generated using previously detailed methods (7). Briefly, the gross tumor volume (GTV) was defined through physical examination, laryngoscopy, and available imaging.…”