Contralateral Lower Neck Sparing Radiotherapy in Stage N1 Nasopharyngeal Carcinoma: Long-Term Survival Outcomes and Late Toxicities

Abstract

PurposeTo explore the feasibility of contralateral lower neck sparing radiotherapy for patients with stage N1 nasopharyngeal carcinoma (NPC) by analyzing long-term survival outcomes and late toxicities.MethodsData of patients with stage N1 NPC who were treated with contralateral lower neck sparing radiotherapy between January 2013 and December 2015 were analyzed. These patients were all staged by magnetic resonance imaging (MRI), and all received irradiation to the upper neck (levels II, III, and Va) bilaterally along with ipsilateral levels IV and Vb, without irradiation of the contralateral lower neck. Treatment outcomes, regional failure patterns, and late toxicities were examined.ResultsA total of 275 eligible patients with stage N1 NPC were included in the present study. The median follow-up period was 62 months (range, 3–93 months). The 5-year overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), locoregional recurrence-free survival (LRRFS), and progression-free survival (PFS) rates were 90.5, 91.3, 94.7, 95.3, 91.2, and 81.7%, respectively. A total of 13 patients (4.7%) developed regional recurrence, all of which occurred in the field and not out of the field. Among 254 patients with available data on late toxicities, the most common late toxicity was xerostomia. No late injuries occurred in the carotid arteries, brachial plexus, or spinal cord. In addition to one case (0.4%) of neck fibrosis and three cases (1.2%) of hearing loss, there were no other grade 3–4 late toxicities observed.ConclusionsContralateral lower neck sparing radiotherapy would be safe and feasible for patients with stage N1 NPC, with the potential to improve the long-term quality of life of patients.

Retrospective analysis of adjuvant radiotherapy in oral cavity or oropharyngeal cancer: Feasibility of omitting lower-neck irradiation

“…According to Tang et al, contralateral LNS intensity-modulated radiation therapy seems to be feasible for patients with NPC experiencing unilateral cervical lymph node metastasis because it does not sacrifice nodal relapse-free survival [ 20 ]. Sun et al reported that after the contralateral lower neck was spared, only 4.7% of their patients developed regional recurrence and that all of which occurred within the field only [ 21 ]. They concluded that contralateral LNS radiotherapy is safe and feasible, with the potential to improve the long-term quality of life of patients.…”

“…Sun et al reported that only 0.4% of their patients developed grade 3 neck fibrosis and 38.6% developed hypothyroidism. Thus, they concluded that omitting the irradiation of the contralateral lower neck decreased the possibility of exposing the dose to the neighboring normal organs and tissues, including the cervical subcutaneous tissues and thyroids [ 21 ]. Xiao et al also noted that patients with omitted lower-neck radiotherapy showed significant decreases in glottic larynx dose and significant improvement in voice quality [ 15 ].…”

Wearing individualized 3D printed oral stent to protect normal tissues in patients with nasopharyngeal carcinoma during radiotherapy

“…This improvement of survival rate makes us pay more and more attention to the quality of life of patients after treatment, and therefore pay more attention to the protection of normal tissues during radiotherapy 5 . However, because the anatomic position of the target volume is close to the oral tissues and nearby organs (especially for those NPC patients with late staging), radiation inevitably causes damage to normal tissues and organs such as oral mucosa, salivary gland and mandible, resulting in complications such as oral mucositis, xerostomia and taste dysfunction 6–8 . These radiation toxicities can aggravate the clinical symptoms of patients, affect their sleep and nutrition intake, and thus adversely affect the effect of radiotherapy and the quality of life after radiotherapy 9–11 …”

Less is more: level IB-sparing radiation therapy in nasopharyngeal cancer

“…As target volume delineation has become more sophisticated, evidence-based consensus guidelines for target volumes in NPC have been suggested [ 9 ]. In addition, the accumulated tumor control and failure pattern data, after selected target volume irradiation, have led to significant advances in personalized treatment for RT targeting in NPC [ 10 - 17 ]. As a result of these efforts, a recent randomized phase III trial involving that elective upper neck irradiation of the uninvolved neck has shown similar regional control with less toxicity compared with whole-neck irradiation in patients with N0-N1 NPC [ 18 ].…”

“…personalized treatment for RT targeting in NPC [10][11][12][13][14][15][16][17]. As a result of these efforts, a recent randomized phase III trial involving that elective upper neck irradiation of the uninvolved neck has shown similar regional control with less toxicity compared with wholeneck irradiation in patients with N0-N1 NPC [18].…”