Comparison of the Clinical Outcomes of Patients with Squamous Cell Carcinoma of the Tonsil Receiving Postoperative Ipsilateral Versus Bilateral Neck Radiotherapy: A Propensity Score Matching Analysis (KROG 11-07)

Abstract

PurposeThe impact of postoperative ipsilateral neck radiotherapy (INRT) versus bilateral neck radiotherapy (BNRT) on the clinical outcomes of patients with tonsillar squamous cell carcinoma was analyzed retrospectively.Materials and MethodsBetween October 2001 and June 2012, 241 patients with T1-2 and N0-N2b tonsillar carcinoma from 16 institutes underwent postoperative INRT (n=84) or BNRT (n=157) following a tonsillectomy. Seventy patients were identified from each group by propensity score matching and compared in terms of the overall survival (OS), disease-free survival (DFS), locoregional relapse-free survival (LRRFS), and distant metastasis-free survival (DMFS) rates calculated using the Kaplan-Meier method with a log-rank test.ResultsThe median follow-up was 55 months (range, 3 to 133 months). The survival outcomes in the INRT and BNRT groups were similar: 5-year OS (92.8% vs. 94.0%, p=0.985), DFS (80.5% vs. 94.2%. p=0.085), LRRFS (88.1% vs. 97.1%, p=0.083), and DMFS (92.7% vs. 97.0%, p=0.370). Subgroup analysis revealed no contralateral neck recurrence in 61 patients with T1-2N0-2a regardless of the treatment groups. For 79 patients with N2b, contralateral neck recurrence was more common in the INRT group than in the BNRT group (7.9% vs. 0.0%), but the difference was not significant (p=0.107). The overall grade ≥ 2 toxicities were lower in the INRT group: acute (45.7% vs. 74.3%, p=0.001) and late (4.3% vs. 31.4%, p < 0.001), respectively.ConclusionINRT is an attractive strategy for patients with T1-2N0-2a tonsillar carcinoma compared to BNRT. For patients with N2b, there was a small risk of contralateral neck recurrence when treated with INRT, but its impact on the OS was limited with successful salvage treatment.

Ipsilateral radiation for squamous cell carcinoma of the tonsil: American Radium Society appropriate use criteria executive summary

“…21 In a propensity-score matched, pooled analysis of 241 patients from 16 institutions who underwent various forms of tonsillectomy (without neck dissection) from 2001 to 2012 followed by adjuvant radiation, 70 selected patients who received ipsilateral adjuvant radiation were matched to another 70 patients with bilateral adjuvant radiation. 22 Of note, the authors did not specifically state if the surgical procedure was simple tonsillectomy or oncologic radical tonsillectomy. The two groups of patients had similar survival outcomes.…”

The impact of tongue-deviating and tongue-depressing oral stents on long-term radiation-associated symptoms in oropharyngeal cancer survivors

“…Although the difference in mean MDASI-HN score between the groups with and without oral stent might be low, there is a significant decreased proportion of patients who had moderate/severe symptoms. Less toxicity has already been reported for unilateral irradiation in cohorts of OPC [22] and tonsil cancers only [23,24] compared to standard bilateral RT by other authors. Despite these patients having in general a lower toxicity profile, the addition of a tongue-deviating stent further decreases long-term patient reported symptoms.…”

Short‐term and long‐term unstimulated saliva flow following unilateral vs bilateral radiotherapy for oropharyngeal carcinoma

“…41 Nonetheless, unilateral RT provided a better chance of sparing contralateral salivary glands including parotid, submandibular, and minor salivary glands, which could result in improvement of xerostomia as reported by others. 42 Unilateral RT is also associated with better swallowing outcomes and quality of life, 43 lower rates of severe acute (46% vs 74%, P = .001) and late (7% vs 19%, P < .001) treatment-related toxicities, 44 and less likelihood of requiring gastrostomy tubes during (18% vs 39%, P < .01) and long after treatment (2% vs 20%, P < .01). 43 Sparing the uninvolved contralateral neck may expose patients to contralateral neck failure and should only be offered to highly selected OPC patients with low risk of contralateral microscopic disease.…”