Risk of contralateral nodal failure following ipsilateral IMRT for node-positive tonsillar cancer

Association of Unilateral Radiotherapy With Contralateral Lymph Node Failure Among Patients With Squamous Cell Carcinoma of the Tonsil: A Systematic Review and Meta-analysis

Importance

Ipsilateral neck radiotherapy (RT) is controversial in some patients with tonsil cancer due to concern for nodal failure within the contralateral nonirradiated neck (hereinafter referred to as contralateral neck failure [CNF]).

Objective

To determine the rate of CNF following ipsilateral neck RT in patients with tonsil cancer.

Data Sources

Databases including PubMed, Embase, Web of Science, and Cochrane Library were queried for peer-reviewed, English language articles published between January 1, 1980, and December 31, 2021.

Study Selection

Studies reporting rates of CNF from at least 20 patients treated with ipsilateral neck RT. Studies were excluded if they lacked full text, reported results from databases or systematic reviews, or did not provide RT details.

Data Extraction and Synthesis

Data were extracted following the PRISMA reporting guideline. Study quality was assessed using criteria from a methodological index for nonrandomized studies. Pooled outcomes were estimated using random-effects models.

Main Outcomes and Measures

Primary outcome was the pooled rate of CNF following ipsilateral neck RT. Secondary outcomes were the pooled rates of CNF by tumor and nodal staging categories from the 7th edition of the AJCC Cancer Staging Manual and rates of toxic effects.

Results

A total of 17 studies (16 retrospective and 1 prospective) including 1487 unique patients were identified. The pooled risk of CNF was 1.9% (95% CI, 1.2%-2.6%). The rate of CNF by tumor (T) category was as follows: 1.3% (95% CI, 0.3%-2.3%) for T1; 3.0% (95% CI, 1.6%-4.4%) for T2; 11.3% (95% CI, 3.3%-19.2%) for T3; and 16.0% (95% CI, -7.8% to 39.8%) for T4. Patients with T3 to T4 tumors had a significantly higher rate of CNF than those with T1 to T2 tumors (11.5% [95% CI, 3.9%-19.1%] vs 1.8% [95% CI, 1.0%-2.6%]; P < .001). The rate of CNF by nodal (N) category was 1.2% (95% CI, 0.1%-2.2%) for N0; 4.8% (95% CI, 2.4%-7.2%) for N1; 3.1% (95% CI, 0.4%-5.8%) for N2a; 3.1% (95% CI, 1.2%-4.9%) for N2b; and 0 (95% CI, not applicable) for N3. Rates of CNF were similar for patients with N2b to N3 and N0 to N2a disease (3.0% [95% CI, 1.2%-4.7%] vs 1.7% [95% CI, 0.6%-2.8%], respectively; P = .07). Compared with bilateral RT, ipsilateral RT was associated with increased risk of CNF (log odds ratio, 1.29 [95% CI, 0.09-2.48]; P = .04). The crude rates of xerostomia of grade 3 or greater and feeding tube use were 0.9% (95% CI, -0.2% to 1.9%) and 13.3% (95% CI, 8.3%-18.3%), respectively.

Conclusions and Relevance

In this systematic review and meta-analysis, ipsilateral neck RT was associated with a low rate of CNF in patients with small, lateralized tonsil cancers. Bilateral neck RT was associated with lower risk of CNF compared with ipsilateral neck RT. Patients with tumors of a higher T category were at increased risk for CNF following ipsilateral neck RT, and advanced nodal stage was not associated with CNF. Rates of toxic effects appeared favorable in patients treated with ipsilateral neck RT.

Long-term Locoregional Control With Unilateral Radiation for AJCC-7 T1-2N2b Tonsillar Cancer

OBJECTIVES

Unilateral radiation to cervical nodes has been used as a de-escalation strategy in well-lateralized tonsil cancers. The efficacy of this approach with multiple ipsilateral nodes is not established. The study hypothesis was that unilateral radiation for American Joint Committee on Cancer (AJCC)-7 T1-2N2b tonsillar cancer results in a low rate of contralateral nodal failure.

MATERIALS AND METHODS

This study was a retrospective chart review of patients with AJCC-7 T1-2N2b tonsillar cancer from 2 academic institutions who were treated with unilateral radiation. The primary endpoint was the contralateral nodal failure rate. Locoregional control, overall survival, and the need for gastrostomy tube placement were additional endpoints.

RESULTS

The study cohort included 66 patients treated between 2005 and 2016. The median follow-up time was 80.9 months; contralateral nodal failure occurred in 2/66 (3.0%) patients at 4.1 and 20.9 months, respectively. Both patients underwent salvage treatment with long-term subsequent survival. Overall locoregional control at both 2 and 5 years was 93.9% and the median duration of control was not reached. Overall survival at 5 years was 92.4%.

CONCLUSIONS

The use of unilateral radiation for AJCC-7 T1-2N2b tonsillar cancer resulted in low rates of contralateral nodal failure. This outcome demonstrates the safety of considering unilateral radiation treatment in patients with a relatively high ipsilateral nodal burden.

Efficacy of Postoperative Unilateral Neck Irradiation in Patients with Buccal Mucosa Squamous Carcinoma with Extranodal Extension: A Propensity Score Analysis

Unilateral radiotherapy (RT) as a postoperative treatment for multiple ipsilateral lymph node (LN) metastases remains controversial. We investigated the efficacy of postoperative unilateral RT for buccal mucosa squamous cell carcinoma (BMSCC) with extranodal extensions (ENEs). We retrospectively reviewed the clinical records of 186 patients with ENE+ BMSCC who received postoperative RT during 1997-2016. Propensity score matching was used to establish comparable cohorts. The endpoints were contralateral nodal control (CLNC), overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS), local control (LC), and regional control (RC). After matching, 123 patients were selected for analysis; 45 (36.6%) and 78 (63.4%) patients underwent unilateral and bilateral RT, respectively. The median follow-up was 36.27 months. The survival outcomes in the unilateral and bilateral RT groups were similar: 3-year CLNC (85.6% vs. 89.1%, p = 0.748), OS (53.2% vs. 57.4%, p = 0.229), DFS (46.5% vs. 48.6%, p = 0.515), DMFS (70.7% vs. 72.0%, p = 0.499), LC (78.0% vs. 75.6%, p = 0.692), and RC (79.9% vs. 76.2%, p = 0.465). On multivariable Cox regression analysis, unilateral and bilateral RT showed comparable outcomes; the number of ENEs ≥ 4 was the only significant prognostic factor for all clinical outcomes. Using decision tree analysis, we classified our patients to have a low, intermediate, or high risk of contralateral failure based on three factors: number of ENEs, margin status, and tumor stage. In conclusion, postoperative unilateral RT did not worsen outcomes in patients with ENE+ BMSCC in this cohort. The decision tree model may assist physicians in optimizing and tailoring radiation fields.

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

BACKGROUND

We conducted the current systemic review to provide up-to-date literature summary and optimal evidence-based recommendations for ipsilateral radiation for squamous cell carcinoma of the tonsil.

METHODS

We performed literature search of peer-reviewed journals through PubMed. The search strategy and subject-specific keywords were developed based on the expert panel's consensus. Articles published from January 2000 to May 2020 with full text available on PubMed and restricted to the English language and human subjects were included. Several prespecified search terms were used to identify relevant publications and additional evidence published since the initial American College of Radiology Appropriateness Criteria Ipsilateral Tonsil Radiation recommendation was finalized in 2012. The full bibliographies of identified articles were reviewed and irrelevant studies were removed.

RESULTS

The initial search and review returned 46 citations. The authors added three citations from bibliographies, websites, or books not found in the literature search. Of the 49 citations, 30 citations were retained for further detailed review, and 14 of them were added to the evidence table. Articles were removed from the bibliography if they were not relevant or generalizable to the topic, or focused on unknown primary disease. Several commonly encountered clinical case variants were created and panelists anonymously rated each treatment recommendation. The results were reviewed and disagreements discussed.

CONCLUSIONS

The panel provided updated evidence and recommendations for ipsilateral radiation for squamous cell carcinoma of the tonsil in the setting of primary radiation-based therapy and postoperative adjuvant radiotherapy. This committee did not reach agreements for some case variants due to a lack of strong evidence supporting specific treatment decisions, indicating a further need for research in these topics.

Screening for irradiation vasculopathy by intima-media thickness sonography in head and neck cancer patients

Purpose

Post-irradiation vasculopathy is a severe form of atherosclerosis and affects the prognosis of head and neck cancer survivors. Sonographic intima-media thickness (IMT) precedes stenosis, plaque formation, and cerebrovascular events. Therefore, IMT may be a valuable screening marker for post-irradiation toxicity. However, the critical irradiation dose and the onset of IMT increase remain unclear.

Methods

The cross-sectional study analysed the carotid artery IMT in 96 irradiated patients and 41 controls regarding irradiation dose, post-irradiation-interval, and cardiovascular risk factors. Distinct irradiation doses to the tumour side and the contralateral hemineck enabled detection of dose depended effects within one patient and control of risk factors.

Results

Radiotherapy caused a dose-dependent increase in IMT. The toxicity did not have saturation effects for > 60 Gy. The IMT increase occurred in short-term following radiotherapy and the risk for a pathological value (> 0.9 mm) rose significantly. The correlation between IMT and radiotherapy was comparable to established cardiovascular risk factors.

Conclusion

Radiotherapists should consider the additional toxicity of high doses for non-metastatic head and neck cancer. If neck metastases require radiotherapy with boost, IMT measurement is suitable for early detection of carotid artery damage.

Patient-reported quality of life and toxicity in unilateral and bilateral radiotherapy for early-stage human papillomavirus associated tonsillar carcinoma

Purpose

The purpose of this study was to compare self-reported health-related quality of life (QoL) and symptom burden in early stage tonsillar carcinoma patients treated with unilateral (URT) and bilateral radiotherapy (BRT).

Methods and materials

This is a secondary analysis of a larger study assessing patient reported outcomes in human papillomavirus (HPV) oropharyngeal cancer (OPC) patients. Recruited patients were ≥12 months from completion of radiotherapy. This analysis included only patients with T1-2, N1-2b tonsil cancer and excluded patients with base of tongue involvement or recurrent disease. QoL and patient reported toxicity was measured using the EORTC QLQ-C30 module and the MDASI-HN.

Results

Patients were enrolled from November 2018 to May 2019. Of the 136 patients recruited to the main study, 43 were eligible for this substudy (22 URT, 21 BRT), with a median age and follow up of 58.2 and 3.0 years respectively. The two groups were balanced with respect to patient, tumor and treatment factors with the exception of higher rates of T2 disease (27% v 71%, p = 0.006) and more extensive GTV nodal volumes (11.0 v 25.5cc, p = 0.006) in the BRT group.BRT patients had lower global health status/QoL (84 v 69, p = 0.0005) and social functioning scores (93 vs 78, p = 0.033) on the EORTC QLQ-C30, and higher symptom severity (0.6 vs. 2.0, p = 0.001) and symptom interference scores (0.8 vs. 2.0, p = 0.010) on the MDASI-HN. Four of the six largest differences observed on MDASI-HN items were attributable to radiotherapy technique (dry mouth, mucous, difficulty swallowing/chewing and taste), with corresponding dose differences to the respective organs (contralateral parotid, oral cavity and pharyngeal constrictors). In every instance, severity of symptoms was worse on average for patients treated with BRT.

Conclusions

In the highly conformal radiotherapy era, BRT in early HPV tonsillar cancer survivors has an enduring impact on long-term QoL and toxicity.