Comparing unilateral vs. bilateral neck management in lateralized oropharyngeal cancer between surgical and radiation oncologists: An international practice pattern survey

Unilateral Neck Treatment with either Surgery and/or Radiotherapy for Squamous Cell Carcinoma for the Tonsil

INTRODUCTION

Strategies for treatment of tonsil carcinoma are under active investigation. Limiting surgical and radiation treatment volumes to the primary tumor and ipsilateral neck in appropriately selected patients are one such approach. Here, we present our institutional experience with treatment through ipsilateral surgical or radiotherapeutic neck management.

METHODS

We retrospectively reviewed our institutional database of patients with tonsil carcinoma treated from 2012 to 2020. Patients were included for analysis if they received definitive radiation therapy (RT), definitive surgery (S), or surgery with postoperative radiation therapy (S-PORT) and whose treatment volumes were limited to the primary tumor and involved/elective ipsilateral neck. Patients who received radiation and/or surgery to the contralateral neck (including those with bilateral nodal involvement), as well as patients with metastatic disease, were excluded. Clinical factors including T- and N-stage (AJCC 7th edition), and HPV status (by p16 and/or HPV DNA PCR) were recorded, as were pathologic factors (when applicable) including margin status, extracapsular extension (ECE), lymphovascular invasion (LVSI), and perineural invasion (PNI). Overall survival (OS), progression-free survival (PFS), and locoregional control (LRC) at 2 years were estimated using the Kaplan-Meier method.

RESULTS

In total, 71 patients were treated with unilateral neck approaches: S (n = 49), RT (n = 10), and S+PORT (n = 12). Among these patients, 32, 36, and 3 had T1, T2, and T3 disease, respectively. N-stage was N0, N1, N2a, N2b, and N3 in 22, 20, 5, 23, and 1 patient(s), respectively. Concurrent chemotherapy was administered in 12 patients. From those with recorded risk factors, 86% were HPV positive, 20% had LVSI, 7% had PNI, 13% had ECE, and 5% had positive margins. From a median follow-up of 27 months, local, regional, and distant failures occurred in 5, 6, and 5 patients, respectively. No contralateral neck failures were recorded. At 2 years, OS, PFS, and LRC were 92% (95% CI 85-99%), 85% (95% CI 75-95%), and 88% (95% CI 80-98%), respectively.

CONCLUSIONS

In patients with early T-stage tonsil carcinoma, treatment of the primary tumor and ipsilateral neck is associated with acceptable OS, PFS, and LRC. In this population, the risk of contralateral neck failure is likely very low regardless of primary treatment modality. Additional prospective studies are needed to determine the impact of limiting treatment extent, either surgical or radiotherapeutic, to the unilateral neck.

A multi-institutional feasibility lead-in trial of lymphatic mapping with SPECT-CT for evaluating contralateral disease in lateralized oropharynx cancer using 99m-technetium sulfur colloid

BACKGROUND

Lymphatic mapping with SPECT-CT has been demonstrated to accurately define lymphatic drainage patterns in oropharyngeal cancer but there has yet to be a study demonstrating its feasibility across multiple institutions.

METHODS

Twelve adult patients with lateralized oropharyngeal carcinoma (T1-T3) who were planned for definitive or adjuvant radiotherapy without contralateral nodal disease underwent injection of 99-m technetium sulfur colloid followed by static planar lymphoscintigraphy to verify tracer migration, and SPECT-CT acquired at 30 ± 15 min (optional) and 3 h (±1 h) (mandatory time-point).

RESULTS

All 12 patients completed the study with 7/12 patients having the injections performed under local anesthetic and 5 patients requiring general anesthetic. There were no tracer migration failures and there were no serious adverse events or complications encountered. Four out of 12 patients (33%) showed contralateral drainage patterns.

CONCLUSIONS

Lymphatic mapping with SPECT-CT of lateralized oropharyngeal squamous cell carcinoma can be performed safely across multiple institutions.

Low contralateral failure rate with unilateral proton beam radiotherapy for oropharyngeal squamous cell carcinoma: A multi-institutional prospective study from the proton collaborative group

INTRODUCTION

Unilateral radiation therapy is appropriate for select patients with oropharyngeal squamous cell carcinoma (OPSCC). The use of proton beam therapy (PBT) in the unilateral setting decreases the dose to the contralateral neck and organs at risk. This study aims to evaluate contralateral recurrences in patients who received ipsilateral PBT.

METHODS

We evaluated the Proton Collaborative Group database for patients treated with PBT for head and neck squamous cell carcinoma between the years 2015-2020 at 12 institutions. Dosimetric analysis was performed in five cases.

RESULTS

Our analysis included 41 patients that received ipsilateral PBT with a mean follow-up of 14.7 months. 37% patients (n = 15) were treated for recurrent disease, and 63% (n = 26) were treated for de novo disease. Oropharyngeal sites included tonsillar fossa (n = 30) and base of tongue (n = 11). The median dose and BED delivered were 69.96 CGE and 84 Gy, respectively. Eight (20%) patients experienced at least one grade 3 dysphagia (n = 4) or esophagitis (n = 4) toxicity. No grade ≥ 4 toxicities were reported. There was one (2.4%) failure in the contralateral neck. The 1-year locoregional control was 88.9% and the freedom from distant metastasis was 95.5% (n = 2). The dosimetric analysis demonstrated similar ipsilateral level II cervical nodal region doses, whereas contralateral doses were higher with photon plans, mean: 15.5 Gy and 0.7CGE, D5%: 25.1 Gy and 6.6CGE.

CONCLUSIONS

Our series is the first to report outcomes for patients with OPSCC receiving unilateral PBT. The contralateral neck failure rate was excellent and comparable to failure rates with photon irradiation.

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.

Patient- and Clinician-Reported Outcomes in Human Papillomavirus-Associated Tonsillar Carcinoma Treated With Unilateral and Bilateral Intensity Modulated Radiation Therapy-A Substudy From TROG 12.01

PURPOSE

The aim of this TROG 12.01 substudy was to report longitudinal variations in patient- (PRO) and clinician-reported outcomes based on receipt of unilateral (URT) or bilateral radiation therapy (BRT).

METHODS AND MATERIALS

Patients with lateralized T1-2 N1-2b human papillomavirus-associated tonsillar carcinoma (AJCC7) enrolled on TROG 12.01 were eligible. The primary endpoint was patient-reported radiation symptom severity score (MDASI-RSS) at 2 years, a composite of 9 MDASI-Head and Neck (HN) symptom items. Secondary endpoints included patient-reported symptom burden and interference (MDASI-HN), quality of life (FACT-HN), emotional distress (HADS), return to work (RTW), clinician-reported performance status scale (PSS-HN), and late adverse events (CTCAE). Mean MDASI-RSS, symptom severity (MDASI-SS), symptom interference (MDASI-SI) and selected single items were compared 1 week, 3 months, and 2 years post-RT.

RESULTS

Seventy-four patients were eligible for analysis (26 URT, 48 BRT). Median follow-up was 3.7 years (1.8-5.2 years). Sociodemographic, staging, and treatment variables were mostly balanced, with larger primaries observed in the BRT group. Four regional failures were reported (3 URT, 1 BRT), including one isolated contralateral regional failure in the URT cohort. Mean MDASI-RSS scores did not differ at 2 years (URT vs BRT, 1.1 vs 1.3; difference 0.1 [95% CI: -0.7 to 0.9], P = .75) or at any other time points for the MDASI-RSS, MDASI-SS, and MDASI-SI scores, except for worse MDASI-SI 1 week after treatment in the BRT group (4.7 vs 5.6). Fatigue (6.6 vs 5.4) at 1 week and dry mouth (3.5 vs 2.0) at 2 years were also worse in the BRT group. FACT-HN, HADS, RTW, PSS-HN, and CTCAE results were similar across the follow-up period.

CONCLUSIONS

In this favorable-risk cohort, treatment laterality resulted in fewer differences than anticipated in patient-reported or clinician-reported outcomes. Two years after treatment patients treated with BRT reported significantly worse dry mouth. Longer follow-up is needed to determine the impact of treatment laterality on late effects.