Healthcare resource utilization following unilateral versus bilateral radiation therapy for oropharyngeal carcinoma

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.

Synchronous tonsillar tumors with differing histopathology: A case report and review of the literature

Background

Tonsillar squamous cell carcinoma (TSCC) due to human papillomavirus (HPV) infection has seen a dramatic increase in recent years. Bilateral tonsillar squamous cell carcinoma (biTSCC) has a much lower incidence than unilateral TSCC and three main hypotheses of biTSCC pathogenesis prevail: field carcinogenesis, single‐clone, and multiple HPV infections.

Case

A 49‐year‐old Male with a remote history of chewing tobacco presented with symptoms of spitting up tissue and occasional hemoptysis. Physical exam showed a sole left tonsillar mass which was confirmed to be TSCC on biopsy. The patient's computed tomographic (CT) scan was consistent with this finding; however, positron emission tomography (PET) scan indicated a second tumor in the contralateral right tonsil. Surgical resection of both masses and selective neck dissection was performed, and the specimens were sent for further pathological analysis. No complications of surgery were noted and the final diagnosis of synchronous biTSCC was made. The tumors were a T2N0M0 left poorly differentiated TSCC (p16+, EGFR+, bcl2+) with basaloid features, and a T1N0M0 right well to moderately differentiated TSCC (p16+, EGFR+, bcl2−).

Conclusion

Our present case was notable for differing tumor pathology and karyotype analysis between the right and left masses, directly supporting the multiple HPV infections hypothesis of biTSCC pathogenesis. Further genetic characterization of tonsillar tumors is needed to better characterize TSCC and best guide medical/surgical therapy.