Purpose

There is controversy about the need to target the mucosa of the larynx and hypopharynx during radiation therapy (RT) for squamous cell carcinoma of an unknown primary site (SCCA-UP). By 1997, the policy in our department was to target only the oropharynx and nasopharynx in patients with SCCA-UP metastatic to the level II cervical nodes. The purpose of this study was to report the rate of cancer recurrence in the larynx or hypopharynx using an approach that excluded these areas from the RT target volumes.

Methods and Materials

The inclusion criteria for this study were RT in our department for SCCA-UP between January 1, 1997, and December 31, 2019; no history of surgery that could disrupt the cervical lymphatics; predominant adenopathy in level IIA; and neck stage N1-2c. We excluded N3 because the incidental dose to the larynx and hypopharynx is usually high in patients with a >6-cm nodal conglomerate.

Results

The study population was comprised of 50 patients with a median follow-up after RT of 7.1 years. No patient developed recurrent cancer in a mucosal site (0/50), 2% (1/50) developed a neck recurrence in a high-dose area with synchronous distant metastases, and 2% (1/50) developed distant metastases with no evidence of local or regional recurrence.

Conclusions

When delivering RT for SCCA-UP metastatic predominantly to level IIA, it is not necessary to target the mucosa of the larynx or hypopharynx. The extent to which the incidental RT dose to these areas contributes to cancer control is not evaluated in this study.

中文翻译：

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放疗保留喉部和下咽部不明原发部位鳞状细胞癌和 IIA 级主要腺病的放射治疗

目的

对于原发灶不明的鳞状细胞癌 (SCCA-UP) 放射治疗 (RT) 期间是否需要靶向喉部和下咽部黏膜存在争议。到 1997 年，我们科的政策是仅针对 SCCA-UP 转移到 II 级颈淋巴结的患者的口咽和鼻咽。本研究的目的是使用将这些区域从 RT 目标体积中排除的方法报告喉部或下咽部的癌症复发率。

方法和材料

本研究的纳入标准是1997年1月1日至2019年12月31日期间在我科进行的SCCA-UP放疗；没有可能破坏颈部淋巴管的手术史；IIA 级主要淋巴结肿大；和颈部阶段 N1-2c。我们排除了 N3，因为对于大于 6 厘米的淋巴结团块的患者，喉部和下咽部的偶然剂量通常很高。

结果

研究人群由 50 名患者组成，放疗后的中位随访时间为 7.1 年。没有患者在黏膜部位发生复发性癌症 (0/50)，2% (1/50) 在高剂量区域发生颈部复发并同时发生远处转移，2% (1/50) 发生远处转移而无局部或区域复发的证据。

结论

当 SCCA-UP 转移性放疗主要达到 IIA 水平时，没有必要针对喉部或下咽部的粘膜。本研究未评估这些区域的偶然放疗剂量对癌症控制的贡献程度。