Clinical outcomes after local field conformal reirradiation of patients with retropharyngeal nodal metastasis

Abstract

Background The purpose of this study was to present our experience with retropharyngeal node reirradiation using highly conformal radiotherapy (RT). Methods A retrospective screen of 2504 consecutively irradiated patients with head and neck malignancies between 2005 and 2015 identified 19 patients who underwent reirradiation for retropharyngeal node metastasis. Clinical and toxicity outcomes were assessed in these patients. Results Thirteen patients (68%) had squamous cell carcinoma. Eleven patients (58%) received conventionally fractionated intensity‐modulated radiotherapy (IMRT) or proton therapy, and 8 patients (42%) received single‐fractionated or hypofractionated stereotactic RT. Fourteen patients (74%) received chemotherapy. Median follow‐up was 14.7 months. The 1‐year local control, locoregional control, overall survival, and progression‐free survival rates were 100%, 94%, 92%, and 92%, respectively. Three patients (16%) experienced acute grade 3 toxicity and occurred in those treated with IMRT. There was no late grade ≥3 toxicity. Conclusion Retropharyngeal node reirradiation with conformal therapy is well tolerated and associated with excellent short‐term disease control.

A prospective evaluation of health‐related quality of life after skull base re‐irradiation

“…IMRT and VMAT are photon-based techniques that can achieve steep dose gradients towards adjacent critical structures such as the brainstem and are well suited to treat irregularly shaped SBTs. 8 The current cohort differs from prior studies in that the majority of patients reported here have larger tumors (median 23.7 cc vs 8.1 cc from Pollard et al) involving the anterior, central and postero-lateral skull base locations. 7,25,26 In centers with access to heavy ion accelerators, PBT is considered an attractive option to treat SBTs because the unique physical beam characteristics of protons produces a sharp dose drop off at the edge of the target and minimal exit dose beyond the tumor thereby minimizing low dose radiation exposure.…”

“…8 In summary, patients were treated with one of the following approaches: conventional fractionation using either IMRT/volumetric arc therapy (VMAT) or proton beam therapy (PBT), or with hypofractionated stereotactic body radiotherapy. 8 In summary, patients were treated with one of the following approaches: conventional fractionation using either IMRT/volumetric arc therapy (VMAT) or proton beam therapy (PBT), or with hypofractionated stereotactic body radiotherapy.…”

“…The radiotherapy planning details for patients undergoing head and neck re-RT at our institution have been previously described. 8 In summary, patients were treated with one of the following approaches: conventional fractionation using either IMRT/volumetric arc therapy (VMAT) or proton beam therapy (PBT), or with hypofractionated stereotactic body radiotherapy. PBT was delivered using passive scatter or active scanning intensity-modulated proton therapy.…”

“…Five-year disease-free survival rate of 40% have been reported for recurrent SBT treated aggressively. 6,8,9 In addition to disease control and physician rated toxicity outcomes, health-related quality of life (HRQoL) is a critical component of assessing head and neck cancer treatment, providing critical insight into the patient's symptoms and function, 10,11 with a focus on the patient's perspective. Re-irradiation (re-RT) is traditionally considered a last resort option because of the risks of severe morbidity associated with overdosing adjacent Oral presentation at the North American Skull Base Society Meeting 2019, Orlando.…”

“…In fact, emerging literature suggests that re-RT of SBT with curative doses is feasible, safe and can achieve durable local control (LC). 6,8,9 In addition to disease control and physician rated toxicity outcomes, health-related quality of life (HRQoL) is a critical component of assessing head and neck cancer treatment, providing critical insight into the patient's symptoms and function, 10,11 with a focus on the patient's perspective. In this prospective study, we report cancer control outcomes (LC and progression free survival) as well as HRQoL outcomes after modern re-RT of malignant recurrent or second primary SBT.…”