SPECT/CT-guided elective nodal irradiation for head and neck cancer: Estimation of clinical benefits using NTCP models. (January 2019)

• Record Type: Journal Article
• Authors: de Veij Mestdagh, Pieter D.; Janssen, Tomas; Lamers, Emmy; Carbaat, Casper; Hamming-Vrieze, Olga; Vogel, Wouter V.; Sonke, Jan-Jakob; Al-Mamgani, Abrahim
• Is Part Of: Radiotherapy and oncology. Volume 130(2019)
• Page Start: 18
• Page End: 24
• Publication Date: 2019-01
• Subjects: cRF contralateral regional failure -- ENI elective nodal irradiation -- HNSCC head and neck squamous cell carcinoma -- HPC hypopharyngeal cancer -- LC laryngeal cancer -- OCC oral cavity cancer -- OPC oropharyngeal cancer -- QoL quality of life -- SSG selective SPECT/CT-guided; Head and neck cancer -- Radiotherapy -- Elective nodal irradiation -- Lymph drainage mapping -- SPECT/CT -- NTCP models; Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2018.07.023
• Languages: English
• ISSNs: 0167-8140

Abstract

Highlights: Lymph drainage mapping can guide elective nodal irradiation in H&N cancer. This greatly reduces mean irradiation dose to various contralateral organs at risk. Likely, this significantly decreases several important radiation-related toxicities. Patients without contralateral lymph drainage profit more than those with it. Oropharyngeal and oral cavity cancer patients profit more than those with other primaries. Abstract: Background and purpose: The great majority of patients with lateralized head and neck squamous cell carcinoma (HNSCC) treated with radiotherapy routinely undergo bilateral elective nodal irradiation (ENI), even though the incidence of contralateral regional failure after unilateral ENI is low. Excluding the contralateral neck from elective irradiation could reduce radiation-related toxicity and improve quality-of-life. The current study investigated the dosimetric benefits of a novel approach using lymph drainage mapping by SPECT/CT to select patients for unilateral ENI. Patients and methods: Forty patients with lateralized cT1-3N0-2bM0 HNSCC underwent lymph drainage mapping. Two radiation plans were made; the real plan with which patients were actually treated (selective SPECT/CT-guided plan irradiating the ipsilateral neck ± any contralateral draining level); and the virtual plan (standard plan according to institutional guidelines, as if the same patient would have been treated bilaterally). Radiation doses to clinically important organs-at-risk were compared between the two plans. We used five normal tissue complication probability (NTCP) models to predict the clinical benefits of this approach. Results: Median dose reductions to the contralateral parotid gland, contralateral submandibular gland, glottic larynx, supraglottic larynx, constrictor muscle and thyroid gland were 19.2, 27.3, 11.4, 9.7, 12.1 and 18.4 Gy, respectively. Median NTCP reductions for xerostomia, contralateral parotid function, dysphagia, hypothyroidism and laryngeal edema were 20%, 14%, 10%, 20% and 5% respectively. Conclusions: Selective SPECT/CT-guided ENI results in significant dose reductions to various organs-at-risk and corresponding NTCP values, and will subsequently reduce the incidence and severity of different troublesome radiation-related toxicities and improve quality-of-life.