Background and purpose: Bilateral elective nodal irradiation (ENI) remains the standard treatment for head and neck squamous cell carcinoma (HNSCC). Unilateral ENI could reduce treatment toxicity... Show moreBackground and purpose: Bilateral elective nodal irradiation (ENI) remains the standard treatment for head and neck squamous cell carcinoma (HNSCC). Unilateral ENI could reduce treatment toxicity and improve health-related quality-of-life (HRQOL). This prospective proof-of-principle trial (NCT02572661) investigated the feasibility, safety and clinical benefits of SPECT/CT-guided ENI of the node-negative contralateral neck.Materials and methods: Patients with lateralized T1-3N0-2bM0 HNSCC of the oropharynx, oral cavity, larynx and hypopharynx underwent SPECT/CT after peritumoral Tc-99m-nanocolloid injection. Patients without contralateral lymph drainage received ipsilateral ENI only. If lymph drainage to only one contralateral hot spot was visible, ENI to the contralateral neck would be limited to only the level containing the hot spot. The primary endpoint was the incidence of contralateral regional failure (CRF) at 2 years. Toxicity and HRQOL were compared with a 1:1 matched historical cohort that received standard bilateral ENI (B-ENI) with identical planning and treatment techniques.Results: Fifty patients were treated with SPECT/CT-guided ENI. After a median follow-up of 33 months (range 18-45), CRF was observed in one patient (2%; 95% confidence interval: 0-6%). Compared to the matched B-ENI group, patients treated with SPECT/CT-guided ENI had significantly lower incidences of grade >= 2 dysphagia (54% vs. 82%; p < 0.001), tube feeding (10% vs. 50%; p < 0.001) and late grade >= 2 xerostomia (9% vs. 54%; p < 0.001). Significant and clinically relevant HRQOL benefits of SPECT/CT-guided ENI were observed on the EORTC QLQ-C30 summary score, and QLQ-HN35 swallowing and dry mouth subscales.Conclusion: SPECT/CT-guided ENI is associated with a low risk of contralateral regional failure. Compared to B-ENI, SPECT/CT-guided ENI significantly reduces dysphagia, feeding tube placement, and late xerostomia and improves HRQOL. (C) 2020 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 147 (2020) 56-63 Show less
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... Show moreBackground 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. (C) 2018 Elsevier B.V. All rights reserved. Show less
To investigate the feasibility of lymph drainage mapping (LDM) using SPECT/CT to help select head and neck cancer (HNSCC) patients for unilateral elective neck irradiation (ENI). Patients with... Show moreTo investigate the feasibility of lymph drainage mapping (LDM) using SPECT/CT to help select head and neck cancer (HNSCC) patients for unilateral elective neck irradiation (ENI). Patients with lateralized HNSCC treated with radiotherapy routinely undergo bilateral ENI, despite the incidence of contralateral regional failure being relatively low even after unilateral ENI. We hypothesized that patients with a lateralized tumor without visible lymph drainage to the contralateral neck have an extremely low risk of contralateral involved nodes. Excluding the contralateral neck from elective irradiation will reduce radiation-induced toxicity and improve quality-of-life.Fifty-five patients with lateralized cT1-3N0-2bM0 HNSCC not crossing the midline underwent LDM. Radiolabeled Tc-99m-nanocolloid was injected in 4-5 depots around and in the primary tumor. Lymph drainage patterns were visualized using planar scintigraphy and SPECT/CT after 4 h. We report on the incidence of contralateral drainage, the location of draining areas, and the size of underlying nodes.Lymphatic drainage was successfully visualized in 54 patients (98%). In 11 patients (20%) with visible contralateral drainage, 14 draining areas (16 nodes; median volume 0.50 cc, diameter 8.0 mm) were identified. Neck levels with contralateral drainage were level II (88%), III (25%), and IV (13%). Contralateral drainage was significantly higher in T3 compared to T1-2 tumors (45 and 14%, respectively, P = 0.035).SPECT/CT-guided LDM is feasible and can be used to guide unilateral ENI in HNSCC patients in prospective studies. In addition, the anatomical confidence in visualization of contralateral drainage indicates a potential for ENI limited to draining levels alone. Show less
