Supplementary Material for: A case of photoimmunotherapy for nasopharyngeal carcinoma requiring emergency tracheostomy

Introduction: Photoimmunotherapy (PIT) is a treatment wherein intravenous cetuximab sarotarocan sodium is administered followed by laser light irradiation. This treatment exhibits a specific antitumor effect if in tumors expressing the epidermal growth factor receptor (EGFR), regardless of the carcinoma [1-3]. The current indications are unresectable, locally advanced, or locally recurrent head and neck cancer. If standard treatments, such as radiotherapy and chemotherapy, are available, they are given priority. However, a significant concern in PIT is the occurrence of airway emergencies related to pharyngeal edema. Prophylactic tracheostomy is often performed in cases of PIT involving the root of the tongue, hypopharynx, or larynx. Case presentation: In this study, we administered transoral PIT to a patient diagnosed with radiation-induced nasopharyngeal carcinoma (squamous cell carcinoma (SCC) cT1N0M0 Stage I). Although previous case reports and our own experiences did not report airway emergencies following PIT for nasopharyngeal carcinoma, a unique case occurred in our study [4,5]. The patient experienced poor oxygenation and a decreased level of consciousness early in the morning following the laser irradiation. Nasal endoscopy revealed airway narrowing due to upper airway edema, and intubation was challenging. Consequently, we performed emergency bedside tracheostomy and the patient’s condition improved. Conclusion: Therefore, it is crucial to note that airway emergencies can be life-threatening and should be diligently monitored as a potential complication of PIT

Supplementary Material for: Intra-Arterial Signal on Arterial Spin Labeling Perfusion MRI to Identify the Presence of Acute Middle Cerebral Artery Occlusion

<b><i>Background:</i></b> The susceptibility vessel sign on gradient echo-type-T2*-weighted imaging is a well-known marker of arterial occlusion. Stagnant flow in front of the middle cerebral artery (MCA) occlusion sites may contribute to the intra-arterial, high-intensity signal on arterial spin labeling magnetic resonance imaging (MRI), making it another potential marker of MCA occlusion. We compared the intra-arterial, high-intensity signal and susceptibility vessel sign in patients with symptomatic MCA occlusion and patients without major vessel occlusion. <b><i>Methods:</i></b> We identified transient ischemic attack or ischemic stroke patients with (1) 3-T MRI performed within 24 h after clinical onset including arterial spin labeling, T2*-weighted imaging, and magnetic resonance angiography (MRA) and (2) either having MCA occlusion (n = 34 patients) or without major vessel occlusion (n = 24 patients). The intra-arterial, high-intensity signal was defined as an enlarged circular or linear bright hyperintensity within the artery. The susceptibility vessel sign was defined as an enlarged spot of hypointensity within the MCA, in which the diameter of the hypointense signal within the vessel exceeded the contralateral vessel diameter. The presence or absence of the intra-arterial, high-intensity signal and susceptibility vessel sign were assessed, along with their inter-rater agreement and consistency with the presence of MCA occlusion on MRA. <b><i>Results:</i></b> The intra-arterial, high-intensity signal was detectable in 30 patients (52%), and susceptibility vessel sign was observed in 17 patients (29%). The sensitivity of the intra-arterial high-intensity signal was significantly higher than that of the susceptibility vessel sign (88% vs. 50%; p < 0.05). The accuracy of the intra-arterial high-intensity signal was also higher than that of the susceptibility vessel sign (93% vs. 71%; p < 0.05). The intra-arterial high-intensity signal was situated in the proximal regions of the susceptibility vessel sign on T2*WI within the MCA. Neither the intra-arterial high-intensity signal nor the susceptibility vessel sign was observed in patients without major vessel occlusion. Inter-rater agreement was good for intra-arterial high-intensity signal detection (κ = 0.73) and moderate for susceptibility vessel sign detection (κ = 0.47). The presence or absence of the intra-arterial high-intensity signal was highly consistent with that of MCA occlusion on MRA (κ = 0.74). <b><i>Conclusions:</i></b> The intra-arterial high-intensity signal on arterial spin labeling appears to be useful to identify the presence of acute MCA occlusion and may be associated with stagnant flow in front of occlusion sites. The intra-arterial high-intensity signal may also be used to identify the occlusion site