xRead - Nasal Obstruction (September 2024) Full Articles

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ICAR SINONASAL TUMORS

examined palliative re-irradiation in a cohort of head and neck cancer patients, including 21 patients with SNM, and found an 11% rate of grade 3 toxicities but no grade 4–5 toxicities. 2147 D Morbidity following proton therapy In contrast to photon therapy, proton beam radiation’s “Bragg peak” property has the advantage of depositing the radiation without exit dose yielding a lower dose to the adjacent normal tissues. 2148 McDonald et al. com pared proton therapy in SNM and NPC patients and found that proton therapy was associated with lower opiate pain medication requirements and lower rates of gastrostomy tube dependence than IMRT. Pasalic et al. examined a cohort of 64 patients treated with protons and found that 20% of patients experienced acute severe toxicities, most commonly dermatitis, mucositis, and pain. 255 Russo et al. found in a similar cohort of 54 patients treated with proton therapy that 15% of patients experienced grade 3 toxicities and 11% experienced grade 4 toxicities, most commonly ocular toxicities and sinonasal fistulae, while Fan et al. examined 86 patients receiving proton therapy and found a 24% rate of acute grade 3 toxicities and a 6% rate of late grade 3 toxicities, including ORN, soft tissue fibrosis and necrosis, and vision loss. 442,528,2149 While proton beam’s main focus has been on toxicity reduction compared to photon-based RT, the application of proton for SNM may improve survival. Patel et al. performed a meta-analysis comparing charged particle versus photon therapy and found improved OS and DFS, with a caveat that noncom parative cohorts were the focus of this analysis. They found a higher rate of neurologic side effects in the charged par ticle group but otherwise equivalent rates of toxicity. The most common toxicities in both groups were hematologic, followed by head and neck and eye-related toxicities. 458 Fan et al. also showed further improvement of local control with intensity-modulated proton therapy versus standard three-dimensional proton therapy for SNM. 442 An option for proton therapy has been added to the most recent NCCN guidelines. 196,458 One of the more common RT complications in the sinonasal region is the development of temporal lobe necrosis (TLN). This was examined by McDonald et al. in a cohort of 66 patients treated with proton therapy for skull base and SNM, and the authors found a 3 year TLN incidence of 12%, 6% of which was grade 2 or

higher, occurring on average 21 months after completion of therapy. 2150 A more recent review by Kitpanit et al. exam ined patients receiving proton therapy for various head and neck subsites in which the field included the skull base and found a 6% rate of TLN, 2% of which was grade 2 or higher. 2151 Although a promising technology with robust retrospective evidence for its efficacy, there is lim ited prospective evidence for reduced toxicity with proton therapy in SNM. A phase two prospective study is currently enrolling (NCT01586767). 2152 E Osteoradionecrosis An important complication of SNM RT is the develop ment of skull base ORN. The literature on ORN incidence in SNM is limited due to the heterogeneity of tumors, though most studies on NPC have found a 0.5%–1% inci dence in patients receiving definitive RT, with the risk increased with larger tumors and prior surgery, as well as RT doses over 70 Gy. 2153–2155 It typically presents with foul odor, headache, and recurrent epistaxis, with exam showing exposed bone, surrounding necrotic tissue, and purulent debris, and occurs with a mean latency of 3–15 years. 2154,2156 Serious complications can occur, includ ing CSF leak, carotid blowout, meningitis, venous sinus thrombosis, and brain abscesses. 2154 Medical treatment is typically attempted first, with both pentoxifylline and vita min E commonly used. 2154,2157 Hyperbaric oxygen (HBO) is also frequently attempted, and small case series have sug gested efficacy in treating maxillary ORN, though a large multicenter study in mandibular ORN failed to show any significant benefit. 2154,2158,2159 In addition, there is some concern that HBO may promote cancer growth and recur rence, although data are conflicting. 2160 Surgical excision is indicated for patients without improvement or at risk for serious complications and includes thorough debride ment and reconstruction with local or free flaps. 2154,2161 Habib et al. reported a cohort of 31 skull base ORN patients treated surgically, with 23 out of 31 treated with free flap reconstruction and the remainder with primary closure. Fourteen percent of those treated with free flaps demon strated recurrence, in contrast with 50% of those closed primarily ( p = 0.04). 2162 Mortality has been suggested to be higher when ORN involves the sphenoid, and treatment necessitates evaluation and management of the ICA (e.g., balloon occlusion testing). 2163 Table XXXII.3 summarizes evidence surrounding QOL after RT for SNM.