xRead - Nasal Obstruction (September 2024) Full Articles

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to be due to the use of RT for advanced tumors and pos itive margins. 398 Thus, while negative margins are ideal, close or microscopic margins with restraint around critical structures appear to provide similar outcomes in the set ting of postoperative RT. Accordingly, ICSB 2019 reported an aggregate grade of evidence of C for primary surgery with consideration of adjuvant RT on a case-by-case basis. 5 Role and extent of surgery in sinonasal ACC

mendation is for a dose of at least 60 Gy to the tumor bed. 1206,1208–1210 Two retrospective cohorts from the same institution reviewed the cases of 105 patients with sinonasal ACC in 2007, and later on 160 patients in 2018, characterizing prognostic factors and treatment approach. 79,398 Over all, surgical resection followed by adjuvant treatment offered the best OS in patients compared to RT or surgery alone. Surgical patients had improved OS and DFS when compared with those treated nonsurgically. The surgical approach varied among open (including radical resection and orbital exenteration in 7.6% of the patients), endo scopic, or combined. Large nerve PNI (40%–65% of the cases) was associated with higher recurrence rates and decreased OS. 79,398 The extent of resection (STR or GTR with microscopic positive or negative margins) did not have any effect on OS or DFS, which might be in part due to the addition of adjuvant RT. RT was given as IMRT or proton therapy. RT doses were 66–70 Gy alone or with concurrent cisplatin chemotherapy for gross residual dis ease, 66 Gy for GTR with positive margins, and 60 Gy for negative margins. 398 In several cohorts where adjuvant RT was recommended only for advanced-stage disease or positive margins, but not for early disease or negative margins, a clear trend toward better survival rates and better local control existed in the groups that received RT. 79,106,1198,1211 Moreover, a multicenter study of 32 patients with advanced ACC with skull base involvement treated with surgical resection and adjuvant RT (17 originating from the paranasal sinuses) revealed a high 10-year LRC rate of 88.2% despite an 81.3% rate of positive surgical margins. 494 In this study, the adjuvant RT doses were based on surgical margin sta tus. Patients with negative margins received 54–56 Gy in 27–30 fractions, while those with positive margins were prescribed 63–66 Gy in 30–33 fractions. RT to critical organs such as brainstem, optic chiasm, and optic nerve was limited to 54 Gy and spinal cord to 45 Gy. 494 Deliv ery techniques included three-dimensional conformal RT until 2008, and IMRT or volumetric modulated arc therapy after 2008. Complications following adjuvant RT included wound breakdown, ORN, and fistula. 79,494 One of the challenging aspects in radiation planning of the skull base is the risk to adjacent critical structures, which limits the dose of conventional photon radiation to the tumor region. 538,1212,1213 Protons are charged parti cles with biological effectiveness like conventional photon radiation. Due to the Bragg peak, proton beam RT (PBRT) and carbon ion RT (CIRT) can provide a more precise dose distribution. This could potentially lead to improved local control and decreased acute and late toxic effects. 1214 Compared with photon-based IMRT, this feature of PBRT improves the therapeutic ratio by introducing a sharp dose

Aggregate grade of evidence

C (Level 2: one study; Level 3: two studies; Level 4: 10 studies) Surgical resection is superior to any other modality in terms of local control and long-term survival. Damage to vital structures or important organs (eye, carotid artery, brain, oral cavity), postoperative complications, and CN deficits. No studies directly assessed cost. However, improved local control implies decreased future cost in terms of hospitalization, imaging, systemic therapy, and so forth. Preponderance of benefits over harms. Endoscopic resection is associated with lower complication rates and improved QOL over the long term in select cases and is comparable to open approaches in terms of survival outcomes. Achieving negative margins will improve local control as well as improve OS. There is a high distant recurrence rate and risk of skip lesions in PNI. Given the high overall local control rate, a strategy of GTR and postoperative RT while preserving function provides QOL without reduction of survival.

Benefit

Harm

Cost

Benefits–harm assessment

Value

judgments

Policy level Recommendation. Intervention Surgical resection should be attempted as the

first line of treatment when feasible, with the goal to achieve GTR (with negative surgical margins whenever possible) while preserving vital structures.

2 Role of radiation therapy While there are no RCTs on this topic, postoperative adju vant RT is advocated as the standard of care, with emphasis on those with positive margins (microscopic or macro scopic) or advanced disease that infiltrates into adjacent structures. 73,79,1198,1205,1207,1208 In patients with ACC of the head and neck overall, it has been observed that improved local control can be achieved with increased RT dose regardless of margin status, and the subsequent recom