# The Role of Surveillance Imaging in Patients with Advanced Laryngeal Cancer
## 4 Discussion
We attempted to evaluate whether patients who were treated with radiotherapy for the primary tumor--either as definitive or adjuvant treatment--and experienced recurrence may benefit from surveillance with imaging. Similar to the general cohort, the patients treated with radiotherapy and diagnosed with imaging had shorter time to recurrence diagnosis, with similar survival rates. As radiotherapy for laryngeal tumors may induce edema, fibrosis, and necrosis, the clinical detection of recurrent disease among these patients based on physical examination may be challenging. Patients' complaints may also be misleading sometimes, since hoarseness, stridor, and dysphagia may be signs of recurrent disease, but may also be a result of the treatment itself [16]. The role of PET-CT in detecting recurrence among patients with laryngeal SCC treated with radiotherapy was described in previous publications with a high sensitivity rate [5,17,18]. While no survival difference was demonstrated in our study, we did show that imaging was associated with an earlier diagnosis of recurrence in patients with advanced laryngeal cancer. Diagnosis of recurrence at an earlier stage can certainly provide the patient with better treatment options, possibly including laryngeal preserving surgery in some cases, and thereby improve the patient's quality of life, even if no survival benefit is gained [19,20]. We believe that with a larger cohort, a survival difference could also be demonstrated among patients whose follow-up include routine post-treatment imaging. [PERSON] et al. [5] evaluated the role of imaging in follow-up after radiotherapy treatment for head and neck SCC. They compared 71 cases of recurrences diagnosed by imaging with 119 recurrences diagnosed clinically and found that imaging allows for an earlier diagnosis of recurrent disease compared with clinical diagnosis (median time of 11 months vs. 16 months, \(p\)-value \(<\) 0.0001). No difference in overall survival was demonstrated. As the majority of imaging-diagnosed recurrences in their cohort were during the first two years, their recommendation is to consider routine surveillance with imaging during the first two years and to focus on clinical follow-up afterwards, except for specific cases. Additionally, they found that imaging was more likely to diagnose distant recurrence compared with recurrences diagnosed by other modalities. As the number of distant recurrences in our cohort was relatively small (N = 9), we were unable to demonstrate significant differences between patients with distant recurrences who were diagnosed by imaging compared with other modalities. The study by [PERSON] et al. also found no difference in survival of patients with distant recurrence diagnosed by imaging compared with clinical diagnosis. Importantly, most cases described in [PERSON] et al. 's cohort were of orophynx origin (82.2%), with only 4.1% of cases of laryngeal cancer. A recent study by [PERSON] et al. [21] investigated the association between surveillance imaging and mortality in patients with head and neck cancer using a population-based study design. They demonstrated that in a cohort of 1004 patients, surveillance imaging using PET/PET-CT was associated with lower mortality among patients with SCC for regionalized and distant cancer stages, with a protective association that was observed up to 2 years after completion of treatment. To our knowledge, no previous study has focused on the yield of imaging follow-up for laryngeal SCC specifically. Most studies published on this issue describe the role of imaging in head and neck cancer in general or in patients treated only by radiotherapy. According to our results, we believe that patients with laryngeal SCC should be followed-up clinically, according to the NCCN guidelines.