Metabolic tumor volume of primary tumor predicts survival better than T classification in the larynx preservation approach

Abstract

We aimed to determine whether pretreatment metabolic tumor volume of the primary tumor (T‐MTV) or T classification would be a better predictor of laryngectomy‐free survival (LFS) and overall survival (OS) after chemoradiotherapy in patients with locally advanced laryngeal or hypopharyngeal cancer requiring total laryngectomy. We analyzed 85 patients using a Cox proportional hazards model and evaluated its usefulness by Akaike's information criterion. A T‐MTV cut‐off value was determined by time‐dependent receiver operating characteristic curve analysis. Interobserver reliability for measuring T‐MTV was estimated by the intraclass correlation coefficient (ICC). After adjustment for covariables, T‐MTV, irrespective of whether a continuous or dichotomized variable, and T classification remained independent predictors of LFS and OS. Large T‐MTV (>28.7 mL) was associated with inferior LFS (hazard ratio [HR], 4.16; 95% confidence interval [CI], 1.97–8.70; P = 0.0003) and inferior OS (HR, 3.18; 95% CI, 1.47–6.69; P = 0.004) compared with small T‐MTV (≤28.7 mL). The T‐MTV model outperformed the T classification model in predicting LFS and OS (P = 0.007 and 0.01, respectively). Three‐year LFS and OS rates for patients with small versus large T‐MTV were 68% vs 9% (P < 0.0001) and 77% vs 25% (P < 0.0001), respectively, whereas those for patients with T2‐T3 versus T4a were 61% vs 31% (P = 0.003) and 71% vs 48% (P = 0.10), respectively. ICC was 0.99 (95% CI, 0.99–1.00). Given the excellent interobserver reliability, T‐MTV is better than T classification to identify patients who would benefit from the larynx preservation approach.

Prognostic significance of pretreatment 18F‐fluorodeoxyglucose positron emission tomography evaluation using metabolic tumor volume of the primary tumor and lymph nodes in advanced hypopharyngeal cancer

“…10,[12][13][14][15][16] Especially, in cases with oropharyngeal cancer, as human papillomavirus infection greatly affects prognosis, it cannot be simply discussed with hypopharyngeal cancer. In this study, MTV-T-3 was found to be a significant prognostic factor for advanced hypopharyngeal cancer with respect to LCR and OS, and almost significant for DSS.…”

“…Although several reports have also shown the effectiveness Abbreviations: 95% CI, 95% confidence interval; CR, complete response; DSS, disease-specific survival; HR, hazard ratio; LCR, local control rate; MTV, metabolic tumor volume; OS, overall survival; PET, positron emission tomography. [13][14][15]23 As the cut-off value of MTV varies depending on the tumor site, stage, and threshold of MTV, the value must be changed according to each patient group and analysis method. 10,[12][13][14][15][16] Especially, in cases with oropharyngeal cancer, as human papillomavirus infection greatly affects prognosis, it cannot be simply discussed with hypopharyngeal cancer.…”

“…Though SUV of 2.5 was commonly used as the MTV threshold in patients with head and neck cancers in several previous reports, [12][13][14][15]17 there is not enough evidence that SUV of 2.5 is optimal. Conversely, MTV-T-10 was not significant for predicting prognosis.…”

“…Although several reports have also shown the effectiveness of MTV in patients with hypopharyngeal cancer, many of those reports had a small number of patients with hypopharyngeal cancer or contained patients with cancers of other regions, such as laryngeal or oropharyngeal cancers. 10,[12][13][14][15][16] Especially, in cases with oropharyngeal cancer, as human papillomavirus infection greatly affects prognosis, it cannot be simply discussed with hypopharyngeal cancer. 28 We think it is meaningful to show the significance of MTV in this research that targeted only patients with advanced hypopharyngeal cancer.…”

“…1 More than 80% of patients with hypopharyngeal cancer have advanced disease (stages III and IV on UICC staging) at primary diagnosis, and 5-year survival is around 30% for stage III and 15% for stage IV. 10,[12][13][14][15][16][17][18] Although several studies evaluated the usefulness of FDG-PET examinations using these parameters for predicting prognosis of patients with head and neck tumors, [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] with regard to advanced hypopharyngeal cancer, the usefulness of FDG-PET imaging has not been sufficiently examined. Parameters frequently used in analysis with FDG-PET examinations are the maximum standard uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV), and total lesion glycolysis (TLG).…”