Akira Baba1, Yumi Okuyama2, Hideomi Yamauchi3, Koshi Ikeda3, Nobuhiro Ogino3, Ayako Kozakai4, Taiki Suzuki4, Hirokazu Saito4, Satoru Ogane4, Shinji Yamazoe2, Takuji Mogami2, Hiroya Ojiri3. 1. Department of Radiology, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan; Department of Radiology, Ichikawa General Hospital Tokyo Dental College, 5-11-13 Sugano, Ichikawa-shi, Chiba 272-8513, Japan. Electronic address: akirababa@jikei.ac.jp. 2. Department of Radiology, Ichikawa General Hospital Tokyo Dental College, 5-11-13 Sugano, Ichikawa-shi, Chiba 272-8513, Japan. 3. Department of Radiology, Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan. 4. Oral Cancer Center, Tokyo Dental College, 5-11-13 Sugano, Ichikawa-shi, Chiba 272-8513, Japan.
Abstract
PURPOSE: By comparing styloglossus and hyoglossus muscle invasion (SHMI) of oral tongue squamous cell cancer (OTSCC) on MR imaging to pathological depth of invasion (DOI) and prognosis, we aimed to evaluate the clinical significance of MR imaging findings of SHMI. METHOD: Forty-five, early stages and clinically N0 OTSCCs were retrospectively reviewed. Data included pathological DOI, DOI on MR imagings, two-year potential cervical lymph node positive, locoregional control, disease-free survival, and overall survival. Data were statistically compared between the groups with MR evidence of SHMI (SHMI+) and without MR evidence of SHMI (SHMI-). RESULTS: There were 17 SHMI + and 28 SHMI-. Elective neck dissections performed on 13 cases revealed five node positive cases, all of which were SHMI + . Pathological DOI in SHMI + was significantly larger than SHMI- (average 9.0 vs 4.6 mm, p < 0.001). All SHMI + revealed pathological DOI larger than 4 mm. The two-year potential cervical lymph node positive rate of SHMI + was significantly higher than SHMI- (p = 0.01). Locoregional control rate and disease-free survival of SHMI+ were significantly lower than in SHMI- (p = 0.02). There was no significant difference in overall survival. Interobserver agreement in evaluation of SHMI on MR imaging was good (kappa value = 0.72, p < 0.001). CONCLUSIONS: Pathological DOIs of SHMI + were all larger than 4 mm, which is the cut-off point that National Comprehensive Cancer Network recommends for neck dissection, and SHMI + had a worse prognosis than SHMI-. SHMI + can be used as a criterion for elective neck dissection.
PURPOSE: By comparing styloglossus and hyoglossus muscle invasion (SHMI) of oral tongue squamous cell cancer (OTSCC) on MR imaging to pathological depth of invasion (DOI) and prognosis, we aimed to evaluate the clinical significance of MR imaging findings of SHMI. METHOD: Forty-five, early stages and clinically N0 OTSCCs were retrospectively reviewed. Data included pathological DOI, DOI on MR imagings, two-year potential cervical lymph node positive, locoregional control, disease-free survival, and overall survival. Data were statistically compared between the groups with MR evidence of SHMI (SHMI+) and without MR evidence of SHMI (SHMI-). RESULTS: There were 17 SHMI + and 28 SHMI-. Elective neck dissections performed on 13 cases revealed five node positive cases, all of which were SHMI + . Pathological DOI in SHMI + was significantly larger than SHMI- (average 9.0 vs 4.6 mm, p < 0.001). All SHMI + revealed pathological DOI larger than 4 mm. The two-year potential cervical lymph node positive rate of SHMI + was significantly higher than SHMI- (p = 0.01). Locoregional control rate and disease-free survival of SHMI+ were significantly lower than in SHMI- (p = 0.02). There was no significant difference in overall survival. Interobserver agreement in evaluation of SHMI on MR imaging was good (kappa value = 0.72, p < 0.001). CONCLUSIONS: Pathological DOIs of SHMI + were all larger than 4 mm, which is the cut-off point that National Comprehensive Cancer Network recommends for neck dissection, and SHMI + had a worse prognosis than SHMI-. SHMI + can be used as a criterion for elective neck dissection.