Image-guided radiotherapy (IGRT) is an advanced auxiliary radiotherapy technique. During cancer treatment, patients with oral cavity cancer (OCC) experience not only disease but also adverse effects due to RT. IGRT provides the relevant advantages of RT by precisely delivering tumoricidal doses via real-time knowledge of the target volume location and achieves maximal tumor control with minimal complications as recommended for cancer treatment. Additionally, studies have shown that IGRT can improve clinical outcomes in terms of not only treatment side effects but also survival benefits for cancer patients. IGRT can be performed alongside various imaging methods, including computed tomography and magnetic resonance imaging, and at different times during the radiotherapy regimen. This article reviews the literature to discuss the effects and importance of IGRT for patients with OCC, examines the rationale underlying the advantages of IGRT, discusses the limitations of IGRT with respect to different techniques, and summarizes the strategies and future prospects of IGRT in the treatment of OCC.
To assess the performance of shear wave elastography (SWE) and an extended model in predicting malignant cervical lymph nodes (LNs). 109 patients who underwent ultrasound (US) and SWE before needle biopsy were enrolled. The optimal cutoff value of elasticity indices (EIs) was determined by receiver operating characteristic (ROC) curves. The c-statistic, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were used to compare extended model and traditional one. Malignant LNs had higher EIs than benign nodes (p < 0.001). The optimal cutoff point was 42 kilopascal, corresponding to 83.3% sensitivity, 64.7% specificity, and 68.8% overall accuracy. A multivariable logistic regression analysis confirmed that EI was an independent predictor for malignancy. The new extended prediction model had a positive NRI (0.96) and IDI (0.10) for predicting malignant neck LNs. Nevertheless, the c-statistic was not significantly different between the two models. The parameter of SWE theoretically improve the model performance. However, its real clinical impact is minor, as the parameters of US-based model is already very robust. SWE can be considered as an adjunctive quantitative tool beyond conventional US examination.
We compared the outcome of patients who received non-image-guided intensity-modulated radiotherapy (IMRT) with those who received helical tomotherapy (HT), a daily image-guided radiotherapy (IGRT), after surgery for oral cavity cancer (OCC). During the period November 2006 to December 2013, a total of 152 postoperative OCC patients underwent either IMRT (n = 79) or daily IGRT (n = 73) 4 to 6 weeks after surgery. Patients in the IMRT group received 6 MV photon beams to 7 fields and those in the IGRT group received daily fractions of 1.8 or 2 Gy on five consecutive days. Patients who received daily IGRT had higher 5-year overall survival than those who received IMRT (87 % versus 48 %, p = 0.015). The local progression-free survival rate was also higher in patients who received IGRT (85 % versus 58 %, p = 0.006). More patients in the IGRT group completed the package of overall treatment time in ≤ 13 weeks and completed their course of radiation therapy in ≤ 8 weeks than patients in the IMRT group (89 % versus 68 %, p = 0.002; 84 % versus 58 %, p = 0.001), respectively. The rate of local failure in the primary tumor area was 24.0 % in the IMRT group and 6.8 % in the IGRT group. Among patients with primary local failure, the marginal failure rate was 52.6 % in the IMRT group and 0 % in the IGRT group. For patients with locally advanced OCC, postoperative IGRT results in better overall survival, better local progression-free survival, less marginal failure and shorter overall treatment time than postoperative non-image-guided IMRT.