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Positron emission tomography (PET) is an imaging modality widely applied in oncology for tumor staging, volume delineation in radiation therapy planning, and therapy response assessment. F-18 fluorodeoxyglucose (FDG) PET combined with computed tomography plays a significant role in the management of locally advanced head and neck cancer patients in the pretreatment setting to predict outcome and prognosis and after chemoradiation therapy (CRT) to assess tumor response. This review aims to evaluate the use of FDG PET acquired during CRT, ad interim FDG (FDG int ), to identify tumor response at an early stage, modify the treatment plan if necessary, or set up alternative strategies to enhance the therapeutic ratio. Most of the studies confirmed the value of FDG int in predicting the response to CRT, whereas a few highlighted the poor predictive value of FDG int compared with FDG acquired 2 to 4 months after the end of CRT, which was well correlated with local and regional control and survival. Such findings deserve to be further analyzed in more homogeneous series with greater patient numbers according to the tumor site and CRT schedules. The best time to assess tumor response during radiation therapy remains a matter of debate, although 2 weeks seems most favorable, still providing the opportunity to adapt the treatment strategy., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: The purpose of this work was to develop and validate an efficient and automatic strategy to generate online virtual computed tomography (CT) scans for adaptive radiation therapy (ART) in head-and-neck (HN) cancer treatment., Method: We retrospectively analyzed 20 patients, treated with intensity modulated radiation therapy (IMRT), for an HN malignancy. Different anatomical structures were considered: mandible, parotid glands, and nodal gross tumor volume (nGTV). We generated 28 virtualCT scans by means of nonrigid registration of simulation computed tomography (CTsim) and cone beam CT images (CBCTs), acquired for patient setup. We validated our approach by considering the real replanning CT (CTrepl) as ground truth. We computed the Dice coefficient (DSC), center of mass (COM) distance, and root mean square error (RMSE) between correspondent points located on the automatically segmented structures on CBCT and virtualCT., Results: Residual deformation between CTrepl and CBCT was below one voxel. Median DSC was around 0.8 for mandible and parotid glands, but only 0.55 for nGTV, because of the fairly homogeneous surrounding soft tissues and of its small volume. Median COM distance and RMSE were comparable with image resolution. No significant correlation between RMSE and initial or final deformation was found., Conclusion: The analysis provides evidence that deformable image registration may contribute significantly in reducing the need of full CT-based replanning in HN radiation therapy by supporting swift and objective decision-making in clinical practice. Further work is needed to strengthen algorithm potential in nGTV localization., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: To compare infrared (IR) optical vs. stereoscopic X-ray technologies for patient setup in image-guided stereotactic radiotherapy., Methods and Materials: Retrospective data analysis of 233 fractions in 127 patients treated with hypofractionated stereotactic radiotherapy was performed. Patient setup at the linear accelerator was carried out by means of combined IR optical localization and stereoscopic X-ray image fusion in 6 degrees of freedom (6D). Data were analyzed to evaluate the geometric and dosimetric discrepancy between the two patient setup strategies., Results: Differences between IR optical localization and 6D X-ray image fusion parameters were on average within the expected localization accuracy, as limited by CT image resolution (3 mm). A disagreement between the two systems below 1 mm in all directions was measured in patients treated for cranial tumors. In extracranial sites, larger discrepancies and higher variability were observed as a function of the initial patient alignment. The compensation of IR-detected rotational errors resulted in a significantly improved agreement with 6D X-ray image fusion. On the basis of the bony anatomy registrations, the measured differences were found not to be sensitive to patient breathing. The related dosimetric analysis showed that IR-based patient setup caused limited variations in three cases, with 7% maximum dose reduction in the clinical target volume and no dose increase in organs at risk., Conclusions: In conclusion, patient setup driven by IR external surrogates localization in 6D featured comparable accuracy with respect to procedures based on stereoscopic X-ray imaging., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: Fatigue is an underevaluated cancer-related and treatment-related symptom. We analyzed fatigue in head and neck cancer patients undergoing radiotherapy (RT)., Methods and Materials: A total of 117 patients were enrolled (mean age, 58 years). Radiation therapy (median dose, 66 Gy) was given with either exclusive or postoperative intent in 52 and 65 patients, respectively. Chemotherapy (CT) was added before and/or during RT in 61 patients. The patients completed a 20-item questionnaire (Multidimensional Fatigue Inventory [MFI-20]) before, during (weekly), and after RT. The impact of patient-, tumor-, and treatment-related factors on fatigue was evaluated with unifactorial and multifactorial tests., Results: Fatigue level increased during RT reaching a maximum at Week 6 and then slowly decreased. In multivariate stepwise regression analysis age (inversely related, p < 0.05), psychologic disorders (p < 0.005), and previous head-and-neck surgery (inversely related, p < 0.005) were correlated with higher pre-RT fatigue level. Pre-RT fatigue score (p < 0.0001), induction and/or concomitant CT (p = 0.035), need of cortisone during RT (p = 0.005), and thyroid disorders (p = 0.032) were correlated with higher during-RT fatigue level. Pre-RT fatigue score (p < 0.0001), induction and/or concomitant CT (p < 0.001), and need of cortisone during RT (p < 0.005) were correlated with higher post-RT fatigue level. No impact of gender, performance status, comorbidities other than psychologic and thyroid, tumor stage/site, RT intent, dose, volume, duration, or toxicity was observed., Conclusion: Fatigue affects all patients undergoing RT for head-and-neck cancer, reaches maximum score at the 6th week of RT, and slowly decreases thereafter. Age, thyroid dysfunction, psychologic disorders, pre-RT fatigue score, CT, and cortisone use are correlated with RT-related fatigue levels.

Purpose: To evaluate the incidence of thyroid disorders and dose distribution to the thyroid in patients treated with radiotherapy for head-and-neck carcinomas., Methods and Materials: A retrospective evaluation of data from 73 patients treated for head-and-neck cancers in our department was performed. Thyroid function was evaluated mainly by the measurement of thyrotropin (thyroid stimulating hormone [TSH]). A retrospective analysis of treatment plans was performed for 57 patients. Percentages of thyroid glandular volume absorbing 10, 30, and 50 Gy (V10, V30, and V50 respectively) were considered for statistical analysis., Results: A majority of patients (61%) had a normal thyroid function whereas 19 patients (26%) had hypothyroidism. Mean thyroid volume was 30.39 cc. Point 3 (located at isthmus) absorbed lower doses compared with other points (p < 0.0001). Median values of V10, V30, and V50 were 92% (range, 57-100%), 75% (range, 28.5-100%), and 35% (range, 3-83%) respectively. Gender was associated with toxicity (presence of any kind of thyroid disorders) (p < 0.05), with females displaying higher levels of TSHr (relative TSH = patient's value/maximum value of the laboratory range) (p = 0.0005) and smaller thyroid volume (p = 0.0012) compared with male population. TSHr values were associated with thyroid volume, and the presence of midline shielding block in the anterior field was associated with relative free thyroxine (FT4r = patient's value/maximum value of the laboratory range) values., Conclusions: Gender and thyroid volume seem to play an important role in the occurrence of thyroid toxicity, but further studies on dose-effect relationship for radiotherapy-induced thyroid toxicity are needed.

Purpose: We performed a phase II study to assess feasibility, pain relief, and toxicity of a tetracaine-based oral gel in the treatment of radiotherapy (RT)-induced mucositis., Methods and Materials: Fifty patients treated with RT for head-and-neck cancer with clinical evidence of acute oral mucositis of grade>or=2 were scheduled to receive the tetracaine gel. A questionnaire evaluating the effect of the gel was given to all subjects., Results: In 38 patients (79.2%), a reduction in oral cavity pain was reported. Thirty-four patients (82.9%) reported no side effect. Seventy-one percent of patients had no difficulties in gel application. Unpleasant taste of the gel and interference with food taste were noticed in 5 (12%) and 16 patients (39%), respectively. Planned RT course was interrupted less frequently in patients who reported benefit from gel application than in patients who did not (p=0.014). None of the patients who experienced pain relief needed a nasogastric tube, opposite to the patients who did not report any benefit from gel application (p=0.001)., Conclusion: Tetracaine oral gel administration seemed feasible and safe while reducing RT-induced mucositis-related oral pain in a sizeable proportion of treated head-and-neck cancer patients. A trial designed to compare efficacy of this gel vs. standard treatment is warranted.