Intensity-modulated radiotherapy in the treatment of head and neck cancer

Radiotherapy Results in Locally Advanced Sinonasal Cancer: Turkish Society for Radiation Oncology, Head and Neck Study Group 01-005

OBJECTIVES

This study aims to examine the treatment outcomes and related factors in locally advanced sinonasal cancer across Turkiye.

METHODS

Twelve centers participants of the Turkish Society for Radiation Oncology Head and Neck Study Group attended the study. One hundred and ninety-four patients treated with intensity-modulated radiation therapy between 2001 and 2021 were analyzed retrospectively. The survival analysis was performed using the Kaplan-Meier method. Acute and late toxicity were recorded per Common Toxicity Criteria for Adverse Events V4.0.

RESULTS

The median age was 58 years and 70% were male. The majority of tumors were located in maxillary sinus (59%). Most of the patients (%83) had T3 and T4A disease. Fifty-three percent of patients were in stage 4A. Radiotherapy was administered to 80% of the patients in the adjuvant settings. Median 66 Gy dose was administered in median 31 fractions. Chemotherapy was administered concomitantly with radiotherapy in 45% of the patients mostly with weekly cisplatin. No grade ≥4 acute and late toxicity was observed. The median follow-up was 43 months. The 5-year and 10-year overall survival (OS); locoregional recurrence-free survival (LRFS); distant metastasis-free survival (DMFS), and progression-free survival (PFS) rates were 61% and 47%; 69% and 61%; 72%, and 69%, and 56% and 49%, respectively. In the multivariate analysis, several factors demonstrated significant influence on OS, such as performance status, surgery, and lymph node involvement. Moreover, surgery was the key prognostic factor for LRFS. For DMFS, lymph node involvement and surgical margin were found to be influential factors. In addition, performance status and lymph node involvement were identified as significantly affecting PFS.

CONCLUSIONS

In our study, the authors obtained promising results with IMRT. Performance status, lymph node involvement, and surgery emerged as the primary factors significantly influencing OS.

Volumetric and geometric changes in the parotid glands and target volume during image-guided radiotherapy for locally advanced oropharyngeal cancers

PURPOSE

This study aimed to evaluate the volumetric and geometric changes in the parotid glands and target volume during image-guided radiotherapy (IGRT) for locally advanced oropharyngeal cancers.

MATERIALS AND METHODS

Twenty patients receiving radiotherapy using IGRT at a dose of 70 Gy/35 fractions/7 weeks for locally advanced oropharyngeal cancers were accrued. Radiotherapy planning computed tomography (CT) scans were performed at pre-radiotherapy (RT), 20, 40, and 60 Gy for each patient. Volume changes in target and parotids along with shifts of parotids were assessed with respect to pre-RT scan after co-registration. In study scans, GTVp and GTVn were recontoured as per particular CT. CTV and PTV were copied from planning CT to study CT. CTV was edited from anatomical barriers, and PTV was edited only from the skin in the study CT. The parotids were recontoured on each study scan. The center of mass (COM) of C2 vertebral body was considered as the reference to evaluate its shifts.

RESULTS

There was a statistically significant percentage regression of ipsilateral and contralateral parotid mean volumes at the rate of 0.85%/0.207 cc and 0.98%/0.26 cc per day, respectively. We observed the mean medial shift of center of mass of ipsilateral parotid of 2.23 mm (p = 0.011) and contralateral parotid of 2.67 mm (p = 0.069) at the end of 60 Gy. GTVp (mean) reduced from 41.87 cc at 0 Gy to 31.13 cc (25.65%) at 60 Gy (p = 0.003), while GTVn (mean) reduced from 19.98 cc at 0 Gy to 10.79 cc (45.99%) at 60 Gy (p = 0.003). There was a statistically significant reduction in CTV and PTV volumes at 60 Gy.

CONCLUSION

Statistically significant volumetric and geometric changes occurred during intensity-modulated radiation (IMRT), which were most prominent after 40 Gy and were maximum at 60 Gy. There was a medial shift of parotid glands toward the high-dose region. This study can be useful to devise an adaptive radiotherapy strategy.

Eating and speech problems in oral and pharyngeal cancer survivors - Associations with treatment-related side-effects and time since diagnosis

AIMS

The aim of this cross-sectional study was to find factors associated with problems with the ability to eat and speak in oral and pharyngeal cancer (OPC) survivors and to evaluate if the panorama of oral problems varied with time since diagnosis.

METHODS AND RESULTS

A questionnaire assessing cancer diagnosis and treatment, oral health-related quality of life, and presence of treatment-related side-effects was sent to members of the Norwegian Head and Neck Cancer Association. Three-quarters (n = 117) of the respondents experienced xerostomia, and 51% (n = 79) had dysphagia. Prevalence of dysphagia, trismus, and dysphonia was lowest among respondents diagnosed within the last 5-10 years prior to the study. Eating problems were reported by 75% (n = 121) of the OPC survivors and were associated with xerostomia, dysphagia, trismus, having removed part of the tongue, cancer diagnosis within 5 years prior to the study and having little problems with caries and tooth fracture. Speaking problems were experienced by 60% (n = 93) of the OPC survivors, and were associated with dysphonia, dysphagia, and trismus.

CONCLUSION

Our study shows a high prevalence of oral problems among OPC survivors and points to targets for interventions for eating and speech impairments that may improve oral health-related quality of life.

Automatic gross tumor segmentation of canine head and neck cancer using deep learning and cross-species transfer learning

Background

Radiotherapy (RT) is increasingly being used on dogs with spontaneous head and neck cancer (HNC), which account for a large percentage of veterinary patients treated with RT. Accurate definition of the gross tumor volume (GTV) is a vital part of RT planning, ensuring adequate dose coverage of the tumor while limiting the radiation dose to surrounding tissues. Currently the GTV is contoured manually in medical images, which is a time-consuming and challenging task.

Purpose

The purpose of this study was to evaluate the applicability of deep learning-based automatic segmentation of the GTV in canine patients with HNC.

Materials and methods

Contrast-enhanced computed tomography (CT) images and corresponding manual GTV contours of 36 canine HNC patients and 197 human HNC patients were included. A 3D U-Net convolutional neural network (CNN) was trained to automatically segment the GTV in canine patients using two main approaches: (i) training models from scratch based solely on canine CT images, and (ii) using cross-species transfer learning where models were pretrained on CT images of human patients and then fine-tuned on CT images of canine patients. For the canine patients, automatic segmentations were assessed using the Dice similarity coefficient (Dice), the positive predictive value, the true positive rate, and surface distance metrics, calculated from a four-fold cross-validation strategy where each fold was used as a validation set and test set once in independent model runs.

Results

CNN models trained from scratch on canine data or by using transfer learning obtained mean test set Dice scores of 0.55 and 0.52, respectively, indicating acceptable auto-segmentations, similar to the mean Dice performances reported for CT-based automatic segmentation in human HNC studies. Automatic segmentation of nasal cavity tumors appeared particularly promising, resulting in mean test set Dice scores of 0.69 for both approaches.

Conclusion

In conclusion, deep learning-based automatic segmentation of the GTV using CNN models based on canine data only or a cross-species transfer learning approach shows promise for future application in RT of canine HNC patients.

A network analysis of self-reported psychoneurological symptoms in patients with head and neck cancer undergoing intensity-modulated radiotherapy

BACKGROUND

Patients with head and neck cancer experience psychoneurological symptoms (PNS) (i.e., depression, fatigue, sleep disturbance, pain, and cognitive dysfunction) during intensity-modulated radiotherapy (IMRT) that decrease their functional status, quality of life, and survival rates. The purpose of this study was to examine and visualize the relationships among PNS within networks over time and evaluate for demographic and clinical characteristics associated with symptom networks.

METHODS

A total of 172 patients (mean age, 59.8 ± 9.9 years; 73.8%, male; 79.4%, White) completed symptom questionnaires four times, namely, before IMRT (T1), 1 month (T2), 3 months (T3), and 12 months (T4) post IMRT. Network analysis was used to examine the symptom-symptom relationships among PNS. Centrality indices, including strength, closeness, and betweenness, were used to describe the degrees of symptom network interconnections. Network comparison test was used to assess the differences between two symptom networks.

RESULTS

Depression was associated with the other four symptoms, and fatigue was associated with the other three symptoms across the four assessments. Based on the centrality indices, depression (rstrength  = 1.3-1.4, rcloseness  = 0.06-0.08, rbetweeness  = 4-10) was the core symptom in all symptom networks, followed by fatigue. Female gender, higher levels of stress, and no alcohol use were associated with stronger symptom networks in network global strength before IMRT.

CONCLUSION

Network analysis provides a novel approach to gain insights into the relationships among self-reported PNS and identify the core symptoms and associated characteristics. Clinicians may use this information to develop symptom management interventions that target core symptoms and interconnections within a network.

LAY SUMMARY

This study describes the symptom-symptom relationships for five common symptoms in patients with head and neck cancer receiving radiotherapy. Depression and fatigue appeared to be two core symptoms that were connected with sleep disturbance, pain, and cognitive dysfunction within a network. Several characteristics (i.e., female, higher stress, no alcohol use) were associated with stronger symptom networks.

Deep learning-based auto segmentation using generative adversarial network on magnetic resonance images obtained for head and neck cancer patients

Purpose

Adaptive radiotherapy requires auto‐segmentation in patients with head and neck (HN) cancer. In the current study, we propose an auto‐segmentation model using a generative adversarial network (GAN) on magnetic resonance (MR) images of HN cancer for MR‐guided radiotherapy (MRgRT).

Material and methods

In the current study, we used a dataset from the American Association of Physicists in Medicine MRI Auto‐Contouring (RT‐MAC) Grand Challenge 2019. Specifically, eight structures in the MR images of HN region, namely submandibular glands, lymph node level II and level III, and parotid glands, were segmented with the deep learning models using a GAN and a fully convolutional network with a U‐net. These images were compared with the clinically used atlas‐based segmentation.

Results

The mean Dice similarity coefficient (DSC) of the U‐net and GAN models was significantly higher than that of the atlas‐based method for all the structures (p < 0.05). Specifically, the maximum Hausdorff distance (HD) was significantly lower than that in the atlas method (p < 0.05). Comparing the 2.5D and 3D U‐nets, the 3D U‐net was superior in segmenting the organs at risk (OAR) for HN patients. The DSC was highest for 0.75–0.85, and the HD was lowest within 5.4 mm of the 2.5D GAN model in all the OARs.

Conclusions

In the current study, we investigated the auto‐segmentation of the OAR for HN patients using U‐net and GAN models on MR images. Our proposed model is potentially valuable for improving the efficiency of HN RT treatment planning.

FDG-PET/CT for oral focus assessment in head and neck cancer patients

Objectives

To compare oral and maxillo-mandibular inflammatory foci on standard oral radiographs (OPT, periapical radiograph) with available fluorine-18-labelled fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) data and to discuss whether additional metabolic information derived from FDG-PET/CT can support oral care specialists when performing oral focus examinations.

Materials and methods

Data from 23 patients with head and neck cancer who underwent FDG-PET/CT and panoramic and periapical radiography in close succession before first-line radiotherapy and/or chemotherapy were included in this exploratory retrospective study. Periapical lesions and marginal periodontal inflammation on FDG-PET/CT scans and standard oral radiographs were analysed and compared with regard to metabolic activity on FDG-PET/CT in comparison to recorded clinical symptoms and radiological scores. Additionally, inflammatory maxillo-mandibular pathologies were analysed using FDG-PET/CT.

Results

The maximum standardised uptake value (SUV_max) in FDG-avid marginal periodontal sites could not be conclusively associated with the radiologically recorded severity of marginal bone loss, but a potential positive correlation was identified. No association was found either between the metabolic activity of periapical lesions and their extent, as recorded on standard oral radiographs, or regarding clinical symptoms (percussion test). Most maxillo-mandibular pathologies did not show increased FDG uptake.

Conclusions

FDG-PET/CT provided additional metabolic information that can help clinicians identify lesions with increased inflammatory activity. The incorporation of available oral FDG-PET/CT findings into the primary oral focus assessment may allow for more accurate oral focus treatment.

Clinical relevance

FDG-PET/CT provides valuable metabolic information for oral care specialists. The detection of inflammatory oral processes using FDG-PET/CT facilitates treatment.

Patterns of the use of advanced radiation therapy techniques for the management of bone metastases and the associated factors in Victoria

INTRODUCTION

To describe the pattern of the use of advanced radiation therapy (RT) techniques, including intensity-modulated RT (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic body RT (SBRT) for the management of bone metastases (BM), and the associated factors in Victoria.

METHODS

We used a population-based cohort of patients from the state-wide Victorian Radiotherapy Minimum Data Set (VRMDS) who received RT for BM between 2012 and 2017. The primary outcome was proportion of RT courses using advanced RT techniques. The Cochran-Armitage test for trend was used to evaluate temporal trend in advanced RT use. Multinomial logistic regression was used to identify factors associated with advanced RT use.

RESULTS

A total of 18,158 courses of RT were delivered to 10,956 patients-16,626 (91.6%) courses were 3D conformal RT, 857 (4.7%) IMRT/VMAT and 675 (3.7%) SBRT. There was a sharp increase in IMRT/VMAT use from <1% in 2012-2015, to 10.1% in 2016 and 16.3% in 2017 (P-trend < 0.001). Increase in SBRT use was more gradual, from 1.2% in 2012 to 4.8% in 2016 and 5.5% in 2017 for SBRT (P-trend<0.001). In multivariate analyses, year of RT was the strongest predictor of IMRT/VMAT use (OR = 41; 95%CI = 25-67; P < 0.001, comparing 2012-2013 and 2016-2017). Primary tumour type (prostate cancer) was the strongest predictor of SBRT use (OR = 6.07; 95% CI = 4.19-8.80; P < 0.001).

CONCLUSION

Overall, there was increasing trend in the use of advanced RT techniques for BM in Victoria, with a distinct pattern for IMRT/VMAT compared with SBRT - SBRT uptake was more gradual while IMRT/VMAT uptake was abrupt, occurring contemporaneously with Medicare Benefit Scheme funding changes in 2016.

Health-Related Quality of Life in Oral Cancer Patients: Scoping Review and Critical Appraisal of Investigated Determinants

Simple Summary

Oral cancer may strongly impair patients’ quality of life. Huge efforts have been made during recent decades in trying to improve the treatment outcomes in terms of patients’ survival, self-perception, and satisfaction. Consequently, the investigation into health-related quality of life (HRQOL) became an established and worldwide practice. Hundreds of studies tried to clarify which could be the most important variables that impact HRQOL in head and neck cancer patients. However, such a complex topic may be influenced by a multitude of interconnected aspects and several controversies were reported. In this study the current literature was reviewed to identify all those possible sources of bias that may be encountered in trying to correlate HRQOL to patient-specific or disease/treatment-specific aspects. As a result, a list of recommendations was reported to enhance the evidence of future studies.

Abstract

Background: health-related quality of life (HRQOL) represents a secondary endpoint of medical interventions in oncological patients. Our aim was to highlight potential sources of bias that could be encountered when evaluating HRQOL in oral cancer patients. Methods: this review followed PRISMA-ScR recommendations. Participants: patients treated for oral cancer. Concept: HRQOL assessed by EORTC QLQ-C30 and QLQ-H&N35/QLQ-H&N43. A critical appraisal of included studies was performed to evaluate the accuracy of data stratification with respect to HRQOL determinants. Results: overall, 30 studies met the inclusion criteria, totaling 1833 patients. In total, 8 sociodemographic (SDG) and 15 disease/treatment-specific (DT) HRQOL determinants (independent variables) were identified. The mean number of the independent variables was 6.1 (SD, 4.3)—5.0 (SD, 4.0) DT-related and 1.1 (SD, 1.8) SDG-related variables per article. None of the included papers considered all the identified determinants simultaneously. Conclusions: a substantial lack of evidence regarding HRQOL determinants was demonstrated. This strongly weakens the reliability of the reported findings due to the challenging presence of baseline confounding, selection, and omitted variable biases. The proposed approach recommends the use of further evaluation tools that gather more variables in a single score together with a selection of more homogeneous, reproducible, and comparable cohorts based on the identified baseline confounding.

Platelet-rich fibrin as a treatment option for osteoradionecrosis: A literature review

The aim of this review is to establish the usefulness and effectiveness of using platelet-rich fibrin (PRF) in the treatment of osteoradionecrosis (ORN) lesions. A review of the literature was performed using keywords through the PubMed-Medline and Cochrane Library search engine. Inclusion criteria were: (1) original publication in either the French or the English language, (2) studies conducted in humans, (3) presence of ORN lesions following head and neck radiotherapy (RT), (4) use of PRF or derivates in the treatment of ORN lesions, (5) clinical variables and outcomes mentioned in the study. Overall, four case reports were retained. Two publications were removed from the initial seven results after application of the inclusion criteria. A recent randomised clinical trial was not considered since the group analysed the effectiveness of leukocyte-enriched Plasmas-Rich-Fibrin (LPRF) in preventing ORN, but not in treating it. Therefore, four publications were retained for analysis. Results suggest that using PRF as an adjunct to surgical therapy is beneficial in treating ORN lesions although no controlled studies were found. Therefore, additional controlled clinical studies are warranted to better define the effectiveness and recommendation of this approach.

Long-term Survivals, Toxicities and the Role of Chemotherapy in Early-Stage Nasopharyngeal Carcinoma Patients Treated with Intensity-modulated Radiation Therapy: A Retrospective Study with 15-year Follow-up

Purpose

This study was aimed to investigate long-term survivals and toxicities of early-stage nasopharyngeal carcinoma (NPC) in endemic area, evaluating the role of chemotherapy in stage II patients.

Materials and Methods

Totally 187 patients with newly diagnosed NPC and restaged American Joint Committee on Cancer/ International Union Against Cancer 8th T1-2N0-1M0 were retrospectively recruited. All received intensity-modulated radiotherapy (IMRT)±chemotherapy (CT) from 2001 to 2010.

Results

With 15.7-year median follow-up, 10-year locoregional recurrence-free survival, distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS) were 93.3%, 93.5%, 92.9% and 88.2%, respectively. Multivariable analyses showed cervical lymph nodes positive and pre-treatment prognostic nutritional index ≥ 52.0 could independently predict DMFS (p=0.036 and p=0.011), DSS (p=0.014 and p=0.026), and OS (p=0.002 and p < 0.001); Charlson comorbidity index < 3 points could predict DSS (p=0.011); age > 45 years (p=0.002) and pre-treatment lactate dehydrogenase ≥ 240 U/L (p < 0.001) predicted OS. No grade 4 late toxicity happened; grade 3 late toxicities included subcutaneous fibrosis (4.3%), deafness or otitis (4.8%), skin dystrophy (2.1%), and xerostomia (1.1%). No differences on survivals were shown between IMRT+CT vs. IMRT alone in stage II patients, even in T2N1M0 (p > 0.05). Unsurprising, patients in IMRT+CT had more acute gastrointestinal reaction, myelosuppression, mucositis, late ear toxicity, and cranial nerve injury (all p < 0.05) than IMRT alone group.

Conclusion

Superior tumor control and satisfying long-term outcomes could be achieved with IMRT in early-stage NPC with mild late toxicities. As CT would bring more toxicities, it should be carefully performed to stage II patients.

Pilocarpine improves submandibular gland dysfunction in irradiated rats by downregulating the tight junction protein claudin-4

OBJECTIVES

To investigate the effects of radiation on paracellular pathway of rat submandibular glands (SMGs) and the mechanism of increasing secretion following treatment with pilocarpine.

MATERIALS AND METHODS

In situ irradiation models of SMGs in Wistar rats were conducted, and the glands were exposed to X-radiation at a single dose of 20 Gy. Pilocarpine was intraperitoneally injected 60 min prior to radiation and continuous 6 days postirradiation for a total of 7 days. Salivary secretion, histological changes, pro-inflammatory cytokines, alterations in tight junctions (TJs), and functional membrane proteins aquaporin-5 (AQP5) and claudin-4 mediated by the muscarinic acetylcholine M3 subtype receptor were determined at 1 and 12 weeks after irradiation.

RESULTS

Salivary secretion of the irradiated glands was reduced at 1 and 12 weeks. As well, acinar cell numbers, TJ width, and the levels of M3 receptor and AQP5 were decreased. In contrast, tumor necrosis factor-α, interleukin 6, interleukin 1α, and the expression of the TJ protein claudin-4 were significantly increased in irradiated SMGs. Notably, all the alterations were attenuated by pilocarpine treatment.

CONCLUSIONS

Pilocarpine could improve the secretory function of irradiated rat SMGs via reducing inflammation, ameliorating the structural injury of TJs, and attenuating the up-regulation of claudin-4 expression.

A comparison of methods for fully automatic segmentation of tumors and involved nodes in PET/CT of head and neck cancers

Target volume delineation is a vital but time-consuming and challenging part of radiotherapy, where the goal is to deliver sufficient dose to the target while reducing risks of side effects. For head and neck cancer (HNC) this is complicated by the complex anatomy of the head and neck region and the proximity of target volumes to organs at risk. The purpose of this study was to compare and evaluate conventional PET thresholding methods, six classical machine learning algorithms and a 2D U-Net convolutional neural network (CNN) for automatic gross tumor volume (GTV) segmentation of HNC in PET/CT images. For the latter two approaches the impact of single versus multimodality input on segmentation quality was also assessed. 197 patients were included in the study. The cohort was split into training and test sets (157 and 40 patients, respectively). Five-fold cross-validation was used on the training set for model comparison and selection. Manual GTV delineations represented the ground truth. Tresholding, classical machine learning and CNN segmentation models were ranked separately according to the cross-validation Sørensen-Dice similarity coefficient (Dice). PET thresholding gave a maximum mean Dice of 0.62, whereas classical machine learning resulted in maximum mean Dice scores of 0.24 (CT) and 0.66 (PET; PET/CT). CNN models obtained maximum mean Dice scores of 0.66 (CT), 0.68 (PET) and 0.74 (PET/CT). The difference in cross-validation Dice between multimodality PET/CT and single modality CNN models was significant (p ≤ 0.0001). The top-ranked PET/CT-based CNN model outperformed the best-performing thresholding and classical machine learning models, giving significantly better segmentations in terms of cross-validation and test set Dice, true positive rate, positive predictive value and surface distance-based metrics (p ≤ 0.0001). Thus, deep learning based on multimodality PET/CT input resulted in superior target coverage and less inclusion of surrounding normal tissue.

Development of a Rat Model of Mandibular Irradiation Sequelae for Preclinical Studies of Bone Repair

Repairing mandibular bone defects after radiotherapy of the upper aerodigestive tract is clinically challenging. Although bone tissue engineering has recently generated a number of innovative treatment approaches for osteoradionecrosis (ORN), these modalities must be evaluated preclinically in a relevant, reproducible, animal model. The objective of this study was to evaluate a novel rat model of mandibular irradiation sequelae, with a focus on the adverse effects of radiotherapy on bone structure, intraosseous vascularization, and bone regeneration. Rats were irradiated with a single 80 Gy dose to the jaws. Three weeks after irradiation, mandibular bone defects of different sizes (0, 1, 3, or 5 mm) were produced in each hemimandible. Five weeks after the surgical procedure, the animals were euthanized. Explanted mandibular samples were qualitatively and quantitatively assessed for bone formation, bone structure, and intraosseous vascular volume by using micro-computed tomography, scanning electron microscopy, and histology. Twenty irradiated hemimandibles and 20 nonirradiated hemimandibles were included in the study. The bone and vessel volumes were significantly lower in the irradiated group. The extent of bone remodeling was inversely related to the defect size. In the irradiated group, scanning electron microscopy revealed a large number of polycyclic gaps consistent with periosteocytic lysis (described as being pathognomonic for ORN). This feature was correlated with elevated osteoclastic activity in a histological assessment. In the irradiated areas, the critical-sized defect was 3 mm. Hence, our rat model of mandibular irradiation sequelae showed hypovascularization and osteopenia. Impact statement Repairing mandibular bone defects after radiotherapy of the upper aerodigestive tract is clinically challenging. Novel tissue engineering approaches for healing irradiated bone must first be assessed in animal models. The current rat model of mandibular irradiation sequelae is based on tooth extraction after radiotherapy. However, the mucosal sequelae of radiotherapy often prevent the retention of tissue-engineered biomaterials within the bone defect. We used a submandibular approach to create a new rat model of mandibular irradiation sequelae, which enables the stable retention of biomaterials within the bone defect and should thus facilitate the assessment of bone regeneration.

A Prospective 10-Year Observational Study of Reduction of Radiation Therapy Clinical Target Volume and Dose in Early-Stage Nasopharyngeal Carcinoma

PURPOSE

Current guideline recommends a uniform method of delineation of subclinical disease within the primary clinical target volume (CTVp) for all stages of nasopharyngeal carcinoma (NPC). We performed a prospective observational study to investigate the outcomes with a reduced CTVp and radiation dose for early-stage NPC.

METHODS AND MATERIALS

Patients with newly diagnosed, biopsy-proven World Health Organization type II-III and American Joint Committee on Cancer/Union for International Cancer Control sixth edition stage T1-2N0-1 disease were enrolled. All patients were treated with intensity modulated radiation therapy alone. We categorized CTVp into CTVp1 (high risk) and CTVp2 (low risk). CTVp1 comprised of gross tumor (on magnetic resonance imaging or contrast-enhanced computed tomography) plus a 5-mm margin (3-mm posteriorly) and was prescribed to 60 Gy in 30 fractions (fr). CTVp2 was generated from CTVp1 plus a 5-mm margin (3 mm posteriorly), excluding the maxillary and cavernous sinuses, and was prescribed to 54 Gy in 30 fr. The prescribed doses to the primary and nodal gross tumor volume (GTVp and GTVn) were 68 Gy in 30 fr and 60 to 66 Gy in 30 fr, respectively. Primary endpoint was local recurrence-free survival. This study was registered in ClinicalTrials.gov, number NCT03839602.

RESULTS

From May 2001 to August 2006, 103 patients were recruited and completed IMRT. With a median follow-up of 15.2 years (range, 2.1-18.1 years), only 1 patient had local failure. Ten-year local recurrence-free survival, regional recurrence-free survival, distant metastasis-free survival, and overall survival were 90.3%, 88.3%, 90.3%, and 91.2%, respectively. Among late IMRT-related adverse events, we recorded 2 patients with G1 cranial nerve injury, 3 patients with G3 hearing loss, and 3 patients with G3 subcutaneous fibrosis. No patients had temporal lobe necrosis, brain stem injury, or trismus.

CONCLUSIONS

Decreased CTV margins and radiation doses can achieve long-term tumor control with mild late toxicities for patients with early-stage NPC.

Dosimetric impact of tracheostomy devices in head and neck cancer patients

INTRODUCTION

The tracheostomy site and adjacent skin is at risk for recurrence in head/neck squamous cell cancer patients. The tracheostomy tube is an in situ device located directly over the tracheostomy site and may have clinical implications on the radiation dose delivered to the peristomal region. This study aimed to investigate this effect by comparing the prescribed treatment planning dose with the actual dose in vivo to the peristomal clinical target region. A retrospective, dosimetric study was performed with approval of the institutional research ethics board.

METHODS

Fifteen patients who had received high-dose radiotherapy to the tracheostomy region with in vivo dose measurements were included. The radiation dose at the skin surface underneath the tracheostomy device was measured using an optically stimulated luminescent dosimeter (OSLD) and was compared with the prescribed dose from the radiation planning system. The effect of the tracheostomy flange and/or soft tissue equivalent bolus on the peristomal dose was calculated.

RESULTS AND DISCUSSION

Patients with tracheostomy equipment in situ were found to have a 3.7% difference between their prescribed and actual dose. With a tissue equivalent bolus there was a 2.0% difference between predicted and actual. The mean prescribed single fraction dose (mean = 191.8 cGy, SD = 40.18) and OSLD measured dose (mean = 194.02 cGy, SD = 44.3) were found to have no significant difference. However, with the flange excluded from the planning simulation (density = air) target skin dose deviated from predicted by an average of 55.3% (range = 12.4-72.9, SD = 22.5) and volume coverage was not achieved.

CONCLUSION

In summary, the tracheostomy flange acts like bolus with a twofold increase in the skin surface dose. Changes in the peristomal apparatus from simulation to treatment needs to be considered to ensure that the simulated dose and coverage is achieved.

Importance of Technique, Target Selection, Contouring, Dose Prescription, and Dose-Planning in External Beam Radiation Therapy for Cervical Cancer: Evolution of Practice From EMBRACE-I to II

PURPOSE

To describe the evolution of external beam radiation therapy (EBRT) from EMBRACE-I (general guidelines for EBRT) to the initial phase of the EMBRACE-II study (detailed protocol for EBRT).

METHODS AND MATERIALS

EMBRACE-I enrolled 1416 locally advanced cervical cancer patients treated with chemoradiation including image-guided adaptive brachytherapy during 2008 to 2015. From March 2016 until March 2018, 153 patients were enrolled in the ongoing EMBRACE-II study, which involves a comprehensive detailed strategy and accreditation procedure for EBRT target contouring, treatment planning, and image guidance. EBRT planning target volumes (PTVs), treated volumes (V43 Gy), and conformity index (CI; V43 Gy/PTV) were evaluated in both studies and compared.

RESULTS

For EMBRACE-I, conformal radiation therapy (60% of patients) or intensity-modulated radiation therapy (IMRT) and volumetric arc therapy (VMAT; 40%) was applied with 45 to 50 Gy over 25 to 30 fractions to the elective clinical target volume (CTV). For pelvic CTVs (82%), median PTV and V43 Gy volumes were 1549 and 2390 mL, respectively, and CI was 1.54. For pelvic plus paraortic nodal (PAN) CTVs (15%), median PTV and V43 Gy volumes were 1921 and 2895 mL, and CI was 1.51. For pelvic CTVs treated with 45 to 46 Gy, the use of conformal radiation therapy was associated with a median V43 Gy volume that was 546 mL larger than with IMRT/VMAT. For pelvic CTVs treated with IMRT, the use of a dose prescription ≥48 Gy was associated with a median V43 Gy volumes that was 428 mL larger than with a dose prescription of 45 to 46 Gy. For EMBRACE-II, all patients were treated with: IMRT/VMAT, daily IGRT, 45 Gy over 25 fractions for the elective CTV, and simultaneously integrated boost for pathologic lymph nodes. For pelvic CTVs (61%), median PTV and V43 Gy volumes were 1388 and 1418 mL, and CI was 1.02. For pelvic plus PAN CTVs (32%), median PTV and V43 Gy volumes were 1720 and 1765 mL, and CI was 1.03. From EMBRACE-I to initial II, median V43 Gy was decreased by 972 mL (41%) and 1130 mL (39%), and median CI decreased from 1.54 to 1.02 and 1.51 to 1.03 for pelvic and pelvic plus PAN irradiation, respectively.

CONCLUSIONS

Application of IMRT/VMAT, IGRT, and a 45-Gy dose provides the potential of higher conformality inducing significant reduction of treated volume. Adherence to a detailed protocol including comprehensive accreditation, as in EMBRACE-II, reduces considerably V43 Gy and V50 Gy and improves conformality and interinstitutional consistency.

Management of the Neck in Squamous Cell Carcinoma of the Oral Cavity and Oropharynx: ASCO Clinical Practice Guideline

PURPOSE

The aim of the current work is to provide evidence-based recommendations to practicing physicians and others on the management of the neck in patients with squamous cell carcinoma of the oral cavity and oropharynx.

METHODS

ASCO convened an Expert Panel of medical oncology, surgery, radiation oncology, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1990 through 2018. Outcomes of interest included survival, regional disease control, neck recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 124 relevant studies to inform the evidence base for this guideline. Six clinical scenarios were devised; three for oral cavity cancer and three for oropharynx cancer, and recommendations were generated for each one.

RECOMMENDATIONS

For oral cavity cancers, clinical scenarios focused on the indications for and the hallmarks of a high-quality neck dissection, indications for postoperative radiotherapy or chemoradiotherapy, and whether radiotherapy alone is sufficient elective treatment of an undissected neck compared with high-quality neck dissection. For oropharynx cancers, clinical scenarios focused on hallmarks of a high-quality neck dissection, factors that would favor operative versus nonoperative primary management, and clarifying criteria for an incomplete response to definitive chemoradiation for which salvage neck dissection would be recommended. Consensus was reached and recommendations were made for all six clinical scenarios. Additional information is available at www.asco.org/head-neck-cancer-guidelines .

Treatment Outcomes in Anaplastic Thyroid Cancer

BACKGROUND

Anaplastic thyroid cancer (ATC) is rare, accounting for 1-2% of thyroid malignancies. Median survival is only 3-10 months, and the optimal therapeutic approach has not been established. This study aimed to evaluate outcomes in ATC based on treatment modality.

METHODS

Retrospective review was performed for patients treated at a single institution between 1990 and 2015. Demographic and clinical covariates were extracted from the medical record. Overall survival (OS) was modeled using Kaplan Meier curves for different treatment modalities. Univariate and multivariate analyses were conducted to assess the relationships between treatment and disease characteristics and OS.

RESULTS

28 patients with ATC were identified (n = 16 female, n = 12 male; n = 22 Caucasian, n = 6 African-American; median age 70.9). Majority presented as Stage IVB (71.4%). Most patients received multimodality therapy. 19 patients underwent local surgical resection. 21 patients received locoregional external beam radiotherapy (EBRT) with a median cumulative dose of 3,000 cGy and median number of fractions of 16. 14 patients received systemic therapy (n = 11 concurrent with EBRT), most commonly doxorubicin (n = 9). 16 patients were never disease free, 11 patients had disease recurrence, and 1 patient had no evidence of disease progression. Median OS was 4 months with 1-year survival of 17.9%. Regression analysis showed that EBRT (HR: 0.174; 95% CI: 0.050-0.613; p=0.007) and surgical resection (HR: 0.198; 95% CI: 0.065-0.598; p=0.004) were associated with improved OS. Administration of chemotherapy was not associated with OS.

CONCLUSIONS

Anaplastic thyroid cancer patients receiving EBRT to the thyroid area/neck and/or surgical resection had better OS than patients without these therapies, though selection bias likely contributed to improved outcomes since patients who can undergo these therapies tend to have better performance status. Prognosis remains poor overall, and new therapeutic approaches are needed to improve outcomes.

Revisiting the dose constraints for head and neck OARs in the current era of IMRT

Head and neck cancer poses a particular challenge in radiation therapy, whilst being an effective treatment modality it requires very high doses of radiation to provide effective therapy. This is further complicated by the fact that the head and neck region contains a large number of radiosensitive tissues, often resulting in patients experiencing debilitating normal tissue complications. In the era of intensity-modulated radiation therapy (IMRT) treatments can be delivered using non-uniform dose distributions selectively aimed at reducing the dose to critical organs-at-risk while still adequately covering the tumor target. Dose-volume constraints for the different risk organs play a vital role in one's ability to devise the best IMRT treatment plan for a head and neck cancer patient. To this end, it is pivotal to have access to the latest and most relevant dose constraints available and as such the goal of this review is to provide a summary of suggested dose-volume constraints for head and neck cancer RT that have been published after the QUANTEC reports were made available in early 2010.

Carbon ion irradiation withstands cancer stem cells' migration/invasion process in Head and Neck Squamous Cell Carcinoma (HNSCC)

Cancer Stem Cells (CSCs) in Head and Neck Squamous Cell Carcinoma (HNSCC) have extremely aggressive profile (high migratory and invasive potential). These characteristics can explain their resistance to conventional treatment. Efficacy of photon and carbon ion irradiation with addition of cetuximab (5 nM) is studied on clonogenic death, migration and invasion of two HNSCC populations: SQ20B and SQ20B/CSCs. SQ20B express E-cadherin and overexpress EGFR while SQ20B/CSCs express N-cadherin and low EGFR. Cetuximab strongly inhibits SQ20B proliferation but has no effect on SQ20B/CSCs. 2 Gy photon irradiation enhances migration and invasiveness in both populations (p < 0.05), while cetuximab only stops SQ20B migration (p < 0.005). Carbon irradiation significantly inhibits invasion in both populations (p < 0.05), and the association with cetuximab significantly inhibits invasion in both populations (p < 0.005). These results highlight CSCs characteristics: EGFR^Low, cetuximab-resistant, and highly migratory. Carbon ion irradiation appears to be a very promising therapeutic modality counteracting migration/invasion process in both parental cells and CSCs in contrast to photon irradiation.

Synchronous Supraglottic and Esophageal Squamous Cell Carcinomas Treated with a Monoisocentric Hybrid Intensity-Modulated Radiation Technique

Risk factors for squamous cell carcinomas (SCCs) of the head and neck (HN) and esophagus are similar. As such, synchronous primary tumors in these areas are not entirely uncommon. Definitive chemoradiation (CRT) is standard care for locally advanced HNSCC and is a preferred option for inoperable esophageal SCC. Simultaneous treatment of both primaries with CRT can present technical challenges. We report a case of synchronous supraglottic and esophageal SCC primary tumors, highlighting treatment with a monoisocentric hybrid radiation technique and normal tissue toxicity considerations.

Can sparing of the superficial contralateral parotid lobe reduce xerostomia following radiotherapy for head and neck cancer?

OBJECTIVE

The purpose of this study is to see whether sparing the superficial contralateral parotid lobe can help limiting xerostomia following radiotherapy for head and neck cancer.

METHODS

88 patients that were included in two prospective randomized studies were analysed in the current study. Using the dosimetry of both the parotid glands, we divided our patients in four groups. Group 1 includes patients where we were able to reduce the radiation dose below the threshold in order to spare both the ipsilateral and contralateral parotid glands, Group 2 consists of patients where only the contralateral parotid gland could be spared. Group 3 consists of patients where only the contralateral superficial parotid lobe could be spared, while in Group 4 not even the contralateral superficial lobe could be spared.

RESULTS

When we compared Group 1 and Group 2, we did not observe a significant difference between both groups in terms of xerostomia scores at 6 or 12 months. When we compared these groups with Group 3, we observed significant differences with more xerostomia in Group 3 where only the contralateral superficial lobe was spared. A significant difference was also observed between Group 3 and Group 4 with more xerostomia in Group 4.

CONCLUSION

Sparing of just one superficial parotid lobe results in less xerostomia when compared to not sparing any lobe of both parotid glands. Advances in knowledge: When sparing of the whole contralateral parotid gland is not possible, delineating both the superficial parotid glands and trying to spare at least one of them can mean a way forward in limiting xerostomia in head and neck cancer patients treated with radiotherapy.

Dual "mAb" HER family blockade in head and neck cancer human cell lines combined with photon therapy

Head and neck cancer stem cells (CSCs) are highly resistant to treatment. When EGFR is overexpressed in head and neck squamous cell carcinoma (HNSCC), HER2 and HER3 are also expressed. The aim of the present study was to investigate the effect of HER1/2/3 blockade through a combination of cetuximab and pertuzumab, with or without photon irradiation, on the proliferation and migration/invasion capabilities of an HNSCC chemo- and radioresistant human cell line (SQ20B) and its corresponding stem cell subpopulation. Cell proliferation, migration and invasion were studied after treatment with cetuximab +/− pertuzumab +/− 10 Gy photon irradiation. EGFR, phospho-EGFR, HER2 and HER3 protein expression levels were studied. Activation or inhibition of the RAS/MAPK and AKT-mTOR downstream signalling cascades was investigated through phospho-AKT and phospho-MEK1/2 expression. Cetuximab strongly inhibited SQ20B and FaDu cell proliferation, migration and invasion, whereas it had little effect on SQ20B-CSCs. Cetuximab–pertuzumab combined with radiation significantly inhibited SQ20B and FaDu cell and SQ20B-CSC proliferation, migration and invasion. Cetuximab–pertuzumab with 10 Gy photon irradiation switched off both phospho-AKT and phospho-MEK1/2 expression in the three populations. The triple therapy is therefore thought to inhibit SQ20B cells, SQ20B-CSCs and FaDu cells through an AKT-mTOR and Ras-MAPK downstream signalling blockade.

Osteoradionecrosis of the mandible in patients with oropharyngeal carcinoma treated with intensity-modulated radiotherapy

BACKGROUND

Osteoradionecrosis (ORN) of the mandible is a late toxicity affecting patients treated with radiotherapy for head and neck malignancies. To the authors' knowledge, ORN has no standardized grading system and its reporting is based on retrospective findings in heterogeneous patient populations. The rate of ORN in the era of intensity-modulated radiotherapy (IMRT) still is unknown.

METHODS

The authors report the incidence of ORN from prospectively collected data regarding 1196 patients who were diagnosed with squamous cell carcinoma of the oropharynx and treated with curative-intent IMRT, with or without concomitant systemic treatment, from January 2005 to December 2014. Each case of ORN was graded according to its severity. Clinical and dosimetric comparisons were performed between patients with ORN and a matched control cohort of patients without ORN.

RESULTS

The actuarial rate of ORN of the mandible was 3% at 1 year, 5% at 3 years, and 7% at 5 years. On multivariable analysis, smoking (hazard ratio, 1.9; 95% confidence interval, 1.07-3.4 [P = .03]) and T classification (hazard ratio, 1.78; 95% confidence interval, 1.02-3.1 [P = .041]) were found to be statistically significant risk factors. The presence of cardiovascular comorbidities, use of bisphosphonates, and pre-IMRT dental extractions were found to be different between the matched cohorts. The mandibular volume receiving 50 grays (Gy) (in cm³ ) and the volume receiving 60 Gy (in cm³ ) were found to be associated with ORN on multivariable analysis in the matched cohort patients receiving an IMRT regimen of 2 Gy per fraction.

CONCLUSIONS

ORN is relatively uncommon among patients with oropharyngeal carcinoma who are treated with IMRT, but continues to occur beyond 5 years after treatment. Modifiable risk factors that are associated with higher rates of ORN include smoking and the use of bisphosphonates. Minimizing the volumes of the mandible receiving >50 Gy or > 60 Gy also may have an effect on the ORN rate. Cancer 2017;123:3691-3700. © 2017 American Cancer Society.

A retrospective study comparing the outcomes and toxicities of intensity-modulated radiotherapy versus two-dimensional conventional radiotherapy for the treatment of children and adolescent nasopharyngeal carcinoma

Purpose

To compare the clinical outcomes and toxicities of two-dimensional conventional radiotherapy (2D-CRT) and intensity-modulated radiotherapy (IMRT) for the treatment of children and adolescent nasopharyngeal carcinoma (NPC).

Methods

A total of 176 children with non-metastatic NPC treated at Sun Yat-sen University Cancer Center between October 2003 and September 2013 were included in this study. Of the 176 patients, 74 received 2D-CRT and 102 were treated with IMRT. The clinical outcomes and acute and late toxicities were determined and compared.

Results

The IMRT group achieved significantly higher overall survival (OS) (90.4% vs. 76.1% at 5 year, P = 0.007) and disease-free survival (DFS) (85.7% vs. 71.2%, P = 0.029) mainly due to an improvement in locoregional relapse-free survival (LRRFS) (97.9 vs. 88.3%, P = 0.049). After stratification by disease stage, IMRT provided significant benefits for patients with stage III–IV disease in terms of OS, LRRFS and DFS. Multivariate analyses indicated that the treatment group (2D-CRT vs. IMRT) was a prognostic factor for OS, LRRFS and DFS. A significant reduction in Grade 2–4 xerostomia (52.7 vs. 34.3%, P = 0.015) and hearing loss (40.5 vs. 22.5%, P = 0.010) was observed in patients treated by IMRT.

Conclusion

IMRT provides better locoregional relapse-free survival and overall survival, especially in late-stage children and adolescent NPC patients, and is associated with a lower incidence of Grade 2–4 xerostomia as well as hearing loss compared with 2D-CRT. Distant metastasis remains a challenge in the treatment of children and adolescent NPC.

Radiotherapy response evaluation using FDG PET-CT-established and emerging applications

Radiation therapy is a common component of curative cancer treatment. However, there is a significant incidence of treatment failure. In these cases, salvage surgical options are sometimes appropriate. Accurate assessment of response and early recognition of treatment success or failure is therefore critical to guide treatment decisions and impacts on survival and the morbidity of treatment. Traditionally, treatment response has depended upon the anatomical measurement of disease. However, this may not correlate well with the presence of disease, especially after radiotherapy. Combined positron emission tomography (PET) and CT imaging employs radioactive tracers to identify molecular characteristics of tissues. PET imaging exploits the fact that malignancies have characteristic molecular profiles which differ compared with surrounding tissues. The complementary anatomical and functional information facilitates accurate non-invasive assessment of surrogate biomarkers of disease activity.

How to minimize morbidity in radiotherapy of pharyngolaryngeal tumors?

PURPOSE OF REVIEW

Radiotherapy is one of the most effective treatment modalities for head and neck cancer. However, because of the intricacy between tumors and normal tissues, it can induce morbidity, such as mucositis, dermatitis, xerostomia, dysphagia, hearing loss, vision impairment, skin fibrosis, and osteoradionecrosis of the jaw, and it can dramatically impact on patient quality of life.

RECENT FINDINGS

Throughout the last decade, significant improvements have been made in head and neck cancer radiotherapy, especially with the introduction on a routine basis of intensity-modulated radiotherapy.

SUMMARY

In this context, this review manuscript will focus on how the implementation of intensity-modulated radiotherapy influences treatment morbidity. Specifically, the issues of target volume and organ-at-risk delineation, sparing of organs at risk, tailored treatment intensity, adaptive treatment, and the use of proton therapy will be discussed.

Automatic detection of MLC relative position errors for VMAT using the EPID-based picket fence test

Multi-leaf collimators (MLCs) ensure the accurate delivery of treatments requiring complex beam fluences like intensity modulated radiotherapy and volumetric modulated arc therapy. The purpose of this work is to automate the detection of MLC relative position errors  ⩾0.5 mm using electronic portal imaging device-based picket fence tests and compare the results to the qualitative assessment currently in use. Picket fence tests with and without intentional MLC errors were measured weekly on three Varian linacs. The picket fence images analysed covered a time period ranging between 14-20 months depending on the linac. An algorithm was developed that calculated the MLC error for each leaf-pair present in the picket fence images. The baseline error distributions of each linac were characterised for an initial period of 6 months and compared with the intentional MLC errors using statistical metrics. The distributions of median and one-sample Kolmogorov-Smirnov test p-value exhibited no overlap between baseline and intentional errors and were used retrospectively to automatically detect MLC errors in routine clinical practice. Agreement was found between the MLC errors detected by the automatic method and the fault reports during clinical use, as well as interventions for MLC repair and calibration. In conclusion the method presented provides for full automation of MLC quality assurance, based on individual linac performance characteristics. The use of the automatic method has been shown to provide early warning for MLC errors that resulted in clinical downtime.

Intensity-modulated radiotherapy for early glottic cancer: transition to a new standard of care?

For decades, the standard of care for radiation treatment of early larynx cancers has been conventional treatment using opposed lateral fields encompassing the larynx and overlying neck structures, including the adjacent carotid arteries. While intensity-modulated radiotherapy (IMRT) has replaced conventional radiotherapy for all other head/neck cancer situations, the use of IMRT to treat early glottic cancers remains controversial. The article reviews the published experience with IMRT for this clinical situation and provides a detailed review of the literature on radiation-induced carotid toxicity and how it might apply to the controversy. Finally, we discuss whether the radiation oncology community should transition to IMRT as a new standard of care for the treatment of early glottic cancers.

The feasibility of atlas-based automatic segmentation of MRI for H&N radiotherapy planning

Atlas‐based autosegmentation is an established tool for segmenting structures for CT‐planned head and neck radiotherapy. MRI is being increasingly integrated into the planning process. The aim of this study is to assess the feasibility of MRI‐based, atlas‐based autosegmentation for organs at risk (OAR) and lymph node levels, and to compare the segmentation accuracy with CT‐based autosegmentation. Fourteen patients with locally advanced head and neck cancer in a prospective imaging study underwent a T1‐weighted MRI and a PET‐CT (with dedicated contrast‐enhanced CT) in an immobilization mask. Organs at risk (orbits, parotids, brainstem, and spinal cord) and the left level II lymph node region were manually delineated on the CT and MRI separately. A ‘leave one out’ approach was used to automatically segment structures onto the remaining images separately for CT and MRI. Contour comparison was performed using multiple positional metrics: Dice index, mean distance to conformity (MDC), sensitivity index (Se Idx), and inclusion index (Incl Idx). Automatic segmentation using MRI of orbits, parotids, brainstem, and lymph node level was acceptable with a DICE coefficient of 0.73−0.91, MDC 2.0−5.1 mm, Se Idx 0.64−0.93, Incl Idx 0.76−0.93. Segmentation of the spinal cord was poor (Dice coefficient 0.37). The process of automatic segmentation was significantly better on MRI compared to CT for orbits, parotid glands, brainstem, and left lymph node level II by multiple positional metrics; spinal cord segmentation based on MRI was inferior compared with CT. Accurate atlas‐based automatic segmentation of OAR and lymph node levels is feasible using T1‐MRI; segmentation of the spinal cord was found to be poor. Comparison with CT‐based automatic segmentation suggests that the process is equally as, or more accurate, using MRI. These results support further translation of MRI‐based segmentation methodology into clinical practice.

PACS number(s): 87.55.de

How does radiotherapy impact swallowing function in nasopharynx and oropharynx cancer? Short-term results of a prospective study

The objective of this study is to report the initial results of a prospective trial assessing instrumental deglutition function in nasopharynx and oropharynx cancers after radio or chemoradiotherapy using intensity-modulated radiotherapy (IMRT). IMRT was delivered aiming to spare the swallowing organ at risk (SWOARs) for Stage II-IV naso- and oropharynx cancer. Objective instrumental assessment included videofluoroscopy (VFS), fiberoptic endoscopic evaluation of swallowing (FEES) and oro-pharyngeal-oesophageal scintigraphy (OPES) at baseline and at 1 month after radiotherapy. Dysphagia parameter scores were calculated at each exam after liquid (L) and semi-liquid (SL) bolus intake: pre-deglutition penetration, aspiration, pharyngeal transit time (PTT) and hypopharyngeal retention index (HPRI). Overall, 20 patients (6 nasophaynx and 14 oropharynx) completed treatment and instrumental assessment after 1 month. Comparison between pre- and post-treatment HPRI score values showed a significant worsening in both FEES-L (p = 0.021) and SL (p = 0.02) and at VFS-L (p = 0.008) and SL (p = 0.005). Moreover, a relationship between HPRI worsening at FEES-L and FEES-SL (p = 0.005) as well as at VFS-L and VFS-SL (p < 0.001) was observed. PTT was not significantly affected by radiotherapy (p > 0.2). Only a few patients experienced pre-deglutition penetration (1 patient with base of tongue cancer at FEES-L and SL) and aspiration (1 patient with nasopharynx cancer at OPES-L and FEES-SL) after radiotherapy. Our early results showed that IMRT-SWOARs sparing caused a significant increase in the post-deglutition HPRI score. Longer follow-up will be necessary to evaluate if the increase of HPRI is related to a high risk of developing late aspiration.

Influence of Dose Rate on the Cellular Response to Low- and High-LET Radiations

Nowadays, head and neck squamous cell carcinoma (HNSCC) treatment failure is mostly explained by locoregional progression or intrinsic radioresistance. Radiotherapy (RT) has recently evolved with the emergence of heavy ion radiations or new fractionation schemes of photon therapy, which modify the dose rate of treatment delivery. The aim of the present study was then to evaluate the in vitro influence of a dose rate variation during conventional RT or carbon ion hadrontherapy treatment in order to improve the therapeutic care of patient. In this regard, two HNSCC cell lines were irradiated with photons or 72 MeV/n carbon ions at a dose rate of 0.5, 2, or 10 Gy/min. For both radiosensitive and radioresistant cells, the change in dose rate significantly affected cell survival in response to photon exposure. This variation of radiosensitivity was associated with the number of initial and residual DNA double-strand breaks (DSBs). By contrast, the dose rate change did not affect neither cell survival nor the residual DNA DSBs after carbon ion irradiation. As a result, the relative biological efficiency at 10% survival increased when the dose rate decreased. In conclusion, in the RT treatment of HNSCC, it is advised to remain very careful when modifying the classical schemes toward altered fractionation. At the opposite, as the dose rate does not seem to have any effects after carbon ion exposure, there is less need to adapt hadrontherapy treatment planning during active system irradiation.

The role of stem cells in the prevention and treatment of radiation-induced xerostomia in patients with head and neck cancer

Xerostomia is an important complication following radiotherapy (RT) for head and neck cancer. Current treatment approaches are insufficient and can only temporarily relieve symptoms. New insights into the physiopathology of radiation‐induced xerostomia might help us in this regard. This review discusses the current knowledge of salivary gland stem cells in radiation‐induced xerostomia and their value in the prevention and treatment of this complication. Salivary gland stem cell transplantation, bone marrow‐derived cell mobilization, molecular regulation of parotid stem cells, stem cell sparing RT, and adaptive RT are promising techniques that are discussed in this study.

Analysis of serial CT images for studying the RT effects in head-neck cancer patients

Images taken during and after RT for head and neck cancer have the potential to quantitatively assess xerostomia. Image information may be used as biomarkers of RT effects on parotid glands with significant potential to support adaptive treatment strategies. We investigated the possibility to extract information based on in-room CT images (kVCT, MVCT), acquired for daily image-guided radiotherapy treatment of head-and-neck cancer patients, in order to predict individual response in terms of toxicity. Follow-up MRI images were also used in order to investigate long term parotid gland deformation.

A critical assessment of oral care protocols for patients under radiation therapy in the regional University Hospital Network of Madrid (Spain)

BACKGROUND

This research was aimed to critically evaluate, under the light of the available scientific evidence, the oral care protocols recommended by different hospitals in head and neck cancer (HNC) patients under radiation therapy.

MATERIAL AND METHODS

A questionnaire requesting all the relevant information for the oral care of these patients was sent to the 9 University Hospitals in Madrid. The answers were categorized and analyzed. In addition, an electronic search was conducted to identify the most relevant papers (systematic reviews [SR] and randomized clinical trials [RCTs]) assessing oral care protocols for patients treated for HNC with radiation therapy.

RESULTS

Eight out of nine centers answered the questionnaire and the retrieved information was tabulated and compared. These recommendations were analyzed by a computerized search on MEDLINE and the Cochrane Oral Health Collaboration Database. The results of the analysis clearly shown a great heterogeneity, in terms of oral health care protocols, regarding the management of irradiated patients (for HNC) within the Hospitals of Madrid region. In addition, some of the recommendations lack solid scientific support.

CONCLUSIONS

The present survey revealed that the recommendations provided by the different hospitals were clearly different. The available evidence, supported by SR and RCTs, suggested the need of an oral assessment before cancer treatment, in order to prevent and treat dental pathologies and avoiding potential complications; during cancer treatment, it is relevant monitoring the patient in order to decrease the severity of the side effects, and to avoid any tooth extraction or surgery and special attention should be paid to mucositis, xerostomia and candidiasis; after cancer treatment, the following are relevant aspects: the risk of osteoradionecrosis, trismus, caries and the risks associated to dental implants.

KEY WORDS

Head and neck cancer, supportive care in cancer, radiotherapy complications, management and oral care on cancer treatment.

Comparative effectiveness of intensity-modulated versus 3D conformal radiation therapy among medicare patients with stage III lung cancer

INTRODUCTION

The clinical benefit of intensity-modulated radiation therapy (IMRT) compared to 3D conformal radiation (3D-RT) has not been well established for locally advanced non-small-cell lung cancer (NSCLC).

METHODS

Using SEER-Medicare, we identified Medicare beneficiaries diagnosed with stage III NSCLC who received potentially curative (≥ 25 fractions) thoracic IMRT or 3D-RT from 2002-2009. Overall survival and number of hospital days within 90 days of radiation were analyzed using Cox proportional hazard and negative binomial regression models, respectively. Propensity score adjustment was used to control for clinical and demographic variables associated with outcomes.

RESULTS

IMRT comprised an increasing proportion of conformal thoracic radiation for NSCLC, rising from 3.0% in 2002 to 26.8% in 2009. Use of IMRT varied significantly by year of diagnosis, facility type, and geographic region and was more likely to be used among patients receiving chemotherapy or with higher comorbidity scores. Among patients receiving potentially curative treatment, there was no difference in overall survival (propensity adj HR .99, p = 0.83) or number of hospital days in the 90 days following radiation start (propensity adj HR 1.15, p = 0.23).

CONCLUSIONS

When radiation is used to treat locally advanced NSCLC, IMRT is increasingly preferred to 3D-RT. However, among patients receiving potentially curative radiation there was no significant difference in overall survival or time spent hospitalized following treatment.

Definitive and adjuvant radiotherapy for sinonasal squamous cell carcinomas: a single institutional experience

BACKGROUND

The aim of this study was to evaluate the disease outcomes of patients treated with definitive and adjuvant radiotherapy for squamous cell carcinomas of the nasal cavity and paranasal sinuses in a single institution.

METHODS

Between 2007-2012 patients were retrospectively identified from electronic databases who had undergone surgery and adjuvant radiotherapy or definitive radiotherapy for sinonasal squamous cell carcinomas with curative intent.

RESULTS

Fourty three patients with sinonasal squamous cell carcinoma were identified (22 nasal cavity, 21 paranasal sinuses). 31/43 (72%) had T3 or T4 disease; nodal stage was N0 in 38, N1 in 4, Na/b in 0 and N2c in 1 patient. Median age was 67 years (range 41-86). 18 (42%) received definitive and 25 (58%) adjuvant radiotherapy. Radiotherapy was delivered using either conventional radiotherapy (n = 39) or intensity modulated radiotherapy (n = 4). Elective neck radiotherapy was delivered to two patients. Chemotherapy was delivered to 6/43 (14%) of patients. Two-year local control, regional control, distant metastases free survival, progression free survival, cause specific survival and overall survival were 81%, 90%, 95%, 71%, 84% and 80% respectively. There was no significant difference in outcome comparing patients who underwent surgery and adjuvant radiotherapy with patients receiving definitive radiotherapy (2 year locoregional disease free survival 75% and 70% respectively, p = 0.98). Pooly differentiated tumours were significantly associated with inferior disease outcomes. Local, regional, combined local and regional, and distant failure occurred in 7 (16%), 3 (7%), 1 (2%) and 2 (5%) of patients; all 3 regional recurrences were in patients with nasal cavity squamous cell carcinomas who had not undergone elective neck treatment.

CONCLUSIONS

Definitive or adjuvant radiotherapy provides an effective treatment for sinonasal malignancies. The main pattern of failure remains local, suggesting the need for investigation of intensified local therapy. Whilst remaining uncommon, the cases of regional failure mean that the merits of elective lymph node treatment should be considered on an individual basis.

Advances in Radiotherapy for Head and Neck Cancer

Over the last few decades, significant improvements have been made in the radiotherapy (RT) treatment of head and neck malignancies. The progressive introduction of intensity-modulated RT and the use of multimodality imaging for target volume and organs at risk delineation, together with the use of altered fractionation regimens and concomitant administration of chemotherapy or targeted agents, have accompanied efficacy improvements in RT. Altogether, such improvements have translated into improvement in locoregional control and overall survival probability, with a decrease in the long-term adverse effects of RT and an improvement in quality of life. Further progress in the treatment of head and neck malignancies may come from a better integration of molecular imaging to identify tumor subvolumes that may require additional radiation doses (ie, dose painting) and from treatment adaptation tracing changes in patient anatomy during treatment. Proton therapy generates even more exquisite dose distribution in some patients, thus potentially further improving patient outcomes. However, the clinical benefit of these approaches, although promising, for patients with head and neck cancer need to be demonstrated in prospective randomized studies. In this context, our article will review some of these advances, with special emphasis on target volume and organ-at-risk delineation, use of molecular imaging for tumor delineation, dose painting for dose escalation, dose adaptation throughout treatment, and potential benefit of proton therapy.

Alterations in anatomic and functional imaging parameters with repeated FDG PET-CT and MRI during radiotherapy for head and neck cancer: a pilot study

Background

The use of imaging to implement on-treatment adaptation of radiotherapy is a promising paradigm but current data on imaging changes during radiotherapy is limited. This is a hypothesis-generating pilot study to examine the changes on multi-modality anatomic and functional imaging during (chemo)radiotherapy treatment for head and neck squamous cell carcinoma (HNSCC).

Methods

Eight patients with locally advanced HNSCC underwent imaging including computed tomography (CT), Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT and magnetic resonance imaging (MRI) (including diffusion weighted (DW) and dynamic contrast enhanced (DCE)) at baseline and during (chemo)radiotherapy treatment (after fractions 11 and 21). Regions of interest (ROI) were drawn around the primary tumour at baseline and during treatment. Imaging parameters included gross tumour volume (GTV) assessment, SUV_max, mean ADC value and DCE-MRI parameters including Plasma Flow (PF). On treatment changes and correlations between these parameters were analysed using a Wilcoxon rank sum test and Pearson’s linear correlation coefficient respectively. A p-value <0.05 was considered statistically significant.

Results

Statistically significant reductions in GTV-CT, GTV-MRI and GTV-DW were observed between all imaging timepoints during radiotherapy. Changes in GTV-PET during radiotherapy were heterogeneous and non-significant. Significant changes in SUV_max, mean ADC value, Plasma Flow and Plasma Volume were observed between the baseline and the fraction 11 timepoint, whilst only changes in SUV_max between baseline and the fraction 21 timepoint were statistically significant. Significant correlations were observed between multiple imaging parameters, both anatomical and functional; 20 correlations between baseline to the fraction 11 timepoint; 12 correlations between baseline and the fraction 21 timepoints; and 4 correlations between the fraction 11 and fraction 21 timepoints.

Conclusions

Multi-modality imaging during radiotherapy treatment demonstrates early changes (by fraction 11) in both anatomic and functional imaging parameters. All functional imaging modalities are potentially complementary and should be considered in combination to provide multi-parametric tumour assessment, to guide potential treatment adaptation strategies.

Trial Registration

ISRCTN Registry: ISRCTN34165059. Registered 2nd February 2015.

IMRT utilization in Ontario: qualitative deployment evaluation

Purpose

– The purpose of this paper is to describe a jurisdiction-wide implementation and evaluation of intensity-modulated radiation therapy (IMRT) in Ontario, Canada, highlighting innovative strategies and lessons learned.

Design/methodology/approach

– To obtain an accurate provincial representation, six cancer centres were chosen (based on their IMRT utilization, geography, population, academic affiliation and size) for an in-depth evaluation. At each cancer centre semi-structured, key informant interviews were conducted with senior administrators. An electronic survey, consisting of 40 questions, was also developed and distributed to all cancer centres in Ontario.

Findings

– In total, 21 respondents participated in the interviews and a total of 266 electronic surveys were returned. Funding allocation, guidelines and utilization targets, expert coaching and educational activities were identified as effective implementation strategies. The implementation allowed for hands-on training, an exchange of knowledge and expertise and the sharing of responsibility. Future implementation initiatives could be improved by creating stronger avenues for clear, continuing and comprehensive communication at all stages to increase awareness, garner support and encourage participation and encouraging expert-based coaching. IMRT utilization for has increased without affecting wait times or safety (from fiscal year 2008/2009 to 2012/2013 absolute increased change: prostate 46, thyroid 36, head and neck 29, sarcoma 30, and CNS 32 per cent).

Originality/value

– This multifaceted, jurisdiction-wide approach has been successful in implementing guideline recommended IMRT into standard practice. The expert based coaching initiative, in particular presents a novel training approach for those who are implementing complex techniques. This paper will be of interest to those exploring ways to fund, implement and sustain complex and evolving technologies.

Comparative effectiveness research in radiation oncology: assessing technology

Technological advances are a major contributor to rising costs in health care, including radiation oncology. Despite the large amount spent on new technologies, technology assessment remains inadequate, leading to potentially costly and unnecessary use of new technologies. Comparative effectiveness studies have an important role to play in evaluating the benefits and harms of new technologies compared with older technologies and have been identified as a priority area for research by the Radiation Oncology Institute. This article outlines the elements of effective technology assessment, identifies key challenges to comparative effectiveness studies of new radiation oncology technologies, and reviews several examples of comparative effectiveness studies in radiation oncology, including studies on conformal radiation, IMRT, proton therapy, and other concurrent new technologies.

Sparing functional anatomical structures during intensity-modulated radiotherapy: an old problem, a new solution

ABSTRACT During intensity-modulated radiotherapy, an organ is usually assumed to be functionally homogeneous and, generally, its anatomical and spatial heterogeneity with respect to radiation response are not taken into consideration. However, advances in imaging and radiation techniques as well as an improved understanding of the radiobiological response of organs have raised the possibility of sparing the critical functional structures within various organs at risk during intensity-modulated radiotherapy. Here, we discuss these structures, which include the critical brain structure, or neural nuclei, and the nerve fiber tracts in the CNS, head and neck structures related to radiation-induced salivary and swallowing dysfunction, and functional structures in the heart and lung. We suggest that these structures can be used as potential surrogate organs at risk in order to minimize their radiation dose and/or irradiated volume without compromising the dose coverage of the target volume during radiation treatment.

Indications for the use of external beam radiation in thyroid cancer

PURPOSE OF REVIEW

The role of external beam radiation therapy (EBRT) in the management of thyroid cancer is not clearly defined. In the absence of randomized studies, the review aims to identify any recent literature that helps define the role.

RECENT FINDINGS

In differentiated thyroid cancer, single institutional studies report durable locoregional disease control in patients considered to be at high risk of local relapse after EBRT and recent guidelines are consistent in their recommendations. In medullary thyroid cancer, the evidence is more limited but again there is benefit in selected cases. In anaplastic thyroid cancer, multimodality therapy is superior to surgery alone in achieving local control and possibly survival but the benefit must be weighed against the toxicity. Newer radiation techniques may help reduce toxicity.

SUMMARY

Although surgery is the main treatment for thyroid carcinoma, EBRT has a role in the adjuvant setting following surgery in high-risk patients and in unresectable cancer. Advances in the delivery of external beam radiotherapy, including intensity-modulated radiotherapy reduces toxicity.