Tumor Volume Reduction Rate during Adaptive Radiation Therapy as a Prognosticator for Nasopharyngeal Cancer

Current state, challenges, and future perspective of adaptive radiotherapy: A narrative review of nasopharyngeal carcinoma

Patients with nasopharyngeal carcinoma often experience weight loss and tumor regression during the course of radiotherapy that lasts for up to 6-7 weeks. Adaptive radiotherapy is a systematic feedback control approach based on image-guided technology that adjusts these changes and optimizes the radiotherapy plans according to new imaging findings during treatment. There is growing evidence that adaptive radiotherapy can reduce side effects, improve the quality of life, and enhance disease control. However, the routine application of adaptive radiotherapy for nasopharyngeal remains relatively limited. This review discusses the necessity, clinical benefits, and limitations of adaptive radiotherapy, and presents the current state, challenges, and future perspective of adaptive radiotherapy strategies for nasopharyngeal carcinoma.

Dosimetric Comparison and Selection Criteria of Intensity-Modulated Proton Therapy and Intensity-Modulated Radiation Therapy for Adaptive Re-Plan in T3-4 Nasopharynx Cancer Patients

BACKGROUND

Proton therapy requires caution when treating patients with targets near neural structures. Intuitive and quantitative guidelines are needed to support decision-making concerning the treatment modality. This study compared dosimetric profiles of intensity-modulated proton therapy (IMPT) and intensity-modulated radiation therapy (IMRT) using helical tomotherapy (HT) for adaptive re-planning in cT3-4 nasopharyngeal cancer (NPCa) patients, aiming to establish criteria for selecting appropriate treatment modalities.

METHODS

HT and IMPT plans were generated for 28 cT3-4 NPCa patients undergoing definitive radiotherapy. Dosimetric comparisons were performed for target coverage and high-priority organs at risk (OARs). The correlation between dosimetric parameters and RT modality selection was analyzed with the target OAR distances.

RESULTS

Target coverages were similar, while IMPT achieved better dose spillage. HT was more favorable for brainstem D1, optic chiasm Dmax, optic nerves Dmax, and p-cord D1. IMPT showed advantages for oral cavity Dmean. Actually, 14 IMPT and 14 HT plans were selected as adaptive plans, with IMPT allocated to most cT3 patients (92.9% vs. 42.9%, p = 0.013). The shortest distances from the target to neural structures were negatively correlated with OAR doses. Receiver operating characteristic curve analyses were carried out to discover the optimal cut-off values of the shortest distances between the target and the OARs (temporal lobes and brainstem), which were 0.75 cm (AUC = 0.908, specificity = 1.00) and 0.85 cm (AUC = 0.857, specificity = 0.929), respectively.

CONCLUSIONS

NPCa patients with cT4 tumor or with the shortest distance between the target and critical neural structures < 0.8 cm were suboptimal candidates for IMPT adaptive re-planning. These criteria may improve resource utilization and clinical outcomes.

Evaluating psychological anxiety in patients receiving radiation therapy using smartwatch

PURPOSE

Patients undergoing radiation therapy (RT) often experience psychological anxiety that manifests as muscle contraction. Our study explored psychological anxiety in these patients by using biological signals recorded using a smartwatch.

MATERIALS AND METHODS

Informed consent was obtained from participating patients prior to the initiation of RT. The patients wore a smartwatch from the waiting room until the conclusion of the treatment. The smartwatch acquired data related to heart rate features (average, minimum, and maximum) and stress score features (average, minimum, and maximum). On the first day of treatment, we analyzed the participants' heart rates and stress scores before and during the treatment. The acquired data were categorized according to sex and age. For patients with more than three days of data, we observed trends in heart rate during treatment relative to heart rate before treatment (HRtb) over the course of treatment. Statistical analyses were performed using the Wilcoxon signed-rank test and paired t-test.

RESULTS

Twenty-nine individuals participated in the study, of which 17 had more than 3 days of data. During treatment, all patients exhibited elevated heart rates and stress scores, particularly those in the younger groups. The HRtb levels decreased as treatment progresses.

CONCLUSION

Patients undergoing RT experience notable psychological anxiety, which tends to diminish as the treatment progresses. Early stage interventions are crucial to alleviate patient anxiety during RT.

Effects of concurrent chemoradiotherapy with or without Endostar on the regression of retropharyngeal lymph node and prognosis of patients with locally advanced nasopharyngeal carcinoma: a retrospective study

BACKGROUND AND PURPOSE

To investigate the effect of combining Endostar with concurrent chemoradiotherapy (ECCRT) compared to concurrent chemoradiotherapy (CCRT) on the regression rate of retropharyngeal lymph nodes (RLNs) and the relationship between regression rate of RLNs and prognosis of patients with locally advanced nasopharyngeal carcinoma (LANPC).

METHODS

A total of 122 LANPC patients with RLNs metastasis were included. Metastatic RLNs were delineated both before and after treatment slice by slice on the magnetic resonance images cross-section. The regression rate of RLNs, adverse effects (AE) were evaluated. The median regression rate of RLNs was taken as the cut-off value, and the patients were furtherly divided into high regression rate (HRR) group and low regression rate (LRR) group, then survival times were evaluated.

RESULTS

The median regression rates of RLNs in the ECCRT and CCRT groups were 81% and 50%, respectively (P < 0.001). There was no statistically significant difference in the incidence of grade 3/4 AEs between the two groups, except for oral mucositis (ECCRT 26.23% vs. CCRT 44.26%, P = 0.037). The 3-year overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS) and locoregional failure-free survival (LRFFS) rates in the HRR and LRR groups were 85.48% and 86.67% (P = 0.983), 80.65% and 68.33% (P = 0.037), 83.87% and 85% (P = 0.704), 93.55% and 81.67% (P = 0.033), respectively.

CONCLUSIONS

Patients in the ECCRT group had higher regression rates of RLNs and lower incidence of severe oral mucositis. Furthermore, patients in the HRR group had a better 3-year PFS and LRFFS rate than those in the LRR group.

Adaptive radiotherapy for head and neck cancer: Pitfalls and possibilities from the radiation oncologist's point of view

BACKGROUND

Patients with head and neck cancer (HNC) may experience substantial anatomical changes during the course of radiotherapy treatment. The implementation of adaptive radiotherapy (ART) proves effective in managing the consequent impact on the planned dose distribution.

METHODS

This narrative literature review comprehensively discusses the diverse strategies of ART in HNC and the documented dosimetric and clinical advantages associated with these approaches, while also addressing the current challenges for integration of ART into clinical practice.

RESULTS AND CONCLUSION

Although based on mainly non-randomized and retrospective trials, there is accumulating evidence that ART has the potential to reduce toxicity and improve quality of life and tumor control in HNC patients treated with RT. However, several questions remain regarding accurate patient selection, the ideal frequency and timing of replanning, and the appropriate way for image registration and dose calculation. Well-designed randomized prospective trials, with a predetermined protocol for both image registration and dose summation, are urgently needed to further investigate the dosimetric and clinical benefits of ART.

Risk stratification of LA-NPC during chemoradiotherapy based on clinical classification and TVRR

PURPOSE

To investigate the correlation between tumor volume reduction rate (TVRR) and prognosis in patients with diverse clinical types of nasopharyngeal carcinoma (NPC) undergoing chemoradiotherapy, thereby aptly categorizing risks and directing the personalized treatment of NPC.

MATERIALS AND METHODS

A total of 605 NPC patients with varying clinical types were enrolled in this study and subsequently segregated into six subgroups based on their clinical types and TVRR. To accentuate the efficacy of grouping, Groups 1-6 underwent clustered analysis of hazard atio (HR) values pertaining to progression-free survival (PFS), forming three risk clusters denoted as low, intermediate, and high. The log-rank test was employed to discern differences, and R 4.1.1 was utilized for cluster analysis.

RESULTS

According to survival rates, we classified the first (G2 and G4), second (G1 and G6), and third (G3 and G5) risk clusters as low-, intermediate-, and high-risk, respectively. When comparing risk stratification with the 8th edition of the TNM staging system, our classification exhibited superior predictive prognostic performance. Subgroup analysis of treatments for each risk cluster revealed that the PFS in the neoadjuvant chemotherapy (NACT) + concurrent chemoradiotherapy (CCRT) group surpassed that of the CCRT group significantly (p < 0.05).

CONCLUSION

The reliance on clinical types and TVRR facilitates risk stratification of NPC during chemoradiotherapy, providing a foundation for physicians to tailor therapeutic strategies. Moreover, the risk cluster delineated for NPC patients during the mid-term of chemoradiotherapy stands as an independent prognostic factor for progression-free survival (PFS), overall survival (OS), distantmetastasis-free survival (DMFS), and local recurrence-free (LRRFS) posttreatment. Additionally, individuals in the high-risk cluster are recommended to undergo adjuvant chemotherapy after CCRT.

Nomograms incorporating primary tumor response at mid-radiotherapy to predict survival in locoregionally advanced nasopharyngeal carcinoma

BACKGROUND

A nomogram that incorporates tumor response at mid-radiotherapy (mid-RT) to predict the prognosis of locoregionally advanced nasopharyngeal carcinoma (LA-NPC) has not been established.

METHODS

This study retrospectively reviewed 583 patients with LA-NPC who underwent magnetic resonance imaging scans at mid-RT (the fourth week of RT) between 2015 and 2019.

RESULTS

Primary tumor (PT) response at mid-RT was found to predict disease-free survival (DFS) and overall survival (OS). Independent factors from multivariable analysis to predict DFS and OS were assembled into nomograms with (nomograms Amid-RT and Bmid-RT ) or without (nomograms Abaseline and Bbaseline ) PT response. Internal validation revealed good performance of these nomograms in discrimination: C-statistics = 0.761 for nomogram Amid-RT and 0.809 for nomogram Bmid-RT , which showed better discrimination performance than (C-statistics: 0.755) nomogram Abaseline and (C-statistics: 0.798) nomogram Bbaseline (Z-statistic = 2.476, p < 0.05; Z-statistic = 1.971, p < 0.05).

CONCLUSION

The nomograms based on PT response at mid-RT showed favorable predictive accuracy for DFS and OS in patients with LA-NPC.

Automated tracking of morphologic changes in weekly magnetic resonance imaging during head and neck radiotherapy

BACKGROUND AND PURPOSE

Anatomic changes during head and neck radiotherapy can impact dose delivery, necessitate adaptive replanning, and indicate patient-specific response to treatment. We have developed an automated system to track these changes through longitudinal MRI scans to aid identification and clinical intervention. The purpose of this article is to describe this tracking system and present results from an initial cohort of patients.

MATERIALS AND METHODS

The Automated Watchdog in Adaptive Radiotherapy Environment (AWARE) was developed to process longitudinal MRI data for radiotherapy patients. AWARE automatically identifies and collects weekly scans, propagates radiotherapy planning structures, computes structure changes over time, and reports important trends to the clinical team. AWARE also incorporates manual structure review and revision from clinical experts and dynamically updates tracking statistics when necessary. AWARE was applied to patients receiving weekly T2-weighted MRI scans during head and neck radiotherapy. Changes in nodal gross tumor volume (GTV) and parotid gland delineations were tracked over time to assess changes during treatment and identify early indicators of treatment response.

RESULTS

N = 91 patients were tracked and analyzed in this study. Nodal GTVs and parotids both shrunk considerably throughout treatment (-9.7 ± 7.7% and -3.7 ± 3.3% per week, respectively). Ipsilateral parotids shrunk significantly faster than contralateral (-4.3 ± 3.1% vs. -2.9 ± 3.3% per week, p = 0.005) and increased in distance from GTVs over time (+2.7 ± 7.2% per week, p < 1 × 10^-5 ). Automatic structure propagations agreed well with manual revisions (Dice = 0.88 ± 0.09 for parotids and 0.80 ± 0.15 for GTVs), but for GTVs the agreement degraded 4-5 weeks after the start of treatment. Changes in GTV volume observed by AWARE as early as one week into treatment were predictive of large changes later in the course (AUC = 0.79).

CONCLUSION

AWARE automatically identified longitudinal changes in GTV and parotid volumes during radiotherapy. Results suggest that this system may be useful for identifying rapidly responding patients as early as one week into treatment.

Tumor volume reduction after induction chemotherapy with gemcitabine plus cisplatin in nasopharyngeal carcinoma

OBJECTIVES

To evaluate the tumor volume reduction after induction chemotherapy (IC) with gemcitabine plus cisplatin (GP) and to build prediction models for tumor volume reduction in nasopharyngeal carcinoma (NPC).

METHODS

NPC patients who received GP IC were retrospectively enrolled. The gross tumor volume of the nasopharynx and lymph nodes (GTVnx and GTVnd) were contoured before and after IC. Univariate and multivariate analyses were performed to identify associated factors. Nomogram models were constructed to predict the possibility of tumor volume reduction.

RESULTS

A total of 192 patients were enrolled. The mean relative volume reduction for GTVnx and GTVnd was 29.66% and 31.75%, respectively. The volume reduction of GTVnx and GTVnd had a weak association (r = 0.229, p < 0.001). For GTVnx volume reduction, pre-treatment neutrophil count (p = 0.043), lymphocyte count (p = 0.026), LDH level (p = 0.005), and BMI (p = 0.020) were independently associated factors. For GTVnd volume reduction, pre-treatment EBV-DNA (p = 0.029), GTVnd volume (p < 0.001), eosinophil count (p = 0.043), NLR (p = 0.039), LDH level (p = 0.026), and serum potassium level (p = 0.027) were independently associated factors. For the GTVnx nomogram model, areas under the receiver-operating characteristic curve (AUC) were 0.702 and 0.698 for the training and validation cohorts, respectively. For the GTVnd nomogram model, the AUC was 0.872 and 0.758 for the training and validation cohorts, respectively.

CONCLUSIONS

Tumor volumes reduce significantly after GP induction chemotherapy. Nomogram models for predicting the possibility of tumor volume reduction are built.

Tumor Volume Reduction Rate to Induction Chemotherapy is a Prognostic Factor for Locally Advanced Head and Neck Squamous Cell Carcinoma: A Retrospective Cohort Study

Introduction: Aim of this retrospective cohort study is to evaluate the prognostic value of tumor volume reduction rate status post-induction chemotherapy in locally advanced head and neck squamous cell carcinoma. Methods: Patients newly diagnosed from year 2007 to 2016 at a single center were included in this retrospective study. All patients had received induction Taxotere, Platinum, Fluorouracil followed by daily definitive intensity-modulated radiotherapy for 70 Gy in 35 fractions concurrent with or without cisplatin-based chemotherapy. Tumor volume reduction rate was measured and calculated by contrast-enhanced computed tomography images at diagnosis, and after at least 1 cycle of induction chemotherapy, and analyzed though a univariate and multivariate Cox regression model. Results: Ninety patients of the primary cancer sites at hypopharynx (31/90, 34.4%), oropharynx (29/90, 32.2%), oral cavity (19/90, 21.1%), and larynx (11/90, 12.2%) were included in this study, with a median follow-up time interval of 3.9 years. In multivariate Cox regression analysis, the tumor volume reduction rate of the primary tumor (TVRR-T) was also an independently significant prognostic factor for disease-free survival (DFS) (hazard ratio 0.77, 95% confidence interval 0.62-0.97; P-value = .02). Other factors including patient's age at diagnosis, the primary cancer site, and RECIST (Response Evaluation Criteria in Solid Tumors), were not significantly related. At a cutoff value using 50% in Kaplan–Meier survival analysis, the DFS was higher with TVRR-T ≥ 50% group (log-rank test, P = .024), and a trend of improved overall survival. (log-rank test, P = .069). Conclusion: TVRR-T is a probable prognostic factor for DFS. With a cut-off point of 50%, TVRR-T may indicate better DFS.

Residual Volume of Lymph Nodes During Chemoradiotherapy Based Nomogram to Predict Survival of Nasopharyngeal Carcinoma Patient Receiving Induction Chemotherapy

Purpose

To accurately stratify nasopharyngeal carcinoma (NPC) patients who were benefit from induction chemotherapy (IC) followed by chemoradiotherapy (CCRT), we established residual volume of lymph nodes during chemoradiotherapy based nomogram to predict survival for NPC patients.

Methods

Cox regression analysis were used to evaluate predictive effects of tumor volume parameters. Multivariate Cox regression analysis was used to identify the prognostic factors, and nomogram models were developed to predict survival of NPC patients receiving IC followed by CCRT.

Results

Compared with other tumor volumetric parameters, midRT GTVnd was the best predictive factor for OS (HR: 1.043, 95%CI: 1.031-1.055), PFS (HR: 1.040, 95%CI: 1.030- 1.051), and DMFS (HR: 1.046, 95%CI: 1.034 – 1.059) according to the HR of Cox regression analysis. Based on multivariate analysis, three nomograms included midRT GTVnd were constructed to predict 4-year survival. The C-index of nomograms for each survival endpoints were as follow (training cohort vs. validation cohort): 0.746 vs. 0.731 for OS; 0.747 vs. 0.735 for PFS; 0.768 vs. 0.729 for DMFS, respectively. AUC showed a good discriminative ability. Calibration curves demonstrated a consistence between actual results and predictions. Decision curve analysis (DCA) showed that the nomograms had better clinical predictive effects than current TNM staging system.

Conclusion

We identified the best volumetric indicator associated with prognosis was the residual volume of lymph nodes at the fourth week of chemoradiotherapy for patients receiving IC followed by CCRT. We developed and validated three nomograms to predict specific probability of 4-year OS, PFS and DMFS for NPC patient receiving IC followed by CCRT.

Semi-Automatic Volumetric and Standard Three-Dimensional Measurements for Primary Tumor Evaluation and Response to Treatment Assessment in Pediatric Rhabdomyosarcoma

Current prognostic classification of rhabdomyosarcoma in children requires precise measurements of the tumor. The purpose of the study was to compare the standard three-dimensional (3D) measurements with semi-automatic tumor volume measurement method concerning assessment of the primary tumor size and the degree of response to treatment for rhabdomyosarcoma in children. Magnetic Resonance Imaging data on 31 children with treated rhabdomyosarcoma based on the Cooperative Weichteilsarkom Studiengruppe (CWS) guidance was evaluated. Tumor sizes were measured by two methods: 3D standard measurements and semi-automatic tumor volume measurement (VOI) at diagnosis, and after 9 and 17/18 weeks of the induction chemotherapy. Response to treatment and prediction values were assessed. The tumor volume medians calculated using VOI were significantly higher in comparison with those calculated using the 3D method both during the diagnosis as well as after 9 weeks of the chemotherapy and during the 17-18th week of the treatment. The volume measurements based on the generalized estimating equations on the VOI method were significantly better than the 3D method (p = 0.037). The volumetric measurements alone can hardly be considered an unequivocal marker used to make decisions on modification of the therapy in patients with rhabdomyosarcoma.

Early Clinical Outcomes of Intensity Modulated Radiation Therapy/Intensity Modulated Proton Therapy Combination in Comparison with Intensity Modulated Radiation Therapy Alone in Oropharynx Cancer Patients

Simple Summary

Intensity-modulated proton therapy (IMPT) is expected to reduce toxicity more effectively than intensity-modulated radiation therapy (IMRT) in treating oropharynx cancer (OPC) patients. Because of long waiting before starting IMPT, authors began IMRT first and then determined whether to continue IMRT or to switch into IMPT at time of adaptive re-plan, based on the rival plan comparison in 148 OPC patients. Early clinical outcomes were analyzed and compared between IMRT alone and IMRT/IMPT combination groups through propensity score matching method. We found that, with comparable oncologic outcomes, more favorable acute toxicity profiles (mucositis and need for analgesic use) were achieved following IMRT/IMPT combination than IMRT alone.

Abstract

Purpose: To report the early clinical outcomes of combining intensity-modulated radiation therapy (IMRT) and intensity-modulated proton therapy (IMPT) in comparison with IMRT alone in treating oropharynx cancer (OPC) patients. Materials and Methods: The medical records of 148 OPC patients who underwent definitive radiotherapy (RT) with concurrent systemic therapy, from January 2016 till December 2019 at Samsung Medical Center, were retrospectively reviewed. During the 5.5 weeks’ RT course, the initial 16 (or 18) fractions were delivered by IMRT in all patients, and the subsequent 12 (or 10) fractions were either by IMRT in 81 patients (IMRT only) or by IMPT in 67 (IMRT/IMPT combination), respectively, based on comparison of adaptive re-plan profiles and availability of equipment. Propensity-score matching (PSM) was done on 76 patients (38 from each group) for comparative analyses. Results: With the median follow-up of 24.7 months, there was no significant difference in overall survival and progression free survival between groups, both before and after PSM. Before PSM, the IMRT/IMPT combination group experienced grade ≥ 3 acute toxicities less frequently: mucositis in 37.0% and 13.4% (p < 0.001); and analgesic quantification algorithm (AQA) in 37.0% and 19.4% (p = 0.019), respectively. The same trends were observed after PSM: mucositis in 39.5% and 15.8% (p = 0.021); and AQA in 47.4% and 21.1% (p = 0.016), respectively. In multivariate logistic regression, grade ≥ 3 mucositis was significantly less frequent in the IMRT/IMPT combination group, both before and after PSM (p = 0.027 and 0.024, respectively). AQA score ≥ 3 was also less frequent in the IMRT/IMPT combination group, both before and after PSM (p = 0.085 and 0.018, respectively). Conclusions: In treating the OPC patients, with comparable early oncologic outcomes, more favorable acute toxicity profiles were achieved following IMRT/IMPT combination than IMRT alone.

Clinical features of post-radiation nasopharyngeal necrosis and their outcomes following surgical intervention in nasopharyngeal cancer patients

PURPOSE

To investigate the incidence and clinical features of post-radiation nasopharyngeal necrosis (PRNN), and effectiveness of surgical intervention for its treatment.

MATERIALS AND METHODS

Retrospectively, we reviewed 380 NPC patients who underwent high dose radiotherapy (RT) (single RT in 355 and re-RT in 25) from January 2008 till December 2017 at the authors' institute, among who 22 developed Grade ≥ 3 PRNN. The management of PRNN was discussed through weekly multidisciplinary head and neck oncology conference, and surgical debridement was performed when feasible.

RESULTS

The incidence of PRNN was significantly higher following re-RT than in single RT (11/355, 3.1% vs. 11/25, 44.0%, p < 0.001). The PRNN patients in single RT group tended to be older and had more advanced initial tumor extents. The intervals from the latest RT start till PRNN assignment were similar between groups (7.3 vs. 6.6 months, p = 0.140). Nineteen patients underwent surgical debridement: two open; and 17 endoscopic approach, respectively. Endoscopic mucosal reconstruction was performed in eight patients. Resolution of PRNN was achieved in 11 patients (64.7%). The rates of 3-year overall survivals (OS) from the initial RT, latest RT (adjusting re-RT), and PRNN assignment were 84.4%, 70.9%, and 54.7%, respectively. Eight patients (36.4%) succumbed to death: NPC progression in three (13.6%); evidently PRNN-related events in two (9.1%), probably PRNN-related events in two (9.1%); and inter-current death in one (4.5%), respectively.

CONCLUSION

PRNN needs close collaboration among head and neck oncologists and could be successfully recovered, without compromising survival, following timely surgical intervention.

Radiotherapy for Head and Neck Cancer: Evaluation of Triggered Adaptive Replanning in Routine Practice

Purpose and Objective

A proportion of patients receiving radiotherapy for head and neck squamous cell carcinoma (HNSCC) require ad hoc treatment re-planning. The aim of this retrospective study is to analyze the patients who required ad hoc re-planning and to identify factors, which may predict need for re-planning.

Materials and Methods

A single center evaluation of all patients receiving radical or adjuvant (chemo)radiotherapy (CRT) for HNSCC between January and December 2016 was undertaken. Patients who underwent ad hoc re-planning during the treatment were identified in electronic records. Reasons for re-planning were categorized as: weight loss, tumor shrinkage, changes in patient position and immobilization-related factors. Potential trigger factors for adaptive radiotherapy such as patient characteristics, primary tumor site, stage, concomitant chemotherapy, weight loss ratios, radical/adjuvant treatment, and nutritional interventions were investigated.

Results

31/290 (10.6%) HNSCC patients who underwent radical/adjuvant radiotherapy required re-planning. The adaptive radiotherapy (ART) was performed at a mean fraction of 15. The most common documented reasons for re-planning were tumor shrinkage (35.5%) and weight loss (35.5%). Among the patient/tumor/treatment factors, nasopharyngeal primary site (p = 0.013) and use of concurrent chemotherapy with radiotherapy (p = 0.034) were found to be significantly correlated with the need for re-planning.

Conclusion

Effective on-treatment verification schedules and close follow up of patients especially with NPC primary and/or treated with concurrent chemoradiotherapy are crucial to identify patients requiring ART. We suggest an individualized triggered approach to ART rather than scheduled strategies as it is likely to be more feasible in terms of utilization of workload and resources.

Predictive Model and Precaution for Oral Mucositis During Chemo-Radiotherapy in Nasopharyngeal Carcinoma Patients

PURPOSE

To explore risk factors for severe acute oral mucositis of nasopharyngeal carcinoma (NPC) patients receiving chemo-radiotherapy, build predictive models and determine preventive measures.

METHODS AND MATERIALS

Two hundred and seventy NPC patients receiving radical chemo-radiotherapy were included. Oral mucosa structure was contoured by oral cavity contour (OCC) and mucosa surface contour (MSC) methods. Oral mucositis during treatment was prospectively evaluated and divided into severe mucositis group (grade ≥ 3) and non-severe mucositis group (grade < 3) according to RTOG Acute Reaction Scoring System. Nineteen clinical features and nineteen dosimetric parameters were included in analysis, least absolute shrinkage and selection operator (LASSO) logistic regression model was used to construct a risk score (RS) system.

RESULTS

Two predictive models were built based on the two delineation methods. MSC based model is more simplified one, it includes body mass index (BMI) classification before radiation, retropharyngeal lymph node (RLN) area irradiation status and MSC V55%, RS = -1.480 + (0.021 × BMI classification before RT) + (0.126 × RLN irradiation) + (0.052 × MSC V55%). The cut-off of MSC based RS is -1.011, with an area under curve (AUC) of 0.737 (95%CI: 0.672-0.801), a specificity of 0.595 and a sensitivity of 0.786. OCC based model involved more variables, RS= -4.805+ (0.152 × BMI classification before RT) + (0.080 × RT Technique) + (0.097 × Concurrent Nimotuzumab) + (0.163 × RLN irradiation) + (0.028 × OCC V15%) + (0.120 × OCC V60%). The cut-off of OCC based RS is -0.950, with an AUC of 0.767 (95%CI: 0.702-0.831), a specificity of 0.602 and a sensitivity of 0.819. Analysis in testing set shown higher AUC of MSC based model than that of OCC based model (AUC: 0.782 vs 0.553). Analysis in entire set shown AUC in these two method-based models were close (AUC: 0.744 vs 0.717).

CONCLUSION

We constructed two risk score predictive models for severe oral mucositis based on clinical features and dosimetric parameters of nasopharyngeal carcinoma patients receiving chemo-radiotherapy. These models might help to discriminate high risk population in clinical practice that susceptible to severe oral mucositis and individualize treatment plan to prevent it.

Prognostication of Half-Life Clearance of Plasma EBV DNA in Previously Untreated Non-metastatic Nasopharyngeal Carcinoma Treated With Radical Intensity-Modulated Radiation Therapy

Introduction: The prognostic role of plasma Epstein–Barr virus (EBV) DNA clearance when intensity-modulated radiotherapy (IMRT) and the 8th edition of American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) TNM Staging Classification are fully implemented remains undeciphered. We investigated if its half-life clearance during radical treatment for non-metastatic nasopharyngeal carcinoma (NPC) was an early prognosticator.

Patients and methods: Patients with previously untreated non-metastatic NPC were prospectively treated with radical IMRT and concurrent chemotherapy +/– induction/adjuvant chemotherapy from 2014 to 2018. Their plasma EBV DNA was measured immediately before treatment followed by weekly schedules until 0 copy/ml in two consecutive measurements. Cox regression models were employed to identify prognostic factors.

Results: Forty-five patients were prospectively recruited and analyzed. After a median follow-up of 30.3 months, 2 (4.5%), 1 (2.3%), and 6 (13.6%) patients experienced local, regional, and distant relapses, respectively. The median half-life clearance of plasma EBV DNA was 7.92 days. Those with half-life clearance of >15 days had a worse 3-years progression-free survival (PFS) (79.5 vs. 25.0%, p = 0.005), distant metastasis-free survival (DMFS) (85.0 vs. 31.3%, p = 0.009), and overall survival (OS) (91.3 vs. 75.0%, p = 0.024) when compared to those with a shorter half-life. Multivariable analyses demonstrated that only half-life (>15 days) was prognostic of DMFS [HR (95% CI): 4.91 (1.31; 18.39), p = 0.01] and OS [HR (95% CI): 5.24 (1.06; 26.05)] while half-life (>15 days) [HR (95% CI): 5.14 (1.28; 22.73), p = 0.02] and sum of pretreatment gross tumor volumes of the primary nasopharyngeal tumor and the radiologically positive neck nodes (GTV_P+N) [HR (95% CI): 1.01 (1.00; 1.03), p = 0.02] were prognostic of PFS.

Conclusion: The half-life clearance of plasma EBV DNA was prognostic in non-metastatic NPC staged and treated in the contemporary era. Earlier biomarker surveillance during treatment should be considered.

Clinical Trial Registration: This study has been registered with ClinicalTrials.gov (Identifier: NCT03830996).

The comparison of prognostic value of tumour volumetric regression ratio and RECIST 1.1 criteria after induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma

PURPOSE

To compare the prognostic value of the sum volumetric regression ratio (SVRR) of the primary tumour and metastatic lymph nodes with treatment response based on RECIST 1.1 criteria after induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

A total of 117 stage III-IVA NPC patients treated with induction chemotherapy followed by concurrent chemoradiotherapy (CCRT) were retrospectively reviewed. The SVRR and the treatment response based on RECIST 1.1 were measured using contrast-enhanced computed tomography (CT) localisations before and after induction chemotherapy. The receiver operating characteristic (ROC) curve analysis was used to identify the optimal cutoff point of the SVRR and compare the prognostic value of the SVRR and RECIST 1.1criteria.

RESULTS

The optimal cutoff points of SVRR for progression-free survival (PFS), locoregional failure-free survival (LRFFS) and distant metastasis-free survival (DMFS) were all 25.15%, while for overall survival (OS) it was 16.63%. The area under the ROC curve (AUC) of optimal cutoff points of SVRR was superior than that of RECIST 1.1 for PFS (AUC: 0.716 vs. 0.578; P = 0.0022), LRFFS (AUC: 0.700 vs. 0.574; P = 0.0080) and DMFS (AUC: 0.736 vs. 0.606; P = 0.0053), respectively. The 3-year PFS, DMFS and OS rates for SVRR less than vs. greater than or equal to the cutoff points were 55.8% vs. 92.2% (P < 0.001, hazard ratio (HR): 0.209, 95% confidence interval (CI): 0.091-0.480), 59.7% vs. 96.7% (P < 0.001, HR: 0.120, 95% CI: 0.043-0.336) and 66.7% vs. 98.1% (P < 0.001, HR: 0.069, 95% CI: 0.014-0.342), while the responses [stable disease (SD), partial response (PR)] based on RECIST 1.1 were not significantly associated with 3-year survival rates. Multivariate analysis indicated that SVRR was an independent prognostic factor for PFS, DMFS and OS (all P < 0.05).

CONCLUSIONS

The sum volumetric regression ratio and response based on RECIST 1.1 were related to the prognosis in locoregionally advanced NPC after induction chemotherapy. Sum volumetric regression ratio is an independent outcome predictor for survival in locoregionally advanced NPC, playing a better prognostic role than RECIST 1.1.

Prognostic value of the tumor volume reduction rate after neoadjuvant chemotherapy in patients with locoregional advanced nasopharyngeal carcinoma

PURPOSE

Aim of this study was to evaluate the prognostic value of the tumor volume reduction rate (TVRR) of neoadjuvant chemotherapy (NACT) in patients with locoregional advanced nasopharyngeal carcinoma (NPC).

METHODS

We collected the clinical data of 263 patients with locoregional advanced NPC receiving NACT and subsequent radiotherapy from two hospitals: a training cohort (n = 130) was obtained from one hospital and a validation cohort was obtained the other hospital (n = 133). By follow-up and calculating the TVRR of all patients, the prognostic value of the TVRR was analyzed though a univariate and multivariate Cox regression model. A cut-off point of the TVRR relating to survival was explored by means of the Youden index, and the prognostic value of the TNM stage plus TVRR was measured by creating receiver operating characteristic (ROC) curves.

RESULTS

12.6%, a cut-off point of TVRR, was found to best predict DFS. Patients with a TVRR > 12.6% had better DFS (hazard ratio, 0.160, 95% confidence interval 0.072-0.354; P < 0.001), LRRFS (0.064, 0.013-0.310; 0.001) and DMFS (0.274, 0.106-0.711; 0.008) than patients with a TVRR ≤ 12.6%. The TVRR was a significant independent prognostic factor for OS, DFS, LRRFS and DMFS. Combining the TVRR and TNM stage enhanced the ability to predict DFS and LRRFS.

CONCLUSIONS

The TVRR of NACT is an independent prognostic factor for patients with locoregional advanced NPC receiving radiotherapy. Adding the TVRR to the original TNM staging system improves the prognostic value for locoregional advanced NPC.

Tumor volume reduction evaluated by cone beam computed tomography during stereotactic body radiotherapy for early stage non-small cell lung cancer

Background

We hypothesized that significant tumor volume reduction (TVR) occurs over the course of stereotactic body radiotherapy (SBRT) for early stage non-small cell lung cancer (NSCLC), and that TVR correlates with clinical outcomes.

Methods

We conducted a retrospective review of patients treated with SBRT for early stage NSCLC across two academic centers. For each patient, we contoured the tumor volume (TV) on cone beam computed tomography (CBCT) images obtained before each treatment fraction. We then calculated TVR based on the TV from the first and last days of treatment. We used log-rank tests to quantify differences in overall survival (OS), progression-free survival (PFS) and recurrence based on TVR.

Results

Data from 69 patients and a total of 73 treated tumors were analyzed. The median follow-up for survivors was 51.8 months (range, 6.9 to 80.0 months). The median TVR for the cohort was 10.1% (range, −5.7% to 43.5%). There was no significant difference in either OS (median 33.4 vs. 29.1 months, P=0.79) or PFS (median 26.3 vs. 12.3 months, P=0.43) for those with high TVRs (≥10.1%) vs. low TVRs (<10.1%), respectively. There was a trend toward superior 2-year PFS in the high TVR group (52.2% vs. 36.7%, P=0.062), but this effect diminished on longer follow-up (4-year PFS 31.9% vs. 26.7%, P=0.15). No associations were observed between TVR and local, regional or distant recurrence.

Conclusions

We were not able to demonstrate that TVR is a reliable predictive imaging marker for stage I/II NSCLC treated with SBRT. Future studies with larger sample sizes are needed to clarify a potential relationship between TVR and early outcomes.

Adaptive radiotherapy for head and neck cancer

Background

Although there have been dramatic improvements in radiotherapy for head and neck squamous cell carcinoma (HNSCC), including robust intensity modulation and daily image guidance, these advances are not able to account for inherent structural and spatial changes that may occur during treatment. Many sources have reported volume reductions in the primary target, nodal volumes, and parotid glands over treatment, which may result in unintended dosimetric changes affecting the side effect profile and even efficacy of the treatment. Adaptive radiotherapy (ART) is an exciting treatment paradigm that has been developed to directly adjust for these changes.

Main body

Adaptive radiotherapy may be divided into two categories: anatomy-adapted (A-ART) and response-adapted ART (R-ART). Anatomy-adapted ART is the process of re-planning patients based on structural and spatial changes occurring over treatment, with the intent of reducing overdosage of sensitive structures such as the parotids, improving dose homogeneity, and preserving coverage of the target. In contrast, response-adapted ART is the process of re-planning patients based on response to treatment, such that the target and/or dose changes as a function of interim imaging during treatment, with the intent of dose escalating persistent disease and/or de-escalating surrounding normal tissue. The impact of R-ART on local control and toxicity outcomes is actively being investigated in several currently accruing trials.

Conclusions

Anatomy-adapted ART is a promising modality to improve rates of xerostomia and coverage in individuals who experience significant volumetric changes during radiation, while R-ART is currently being studied to assess its utility in either dose escalation of radioresistant disease, or de-intensification of surrounding normal tissue following treatment response. In this paper, we will review the existing literature and recent advances regarding A-ART and R-ART.

Pretreatment Prediction of Adaptive Radiation Therapy Eligibility Using MRI-Based Radiomics for Advanced Nasopharyngeal Carcinoma Patients

Background and purpose: Adaptive radiotherapy (ART) can compensate for the dosimetric impacts induced by anatomic and geometric variations in patients with nasopharyngeal carcinoma (NPC); Yet, the need for ART can only be assessed during the radiation treatment and the implementation of ART is resource intensive. Therefore, we aimed to determine tumoral biomarkers using pre-treatment MR images for predicting ART eligibility in NPC patients prior to the start of treatment. Methods: Seventy patients with biopsy-proven NPC (Stage II-IVB) in 2015 were enrolled into this retrospective study. Pre-treatment contrast-enhanced T1-w (CET1-w), T2-w MR images were processed and filtered using Laplacian of Gaussian (LoG) filter before radiomic features extraction. A total of 479 radiomics features, including the first-order (n = 90), shape (n = 14), and texture features (n = 375), were initially extracted from Gross-Tumor-Volume of primary tumor (GTVnp) using CET1-w, T2-w MR images. Patients were randomly divided into a training set (n = 51) and testing set (n = 19). The least absolute shrinkage and selection operator (LASSO) logistic regression model was applied for radiomic model construction in training set to select the most predictive features to predict patients who were replanned and assessed in the testing set. A double cross-validation approach of 100 resampled iterations with 3-fold nested cross-validation was employed in LASSO during model construction. The predictive performance of each model was evaluated using the area under the receiver operator characteristic (ROC) curve (AUC). Results: In the present cohort, 13 of 70 patients (18.6%) underwent ART. Average AUCs in training and testing sets were 0.962 (95%CI: 0.961-0.963) and 0.852 (95%CI: 0.847-0.857) with 8 selected features for CET1-w model; 0.895 (95%CI: 0.893-0.896) and 0.750 (95%CI: 0.745-0.755) with 6 selected features for T2-w model; and 0.984 (95%CI: 0.983-0.984) and 0.930 (95%CI: 0.928-0.933) with 6 selected features for joint T1-T2 model, respectively. In general, the joint T1-T2 model outperformed either CET1-w or T2-w model alone. Conclusions: Our study successfully showed promising capability of MRI-based radiomics features for pre-treatment identification of ART eligibility in NPC patients.

Early clinical outcomes of helical tomotherapy/intensity-modulated proton therapy combination in nasopharynx cancer

This study aimed to evaluate the feasibility of combining helical tomotherapy (HT) and intensity‐modulated proton therapy (IMPT) in treating patients with nasopharynx cancer (NPC). From January 2016 to March 2018, 98 patients received definitive radiation therapy (RT) with concurrent chemotherapy (CCRT). Using simultaneous integrated boost and adaptive re‐plan, 3 different dose levels were prescribed: 68.4 Gy in 30 parts to gross tumor volume (GTV), 60 Gy in 30 parts to high‐risk clinical target volume (CTV), and 36 Gy in 18 parts to low‐risk CTV. In all patients, the initial 18 fractions were delivered by HT, and, after rival plan evaluation on the adaptive re‐plan, the later 12 fractions were delivered either by HT in 63 patients (64.3%, HT only) or IMPT in 35 patients (35.7%, HT/IMPT combination), respectively. Propensity‐score matching was conducted to control differences in patient characteristics. In all patients, grade ≥ 2 mucositis (69.8% vs 45.7%, P = .019) and grade ≥ 2 analgesic usage (54% vs 37.1%, P = .110) were found to be less frequent in HT/IMPT group. In matched patients, grade ≥ 2 mucositis were still less frequent numerically in HT/IMPT group (62.9% vs 45.7%, P = .150). In univariate analysis, stage IV disease and larger GTV volume were associated with increased grade ≥ 2 mucositis. There was no significant factor in multivariate analysis. With the median 14 month follow‐up, locoregional and distant failures occurred in 9 (9.2%) and 12 (12.2%) patients without difference by RT modality. In conclusion, comparable early oncologic outcomes with more favorable acute toxicity profiles were achievable by HT/IMPT combination in treating NPC patients.

Less is more: role of additional chemotherapy to concurrent chemoradiotherapy in locoregionally advanced nasopharyngeal cancer management

Concurrent chemoradiation therapy (CCRT) has played the most important and central role in the definitive therapy for the patients with locoregionally advanced stage nasopharynx cancer. The addition of induction chemotherapy (IC) or adjuvant chemotherapy (AC) to CCRT have been widely accepted with the rationale of improving distant control in the clinical practices. This review article investigated the role of IC and AC based on 11 recent meta-analysis publications, and found that the clinical benefits obtained by the additional IC or AC to CCRT, at the cost of the increased risks of more frequent and more severe side effects, seemed not big enough. More intervention is not always better, however, less seems frequently good enough. The author would speculate that 'less is more' and would advocate CCRT alone as the current standard.

Which nasopharyngeal cancer patients need adaptive radiotherapy?

Background

Adaptive radiotherapy (ART) has potential benefits in patients with nasopharyngeal cancer (NPC). This retrospective study aimed to identify the factors favoring ART.

Materials and methods

Forty NPC patients were retrospectively included in this study. All patients received two-phase, volumetric modulated arc radiotherapy (VMAT) and underwent a second computed tomography (CT) for the phase II ART. We generated phantom, non-ART plans by a hybrid method for comparison with ART plans. A paired t-test was used to evaluate the dose differences between these two plans. A subgroup analysis through a paired t-test was used to evaluate the factors favoring ART.

Results

The second CT images were captured at the median 22 fractions. The median total dose of the planning target volume-one (PTV-1) was 72 Gy, and the phase II dose was 16 Gy. The volumes of the ipsilateral parotid gland (23.2 vs. 19.2 ml, p <  0.000), contralateral parotid gland (23.0 vs. 18.4 ml, p <  0.000), clinical target volume-1 (CTV-1, 32.2 vs. 20.9 ml, p <  0.000), and PTV-1 (125.8 vs. 107.3 ml, p <  0.000) all shrunk significantly between these two CT simulation procedures. Among the nearby critical organs, only the ipsilateral parotid gland displayed significant dose reduction by the ART plan (5.3 vs. 6.0 Gy, p = 0.004). Compared to the phantom plan, the ART could significantly improve the PTV-1 target volume coverage of D₉₈ (15.4 vs. 12.3 Gy, p < 0.000). Based on the D₉₈ of PTV-1, the factors of a large initial weight (> 60 kg, p < 0.000), large body mass index (BMI) (> 21.5, p < 0.000), obvious weight loss (> 2.8 kg, p < 0.000), concurrent chemoradiotherapy (p < 0.000), and stages III–IV (p < 0.000) favored the use of ART.

Conclusions

ART could significantly reduce the mean dose to the ipsilateral parotid gland. ART has dosimetrical benefit for patients with a heavy initial weight, large BMI, obvious weight loss, concurrent chemoradiotherapy, and cancer in stages III–IV.