Quality of life and survival outcome for patients with nasopharyngeal carcinoma treated by volumetric-modulated arc therapy versus intensity-modulated radiotherapy

Quality of life in patients with nasopharyngeal carcinoma receiving IMRT vs IMPT: a multicenter prospective longitudinal study

PURPOSE

Nasopharyngeal carcinoma (NPC) patients may experience symptom distress and depression during and after radiation therapy, which negatively impacts quality of life (QOL). We sought to identify trajectories of symptom distress, depression, social support, and QOL in patients with NPC receiving intensity-modulated radiation therapy (IMRT) vs intensity-modulated proton therapy (IMPT).

METHODS

A multicenter prospective longitudinal study recruited NPC patients from two leading medical centers in Taiwan. The 121 NPC patients were followed from before RT (T0), at 4 weeks after beginning RT (T1), at 6 weeks of RT or the end of treatment (T2), and at 4 weeks post-RT (T3). Generalized estimating equation analysis was used to identify the factors related to QOL.

RESULTS

Patients' symptom distress and depression increased from T0, peaked at T2, and decreased at T3. Physical-QOL and psychosocial-QOL decreased from T0 to T2, then increased by T3. Patients who had early-stage cancer, received a lower RT dose, had less symptom distress, and had less depression were more likely to have better QOL. Greater physical-QOL was associated with IMPT receipt, higher education level, early cancer stage, lower radiation dose, less symptom distress, and less depression. Patients who had good physical performance, received a lower radiation dose, had less symptom distress, and had less depression were more likely to have better psychosocial-QOL.

CONCLUSION

Radiation dose, symptom distress, and depression were the most important factors affecting QOL in patients with NPC. Understanding the factors associated with the trajectory of QOL can guide care during radiation treatment.

A Neural Network-based Method for Predicting Dose to Organs at Risk in Intensity-modulated Radiotherapy for Nasopharyngeal Carcinoma

OBJECTIVE

A neural network method was used to establish a dose prediction model for organs at risk (OARs) during intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

In total, 103 patients with NPC were randomly selected for IMRT. Suborgans were automatically generated for OARs using ring structures based on distance to the target using a MATLAB program and the corresponding volume of each suborgan was determined. The correlation between the volume of each suborgan and the dose to each OAR was analysed and neural network prediction models of the OAR dose were established using the MATLAB Neural Net Fitting application. The R-value and mean square error in the regression analysis were used to evaluate the prediction model.

RESULTS

The OAR dose was related to the volume of the corresponding sub-OAR. The average R-values for the normalised mean dose (Dnmean) to parallel organs and serial organs and the normalised maximum dose (Dn0) to serial organs in the training set were 0.880, 0.927 and 0.905, respectively. The mean square error for each OAR in the prediction model was low (ranging from 1.72 × 10-4 to 7.06 × 10-3).

CONCLUSION

The neural network-based model for predicting OAR dose during IMRT for NPC is simple, reliable and worth further investigation and application.

Impairment mechanism of nasal mucosa after radiotherapy for nasopharyngeal carcinoma

The nasal mucosa, which performs the crucial functions of filtering, humidifying and temperature regulation, is one of the most vulnerable areas of nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT). Following RT, NPC patients experience a series of pathological changes in the nasal mucosa, ultimately leading to physiological dysfunction of the nasal epithelium. This article systematically reviews the clinical and pathological manifestations of RT-related nasal damage in NPC patients and summarizes the potential mechanism of damage to the human nasal epithelium by RT. Finally, we outline the current mechanistic models of nasal epithelial alterations after RT in NPC patients and provide additional information to extend the in-depth study on the impairment mechanisms of the nasal mucosa resulting from RT. We also describe the relationship between structural and functional alterations in the nasal mucosa after RT to help mitigate and treat this damage and provide insights informing future clinical and fundamental investigations.

Particle beam therapy for nasopharyngeal cancer: A systematic review and meta-analysis

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Particle beam therapy yields excellent short-term treatment outcomes among NPC patients.

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Particle beam therapy is generally safe in primary and recurrent NPC patients, with ≥G3 late toxicity rates of 20 % or less.

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An approximately 5% mortality rate was reported among recurrent NPC patients.

Background/purpose

A systematic review and meta-analysis were performed to better understand the benefits of particle beam therapy for nasopharyngeal cancer (NPC) treatment. The survival outcomes and toxicity of primary and recurrent NPC patients treated with proton or carbon ion beam therapy were investigated.

Method

PubMed, Scopus, and Embase were searched between 1 January 2007 to 3 November 2021. The inclusion and exclusion criteria included studies with either primary or recurrent NPC patients, sample size of ≥10 patients, and proton or carbon ion beam therapy as interventions. Twenty-six eligible studies with a total of 1502 patients were included. We used a random-effect meta-analysis to examine the impact of particle beam therapy on primary NPC patients and qualitatively described the results among recurrent patients. The primary outcome was overall survival (OS), while secondary outcomes included progression-free survival (PFS), local control (LC) and toxicity.

Results

The pooled OS at 1-year, 2-year and 3-year and 5-year for primary NPC patients who received particle beam therapy were 96 % (95 % confidence interval (CI) = 92 %-98 %), 93 % (95 % CI = 83 %-97 %), 90 % (95 % CI = 73 %-97 %) and 73 % (95 % CI = 52 %-87 %) respectively. The pooled 1-year and 2-year PFS, and LC for these patients were above 90 %. For locally recurrent NPC patients, the 1-year OS rate ranged from 65 % to 92 %, while the 1-year LC rate ranged from 80 % to 88 %. Both proton and carbon ion beam therapy were generally safe among primary and recurrent patients, with ≥G3 late toxicity rates of 20 % or less. Approximately a 5 % mortality rate was reported among recurrent patients.

Conclusions

This systematic review and meta-analysis demonstrated particle beam therapy has great potential in treating NPC, yielding excellent survival outcomes with low toxicity. However, further investigations are needed to assess the long-term outcomes and cost-effectiveness of this newer form of radiotherapy.

Volumetric modulated arc therapy (VMAT): a review of clinical outcomes—what is the clinical evidence for the most effective implementation?

Modern conformal radiation therapy using techniques such as modulation, image guidance and motion management have changed the face of radiotherapy today offering superior conformity, efficiency, and reproducibility to clinics worldwide. This review assesses the impact of these advanced radiotherapy techniques on patient toxicity and survival rates reported from January 2017 to September 2020. The main aims are to establish if dosimetric and efficiency gains correlate with improved survival and reduced toxicities and to answer the question ‘What is the clinical evidence for the most effective implementation of VMAT?’. Compared with 3DCRT, improvements have been reported with VMAT in prostate, locally advanced cervical carcinoma and various head and neck applications, leading to the shift in technology to VMAT. Other sites such as thoracic neoplasms and nasopharyngeal carcinomas have observed some improvement with VMAT although not in line with improved dosimetric measures, and the burden of toxicity and the incidence of cancer related deaths remain high, signaling the need to further mitigate toxicity and increase survival. As technological advancement continues, large randomised long-term clinical trials are required to determine the way-forward and offer site-specific recommendations. These studies are usually expensive and time consuming, therefore utilising pooled real-world data in a prospective nature can be an alternative solution to comprehensively assess the efficacy of modern radiotherapy techniques.

Can Epstein-Barr virus-deoxyribonucleic acid load after induction chemotherapy combined with American Joint Committee on Cancer stage determine the chemotherapy intensity of locally advanced nasopharyngeal carcinoma?

BACKGROUND

Induction chemotherapy (IC) comprising docetaxel, cisplatin, and fluorouracil (TPF), combined with concurrent chemoradiotherapy (CCRT) effectively improves the survival rate of locally advanced nasopharyngeal carcinoma (LA-NPC). Selecting patients whose risk of tumor recurrence and metastasis is high and the appropriate chemotherapy intensity is a concern. We combined tumor-node-metastasis staging with the load of Epstein-Barr virus (EBV) after IC to select the individualized chemotherapy strength.

METHODS

The clinical data and prognostic factors of patients with stage III-IV LA-NPC treated with TPF IC combined with CCRT were analyzed retrospectively. The conventional treatment group received the standard three cycles TPF IC combined with CCRT. For the new treatment group, the cycles of IC were determined according to whether the EBV-DNA disappeared completely after a certain course of IC, if so, subsequent IC was stopped and the chemoradiotherapy stage was entered. Propensity score matching (PSM) was performed at a ratio of 1:1 to balance baseline characteristics. Survival outcomes and adverse events between the conventional treatment group and the new method treatment group were compared.

RESULTS

The study included 256 patients, among whom 192 were matched successfully into 96 pairs. The patients were followed up for a median of 51 months. The proportions of patients receiving three, two, and one cycle of IC after PSM in the routine and new treatment cohorts were 93.8%, 3.1%, 3.1% versus 21.9%, 49.0%, 24.0%, respectively. However, their 3-year distant metastasis-free survival, local recurrence-free survival, progression-free survival, and overall survival did not differ significantly. The incidence of grade 3-4 neutropenia toxicity in CCRT decreased significantly in patients receiving the new treatment method compared with that in the conventional treatment group (p = 0.026).

CONCLUSION

Combining TNM stage and EBV-DNA load after IC to determine the courses of IC in patients with LA-NPC did not alter the curative effect but decreased toxicity.

Evaluation of plan robustness on the dosimetry of volumetric arc radiotherapy (VMAT) with set-up uncertainty in Nasopharyngeal carcinoma (NPC) radiotherapy

Purpose

To evaluate the sensitivity to set up the uncertainty of VMAT plans in Nasopharyngeal carcinoma (NPC) treatment by proposing a plan robustness evaluation method.

Methods

10 patients were selected for this study. A 2-arc volumetric-modulated arc therapy (VMAT) plan was generated for each patient using Varian Eclipse (13.6 Version) treatment planning system (TPS). 5 uncertainty plans (U-plans) were recalculated based on the first 5 times set-up errors acquired from cone-beam computer tomography (CBCT). The dose differences of the original plan and perturbed plan corresponded to the plan robustness for the structure. Tumor control probability (TCP) and normal tissues complication probability (NTCP) were calculated for biological evaluation.

Results

The mean dose differences of D_98% and D_95% (ΔD_98% and ΔD_95%) of PTVp were respectively 3.30 Gy and 2.02 Gy. The ΔD_98% and ΔD_95% of CTVp were 1.12 Gy and 0.58 Gy. The ΔD_98% and ΔD_95% of CTVn were 1.39 Gy and 1.03 Gy, distinctively lower than those in PTVn (2.8 Gy and 2.0 Gy). The CTV-to-PTV margin increased the robustness of CTVs. The ΔD_98% and ΔD_95% of GTVp were 0.56 Gy and 0.33 Gy. GTVn exhibited strong robustness with little variation of D_98% (0.64 Gy) and D_95% (0.39 Gy). No marked mean dose variations of D_mean were seen. The mean reduction of TCP (ΔTCP) in GTVp and CTVp were respectively 0.4% and 0.3%. The mean ΔTCPs of GTVn and CTVn were 0.92% and 1.3% respectively. The CTV exhibited the largest ΔTCP (2.2%). In OARs, the brain stem exhibited weak robustness due to their locations in the vicinity of PTV. Bilateral parotid glands were sensitive to set-up uncertainty with a mean reduction of NTCP (ΔNTCP) of 6.17% (left) and 7.70% (right). The D_max of optical nerves and lens varied slightly.

Conclusion

VMAT plans had a strong sensitivity to set-up uncertainty in NPC radiotherapy, with increasing risk of underdose of tumor and overdose of vicinal OARs. We proposed an effective method to evaluate the plan robustness of VMAT plans. Plan robustness and complexity should be taken into account in photon radiotherapy.

Recommendations for surgical management of recurrent nasopharyngeal carcinoma during COVID-19 pandemic

Nasopharyngeal carcinoma is endemic in southern parts of China including Hong Kong. Primary treatment entails radiotherapy ± chemotherapy depending on disease stage at presentation. Surgery is offered as a means of salvage for persistent and recurrent disease. Comprehensive preoperative work-up, careful patient selection, attention to details perioperation and multidisciplinary approach is essential in ensuring optimal outcomes after salvage surgery for recurrent nasopharyngeal carcinoma patients. Since the COVID-19 outbreak, we are faced with unprecedented challenges with priorities of care and resources being shifted to combat the virus. These include patient selection and timing of treatment, while preventing disease transmission to heath care providers. Practices and recommendations made in this document are intended to support safe clinical practice and efficient use of resources during this challenging time.