Comparison of the efficacy between intensity-modulated radiotherapy and two-dimensional conventional radiotherapy in stage II nasopharyngeal carcinoma

Manejo odontológico de las manifestaciones orales inducidas por radioterapia de cabeza y cuello

La radioterapia es una de las primeras opciones de tratamiento para el cáncer de cabeza y cuello; sin embargo, puede ocasionar diversas manifestaciones secundarias en la cavidad oral tales como mucositis oral, xerostomía, infecciones orales oportunistas, osteorradionecrosis y trismo. El presente artículo tiene como objetivo describir el manejo preventivo y terapéutico de las complicaciones orales inducidas por radioterapia de cabeza y cuello en la práctica odontológica propuestos hasta la actualidad. Se encontraron diversas medidas que han logrado reducir la incidencia y gravedad de dichas manifestaciones orales; sin embargo, aún existen algunas que requieren de más estudios para confirmar su efectividad. Palabras clave: cáncer de cabeza y cuello; manifestaciones bucales; radioterapia; terapéutica.

A prediction model for xerostomia in locoregionally advanced nasopharyngeal carcinoma patients receiving radical radiotherapy

Background

This study was to evaluate the predictors of xerostomia and Grade 3 xerostomia in locoregionally advanced nasopharyngeal carcinoma (NPC) patients receiving radical radiotherapy and establish prediction models for xerostomia and Grade 3 xerostomia based on the predictors.

Methods

Totally, 365 patients with locoregionally advanced NPC who underwent radical radiotherapy were randomly divided into the training set (n = 255) and the testing set (n = 110) at a ratio of 7:3. All variables were included in the least absolute shrinkage and selection operator regression to screen out the potential predictors for xerostomia as well as the Grade 3 xerostomia in locoregionally advanced NPC patients receiving radical radiotherapy. The random forest (RF), a decision tree classifier (DTC), and extreme-gradient boosting (XGB) models were constructed. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), area under the curve (AUC) and accuracy were analyzed to evaluate the predictive performance of the models.

Results

In the RF model for predicting xerostomia, the sensitivity was 1.000 (95%CI 1.000–1.000), the PPV was 0.990 (95%CI 0.975–1.000), the NPV was 1.000 (95%CI 1.000–1.000), the AUC was 0.999 (95%CI 0.997–1.000) and the accuracy was 0.992 (95%CI 0.981–1.000) in the training set. The sensitivity was 0.933 (95%CI 0.880–0.985), the PPV was 0.933 (95%CI 0.880–0.985), and the AUC was 0.915 (95%CI 0.860–0.970) in the testing set. Hypertension, age, total radiotherapy dose, dose at 50% of the left parotid volume, mean dose to right parotid gland, mean dose to oral cavity, and course of induction chemotherapy were important variables associated with the risk of xerostomia in locoregionally advanced NPC patients receiving radical radiotherapy. The AUC of DTC model for predicting xerostomia was 0.769 (95%CI 0.666–0.872) in the testing set. The AUC of the XGB model for predicting xerostomia was 0.834 (0.753–0.916) in the testing set. The RF model showed the good predictive ability with the AUC of 0.986 (95%CI 0.972–1.000) in the training set, and 0.766 (95%CI 0.626–0.905) in the testing set for identifying patients who at high risk of Grade 3 xerostomia in those with high risk of xerostomia.

Conclusions

An RF model for predicting xerostomia in locoregionally advanced NPC patients receiving radical radiotherapy and an RF model for predicting Grade 3 xerostomia in those with high risk of xerostomia showed good predictive ability.

Survival among subgroups of patients with stage II nasopharyngeal carcinoma

To assess survival between subgroups (T1N1, T2N0, and T2N1) of patients with stage II nasopharyngeal carcinoma (NPC). This retrospective cohort study evaluated pathologically confirmed stage II NPC patients from The Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2016. The included patients were divided into three subgroups: T1N1, T2N0, and T2N1. Overall survival (OS) and cancer-specific survival (CSS) were assessed using the Kaplan-Meier method among the three subgroups. This study investigated 836 patients: 383 (45.8%) patients were in the T1N1 subgroup, 175 (20.9%) patients were in the T2N0 subgroup, and 278 (33.3%) patients were in the T2N1 subgroup. The 5-year OS (75.7%, 68.6%, and 75.7%) and CSS (85.3%, 83.4%, and 84.5%) were similar among the T1N1, T2N0, and T2N1 subgroups. Univariate and multivariate regression analyses revealed that the subgroup (T1N1, T2N0, and T2N1) of stage II NPC was not an independent prognostic factor for OS or CSS. Survival was comparable among subgroups (T1N1, T2N0, and T2N1) of stage II NPC patients. However, patients with T1N1, T2N0, and T2N1 stage disease who receive different treatments might have different prognoses.

IMRT improves local control in patients with nasopharyngeal carcinoma compared with conventional radiotherapy: propensity score-matched analysis

BACKGROUND

It is still controversial whether intensity-modulated radiotherapy has an obvious advantage over conventional radiotherapy. The purposes of this study were to evaluate prognostic factors in pre-treatment characteristics for nasopharyngeal carcinoma and to compare treatment outcomes in patients who received intensity-modulated radiotherapy and patients who received two-dimensional radiotherapy or three-dimensional radiotherapy.

METHODS

We reviewed patients with nasopharyngeal carcinoma who received chemoradiotherapy in our hospital during the period from 2000 to 2017, and we excluded patients who had a history of surgery for nasopharyngeal carcinoma and those who had distant metastases before treatment. A total of 72 patients who were treated by radiotherapy with concurrent chemotherapy were enrolled. All of the patients were irradiated with a total dose of 58-70 Gy. Overall survival, locoregional control and progression-free survival rates were compared in the groups treated by intensity-modulated radiotherapy and two-dimensional/three-dimensional radiotherapy. Propensity score matching was performed to homogenize the two groups.

RESULTS

The median follow-up period was 62.5 months. After propensity score matching, in patients treated with intensity-modulated radiotherapy, the 5-year rate of overall survival, locoregional control and progression-free survival were 73.5, 95.2 and 72.7%, respectively. In patients treated with two-dimensional/three-dimensional radiotherapy, the 5-year rate of overall survival, locoregional control and progression-free survival were 69.1, 67.7 and 51.8%, respectively. There was a significant difference between the groups only in locoregional control. Late toxicities of grade 2 or higher were occurred in 38.5 and 24.2% of the patients treated by two-dimensional/three-dimensional radiotherapy and intensity-modulated radiotherapy, respectively.

CONCLUSIONS

Our results suggested that intensity-modulated radiotherapy is more effective than two-dimensional/three-dimensional radiotherapy in patients with nasopharyngeal carcinoma, especially in locoregional control.

Follow-up strategy based on event dynamics for stage II nasopharyngeal carcinoma

PURPOSE

To investigate the follow-up strategy of stage II NPC based on event dynamics.

METHODS

Stage II NPC patients were retrospectively assessed from January 2007 to December 2014 at Guangxi Medical University Cancer Hospital. Event dynamics for patterns of recurrence and metastasis were calculated based on the hazard rates.

RESULTS

A total of 251 patients were included. After treatment, 10 (4.0%) patients developed recurrence and 6 (2.4%) patients developed metastasis. The hazard rate curve of recurrence showed a bimodal recurrence pattern. The maximum hazard rates were 0.048 and 0.072 at the intervals of 36-42 and 90-96 months, respectively. The maximum hazard rate was 0.036 at the interval of 48-54 months in the hazard rate curve of metastasis.

CONCLUSIONS

Follow-up strategies of stage II NPC should be performed based on currently recommended guidelines. In the future, it should be modified to meet the needs of individual patients.

Prognostic nomogram of xerostomia for patients with nasopharyngeal carcinoma after intensity-modulated radiotherapy

Xerostomia is a common radiation-induced late complication after radiotherapy. Identifying predictive factors for xerostomia will lead to better treatments and improve the quality of life. This study was conducted to establish an effective predictive nomogram for xerostomia by assessing stage I-IVb (AJCC 7th edition) NPC patients between September 2015 and March 2016. Xerostomia was evaluated via the RTOG/EORTC system. The primary endpoint was grade 2-3 xerostomia 1 year after treatment. The predictive factors for xerostomia were analysed using logistic regression analysis. A nomogram was constructed based on combining the predictors and clinical variables. In total, 102 patients with grade 0-1 xerostomia and 93 patients with grade 2-3 xerostomia were included. The independent predictive factors for xerostomia were V25, V30, V35, and V45 of the ipsilateral parotid gland and mean dose of the contralateral parotid gland. The calibration plot for the probability of xerostomia showed good agreement between prediction by the nomogram and actual observation. The concordance index of the nomogram for predicting xerostomia was 0.796 (95% CI: 0.735-0.857, P <0.001), which was higher than any single dosimetric parameter. Our results indicated that the nomogram provided a more accurate prediction of grade 2-3 xerostomia 1 year after treatment.

Neutrophil-to-lymphocyte ratio predicts the prognosis of stage II nasopharyngeal carcinoma

Purpose

To assess the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in stage II nasopharyngeal carcinoma (NPC).

Methods

Stage II (2010 UICC/AJCC staging system) NPC patients treated between January 2007 and December 2014 were retrospectively analyzed. The NLR was calculated from peripheral blood cell counts before treatment. The optimal cut-off value of NLR was determined by receiver operating characteristic curve analysis. Survival rates were compared according to the NLR value. Multivariable Cox regression analyses were performed to assess the association between the NLR and overall survival (OS), locoregional-free survival (LRFS), and distant metastasis-free survival (DMFS).

Results

Two hundred and fifty-one stage II NPC patients were included in this study. The NLR was correlated with T stage (r=0.158, p=0.012). An NLR ≥2.92 was associated with poor 5-year OS (84.3% vs 97.4%, p=0.001) and LRFS (91.4% vs 98.4%, p=0.003). An NLR ≥2.82 was associated with poor 5-year DMFS (92.6% vs 98.2%, p=0.033). The multivariate Cox regression analysis showed that an NLR ≥2.92 was an independent prognostic biomarker in stage II NPC.

Conclusion

The NLR is an independent prognostic factor in stage II NPC.

Predictors for improvement of xerostomia in nasopharyngeal carcinoma patients receiving intensity-modulated radiotherapy

To identify predictors for improvement of xerostomia in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT).Patients diagnosed with stage I-IVb NPC (according to the 7th edition of the American Joint Committee on Cancer) between September 2015 and March 2016 were retrospectively analyzed. All the patients received IMRT. Predictors for improvement of xerostomia were analyzed using logistic regression analysis. Receiver operating characteristic curve analysis was used to identify the most appropriate cut-off values for predicting factors.This study included 195 patients: xerostomia improved in 109 patients and xerostomia remained unchanged in 86 patients. Volume of the parotid gland ≤52.2 cm was a risk factor for xerostomia improvement (odds ratio [OR] = 3.506, 95% confidence interval [CI]: 1.932-6.362, P = .001). The mean dose of <39 Gy to the ipsilateral parotid gland was a protective factor (OR = 0.417, 95% CI: 0.271-0.641, P = .001). V30 of the contralateral parotid gland ≤52% was a protective factor (OR = 0.593, 95% CI: 0.462-0.760, P = .001).Volume of the parotid gland, the mean dose of the ipsilateral parotid gland, and V30 of the contralateral parotid gland were independent predictors for improvement of xerostomia.

Predictive factors of chemotherapy use in stage II nasopharyngeal carcinoma: A retrospective cohort study

Identification of predictive factors of chemotherapy use and assessment of the roles of these factors in prognosis will aid therapeutic decision-making in stage II nasopharyngeal carcinoma (NPC).Using logistic regression, we retrospectively assessed factors predicting chemotherapy use in 251 stage II (2010  UICC/AJCC staging system) NPC patients. Five-year overall survival (OS), locoregional-free survival (LRFS), and distant metastasis-free survival (DMFS) were analyzed based on the predictive factors.Logistic regression found that N1 stage was an independent factor predicting chemotherapy use in stage II NPC patients. However, 5-year OS (96.5% vs 94.9%, P = .564), LRFS (98.2% vs 96.9%, P = .652), and DMFS (95.9% vs 97.6%, P = .560) did not differ between N0 and N1 stage patients. Moreover, addition of chemotherapy use did not improve treatment outcomes in N1 stage compared with radiotherapy alone.N1 stage predicted chemotherapy use in stage II NPC patients. But, the addition of chemotherapy did not provide a survival benefit.

Chemotherapy use and survival in stage II nasopharyngeal carcinoma

Although common, the use of chemotherapy for stage II nasopharyngeal carcinoma (NPC) is controversial due to its undefined clinical benefits. We therefore conducted a retrospective cohort study to investigate whether chemotherapy confers survival gains to stage II NPC patients. A total of 251 stage II (2010 UICC/AJCC staging system) NPC patients treated between January 2007 and December 2014 were retrospectively analyzed. Patients were matched using the propensity-score matching method. The primary endpoint was overall survival (OS). Secondary endpoints were locoregional-free survival (LRFS) and distant metastasis-free survival (DMFS). Our analyses revealed no significant differences in OS, LRFS, or DMFS for stage II NPC patients treated with radiotherapy (RT) alone, concurrent chemoradiotherapy (CCRT), or CCRT + adjuvant chemotherapy (AC). T2N1 (OR = 6.690; 95% CI, 3.091–14.481) and T1N1 (OR = 5.857; 95% CI, 2.278–15.061) patients were more likely to receive CCRT than T2N0 patients. Similarly, both T2N1 (OR = 10.513; 95% CI, 3.439–32.137) and T1N1 (OR = 7.321; 95% CI, 1.978–27.098) patients were more likely to receive CCRT + AC than T2N0 patients. The present matched survival analysis suggests potential overuse of chemotherapy in stage II NPC, as the addition of chemotherapy did not provide a survival benefit in this group of patients.