Local and Lymph Node Relapse of Nasopharyngeal Carcinoma: A Single-Center Experience

Early prediction of long-term survival of patients with nasopharyngeal carcinoma by multi-parameter MRI radiomics

Purpose

The objective is to create a comprehensive model that integrates clinical, semantic, and radiomics features to forecast the 5-year progression-free survival (PFS) of individuals diagnosed with non-distant metastatic Nasopharyngeal Carcinoma (NPC).

Methods

In a retrospective analysis, we included clinical and MRI data from 313 patients diagnosed with primary NPC. Patient classification into progressive and non-progressive categories relied on the occurrence of recurrence or distant metastasis within a 5-year timeframe. Initial screening comprised clinical features and statistically significant image semantic features. Subsequently, MRI radiomics features were extracted from all patients, and optimal features were selected to formulate the Rad-Score.Combining Rad-Score, image semantic features, and clinical features to establish a combined model Evaluation of predictive efficacy was conducted using ROC curves and nomogram specific to NPC progression. Lastly, employing the optimal ROC cutoff value from the combined model, patients were dichotomized into high-risk and low-risk groups, facilitating a comparison of 10-year overall survival (OS) between the groups.

Results

The combined model showcased superior predictive performance for NPC progression, reflected by AUC values of 0.84, an accuracy rate of 81.60%, sensitivity at 0.77, and specificity at 0.81 within the training group. In the test set, the AUC value reached 0.81, with an accuracy of 74.6%, sensitivity at 0.82, and specificity at 0.66.

Conclusion

The amalgamation of Rad-Score, clinical, and imaging semantic features from multi-parameter MRI exhibited significant promise in prognosticating 5-year PFS for non-distant metastatic NPC patients. The combined model provided quantifiable data for informed and personalized diagnosis and treatment planning.

Clinical course of longer than five years after definitive radiotherapy for nasopharyngeal carcinoma

BACKGROUND

This study aimed to reveal the long-term outcomes and late toxicities (> 5 years) after definitive intensity-modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC).

METHODS

Data from 43 patients (median age, 55 years; range, 17-72 years) with NPC who underwent definitive IMRT between 2001 and 2018 were analyzed. All patients were alive and disease-free 5 years after IMRT. A total dose of 70 (range, 66-70) Gy was delivered in 35 (33-35) fractions with concurrent cisplatin chemotherapy.

RESULTS

The median follow-up duration was 119 (range, 61.5-242.1) months. Three patients developed locoregional failure at 79, 92, and 149 months after IMRT, respectively. Of these, 2 patients died of disease progression at 136 and 153 months after IMRT. One patient died of aspiration pneumonia 141 months after IMRT, despite salvage of the recurrent tumor by re-irradiation. In addition, one patient died of aspiration pneumonia 62 months after the IMRT. Thus, the 10-year overall survival, progression-free survival, and locoregional control rates were 98%, 92%, and 94%, respectively. Grade ≥ 2 and ≥ 3 late toxicities were observed in 28 (65%) and 9 (21%) patients, respectively. Nine second primary cancers, including five tongue cancers and two external auditory canal carcinomas, were observed in seven (16%) patients.

CONCLUSION

Late recurrences, severe late toxicities, and second primary cancers were observed > 5 years after IMRT. A long-term follow-up of > 5 years is needed in patients with NPC.

Set-up errors of the neck are underestimated using the overall registration frame of head and neck in IMRT for NPC

BACKGROUND

There is no standardized registration frame of cone beam CT (CBCT) in intensity modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC). The overall registration frame that covers the whole head and neck is the most commonly used CBCT registration frame for NPC patients in IMRT.

OBJECTIVE

To compare the set-up errors using different registration frames of CBCT for NPC to assess the set-up errors for different region of the commonly used clinical overall registration frame.

METHODS

294 CBCT images of 59 NPC patients were collected. Four registration frames were used for matching. The set-up errors were obtained using an automatic matching algorithm and then compared. The expansion margin from the clinical target volume (CTV) to the planned target volume (PTV) in the four groups was also calculated.

RESULTS

The average range of the isocenter translation and rotation errors of four registration frames are 0.89∼2.41 mm and 0.49∼1.53°, respectively, which results in a significant difference in the set-up errors (p < 0.05). The set-up errors obtained from the overall frame are smaller than those obtained from the head, upper neck, and lower neck frames. The margin ranges of the overall, head, upper neck, and lower neck frames in three translation directions are 1.49∼2.39 mm, 1.92∼2.45 mm, 1.86∼3.54 mm and 3.02∼4.78 mm, respectively. The expansion margins calculated from the overall frame are not enough, especially for the lower neck.

CONCLUSION

Set-up errors of the neck are underestimated by the overall registration frame. Thus, it is important to improve the position immobilization of the neck, especially the lower neck. The margin of the target volume of the head and neck region should be expanded separately if circumstances permit.