Sparing level Ib lymph nodes by intensity-modulated radiotherapy in the treatment of nasopharyngeal carcinoma

Node-sparing modified short-course Radiotherapy Combined with CAPOX and Tislelizumab for locally Advanced MSS of Middle and low rectal Cancer (mRCAT): an open-label, single-arm, prospective, multicentre clinical trial

BACKGROUND

Neoadjuvant chemoradiotherapy followed by total mesorectal excision is a standard treatment for locally advanced rectal cancer. Mismatch repair-deficient locally advanced rectal cancer (LARC) was highly sensitive to PD-1 blockade. However, most rectal cancers are microsatellite stable (MSS) or mismatch repair-proficient (pMMR) subtypes for which PD-1 blockade is ineffective. Radiation can trigger the activation of CD8 + T cells, further enhancing the responses of MSS/pMMR rectal cancer to PD-1 blockade. Radioimmunotherapy offers a promising therapeutic modality for rectal cancer. Progenitor T exhausted cells are abundant in tumour-draining lymph nodes and play an important role in immunotherapy. Conventional irradiation fields include the mesorectum and regional lymph nodes, which might cause considerable damage to T lymphocytes and radiation-induced fibrosis, ultimately leading to a poor response to immunotherapy and rectal fibrosis. This study investigated whether node-sparing modified short-course irradiation combined with chemotherapy and PD-1 blockade could be effective in patients with MSS/ pMMR LARC.

METHODS

This was a open-label, single-arm, multicentre, prospective phase II trial. 32 LARC patients with MSS/pMMR will receive node-sparing modified short-course radiotherapy (the irradiated planned target volume only included the primary tumour bed but not the tumour-draining lymph nodes, 25 Gy/5f, 5 Gy/f) followed by CAPOX and tislelizumab. CAPOX and tislelizumab will be started two days after the completion of radiotherapy: oxaliplatin 130 mg/m2 intravenous infusion, day 1; capecitabine 1000 mg/m2 oral administration, days 1-14; and tislelizumab 200 mg, intravenous infusion, day 1. There will be four 21-day cycles. TME will be performed at weeks 14-15. We will collect blood, tumour, and lymphoid specimens; perform flow cytometry and in situ multiplexed immunofluorescence detection; and analyse the changes in various lymphocyte subsets. The primary endpoint is the rate of pathological complete response. The organ preservation rate, tumour regression grade, local recurrence rate, disease-free survival, overall survival, adverse effects, and quality of life will also be analysed.

DISCUSSION

In our research, node-sparing modified radiotherapy combined with immunotherapy probably increased the responsiveness of immunotherapy for MSS/pMMR rectal cancer patients, reduced the occurrence of postoperative rectal fibrosis, and improved survival and quality of life. This is the first clinical trial to utilize a node-sparing radiation strategy combined with chemotherapy and PD-1 blockade in the neoadjuvant treatment of rectal cancer, which may result in a breakthrough in the treatment of MSS/pMMR rectal cancer.

TRIAL REGISTRATION

This study was registered at www.

CLINICALTRIALS

gov .

TRIAL REGISTRATION NUMBER

NCT05972655. Date of registration: 31 July 2023.

The feasibility of level Ib-sparing intensity-modulated radiation therapy in patients with nasopharyngeal carcinoma and high-risk factors classified based on the International Guideline

BACKGROUND AND PURPOSE

To examine the feasibility of level Ib-sparing intensity-modulated radiation therapy (IMRT) in patients with nasopharyngeal carcinoma (NPC) who had high-risk factors classified based on the International Guideline (IG).

MATERIALS AND METHODS

We evaluated 961 non-metastatic NPC cases based on IG recommendations for prophylactic Ib irradiation. Four high-risk factors were used to categorise patients into three cohorts: A, B, and C. Propensity score matching was used to balance baseline characteristics in Cohort C, resulting in a matched Cohort C. Recurrence rates at level Ib and regional relapse-free survival (RRFS) rates were evaluated.

RESULTS

Among patients with negative Ib lymph nodes (LNs), 18, 54, 420, and 444 exhibited involvement of structures that drain to level Ib as the first echelon (FES), involvement of the submandibular gland (SMG), level II LNs with radiologic extranodal extension (rENE), and level II nodes with a maximal axial diameter (MAD) ≥ 2 cm, respectively. The recurrence rate was highest in Cohort A (11.1 %). Cohort B had no level Ib recurrence. In matched Cohort C, recurrence rates were low in both groups (Ib-sparing group: 0.6 % vs. Ib-covering group: 0.6 %, P > 0.999). No significant differences were observed in 5-year RRFS rates between the two groups in cohort A (p = 0.208), cohort B (p = 0.905), and matched cohort C (p = 0.423).

CONCLUSIONS

Level Ib-sparing IMRT could be performed safely for NPC patients with level II LNs who had rENE and/or MAD ≥ 2 cm. Further research should determine the necessity of level Ib prophylactic irradiation for patients with FES or SMG involvement.

Patterns and prognosis of regional recurrence in nasopharyngeal carcinoma after intensity-modulated radiotherapy

OBJECTIVE

We analyzed the patterns of lymph node (LN) failure and prognosis in patients with regional recurrent nasopharyngeal carcinoma (rNPC) alone after primary intensity-modulated radiotherapy (IMRT).

METHODS

A total of 175 patients who were treated with IMRT between 2010 and 2015 and who experienced regional recurrence alone were included. Recurrent LNs were re-located in the initial pretreatment imaging and IMRT plan and failures were classified as in-field or out-field based on target volume delineation. All patients underwent curative salvage treatment. Independent prognostic factors for overall survival (OS) were selected by multivariate Cox analysis.

RESULTS

Level IIb (49.1%, 86/175) was the most frequent recurrence site, followed by level IIa (36%), level III (18.9%), level IVa (12%), the retropharyngeal region (8%), level Va (6.9%), and the parotid region (6.9%). A total of 264 recurrent LNs were recorded: 149 (56.4%) were classified as in-field failure with a prescribed dose ≥66 Gy, 60 (22.7%) with 60 to <66 Gy, 32 (12.1%) with 50 to <60 Gy, and 23 (8.7%) as an out-field failure, which mainly occurred in the parotid region and level Ib. After a median follow-up of 52.8 months, the estimated 5-year OS rate was 66.9%. Multivariate analysis showed that age, plasma Epstein-Barr virus DNA level, extranodal extension, lower neck involvement, and parotid LN recurrence were independent prognostic factors of OS.

CONCLUSIONS

In-field failure represented the main pattern of regional recurrence and out-field failure mainly occurred in the parotid gland and level Ib. Patients with regional rNPC alone had a good prognosis after salvage treatment.

Neck level Ib-sparing versus level Ib-irradiation in intensity-modulated radiotherapy for the treatment of nasopharyngeal carcinoma with high-risk factors: A propensity score-matched cohort study

AIM

Level Ib lymph nodes metastasis is rare in nasopharyngeal carcinoma (NPC). We aimed to evaluate the feasibility of sparing level Ib-irradiation in NPC patients with high-risk factors.

MATERIALS AND METHODS

Four hundred forty-three NPC patients with radiologic extranodal extension (rENE) or level II lymph node maximal axial diameter (MAD) ≥ 20 mm treated by intensity-modulated radiotherapy (IMRT) between 2009 and 2012 were included in this study. Propensity score matching (PSM) was applied to balance potential prognostic factors (including age, sex, T and N stage, pretreatment EBV DNA level, and level II rENE and MAD) between patients who received and omitted level Ib irradiation. Kaplan-Meier analysis and the log-rank test were used to compare regional survival outcomes.

RESULTS

PSM resulted in 169 matched pairs of eligible patients. The median follow-up period was 119 months in the matched cohort. The number of level Ib failure in the level Ib-sparing and level-Ib irradiation groups were 3/169 (1.8 %) vs 2/169 (1.2 %), P > 0.999. And the 5-year regional relapse-free survival (RRFS) rates of the two groups were 88.4 % vs 92.6 %, respectively. After PSM, RRFS (hazard ratio [HR]: 1.508, 95 % confidence interval [CI]: 0.762-2.986, P = 0.239), OS (HR: 1.219, 95 % CI: 0.754-1.972, P = 0.418), distant metastasis-free survival (DMFS) (HR: 1.605, 95 % CI: 0.900-2.863, P = 0.109), and local relapse-free (LRFS) (HR: 0.956, 95 % CI: 0.436-2.095, P = 0.910) were similar in the two arms. The incidence of grade ≥ 1 dry mouth after 5 years was higher in the level Ib-irradiation group (27.5 % vs 16.5 %, P = 0.029). However, the incidences of grade 3-4 late toxicities were similar between the two groups.

CONCLUSION

Neck level Ib-sparing appears to be safe and feasible in NPC patients with rENE or level II MAD ≥ 20 mm and negative level Ib lymph nodes. Compared with cervical level Ib-irradiation, omission of irradiation to level Ib provides less dry mouth symptom.

Feasibility and safety of neck level IB-sparing radiotherapy in nasopharyngeal cancer: a long-term single institution analysis

PURPOSE

Nasopharyngeal cancer (NPC) has a higher prevalence of regional nodal metastasis than other head and neck cancers; however, level IB lymph node involvement is rare. We evaluated the safety and feasibility of level IB-sparing radiotherapy (RT) for NPC patients.

MATERIALS AND METHODS

We retrospectively reviewed 236 patients with NPC who underwent definitive intensity-modulated RT with or without chemotherapy between 2004 and 2018. Of them, 212 received IB-sparing RT, and 24 received non-IB-sparing RT. We conducted a propensity score matching analysis to compare treatment outcomes according to IB-sparing status. In addition, dosimetric analysis of the salivary glands was performed to identify the relationship between xerostomia and the IB-sparing RT.

RESULTS

The median follow-up duration was 78 months (range, 7 to 194 months). Local, regional, and distant recurrences were observed in 11.9%, 6.8%, and 16.1% of patients, respectively. Of the 16 patients with regional recurrence, 14 underwent IB-sparing RT. The most common site categorization of regional recurrence was level II (75%), followed by retropharyngeal lymph nodes (43.8%); however, there was no recurrence at level IB. In the matched cohorts, IB-sparing RT was not significantly related to treatment outcomes. However, IB-sparing RT patients received a significantly lower mean ipsilateral and contralateral submandibular glands doses (all, p < 0.001) and had a lower incidence of chronic xerostomia compared with non-IB-sparing RT patients (p = 0.006).

CONCLUSION

Our results demonstrated that IB-sparing RT is sufficiently safe and feasible for treating NPC. To reduce the occurrence of xerostomia, IB-sparing RT should be considered without compromising target coverage.

Radiotherapy: Brightness and darkness in the era of immunotherapy

The introduction of immunotherapy into cancer treatment has radically changed clinical management of tumors. However, only a minority of patients (approximately 10 to 30%) exhibit long-term response to monotherapy with immunotherapy. Moreover, there are still many cancer types, including pancreatic cancer and glioma, which are resistant to immunotherapy. Due to the immunomodulatory effects of radiotherapy, the combination of radiotherapy and immunotherapy has achieved better therapeutic effects in a number of clinical trials. However, radiotherapy is a double-edged sword in the sense that it also attenuates the immune system under certain doses and fractionation schedules, not all clinical trials show improved survival in the combination of radiotherapy and immunotherapy. Therefore, elucidation of the interactions between radiotherapy and the immune system is warranted to optimize the synergistic effects of radiotherapy and immunotherapy. In this review, we highlight the dark side as well as bright side of radiotherapy on tumor immune microenvironment and immune system. We also elucidate current status of radioimmunotherapy, both in preclinical and clinical studies, and highlight that combination of radiotherapy and immunotherapy attenuates combinatorial effects in some circumstances. Moreover, we provide insights for better combination of radiotherapy and immunotherapy.

Level Ib sparing intensity-modulated radiation therapy in selected nasopharyngeal carcinoma patients based on the International Guideline

BACKGROUND AND PURPOSE

To investigate the feasibility of level Ib sparing in selected nasopharyngeal carcinoma (NPC) patients during intensity-modulated radiation therapy (IMRT) based on the International Guideline.

PATIENTS AND MATERIALS

Patients with histologically-proven NPC who received definitive IMRT at our group were candidates for this analysis. Other eligibility criteria for analysis were designed according to the recommendation of International Guideline for selective coverage of level Ib. Survival outcomes focused on regional recurrence-free survival (RRFS) and level Ib recurrence rate were analyzed.

RESULTS

A total of 450 patients were included, 60 of them received level Ib-covering IMRT due to the first three principles of the International Guideline according to our protocol. Of note, patients with level Ib involvement would receive ultrasound guided puncture, only those with positive pathological results would undergo level Ib-covering IMRT. For the remaining 390 patients who only fulfilled the last two criteria and/or level Ib involvement with negative pathological results, level Ib-sparing IMRT was delivered, with a median follow-up time of 112 months (range 6 to 194 months), reported 5- and 10-year RRFS were 95.4% and 92.9%, respectively. Twenty-two patients occurred regional recurrence at censorship (median 44.5 months), only 4(4/390, 1.03%) were recorded as level Ib recurrence.

CONCLUSION

Level Ib-sparing IMRT should be safe and feasible for patients who only had level II involvement with ECE, and/or had a MAD of greater than 2 cm in level II, and/or level Ib involvement with negative pathological results. Further well-designed multi-center prospective trials should be conducted.

Moving towards the Future of Radio-Immunotherapy: Could We “Tailor” the Abscopal Effect on Head and Neck Cancer Patients?

The abscopal effect (AbE) is defined as radiation-induced shrinkage of distant, non-treated, neoplastic lesions and it is considered the best clinical picture of the efficient immune stimulation by irradiation. The first report about abscopal tumor regression upon radiotherapy dates back to the beginning of the 20th century. The growing preclinical and clinical synergism between radiation and immunotherapy gave birth the purpose to more easily reproduce the abscopal effect, nevertheless, it is still rare in clinical practice. In this review we summarize immunological modulation of radiotherapy, focusing on the well-balanced equilibrium of tumor microenvironment and how radio-immunotherapy combinations can perturb it, with particular attention on head and neck squamous cell cancer. Finally, we investigate future perspectives, with the aim to “tailor” the abscopal effect to the patient.

The Chinese Society of Clinical Oncology (CSCO) clinical guidelines for the diagnosis and treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor originating in the nasopharynx and has a high incidence in Southeast Asia and North Africa. To develop these comprehensive guidelines for the diagnosis and management of NPC, the Chinese Society of Clinical Oncology (CSCO) arranged a multi‐disciplinary team comprising of experts from all sub‐specialties of NPC to write, discuss, and revise the guidelines. Based on the findings of evidence‐based medicine in China and abroad, domestic experts have iteratively developed these guidelines to provide proper management of NPC. Overall, the guidelines describe the screening, clinical and pathological diagnosis, staging and risk assessment, therapies, and follow‐up of NPC, which aim to improve the management of NPC.

Contemporary management of the neck in nasopharyngeal carcinoma

Up to 85% of the patients with nasopharyngeal carcinoma present with regional nodal metastasis. Although excellent nodal control is achieved with radiotherapy, a thorough understanding of the current TNM staging criteria and pattern of nodal spread is essential to optimize target delineation and minimize unnecessary irradiation to adjacent normal tissue. Selective nodal irradiation with sparing of the lower neck and submandibular region according to individual nodal risk is now emerging as the preferred treatment option. There has also been continual refinement in staging classification by incorporating relevant adverse nodal features. As for the uncommon occurrence of recurrent nodal metastasis after radiotherapy, surgery remains the standard of care.

Contralateral Lower Neck Sparing Radiotherapy in Stage N1 Nasopharyngeal Carcinoma: Long-Term Survival Outcomes and Late Toxicities

Purpose

To explore the feasibility of contralateral lower neck sparing radiotherapy for patients with stage N1 nasopharyngeal carcinoma (NPC) by analyzing long-term survival outcomes and late toxicities.

Methods

Data of patients with stage N1 NPC who were treated with contralateral lower neck sparing radiotherapy between January 2013 and December 2015 were analyzed. These patients were all staged by magnetic resonance imaging (MRI), and all received irradiation to the upper neck (levels II, III, and Va) bilaterally along with ipsilateral levels IV and Vb, without irradiation of the contralateral lower neck. Treatment outcomes, regional failure patterns, and late toxicities were examined.

Results

A total of 275 eligible patients with stage N1 NPC were included in the present study. The median follow-up period was 62 months (range, 3-93 months). The 5-year overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), locoregional recurrence-free survival (LRRFS), and progression-free survival (PFS) rates were 90.5, 91.3, 94.7, 95.3, 91.2, and 81.7%, respectively. A total of 13 patients (4.7%) developed regional recurrence, all of which occurred in the field and not out of the field. Among 254 patients with available data on late toxicities, the most common late toxicity was xerostomia. No late injuries occurred in the carotid arteries, brachial plexus, or spinal cord. In addition to one case (0.4%) of neck fibrosis and three cases (1.2%) of hearing loss, there were no other grade 3-4 late toxicities observed.

Conclusions

Contralateral lower neck sparing radiotherapy would be safe and feasible for patients with stage N1 NPC, with the potential to improve the long-term quality of life of patients.

Treatment Deescalation Strategies for Nasopharyngeal Cancer: A Review

IMPORTANCE

Since the advent of modern radiotherapy techniques and incorporation of systemic chemotherapy for nasopharyngeal cancer, locoregional control has been excellent. However, the rate of treatment-related complications, many of which are irreversible, remains high. New approaches are being explored to determine whether the toxic effects of treatment can be relieved while maintaining disease control. This review presents the current state of deescalation strategies for nasopharyngeal cancer.

OBSERVATIONS

A review of the literature shows that deescalation approaches can be generally categorized into deescalating systemic therapy vs deescalating radiotherapy. This review discusses studies that have explored sparing chemotherapy in selected patients with stage II cancer as well as altering the chemotherapy scheduling, dosing, and agent from the current standard of care, cisplatin. Deescalating radiotherapy has involved decreasing the dose and the treatment volume. In many cases, these approaches are being guided by measuring Epstein-Barr virus DNA levels, which is a robust biomarker for screening, treatment monitoring, and surveillance. Ongoing work with various imaging modalities, such as fluorodeoxyglucose positron emission tomography and dynamic contrast-enhanced or diffusion-weighted magnetic resonance imaging sequences, have shown promise as another biomarker to safely guide practitioners toward deescalation.

CONCLUSIONS AND RELEVANCE

Various strategies to deescalate treatment in nasopharyngeal cancer have been explored, and outcomes have remained excellent in most approaches. Patient selection remains key, and long-term outcomes and late complications are still to be determined. Continued investigation with prospective, multi-institutional studies are needed to better elucidate how treatment for nasopharyngeal carcinoma can best be individualized and deescalated.

[Individualization of dose and fractionation of radiotherapy for head and neck cancers]

Head and neck cancers comprise a variety of tumours depending on the sub-site, for which target volumes and the prescribed doses need to be individualized according to each patient's history and presentation. This article aims at describing the main factors involved in decision-making regarding dose and volume, as well as ongoing research. Contouring and treatment guidelines, use of altered fractionation, major prognostic factors, the role of Human papillomavirus and of functional imaging will be presented and discussed.

Risk factors and distribution features of level IB lymph nodes metastasis in nasopharyngeal carcinoma

OBJECTIVE

The objective of this study is to investigate the risk factors and distribution features for level IB metastasis in nasopharyngeal carcinoma (NPC) and provide clinical evidence for defining the indications and clinical target volume (CTV) of prophylactic level IB irradiation.

METHODS

We retrospectively analyzed 798 patients with newly-diagnosed, non-metastatic and histologically confirmed NPC underwent intensity-modulated radiation therapy (IMRT). Two sides of neck in each patient have been analyzed separately. The correlations of level IB metastasis and the clinical risk factors were analyzed with Chi-square test and logistic regression model. The risk score model (RSM) of level IB metastasis was calculated by totaling up the scores of each independent variable. We divided level IB into three areas, including anterolateral space of submandibular glands, medial space of the submandibular glands and submandibular glands.

RESULTS

Maximal axial diameter (MAD) of level IIA nodes >20mm or extra capsular spread (ES) of level IIA nodes, anterior half of nasal cavity involvement and submandibular gland involvement/compression were independently significantly risk factors for level IB lymph nodes (LNs) metastasis at diagnosis. Two groups based on RSM were obtained: low risk (total score=0-2.5); high risk (4-8.5). The incidence of IB LNs metastasis at diagnosis of the two groups were 0.9% and 6.3%, respectively (P<0.001). The cervical lymph nodes of level IB were distributed in the anterolateral space of submandibular glands. There was no positive/negative LNs inside or medial space of the submandibular glands.

CONCLUSION

Level IB LNs metastasis is associated with MAD of level IIA nodes >20mm or ES of level IIA nodes, anterior half of nasal cavity involvement and submandibular gland involvement/compression in NPC patients. Omission of level IB irradiation may be feasible for patients with low-risk IB LNs metastasis at diagnosis. The submandibular gland should not be included in level IB.

The feasibility analysis of omission of elective irradiation to level IB lymph nodes in low-risk nasopharyngeal carcinoma based on the 2013 updated consensus guideline for neck nodal levels

Background

Level IB metastasis is rare in nasopharyngeal carcinoma (NPC). The purpose of this study is to investigate the high-risk factors for level IB metastasis and evaluate the feasibility of omission of elective irradiation to level IB in the low-risk subgroups in NPC.

Methods

This retrospective study identified 532 patients with NPC treated by definitive radiation in our institution from 2009 to 2010. Level IB nodes were electively irradiated based on the physician’s decision. Diagnostic head and neck MRIs were reviewed. The involvements of nodal levels were evaluated according to 2013 updated guidelines of RTOG. The correlations of level IB metastasis and other factors were studied using Chi-square test and logistic regression model. Log-rank tests were used to compare survival rates. Cox proportional-hazards models were used to evaluate the effect of various factors. Patient-reported xerostomia was recoded in every follow-up and the extents of delayed xerostomia at 1 year post-radiation were compared between those with/without elective level IB irradiation.

Results

N stage, bilateral nodal metastasis, level II involvement, level IIA involvement, level IIA with multiple levels involvement, maximal axial diameter (MAD) of level IIA nodes > 20 mm, MAD of neck lymph nodes > 30 mm, necrosis of level IIA nodes, extracapsular spread of level IIA correlated with level IB metastasis by univariate analysis. In multivariate analysis (MVA), bilateral nodal involvement, MAD of level IIA nodes > 20 mm or extracapsular spread of level IIA nodes, were independent predictive factors for level IB metastasis. Patients without either these factors were denoted low-risk group and the rest high-risk group. Of the low-risk group, there was no significant difference of regional control and overall survival (OS) between those with or without elective irradiation. The percentage of level IB recurrence of those without elective irradiation was 0.46%. Elective level IB irradiation was not significant upon MVA both for regional control and OS. Of the high-risk group, elective level IB irradiation was marginal significant for regional control, but not for OS upon MVA. No regional recurrence located at level IB. Overall, omission of elective irradiation to level IB reduced the mean doses of submandibular glands, but did not improve patient-reported xerostomia.

Conclusion

For patients without high-risk factors of level IB metastasis, omission of elective level IB irradiation did not impair regional control and OS in NPC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-017-0869-x) contains supplementary material, which is available to authorized users.

Long-term Patterns of Regional Failure for Nasopharyngeal Carcinoma following Intensity-Modulated Radiation Therapy

Purpose: To analyze the long-term patterns of regional failure following intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC).

Methods: From January 2005 to December 2010, 275 non-metastatic NPC patients treated with IMRT were retrospectively enrolled. Patients staged as II (lymph nodes measuring 4 or more cm in diameter), III or IV also received chemotherapy. Failures were assessed as in-field or out-field relative to the pretreatment planning computed tomography data sets. Univariate and multivariate analyses were performed with Cox proportional hazards model to analyze the effect of various prognostic factors on regional failure-free survival (RFFS) and overall survival (OS).

Results: During a median follow-up of 71 months, the RFFS and OS rates were 94.3% and 83.9%, respectively. Seventeen patients developed regional failures, of which 16 were in-field; one patient showed an out-field failure in the parotid gland, and no recurrences were seen for level Ib. Failures in level II and in the retropharyngeal area accounted for 70.6% (12/17) and 52.9% (9/17) of all failures, respectively. The 5-year RFFS rates for patients with classifications of N0-1 and N2-3 were 98.5% and 90.2%, respectively (p = 0.001). Multivariate analysis showed that N stage was the only independent prognostic predictor of RFFS (HR 7.363, 95% CI 1.516-35.756, p = 0.013).

Conclusions: The regional failure of NPC after treatment with IMRT is uncommon but is significantly higher in N2-3 patients than in N0-1 patients. In-field failures represent the main pattern of regional recurrence and are most often detected in level II and in the retropharyngeal area, while out-field failure is rare. Close attention should be directed to NPC patients with advanced N stages.

Effects of omitting elective neck irradiation to nodal Level IB in nasopharyngeal carcinoma patients with negative Level IB lymph nodes treated by intensity-modulated radiotherapy: a Phase 2 study

OBJECTIVE

To investigate the need for elective neck irradiation (ENI) to nodal Level IB in patients with nasopharyngeal carcinoma (NPC) with negative Level IB lymph nodes (IB-negative) treated by intensity-modulated radiotherapy (IMRT).

METHODS

We conducted a Phase 2 prospective study in 123 newly diagnosed IB-negative patients with NPC treated by IMRT, who met at least 1 of the following criteria: (1) unilateral or bilateral Level II involvement with 1 of the following: Level IIA involvement or any Level II node ≥2 cm/with extracapsular spread; (2) ≥2 unilateral node-positive regions. Bilateral Level IB nodes were not contoured as part of the treatment target and treated electively. Level IB regional recurrence rate; pattern of treatment failure; 3-year overall survival (3y-OS), 3-year local control (3y-LC) and 3-year regional control (3y-RC) rates; toxicities; and dosimetric data for planning target volumes, organs at risk, Level IB and submandibular glands (SMGs) were evaluated.

RESULTS

Two patients developed failures at Level IB (1.6%). The 3y-LC, 3y-RC and 3y-OS rates were 93.5%, 93.5% and 78.0%, respectively. Bilateral Level IB received unplanned high-dose irradiation with a mean dose (Dmean) ≥50 Gy in 60% of patients. The average Dmean of bilateral SMGs was approximately 53 Gy.

CONCLUSION

ENI to Level IB may be unnecessary in IB-negative patients with NPC treated by IMRT. A further Phase 3 study is warranted.

ADVANCES IN KNOWLEDGE

Based on the results of this first Phase 2 study, we suggest omitting ENI to Level IB in Ib-negative patients with NPC with extensive nodal disease treated by IMRT.

Tumor Regression and Patterns of Distant Metastasis of T1-T2 Nasopharyngeal Carcinoma with Intensity-Modulated Radiotherapy

Purpose

To study tumor regression and failure patterns in T1-T2 non-metastatic nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy (IMRT).

Methods

A retrospective analysis of 139 nasopharyngeal carcinoma patients treated with IMRT between January 2005 and December 2010 in our center was performed. According to the AJCC staging system, all primary lesions were attributed to T1 and T2. The prescription doses were 66 Gy at 30 fractions to gross tumor volume of the nasopharynx and the positive neck nodes, 60 Gy to high-risk clinical target volume and 54 Gy to low-risk clinical target volume. Patients staged III, IV A/B or II (lymph node measured 4 cm or more in diameter) received platinum-based chemotherapy.

Results

By the end of radiotherapy, 7.2% (10/139), 23.7% (33/139), and 9.4% (13/139) of patients had residual lesions in the nasopharynx, cervical lymph nodes and retropharyngeal lymph nodes, respectively. The majority of patients had complete remission within 6 months of radiotherapy completion. Five months after IMRT, three patients with residual tumors in the cervical lymph nodes underwent surgery. Among these patients, two patients had positive pathological findings, and one patient had negative findings. With a median follow-up of 59 months, the 5-year overall survival, local control, regional control and distant metastasis-free rates were 87.8%, 96.7%, 94.9% and 89.1%, respectively. Fifteen patients developed distant metastases, representing the primary failure pattern.

Conclusions

Most residual lesions that persisted after IMRT vanished completely in six months. Considering the potential damage to normal structures, clinicians should be cautious when considering the use of boost irradiation after radiotherapy. Distant metastasis was the primary cause of treatment failure, which was significantly higher in N2-3 patients than in N0-1. Additional studies to better understand distant metastases are needed.

Investigation of the feasibility of elective irradiation to neck level Ib using intensity-modulated radiotherapy for patients with nasopharyngeal carcinoma: a retrospective analysis

BACKGROUND

To assess the feasibility of elective neck irradiation to level Ib in nasopharyngeal carcinoma (NPC) using intensity-modulated radiation therapy (IMRT).

METHODS

We retrospectively analyzed 1438 patients with newly-diagnosed, non-metastatic and biopsy-proven NPC treated with IMRT.

RESULTS

Greatest dimension of level IIa LNs (DLN-IIa) ≥ 20 mm and/or level IIa LNs with extracapsular spread (ES), oropharynx involvement and positive bilateral cervical lymph nodes (CLNs) were independently significantly associated with metastasis to level Ib LN at diagnosis. No recurrence at level Ib was observed in the 904 patients without these characteristics (median follow-up, 38.7 months; range, 1.3-57.8 months), these patients were classified as low risk. Level Ib irradiation was not an independent risk factor for locoregional failure-free survival, distant failure-free survival, failure-free survival or overall survival in low risk patients. The frequency of grade ≥ 2 subjective xerostomia at 12 months after radiotherapy was not significantly different between low risk patients who received level Ib-sparing, unilateral level Ib-covering or bilateral level Ib-covering IMRT.

CONCLUSION

Level Ib-sparing IMRT should be safe and feasible for patients without a DLN-IIa ≥ 20 mm and/or level IIa LNs with ES, positive bilateral CLNs or oropharynx involvement at diagnosis. Further investigations based on specific criteria for dose constraints for the submandibular glands are warranted to confirm the benefit of elective level Ib irradiation.