Effect of total dose and fraction size on survival of patients with locally recurrent nasopharyngeal carcinoma treated with intensity-modulated radiotherapy: a phase 2, single-center, randomized controlled trial

Unraveling the mechanism of Yiqi Jiedu formula against nasopharyngeal carcinoma: An investigation integrating network pharmacology, serum pharmacochemistry, and metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Yiqi Jiedu formula (YQJDF), rooted in the traditional Chinese medicinal principle of "tonifying qi and detoxifying", is remarkably efficacious in the clinical treatment of nasopharyngeal carcinoma (NPC). Previous studies have shed light on some of its anti-NPC effects and mechanisms, but the responsible pharmacological substances and their precise mechanisms of action remain unclear.

AIM OF THE STUDY

The purpose of this study was to identify components of YQJDF that entered the bloodstream and to investigate their mechanisms of action against NPC through network pharmacology and serum metabolomics.

MATERIAL AND METHODS

Components of YQJDF in serum were identified using liquid chromatography-tandem mass spectrometry. With these serum species as the focus of our research, network pharmacology analysis was used to identify active compounds and target genes that might mediate the efficacy of YQJDF in the treatment of NPC. Following establishment of an NPC xenograft model in nude mice, a non-targeted metabolomics approach was adopted to identify significant serum metabolites and metabolic pathways influenced by YQJDF.

RESULTS

Thirty-six components of YQJDF were identified, primarily consisting of alkaloids, phenylpropanoids, and flavonoids. Notably, pathways such as PI3K/AKT, factors associated with Epstein-Barr virus infection, IL-17 signaling, and lipid metabolism, were highlighted as potential therapeutic targets of YQJDF during NPC treatment. Additionally, our findings suggested that YQJDF modified the metabolism of arginine and proline in the serum of mice bearing nasopharyngeal tumor grafts.

CONCLUSIONS

This study identified the primary active components of YQJDF, highlighting its holistic role in the treatment of NPC through multiple targets and pathways. Furthermore, our findings provided a roadmap for future research into the mechanism of YQJDF in the therapy of NPC, setting the stage for its clinical application.

Reirradiation of head and neck squamous cell carcinomas: a pragmatic approach-part I: prognostic factors and indications to treatment

INTRODUCTION

Reirradiation (reRT) of locally recurrent/second primary tumors of the head and neck region is a potentially curative treatment for patients not candidate to salvage surgery. Aim of the present study is to summarize available literature on both prognostic factors and indications to curative reRT in this clinical setting.

MATERIALS AND METHODS

A narrative review of the literature was performed on two topics: (1) patients' selection according to prognostic factors and (2) dosimetric feasibility of reRT. Postoperative reRT and palliative intent treatments were out of the scope of this work.

RESULTS

Patient-tumor and treatment-related prognostic factors were analyzed, together with dosimetric parameters concerning target volume and organs at risk. Based on available evidence, a stepwise approach has been proposed aiming to provide a useful tool to identify suitable candidates for curative reRT in clinical practice. This was then applied to two clinical cases, proposed at the end of this work.

CONCLUSION

A second course of RT in head and neck recurrence/second primary tumors is a personalized approach that can be offered to selected patients only in centers with expertise and dedicated equipment following a multidisciplinary team discussion.

Endoscopic surgery versus intensity-modulated radiotherapy in locally advanced recurrent nasopharyngeal carcinoma: a multicenter, case-matched comparison

BACKGROUND

The management of locally advanced recurrent nasopharyngeal carcinoma (rNPC) is challenging. The objective of our study was to compare salvage endoscopic nasopharyngectomy (ENPG) with intensity-modulated radiotherapy (IMRT) in clinical outcomes and complications of locally advanced rNPC.

METHODS

Patients with histologically confirmed rNPC in rT3-4N0-3M0 stages were retrospectively enrolled between January 2013 and December 2019 in this multicenter, case-matched study. The baseline clinicopathological characteristics of patients were balanced by propensity score matching between the ENPG and IMRT groups. ENPG was performed in patients with easily or potentially resectable tumors. The oncological outcomes as well as treatment-related complications were compared between two groups.

RESULTS

A total of 176 patients were enrolled and 106 patients were matched. The ENPG group (n = 53) and the IMRT group (n = 53) showed comparable outcomes in the 3-year overall survival rate (68.4% vs. 65.4%, P = 0.401), cancer-specific survival rate (80.9% vs. 74.4%, P = 0.076), locoregional failure-free survival rate (36.6% vs. 45.3%, P = 0.076), and progression-free survival rate (27.5% vs. 32.3%, P = 0.216). The incidence of severe treatment-related complications of patients in the ENPG group was lower than that in the IMRT group (37.7% vs. 67.9%, P = 0.002). The most common complications were post perioperative hemorrhage (13.2%) in ENPG group and temporal lobe necrosis (47.2%) in IMRT group, respectively.

CONCLUSION

Salvage ENPG exhibits comparable efficacy but less toxicities than IMRT in carefully screened patients with locally advanced rNPC, which may be a new choice of local treatment.

Hypofractionated radiotherapy compared with conventionally fractionated radiotherapy to treat initial distant metastases in nasopharyngeal carcinoma: A multicenter, prospective, randomized, phase II trial

BACKGROUND AND PURPOSE

To investigate the safety and efficacy of hypofractionated plus chemotherapy in patients with initially distant metastatic nasopharyngeal carcinoma (mNPC).

MATERIALS AND METHODS

Between May 2014 and June 2020, 35 patients initially diagnosed with mNPC were enrolled on prospective trial. The enrolled patients were assigned randomly to receive either hypofractionated plus chemotherapy (HFRT) or conventionally fractionated radiotherapy plus chemotherapy (CFRT). 60 Gy over 25 fractions was administered to the HFRT group (n = 17) and 69.96 Gy over 33 fractions was administered to the CFRT group (n = 18), both groups five times each week.Progression free survival (PFS) comprised the primary endpoint. Overall survival (OS), locoregional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS), and acute and late toxicity comprised the secondary endpoints.

RESULTS

Twenty-eight patients (seven were excluded) were enrolled. The 2-year PFS was 33.3% (HFRT group) versus 30.0% (CFRT group) (stratified hazard ratio (HR):1.09; 95% confidence interval (CI): 0.45-2.65, P = 0.843). The 2-year OS was 66.7% (HFRT group) versus with 62.5% (CFRT group) (stratified HR, 0.88; 95% CI; 0.31-2.51, P = 0.806). All patients experienced acute grade 1 or 2, skin toxicity, oral mucositis, difficulty swallowing, xerostomia, but no acute grade 3 or 4 toxicities. All patients had grade 1 late xerostomia. Two patients experienced hearing loss in the HFRT group (one grade 1 and one grade 3), and three patients experienced grade 1 hearing loss in the CFRT group. One patient developed mucosal necrosis in the HFRT group.

CONCLUSION

Improving the balance between severe late toxicities and local control by appropriately reducing the total dose but increasing the fractionated dose has marked clinical significance for those patients.

Prospective randomized clinical studies involving reirradiation: update of a systematic review

BACKGROUND

Reirradiation is a potentially useful option for many patients with recurrent cancer, aiming at cure or symptom palliation, depending on disease/recurrence type and stage. The purpose of this follow-up study to a previous review from 2016 was to summarize all recently published randomized trials. Points of interest again included identifcation of methodological strengths and weaknesses, practice-changing results, and open questions.

MATERIAL AND METHODS

Systematic review of trials published between 2015 and February 2023.

RESULTS

We reviewed 7 additional trials, most of which addressed reirradiation of head and neck or brain tumours. The median number of patients was 60. Mirroring the previous review, trial design, primary endpoints and statistical hypotheses varied widely. The updated results only impact on decision making for reirradiation of nasopharynx cancer and glioma. Patients with one of these diseases, as well as other head and neck cancers, may benefit from reirradiation-induced local control, e.g. in terms of progression-free survival. For the first time, hyperfractionated radiotherapy emerged as preferred option for recurrent, inoperable nasopharynx cancer. Despite better therapeutic ratio with hyperfractionation, serious toxicity remains a concern after high cumulative total doses. Randomized trials are still lacking for prostate cancer and other sites.

CONCLUSION

Multicentric randomized trials on reirradiation are feasible and continue to refine the current standard of care for recurrent disease after previous radiotherapy. Ongoing prospective studies such as the European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer (ESTRO-EORTC) observational cohort ReCare (NCT: NCT03818503) will further shape the clinical practice of reirradiation.

Robotic stereotactic body radiotherapy for recurrent nasopharyngeal carcinoma

Background

We aimed to evaluate the outcomes of patients reirradiated with stereotactic body radiotherapy for recurrent nasopharyngeal carcinoma (r-NPC) in our hospital.

Methods

We retrospectively analyzed 10 patients with r-NPC previously irradiated with definitive radiotherapy. Local recurrences were irradiated with a dose of 25 to 50 Gy (median: 26.25 Gy) in 3 to 5 fractions (fr) (median: 5 fr). The survival outcomes calculated from the time of recurrence diagnosis were obtained using Kaplan-Meier analysis and compared with the log-rank test. Toxicities were assessed by using Common Terminology Criteria for Adverse Events Version 5.0.

Results

The median age was 55 years (37-79 years), and nine patients were men. The median follow-up was 26 months (3-65 months) after reirradiation. The median overall survival (OS) was 40 months, OS in 1 and 3 years were 80% and 57%, respectively. OS rate of rT4 (n = 5, 50%) was worse compared with rT1, rT2, and rT3 (P = 0.040). In addition, those with less than 24 months of interval between first treatment and recurrence had worse OS (P = 0.017). One patient exhibited Grade 3 toxicity. There is no other Grade ≥3 acute or late toxicities.

Conclusion

In r-NPC, reirradiation is inevitable for patients who are not suitable for radical surgical resection. However, serious complications and side effects prevent dose escalation due to the critical structures previously irradiated. Prospective studies with a large number of patients are required to find the optimal acceptable dose.

Identifying the prognostic value of MRI-based tumor response and predicting the risk of radio-resistance in re-radiotherapy for locally recurrent nasopharyngeal carcinoma

OBJECTIVE

To investigate the prognostic value of tumor response (TR) for locoregionally recurrent nasopharyngeal carcinoma (lrNPC) patients at the end of re-radiotherapy (re-RT) and develop a risk score model to predict patient's radiosensitivity to re-RT.

MATERIALS AND METHODS

A total of 594 patients with lrNPC from 2010 to 2020 were retrospectively reviewed as the total cohort. Among these, 310 patients with complete first-line treatment data were reviewed as a secondary cohort. Overall survival (OS) was the primary endpoint. Locoregional control (LRC) was the secondary endpoint. Multivariate Cox analysis was performed to investigate the prognostic value of TR at the end of re-RT (rTR). A risk score model for predicting rTR was obtained by logistic regression analysis, and its effectiveness was compared using receiver operating characteristic (ROC) analysis.

RESULTS

Patients with complete response (CR) to rTR had higher 5-year OS and LRC rate than non-CR patients in both the total and secondary cohort. rTR was an independent prognostic factor for OS (P=0.002) and LRC (P=0.008). We developed a risk score model including four significant risk factors (relapse T stage, relapse gross tumor volume, time to recurrence, and initial TR). The area under the curve of the risk score model was 0.73 (95% CI: 0.678 to 0.780), which was significantly higher than that of each variable alone. Patients with the highest risk scores may be insensitive to re-RT and had a residual tumor risk of 89.9% after rRT.

CONCLUSION

rTR was an independent prognostic factor for OS and LRC in lrNPC patients. We developed a risk score model for predicting patients' sensitivity to re-RT to screen for radiosensitive patients. This can serve as a treatment decision-making tool for clinicians.

Hyperfractionation compared with standard fractionation in intensity-modulated radiotherapy for patients with locally advanced recurrent nasopharyngeal carcinoma: a multicentre, randomised, open-label, phase 3 trial

BACKGROUND

Reirradiation in standard fractionation for locally advanced recurrent nasopharyngeal carcinoma after a previous course of high-dose radiotherapy is often associated with substantial late toxicity, negating its overall benefit. We therefore aimed to investigate the efficacy and safety of hyperfractionation compared with standard fractionation in intensity-modulated radiotherapy.

METHODS

This multicentre, randomised, open-label, phase 3 trial was done in three centres in Guangzhou, China. Eligible patients were aged 18-65 years with histopathologically confirmed undifferentiated or differentiated, non-keratinising, advanced locally recurrent nasopharyngeal carcinoma. Participants were randomly assigned (1:1) to either receive hyperfractionation (65 Gy in 54 fractions, given twice daily with an interfractional time interval of at least 6 h) or standard fractionation (60 Gy in 27 fractions, given once a day). Intensity-modulated radiotherapy was used in both groups. A computer program generated the assignment sequence and randomisation was stratified by treatment centre, recurrent tumour stage (T2-T3 vs T4), and recurrent nodal stage (N0 vs N1-N2), determined at the time of randomisation. The two primary endpoints were the incidence of severe late complications defined as the incidence of grade 3 or worse late radiation-induced complications occurring 3 months after the completion of radiotherapy until the latest follow-up in the safety population, and overall survival defined as the time interval from randomisation to death due to any cause in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02456506.

FINDINGS

Between July 10, 2015, and Dec 23, 2019, 178 patients were screened for eligibility, 144 of whom were enrolled and randomly assigned to hyperfractionation or standard fractionation (n=72 in each group). 35 (24%) participants were women and 109 (76%) were men. After a median follow-up of 45·0 months (IQR 37·3-53·3), there was a significantly lower incidence of grade 3 or worse late radiation-induced toxicity in the hyperfractionation group (23 [34%] of 68 patients) versus the standard fractionation group (39 [57%] of 68 patients; between-group difference -23% [95% CI -39 to -7]; p=0·023). Patients in the hyperfractionation group had better 3-year overall survival than those in the standard fractionation group (74·6% [95% CI 64·4 to 84·8] vs 55·0% [43·4 to 66·6]; hazard ratio for death 0·54 [95% CI 0·33 to 0·88]; p=0·014). There were fewer grade 5 late complications in the hyperfractionation group (five [7%] nasal haemorrhage) than in the standard fractionation group (16 [24%], including two [3%] nasopharyngeal necrosis, 11 [16%] nasal haemorrhage, and three [4%] temporal lobe necrosis).

INTERPRETATION

Hyperfractionated intensity-modulated radiotherapy could significantly decrease the rate of severe late complications and improve overall survival among patients with locally advanced recurrent nasopharyngeal carcinoma. Our findings suggest that hyperfractionated intensity-modulated radiotherapy could be used as the standard of care for these patients.

FUNDING

Key-Area Research and Development of Guangdong Province, the National Natural Science Foundation of China, the Special Support Program for High-level Talents in Sun Yat-sen University Cancer Center, the Guangzhou Science and Technology Plan Project, and the National Ten Thousand Talents Program Science and Technology Innovation Leading Talents, Sun Yat-Sen University Clinical Research 5010 Program.

Reirradiation for local recurrence of oral, pharyngeal, and laryngeal cancers: a multi-institutional study

This study aimed to examine the efficacy and toxicity of reirradiation in patients with locally recurrent oral, pharyngeal, and laryngeal cancers. We conducted a retrospective, multi-institutional analysis of 129 patients with previously irradiated cancer. The most frequent primary sites were the nasopharynx (43.4%), oral cavity (24.8%), and oropharynx (18.6%). With a median follow-up duration of 10.6 months, the median overall survival was 14.4 months and the 2-year overall survival rate was 40.6%. For each primary site, the 2-year overall survival rates were 32.1%, 34.6%, 30%, 60.8%, and 5.7% for the hypopharynx, oral cavity, larynx, nasopharynx, and oropharynx, respectively. Prognostic factors for overall survival were primary site (nasopharynx versus other sites) and gross tumor volume (GTV) (≤ 25 cm³ versus > 25 cm³). The 2-year local control rate was 41.2%. Twenty-four patients (18.6%) presented with grade ≥ 3 toxicities, including nine with hemorrhages that led to grade 5 toxicities in seven patients. All nine tumors that caused hemorrhage showed tumor encasement of the carotid ≥ 180 degrees and eight of nine tumors had larger GTV > 25 cm³. Reirradiation is a feasible treatment option for small local recurrence of oral, pharyngeal, and laryngeal cancers, with the requirement of a strict eligibility assessment for large tumors with carotid encasement.

Efficacy and safety of PLDR-IMRT for the re-irradiation of recurrent NPC: A prospective, single-arm, multicenter trial

Salvage treatment of locoregionally recurrent nasopharyngeal carcinoma (NPC) requires weighing the benefits of re-irradiation against increased risks of toxicity. Here, we evaluated the outcomes of patients treated with intensity-modulated-based pulsed low-dose-rate radiotherapy (PLDR-IMRT) to enhance the curative effect of salvage treatment and reduce RT-related SAEs. A prospective clinical trial was conducted from March 2018 to March 2020 at multiple institutions. NPC patients who experienced relapse after radical therapy were re-irradiated with a median dose of 60 Gy (50.4-70 Gy)/30 f (28-35 f) using PLDR-IMRT. Thirty-six NPC patients who underwent PLDR-IMRT for locoregional recurrence were identified. With a median follow-up of 26.2 months, the objective response rate (ORR) of the entire cohort was 91.6%. The estimated mPFS duration was 28 months (95% CI: 24.9-31.1), and the estimated mLRFS duration was 30.4 months (95% CI: 25.2-35.5). The overall survival (OS) rate for all patients was 80.6%, the progression-free survival (PFS) rate was 75% and the cancer-specific survival (CSS) rate was 88.9% at 1 year. The LRFS and DMFS rates were 88.9% and 91.7%, respectively, at 1 year. A combination of systematic therapies could provide survival benefits to patients who experience NPC relapse (p < 0.05), and a Karnofsky performance status (KPS) score of ≥90 was a favorable factor for local control (p < 0.05). The incidence of acute SAEs (grade 3+) from PLDR was 22.2%, and the incidence of chronic SAEs was 19.4% among all patients. PLDR-IMRT combined with systematic therapy can effectively treat patients with locoregionally recurrent nasopharyngeal carcinoma and causes fewer adverse events than the rates expected with IMRT.

Salvage treatments for locally recurrent nasopharyngeal cancer: Systematic review and meta-analysis

The present study aimed to evaluate the effectiveness and safety of various salvage treatments to treat locally recurrent nasopharyngeal carcinoma (IrNPC). A comprehensive search was conducted to gather relevant research publications on salvage treatment for IrNPC. Specifically, 2-, 3-, and 5-year overall survival were the primary outcome. A total of 89 studies with 101 cohorts were collected. Endoscopic nasopharyngectomy was found to be associated with a significantly improved 5-year OS compared with CRT (p = 0.027) and IMRT (p = 0.016). Moreover, based on recurrence T classification, the 2-, 3-, and 5-year OS were similar across different treatments. Endoscopic nasopharyngectomy was associated with a significant reduction in treatment-related complications (grade ≥ 3) compared with IMRT (p < 0.001) and open nasopharyngectomy (p = 0.028). Endoscopic nasopharyngectomy may provide comparable treatment outcomes to re-irradiation, while offering a better safety profile for selective patients with resectable IrNPC.

Ways to unravel the clinical potential of carbon ions for head and neck cancer reirradiation: dosimetric comparison and local failure pattern analysis as part of the prospective randomized CARE trial

Background

Carbon ion radiotherapy (CIRT) yields biophysical advantages compared to photons but randomized studies for the reirradiation setting are pending. The aim of the current project was to evaluate potential clinical benefits and drawbacks of CIRT compared to volumetric modulated arc therapy (VMAT) in recurrent head and neck cancer.

Methods

Dose-volume parameters and local failure patterns of CIRT compared to VMAT were evaluate in 16 patients from the randomized CARE trial on head and neck cancer reirradiation.

Results

Despite an increased target dose, CIRT resulted in significantly reduced organ at risk (OAR) dose across all patients (− 8.7% Dmean). The dose-volume benefits were most pronounced in the brainstem (− 20.7% Dmax) and the optic chiasma (− 13.0% Dmax). The most frequent local failure was type E (extraneous; 50%), followed type B (peripheral; 33%) and type A (central; 17%). In one patient with type A biological and/or dosimetric failure after CIRT, mMKM dose recalculation revealed reduced target coverage.

Conclusions

CIRT resulted in highly improved critical OAR sparing compared to VMAT across all head and neck cancer reirradiation scenarios despite an increased prescription dose. Local failure pattern analysis revealed further potential CIRT specific clinical benefits and potential pitfalls with regard to image-guidance and biological dose-optimization.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-022-02093-4.

Retreatment of Recurrent or Second Primary Head and Neck Cancer After Prior Radiation: Executive Summary of the American Radium Society® (ARS) Appropriate Use Criteria (AUC): Expert Panel on Radiation Oncology - Head and Neck Cancer

BACKGROUND

Re-treatment of recurrent or second primary head and neck cancers occurring in a previously irradiated field is complex. Few guidelines exist to support practice.

METHODS

We performed an updated literature search of peer-reviewed journals in a systematic fashion. Search terms, key questions, and associated clinical case variants were formed by panel consensus. The literature search informed the committee during a blinded vote on the appropriateness of treatment options via the modified Delphi method.

RESULTS

The final number of citations retained for review was 274. These informed five key questions, which focused on patient selection, adjuvant re-irradiation, definitive re-irradiation, stereotactic body radiation (SBRT), and re-irradiation to treat non-squamous cancer. Results of the consensus voting are presented along with discussion of the most current evidence.

CONCLUSIONS

This provides updated evidence-based recommendations and guidelines for the re-treatment of recurrent or second primary cancer of the head and neck.

Outcomes of Recurrent Nasopharyngeal Carcinoma Patients Treated With Salvage Surgery: A Meta-Analysis

Objective

To assess the efficacy of treatment outcomes of salvage surgery for recurrent nasopharyngeal carcinoma (rNPC).

Methods

We conducted a detailed search of the literatures in biomedical databases published from January 1990 to December 2020. The main research features and results of interest were retrieved from the articles that met the selection criteria for meta-analysis.

Results

A total of 21 articles with 778 patients were included, 17 of which met the meta-analysis inclusion criteria. The pooled 2-year overall survival (OS), 5-year OS, and 2-year disease-free survival (DFS) were 71%, 50% and 61%, respectively. Subgroup analysis was conducted with postoperative adjuvant therapy. The pooled 2-year OS, 5-year OS and 2-year DFS of the postoperative adjuvant therapy group compared with the surgery alone group were 69% vs 72%, 44% vs 56%, and 77% vs 54%, respectively. Univariate and multivariate analyses were performed on 178 patients with detailed individual postoperative survival data in 10 articles. On multivariate analysis, recurrent T (RT) stage and adjuvant therapy were independent predictors of outcomes.

Conclusions

This meta-analysis indicated that recurrent NPC patients can obtain survival benefits from salvage surgery. Accurately assessing the RT stage of the tumor and choosing the appropriate surgical method are important to the success of the surgery. Although the prognostic factors influencing outcome have been studied, conclusive data on the survival benefits are still lacking. Random controlled trials (RCTs) to compare surgery alone and postoperative adjuvant therapy are needed in patients with positive margin status after salvage surgery.

A novel dosimetric metrics-based risk model to predict local recurrence in nasopharyngeal carcinoma patients treated with intensity-modulated radiation therapy

Background

To develop a risk model based on dosimetric metrics to predict local recurrence in nasopharyngeal carcinoma (NPC) patients treated with intensive modulated radiation therapy (IMRT).

Methods

493 consecutive patients were included, among whom 44 were with local recurrence. One-to-two propensity score matching (PSM) was used to balance variables between recurrent and non-recurrent groups. Dosimetric metrics were extracted, and critical dosimetric predictors of local recurrence were identified by Cox regression model. Moreover, recurrent sites and patterns were examined by transferring the recurrent tumor to the pretreatment planning computed tomography.

Results

After PSM, 44 recurrent and 88 non-recurrent patients were used for dosimetric analysis. The univariate analysis showed that eight dosimetric metrics and homogeneity index were significantly associated with local recurrence. The risk model integrating D₅ and D₉₅ achieved a C-index of 0.706 for predicting 3-year local recurrence free survival (LRFS). By grouping patients using median value of risk score, patients with risk score ˃ 0.885 had significantly lower 3-year LRFS (66.2% vs. 86.4%, p = 0.023). As for recurrent features, the proportion of relapse in nasopharynx cavity, clivus, and pterygopalatine fossa was 61.4%, 52.3%, and 40.9%, respectively; and in field, marginal, and outside field recurrence constituted 68.2%, 20.5% and 11.3% of total recurrence, respectively.

Conclusions

The current study developed a novel risk model that could effectively predict the LRFS in NPC patients. Additionally, nasopharynx cavity, clivus, and pterygopalatine fossa were common recurrent sites and in field recurrence remained the major failure pattern of NPC in the IMRT era.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01911-5.

Dosimetric comparison of intensity modulated radiotherapy and intensity modulated proton therapy in the treatment of recurrent nasopharyngeal carcinoma

BACKGROUND AND PURPOSE

To compare the dosimetric performance of Intensity Modulated Proton Therapy (IMPT) and Intensity Modulated Radiotherapy (IMRT) in terms of target volume coverage and sparing of neurological organs-at-risk (OARs) in salvaging recurrent nasopharyngeal carcinoma (rNPC). The maximum dose to the internal carotid artery (ICA) and nasopharyngeal (NP) mucosa, which are associated with potential carotid blowout and massive epistaxis, were also evaluated.

MATERIALS AND METHODS

IMRT and IMPT treatment plans were created for twenty patients with locally advanced rNPC. Planning Target Volume (PTV) was used to account for the setup and spatial error/uncertainty in the IMRT planning. Robust optimization on Clinical Target Volume (CTV) coverage with consideration of range and setup uncertainty was employed to produce two IMPT plans with 3-field and 4-field arrangements. The planning objective was to deliver 60 Gy to the PTV (IMRT) and CTV (IMPT) without exceeding the maximum lifetime cumulative Biologically Effective Dose (BED) of the neurological OARs (applied to the Planning organs-at-risk volume). The target dose coverage as well as the maximum dose to the neurological OARs, ICA, and NP mucosa were compared.

RESULTS

Compared with IMRT, 3-field IMPT achieved better coverage to GTV V100% (83.3% vs. 73.2%, P <0.01) and CTV V100% (80.5% vs. 72.4%, P <0.01), and lower maximum dose to the critical OARs including the spinal cord (19.2 Gy vs. 22.3 Gy, P <0.01), brainstem (30.0 Gy vs. 32.3 Gy, P <0.01) and optic chiasm (6.6 Gy vs. 9.8 Gy, P <0.01). The additional beam with the 4-fields IMPT plans further improved the target coverage from the 3-field IMPT (CTV V98%: 85.3% vs. 82.4%, P <0.01) with similar OAR sparing. However, the target dose was highly non-uniform with both IMPT plans, leading to a significantly higher maximum dose to the ICA (∼68 Gy vs. 62.6 Gy, P <0.01) and NP mucosa (∼72 Gy vs. 62.8 Gy, P <0.01) than IMRT.

CONCLUSION

IMPT demonstrated some dosimetric advantage over IMRT in treating rNPC. However, IMPT could also result in very high dose hot spots in the target volume. Careful consideration of the ICA and NP mucosal complications is recommended when applying IMPT on rNPC patients.

Outcomes for the treatment of locoregional recurrent nasopharyngeal cancer: A systematic review and pooled analysis

Despite advances in the treatment of primary nasopharyngeal carcinoma, locoregional recurrence (lrNPC) occurs at 10%-50% at 5 years. This review aims to evaluate salvage treatment for locally recurrent nasopharyngeal cancer. A literature search for all original articles published on the treatment of lrNPC from January 1990 to January 2021 was conducted. Pooled analysis was performed using a random effects model and assessed statistical heterogeneity of the combined results with I² index. Overall, 66 studies were included for analysis. A total of 5286 patients treated with intensity-modulated radiation therapy (39%), conformal radiotherapy (31%), open nasopharyngectomy (12%), endoscopic nasopharyngectomy (10%), stereotactic radiosurgery (4%), and brachytherapy (4%) were included. Surgical therapy has similar overall survival outcomes to re-irradiation but with decreased treatment-related morbidity and mortality. Both surgical and re-irradiation for lrNPC have similar long-term survival. Surgical approaches to lrNPC may offer similar survival while avoiding treatment-associated morbidity and mortality.

International Recommendations on Reirradiation by Intensity Modulated Radiation Therapy for Locally Recurrent Nasopharyngeal Carcinoma

PURPOSE

Reirradiation for locally recurrent nasopharyngeal carcinoma (NPC) is challenging because prior radiation dose delivered in the first course is often close to the tolerance limit of surrounding normal structures. A delicate balance between achieving local salvage and minimizing treatment toxicities is needed. However, high-level evidence is lacking because available reports are mostly retrospective studies on small series of patients. Pragmatic consensus guidelines, based on an extensive literature search and the pooling of opinions by leading specialists, will provide a useful reference to assist decision-making for these difficult decisions.

METHODS AND MATERIALS

A thorough review of available literature on recurrent NPC was conducted. A set of questions and preliminary draft guideline was circulated to a panel of international specialists with extensive experience in this field for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the whole panel for review and reconsideration. The current guideline was based on majority voting after repeated iteration for final agreement.

RESULTS

The initial round of questions showed variations in clinical practice even among the specialists, reflecting the lack of high-quality supporting data and the difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of reirradiation (including patient selection, targets contouring, dose prescription, and constraints).

CONCLUSION

This paper provides useful reference on radical salvage treatment strategies for recurrent NPC and optimization of reirradiation through review of published evidence and consensus building. However, the final decision by the attending clinician must include full consideration of an individual patient's condition, understanding of the delicate balance between risk and benefits, and acceptance of risk of complications.

Re-irradiation with Moderate Hypo-Fractionation Using Intensity Modulated Photon or Proton Radiation Therapy in Locally Recurrent Squamous Cell Carcinoma of Nasopharynx

Purpose

This study aimed to analyze the treatment outcomes of locally recurrent nasopharyngeal cancer (NPC) patients following moderate hypo-fractionation re-irradiation (re-RT).

Materials and Methods

Sixty locally recurrent NPC patients underwent hypo-fractionation re-RT. 48.3% had rT3-4, and 30.0% did keratinizing squamous cell carcinoma. Intensity-modulated radiation therapy (IMRT), with or without intensity-modulated proton therapy (IMPT), was used in 66.7% of patients.

Results

With the median follow up of 22 (2~254) months, 31 patients (51.7%) died, 38 (63.3%) developed further treatment failure, and 30 (50.0%) developed ≥Grade 3 toxicity (including seven Grade 5) at time of analysis. The 2- and 5-year rates of overall survival, local failure-free survival, and ≥Grade 3 toxicity-free survival were 57.9% and 45.8%, 64.1% and 52.5%, and 54.8% and 44.9%, respectively. In multivariate analyses, worse factors for OS were iT3-4 (p=0.010) and age at re-RT ≥53 years (p=0.003), those for LFFS were rT3-4 (p=0.022) and rN0-1 (p=0.035), and those for TFS were iT3-4 (p=0.020) and rIMRT/IMPT (p=0.030), respectively. Cumulative dose or fraction size ≥3 Gy at re-RT, however, showed no significance for OS, LFFS and TFS.

Conclusion

Current re-RT with modern RT techniques by moderate hypo-fractionation scheme seemed feasible in treating locally recurrent NPC patients.

Development of a Comorbidity-Based Nomogram to Predict Survival After Salvage Reirradiation of Locally Recurrent Nasopharyngeal Carcinoma in the Intensity-Modulated Radiotherapy Era

Purpose

To assess the impact of comorbidity on treatment outcomes in patients with locally recurrent nasopharyngeal carcinoma (lrNPC) using intensity-modulated radiotherapy (IMRT) and to develop a nomogram that combines prognostic factors to predict clinical outcome and guide individual treatment.

Methods

This was a retrospective analysis of patients with lrNPC who were reirradiated with IMRT between 2003 and 2014. Comorbidity was evaluated by Adult Comorbidity Evaluation-27 grading (ACE-27). The significant prognostic factors (P < 0.05) by multivariate analysis using the Cox regression model were adopted into the nomogram model. Harrell concordance index (C-index) calibration curves were applied to assess this model.

Results

Between 2003 and 2014, 469 lrNPC patients treated in our institution were enrolled. Significant comorbidity (moderate or severe grade) was present in 17.1% of patients by ACE-27. Patients with no or mild comorbidity had a 5-year overall survival (OS) rate of 36.2 versus 20.0% among those with comorbidity of moderate or severe grade (P < 0.0001). The chemotherapy used was not significantly different in patients with lrNPC (P > 0.05). For the rT3-4 patients, the 5-year OS rate in the chemotherapy + radiation therapy (RT) group was 30.0 versus 16.7% for RT only (P = 0.005). The rT3-4 patients with no or mild comorbidity were associated with a higher 5-year OS rate in the chemotherapy + RT group than in the RT only group (32.1 and 17.1%, respectively; P=0.003). However, for the rT3-4 patients with a comorbidity (moderate or severe grade), the 5-year OS rate in the chemotherapy + RT group vs. RT alone was not significantly different (15.7 vs. 15.0%, respectively; p > 0.05). Eight independent prognostic factors identified from multivariable analysis were fitted into a nomogram, including comorbidity. The C-index of the nomogram was 0.715. The area under curves (AUCs) for the prediction of 1-, 3-, and 5-year overall survival were 0.770, 0.764, and 0.780, respectively.

Conclusion

Comorbidity is among eight important prognostic factors for patients undergoing reirradiation. We developed a nomogram for lrNPC patients to predict the probability of death after reirradiation and guide individualized management.

Recurrent Nasopharyngeal Cancer: Critical Review of Local Treatment Options Including Recommendations during the COVID-19 Pandemic

Simple Summary

Options for the curative treatment of locally recurrent nasopharyngeal carcinoma include surgery or re-irradiation. Both approaches have been scientifically explored, yet there is no consensus on the indication or definitive preference of the above two salvage treatments. The aim of this review is to summarize the current evidence on the local treatment of recurrent nasopharyngeal carcinoma. The feasibility, safety, and efficacy of salvage surgery and radical re-irradiation are discussed. Recommendations on treatment modifications during the coronavirus disease 2019 pandemic are included as well.

Abstract

Recurrent nasopharyngeal carcinoma represents an extremely challenging therapeutic situation. Given the vulnerability of the already pretreated neurological structures surrounding the nasopharynx, any potential salvage retreatment option bears a significant risk of severe complications that result in high treatment-related morbidity, quality of life deterioration, and even mortality. Yet, with careful patient selection, long-term survival may be achieved after local retreatment in a subgroup of patients with local or regional relapse of nasopharyngeal cancer. Early detection of the recurrence represents the key to therapeutic success, and in the case of early stage disease, several curative treatment options can be offered to the patient, albeit with minimal support in prospective clinical data. In this article, an up-to-date review of published evidence on modern surgical and radiation therapy treatment options is summarized, including currently recommended treatment modifications of both therapeutic approaches during the coronavirus disease 2019 pandemic.

Carotid blowout syndrome after reirradiation for head and neck malignancies: a comprehensive systematic review for a pragmatic multidisciplinary approach

AIM

To provide a literature review on risk factors and strategies to prevent acute carotid blowout (CBO) syndrome in patients who underwent reirradiation (reRT) for recurrent head and neck (HN) malignancies.

PATIENTS AND METHODS

Inclusion criteria were: 1) CBO following reRT in the HN region, 2) description on patient-, tumor- or treatment-related risk factors, 3) clinical or radiological signs of threatened or impending CBO, and 4) CBO prevention strategies.

RESULTS

Thirty-five studies were selected for the analysis from five hundred seventy-seven records. Results provided indications on clinical, radiological and dosimetric parameters possibly associated with higher risk of CBO. Endovascular procedures (artery occlusion and stenting) to prevent acute massive hemorrhage in high risk patients were discussed.

CONCLUSION

Literature data are still scarce with a low level of evidence. Nevertheless, the present work provides a comprehensive review useful for clinicians as a multidisciplinary pragmatic tool in their clinical practice.

Organs at risk's tolerance and dose limits for head and neck cancer re-irradiation: A literature review

Re-irradiation is becoming an established treatment option for recurrent or second primary head and neck cancer(HNC). However, acute and long-term RT-related toxicities could dramatically impact patients' quality of life. Due to the sparse literature regarding HNC re-irradiation, data on tolerance doses for various organs at risk (OARs) are scarce. Our aim was to systematically review the clinical literature regarding HNC re-irradiation, focusing on treatment toxicity, OARs tolerance, and dose limit recommendations. Thirty-nine studies (three randomized, five prospective, 31 retrospective) including 3766 patients were selected. The median interval time between the first course and re-irradiation was 28  months (range, 6-90). In 1043 (27.6%) patients, postoperative re-irradiation was performed. Re-irradiation doses ranged from 30 Gy in 3 fractions using stereotactic technique to 72 Gy in conventional fractionation using intensity-modulated radiotherapy. Pooled acute and late toxicityrates ≥G3 were 32% and 29.3%, respectively. The most common grade 3-4 toxic effects were radionecrosis, dysphagia requiring feeding tube placement and trismus. In 156 (4.1%) patients, carotid blowout was reported. Recommendations for limiting toxicity included the time interval between radiation treatments, the fractionation schedules, and the re-irradiation treatment volumes. Cumulative dose limit suggestions were found and discussed for the carotid arteries, temporal lobes, and mandible.

Management of locally recurrent nasopharyngeal carcinoma

As a consequence of the current excellent loco-regional control rates attained using the generally accepted treatment paradigms involving intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC), only 10-20% of patients will suffer from local and/or nodal recurrence after primary treatment. Early detection of recurrence is important as localized recurrent disease is still potentially salvageable, but this treatment often incurs a high risk of major toxicities. Due to the possibility of radio-resistance of tumors which persist or recur despite adequate prior irradiation and the limited tolerance of adjacent normal tissues to sustain further additional treatment, the management of local failures remains one of the greatest challenges in this disease. Both surgical approaches for radical resection and specialized re-irradiation modalities have been explored. Unfortunately, available data are based on retrospective studies, and the majority of them are based on a small number of patients or relatively short follow-up. In this article, we will review the different salvage treatment options and associated prognostic factors for each of them. We will also propose a treatment algorithm based on the latest available evidence and discuss the future directions of treatment for locally recurrent NPC.

Establishment of prognostic factors in recurrent nasopharyngeal carcinoma patients who received salvage intensity-modulated radiotherapy: A meta-analysis

Local recurrence remains a major cause of therapeutic failure in patients with nasopharyngeal carcinoma (NPC) and the effective treatment of recurrent NPC (r-NPC) is still a challenge. Intensity-modulated radiotherapy (IMRT) is considered as a favorable technique in the management of r-NPC, especially for extensive lesions. However, local r-NPC is a highly heterogeneous disease and the survival outcome following salvage IMRT varies. Furthermore, due to varied samples and therapeutic protocols, no consensus has been reached in the establishment of prognostic values. Hence, we used Medline and Embase electronic databases to conducted a meta-analysis to generate the best estimation of the prognostic factors in local r-NPC following salvage IMRT. Finally, a total of 783 patients in seven studies were enrolled. Overall, the pooled HR for OS of recurrent T stage and recurrent tumor volume was 1.77 (95% CI = 1.15-2.39) and 2.12 (95% CI = 1.42-2.82), without any heterogeneity. In addition, despite a significant association was observed in the pooled HR of significant compliance for OS, however, significant heterogeneity was also observed (I² = 76.6%, p = 0.039). Furthermore, no significant association was observed among the pooled HRs for OS in terms of age, gender, recurrent time interval, synchronous nodal recurrence, chemotherapy and total re-irradiation dose. Therefore, the present meta-analysis demonstrated that recurrent T stage and tumor volume may serve as the prognostic factors for OS in patients with r-NPC who received salvage IMRT. The other factors such as age, gender, and optimal re-irradiation dose warranted further investigation.

The challenge in treating locally recurrent T3-4 nasopharyngeal carcinoma: the survival benefit and severe late toxicities of re-irradiation with intensity-modulated radiotherapy

Background

Effective treatments for patients with advanced locally recurrent nasopharyngeal carcinoma (NPC) are limited. This investigation was to determine the potential benefits from re-irradiation by intensity-modulated radiotherapy (IMRT) on survival and the effects of severe late toxicities.

Methods

A retrospective study was conducted in 245 patients diagnosed with locally recurrent T3–T4 NPC who had undergone re-irradiation with IMRT. Follow-up data was colleted and factors associated with survival and severe late toxicities were analyzed.

Results

The 5-year local-regional failure-free survival, distant failure-free survival and overall survival rates were 60.9%, 78.3% and 27.5%, respectively. The presence of severe late complications, recurrent T4 disease and gross tumor volume >30 cm³ were associated with poor survival. The incidences of mucosal necrosis, temporal lobe necrosis, cranial neuropathy and trismus were 22.0%, 14.6%, 27.0% and 14.6% respectively. Conclusions: Re-irradiation with IMRT is an effective choice in patients with locally recurrent T3–T4 NPC. However, the survival benefits can be partly offset by severe late complications and optimum treatments in these patients remain a challenge.

Prognostic Model for Stratification of Radioresistant Nasopharynx Carcinoma to Curative Salvage Radiotherapy

Purpose

To investigate for a prognostic index (PI) to personalize recommendations for salvage intensity-modulated radiotherapy (IMRT) in patients with locally recurrent nasopharyngeal carcinoma (lrNPC).

Methods

Patients with lrNPC from two academic institutions (Sun Yat-Sen University Cancer Center [SYSUCC-A; n = 251 (training cohort)] and National Cancer Centre Singapore [NCCS; n = 114] and SYSUCC-B [n = 193 (validation cohorts)]) underwent salvage treatment with IMRT from 2001 to 2015. Primary and secondary clinical end points were overall survival (OS) and grade 5 toxicity-free rate (G5-TFR), respectively. Covariate inclusion to the PIs was qualified by a multivariable two-sided P < .05. Discrimination and calibration of the PIs were assessed.

Results

The primary PI comprised covariates that were adversely associated with OS in the training cohort (gross tumor volumerecurrence hazard ratio [HR], 1.01/mL increase [ P < .001], agerecurrence HR, 1.02/year increase [ P = .008]; repeat IMRT equivalent dose in 2-Gy fractions [EQD2] ≥ 68 Gy HR, 1.42 [ P = .03]; prior radiotherapy-induced grade ≥ 3 toxicities HR, 1.90 [ P = .001]; recurrent tumor [rT]-category 3 to 4 HR, 1.96 [ P = .005]), in ascending order of weight. Discrimination of the PI for OS was comparable between training and both validation cohorts (Harrell’s C = 0.71 [SYSUCC-A], 0.72 [NCCS], and 0.69 [SYSUCC-B]); discretization by using a fixed PI score cutoff of 252 determined from the training data set yielded low- and high-risk subgroups with disparate OS in the validation cohorts (NCCS HR, 3.09 [95% CI, 1.95 to 4.89]; SYSUCC-B HR, 3.80 [95% CI, 2.55 to 5.66]). Our five-factor PI predicted OS and G5-TFR (predicted v observed 36-month OS and G5-TFR, 22% v 15% and 38% v 44% for high-risk NCCS and 26% v 31% and 45% v 46% for high-risk SYSUCC-B).

Conclusion

We present a validated PI for robust clinical stratification of radioresistant NPC. Low-risk patients represent ideal candidates for curative repeat IMRT, whereas novel clinical trials are needed in the unfavorable high-risk subgroup.

Second re-irradiation: a narrative review of the available clinical data

BACKGROUND

Considerable controversy exists about the safety and efficacy of second re-irradiations (three courses of radiotherapy to overlapping volumes). Therefore, all published clinical studies were reviewed.

MATERIAL AND METHODS

Contemporary and historical articles were identified. Outcomes such as survival, local control, symptom improvement and side effects were extracted. Contemporary results were grouped by anatomical location of the re-irradiated region in the body.

RESULTS

Most data were derived from central nervous system tumors, pelvic tumors and bone metastases. We could include nine contemporary, retrospective studies with 2-25 patients each. Nearly, all patients were treated with palliative intent. Most of the prescribed re-irradiation regimens were highly individualized and thus difficult to compare. Symptomatic responses were recorded in most patients. In palliatively treated patients with pelvic and bony target volumes, high-grade toxicity was uncommon.

CONCLUSIONS

Despite of issues related to study size, length of follow-up and calculation of lifetime cumulative equivalent dose, the available data provide an initial framework for future studies and discussion of dose constraints. Selected dose-fractionation regimens may result in a satisfactory therapeutic ratio even after two previous courses of radiotherapy, if these were well tolerated.

Prospective, Multicenter, Phase 2 Trial of Induction Chemotherapy Followed by Bio-Chemoradiotherapy for Locally Advanced Recurrent Nasopharyngeal Carcinoma

PURPOSE

To evaluate, in a phase 2 study, whether induction docetaxel, cisplatin, and fluorouracil (TPF) followed by weekly docetaxel and cetuximab in concurrence with intensity modulated radiation therapy can improve the treatment outcome for patients with advanced locally recurrent nasopharyngeal carcinoma (rNPC).

METHODS AND MATERIALS

Thirty-three patients with rNPC (T3-T4, N0-N1, M0) were recruited. Of these, 19 patients (57.6%) had stage rT3 recurrence, and the rest had stage rT4. Eight patients also had rN1 at the time of relapse. Treatment outcomes and safety were evaluated.

RESULTS

Among these 33 patients, 1 died after 1 cycle of TPF, 5 patients withdrew from the study during the induction period because of grade ≥3 toxicities; 27 patients completed the whole course of treatment, but 1 died before any assessment could be made. The median follow-up period was 28.5 months. The progression-free survival and overall survival at 3 years for the whole group were 35.7% and 63.8%, respectively. Among the 26 patients who could be assessed after treatment, the complete response rate was 30.8%, and the locoregional control rate at 3 years was 49.2%. Temporal lobe necrosis (TLN) developed in 8 cases. The rates of grade ≥3 hearing loss, soft tissue necrosis, dysphagia, and trismus were 30.8%, 15.4%, 11.5%, and 19.2%, respectively. Overall, 5 patients died owing to acute (1 after cycle 1 TPF and 1 after completion of bio-chemoradiotherapy) or late (2 epistaxis and 1 TLN) treatment-related complications.

CONCLUSIONS

The proposed salvage treatment regimen for advanced locally recurrent NPC could achieve a better treatment outcome than seen in previous studies. However, poor tolerability of induction TPF and the high rate of TLN limit its applicability outside clinical trials.

Long-term outcomes after reirradiation in nasopharyngeal carcinoma with intensity-modulated radiotherapy: A meta-analysis

BACKGROUND

The purpose of this clinical review was to summate the published data for the long-term outcomes of reirradiation with intensity-modulated radiotherapy (IMRT) for locally recurrent nasopharyngeal carcinoma (NPC).

METHODS

We searched biomedical literature databases for eligible studies published from January 2005 to September 2016. Outcomes of interests were 5-year local failure-free survival, distant failure-free survival, overall survival (OS), and toxicities. Meta-analysis was performed using a random effects model.

RESULTS

We found 4 comparative and 8 noncomparative studies (n = 1768). Reirradiation was associated with pooled event rates of 72% (95% confidence interval [CI] 66%-78%; I²  = 84%), 85% (95% CI 82%-88%; I²  = 69%), and 41% (95% CI 36%-47%; I²  = 80%) for 5-year local failure-free survival, distant failure-free survival, and OS, respectively, with significant heterogeneity among the study results. The pooled event rate for grade 5 toxicities was 33% (95% CI 30%-35%; I²  = 0%) with minimal heterogeneity.

CONCLUSION

Reirradiation with IMRT for locally recurrent NPC could confer long-term disease control and survival but is associated with significant mortality.

Preserving the legacy of reirradiation: A narrative review of historical publications

PURPOSE

The purpose of this study is to illustrate the historical development of reirradiation during several decades of the 20th century, in particular between 1920 and 1960.

METHODS AND MATERIALS

We chose the format of a narrative review because the historical articles are heterogeneous. No systematic extraction of baseline data, treatment details, or follow-up care was possible in many cases.

RESULTS

Both hematological malignancies and solid tumors were treated with a second course of radiation therapy, and indications included local relapse, regional nodal recurrence, and second primary tumors developing in a previously treated region. The literature consists of retrospective single-institution analyses describing treatment approaches that included external beam radiation therapy, brachytherapy, or combinations thereof. Data on toxicities and survival were often provided. Breast cancer and gynecological, head and neck, brain, and skin tumors are among the entities included in this review.

CONCLUSIONS

The leading pioneers in the field are fully aware of many of the challenges we continue to debate today. These include the process of late tissue changes and development of personalized treatment approaches and better ways to select patients who are likely to benefit from a second course of radiation therapy.

Reirradiation with intensity-modulated radiotherapy for locally recurrent T3 to T4 nasopharyngeal carcinoma

BACKGROUND

The purpose of this study was to assess the efficacy and toxicities of reirradiation using intensity-modulated radiotherapy (IMRT) in patients with locally advanced recurrent nasopharyngeal carcinoma (NPC).

METHODS

Thirty-eight patients with consecutive rT3 to rT4 NPC treated between 2005 and 2013 were retrospectively analyzed.

RESULTS

The 3-year overall survival (OS), progression-free survival (PFS), and local control rate were 47.2%, 17.5%, and 44.3%, respectively. Gross target volume (GTV) D₉₅ , GTV D₅₀ , and age were all important prognostic factors for OS and PFS, but only GTV D₉₅ was an important determinant for local control. A total of 73.7% patients experienced ≥1 grade 3 late toxicities and 3 patients died of massive epistaxis. Temporal lobe necrosis (TLN) developed sooner with a higher total biological equivalent dose.

CONCLUSION

Adequate tumor dose coverage was important for treating rT3 to rT4 NPC. Although late complications were common, treatment-related mortality was solely vascular in nature. Dose constraints of neurologic structures for reirradiation should be revised with the latest information on late toxicities. © 2016 Wiley Periodicals, Inc. Head Neck 39: 533-540, 2017.

Prospective randomized clinical studies involving reirradiation : Lessons learned

BACKGROUND

Reirradiation is a potentially useful option for many patients with recurrent cancer. The purpose of this study was to review all recently published randomized trials in order to identify methodological strengths and weaknesses, comment on the results, clinical implications and open questions, and give advice for the planning of future trials.

MATERIALS AND METHODS

Systematic review of trials published between 2000 and 2015 (databases searched were PubMed, Scopus and Web of Science).

RESULTS

We reviewed 9 trials, most of which addressed reirradiation of head and neck tumours. The median number of patients was 69. Trial design, primary endpoint and statistical hypotheses varied widely. The results contribute mainly to decision making for reirradiation of nasopharynx cancer and bone metastases. The trials with relatively long median follow-up confirm that serious toxicity remains a concern after high cumulative total doses.

CONCLUSION

Multi-institutional collaboration is encouraged to complete sufficiently large trials. Despite a paucity of large randomized studies, reirradiation has been adopted in different clinical scenarios by many institutions. Typically, the patients have been assessed by multidisciplinary tumour boards and advanced technologies are used to create highly conformal dose distributions.

Outcomes after reirradiation for recurrent nasopharyngeal carcinoma: North American experience

BACKGROUND

The purpose of this article was to report outcomes of reirradiation for locoregionally recurrent nasopharyngeal carcinoma (NPC).

METHODS

A retrospective review was conducted of all patients with locoregionally recurrent NPC who received reirradiation between 2001 and 2012. Overall survival (OS), local control, regional control, distant control, and Radiation Therapy Oncology Group (RTOG) grades 3 to 4 late toxicity were examined.

RESULTS

A total of 42 recurrent cases treated with intensity-modulated radiotherapy (IMRT; 27 patients) or non-IMRT (stereotactic radiotherapy [RT], 12 patients; 3D conformal RT, 3 patients) were identified. Median time from initial RT to recurrence was 4.6 years. Hyperfractionation with 1.1 to 1.4 Gy/fraction twice daily to a total of 40 to 60 Gy was used in 27 IMRT and 5 non-IMRT patients. The remaining 10 patients received conventional fractionation 1.8 to 2.0 Gy/fraction to 50 to 60 Gy. Median follow-up was 3.0 years. The 3-year OS, local control, regional control, distant control, and late toxicity rates were 49%, 46%, 71%, 79%, and 37%, respectively.

CONCLUSION

Reirradiation for recurrent NPC, delivered mostly with hyperfractionated IMRT, can result in durable disease control with acceptable late toxicity. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1102-E1109, 2016.

LB100, a small molecule inhibitor of PP2A with potent chemo- and radio-sensitizing potential

Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase that plays a significant role in mitotic progression and cellular responses to DNA damage. While traditionally viewed as a tumor suppressor, inhibition of PP2A has recently come to attention as a novel therapeutic means of driving senescent cancer cells into mitosis and promoting cell death via mitotic catastrophe. These findings have been corroborated in numerous studies utilizing naturally produced compounds that selectively inhibit PP2A. To overcome the known human toxicities associated with these compounds, a water-soluble small molecule inhibitor, LB100, was recently developed to competitively inhibit the PP2A protein. This review summarizes the pre-clinical studies to date that have demonstrated the anti-cancer activity of LB100 via its chemo- and radio-sensitizing properties. These studies demonstrate the tremendous therapeutic potential of LB100 in a variety of cancer types. The results of an ongoing phase 1 trial are eagerly anticipated.