Reduction of Target Volume and the Corresponding Dose for the Tumor Regression Field after Induction Chemotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma

Reduced-volume radiotherapy versus conventional-volume radiotherapy after induction chemotherapy in nasopharyngeal carcinoma: An open-label, noninferiority, multicenter, randomized phase 3 trial

BACKGROUND

Nearly 90% locoregionally advanced nasopharyngeal carcinoma (LANPC) responds to induction chemotherapy (IC) with significant tumor volume shrinkage. Radiotherapy always follows IC, and reduced volume has been proposed. However, the efficacy and safety of reduced-volume radiotherapy is uncertain.

METHODS

In this multi-center, noninferiority, randomized, controlled trial, patients with LANPC who completed IC were randomly assigned (1:1) to receive reduced-volume radiotherapy based on post-IC tumor volume (Post-IC group) or conventional volume radiotherapy based on pre-IC tumor volume (Pre-IC group). The primary endpoint was locoregional relapse-free survival, with a noninferiority margin of 8%. Secondary endpoints comprised adverse events, and quality of life (QoL).

RESULTS

Between August 7, 2020, and May 27, 2022, 445 patients were randomly assigned to Post-IC (n = 225) or Pre-IC (n = 220) groups. The average volume receiving radical dose was 66.6 cm3 in Post-IC group versus 80.9 cm3. After a median follow-up of 40.4 months, the 3-year locoregional relapse-free survival was 91.5% in the Post-IC group versus 91.2%, with a difference of 0.3% (95% confidence interval -4.9% to 5.5%). The incidence of grade 3-4 radiation-related toxicity was lower in the Post-IC group including: acute mucositis (19.8% vs 34.1%), late otitis media (9.5% vs 20.9%) and late dry month (3.6% vs 9.5%). The Post-IC group had better QoL for global health status, physical functioning, emotional functioning, dry mouth and sticky saliva.

CONCLUSIONS

In this trial, reduced-volume radiotherapy was noninferior to conventional volume radiotherapy in locoregional relapse-free survival, and was associated with lower toxicities and improved QoL. (ClinicalTrials.gov identifier NCT04384627).

Efficacy and Failure Patterns Following Target Volume and Dose Reduction After Neoadjuvant Therapy in Locoregionally Advanced Head and Neck Squamous Cell Carcinoma

BACKGROUND

In this study, we aimed to analyze the efficacy and failure patterns of contouring target volume based on the residual tumor and decreasing the dose to the area of tumor regression after neoadjuvant therapy in locoregionally advanced head and neck squamous cell carcinoma (HNSCC).

METHODS

We retrospectively analyzed the patients with locoregionally advanced HNSCC treated by our group from May 2011 to June 2023. All patients received neoadjuvant therapy followed by intensity-modulated radiation therapy. Gross tumor volumes for the primary tumor and metastatic lymph nodes were delineated according to postneoadjuvant extension. The tumor shrinkage after neoadjuvant therapy was included in the high-risk clinical target volume (CTV1) and prescribed a dose of 60 Gy. Kaplan-Meier analysis was employed to calculate local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), overall survival (OS), and distant metastasis-free survival (DMFS). Failure patterns were analyzed by mapping the location and extent of locoregional recurrence onto pretreatment planning CT.

RESULTS

This study included a total of 114 patients, with a median follow-up of 34 months. The 5-year LRFS, RRFS, OS, and DMFS rates were 70.2%, 70.7%, 74.8%, and 73.8%, respectively. Among the 14 patients with recurrences, there were 5 local failures, 6 regional recurrences, and 3 both local and regional recurrences. All local recurrences occurred within the 95% isodose line, classified as in-field failures. Only one regional recurrence was marginal failure. No out-of-field failure was observed.

CONCLUSION

Reduction of target volume after neoadjuvant therapy and distribution of 60 Gy of dose to the tumor regression area may be feasible.

International Consensus Guidelines on the Delineation of Radiation Therapy Target Volumes for Nasopharyngeal Carcinoma After Induction Chemotherapy Using a 2-Round Modified Delphi Survey

PURPOSE

Induction chemotherapy (ICT), a new standard in the management of locally advanced nasopharyngeal carcinoma (NPC), is increasingly used in endemic regions. Radiation therapy (RT) target volume delineation protocols and dose level prescriptions vary significantly in the literature. High-level evidence to support a particular approach is currently lacking. We developed an international consensus guideline toward harmonizing practices based on a literature review and expert opinion.

METHODS AND MATERIALS

The study entailed the following: consensus scope definition by focus group discussion (FGD); evidence gap identification by a scoping review of guidelines and literature reviews; evidence review and synthesis by a systematic review of experimental and observational studies and drafting of consensus statements by FGD; and consensus voting by modified Delphi process and FGD. The task force consisted of radiation oncologists from intermediate- and high-endemicity regions with expertise in treating NPC, evidence review, and consensus guideline development. The consensus panel consisted of relevant specialists from intermediate- and high-endemicity regions or with expertise in treating NPC. A modified e-Delphi method was used.

RESULTS

Four clinical situations after ICT for patients with NPC were selected for the consensus questions: optimal timing of chemoradiation; optimal imaging modalities for simulation and target volume delineation; optimal dose and fractionation; and RT target volume delineation. The consensus panel consisted of radiation oncologists (12), clinical oncologists (4), radiologists (3), a nuclear medicine specialist, medical physicists (2), and dosimetrists (2). The consensus guidelines were formulated after 2 rounds of Delphi voting and FGD; iterative revisions were made based on 2 rounds of internal review. The guidelines were subjected to external review and open commentary; further revisions were made if the consensus vote was not invalidated.

CONCLUSIONS

An international consensus guideline on delineating RT target volumes and corresponding dose levels in post-ICT NPC, as well as timing and modalities for imaging, was developed to help harmonize practices and enhance the comparability of interpretations of reported outcomes.

Recurrent Patterns in Patients With Nasopharyngeal Caricinoma and Risks Leading to Inaccurate Delineation in Marginal Failure in the Era of Intensity-Modulated Radiotherapy

OBJECTIVE

To investigate the failure patterns of recurrent nasopharyngeal carcinoma (NPC), especially to identify the relationship between the recurrent-prone anatomic structures and the tumor regression sites after the introduction of chemotherapy (IC).

METHOD

A cohort of 1121 non-metastatic patients with NPC was retrospectively enrolled. The pretreatment and recurrent images of each patient were registered to the planning CT. Tumor regression sites after IC (Vicr) overlapped with recurrent tumor (rGTV) were evaluated for the delineation accuracy and dose sufficiency in marginal failure patients.

RESULTS

A total of 126 (11.24%) experienced tumor recurrence. Re-evaluation of 12 patients with local marginal recurrence, their rGTV within Vicr predominantly located at choanae, sphenoidal sinus, and cavernous sinus. The regression sites did not receive the full 70 Gy but over half receiving with 60Gy.

CONCLUSION

Analysis from marginal failure that exempts tumor regression sites from GTV or an insufficient prescription dose of less than 70 Gy may contribute to marginal failure.

Comparison of TPF and PF induction chemotherapy combined with cisplatin concurrent chemoradiotherapy for locoregionally advanced nasopharyngeal carcinoma: A systematic review and meta-analysis

BACKGROUND

The standard of care for locoregionally advanced nasopharyngeal carcinoma (LA-NPC) is induction chemotherapy (ICT) followed by concurrent chemoradiation (CCRT). However, the ideal ICT regimen for LA-NPC remains unclear. We conducted a meta-analysis to evaluate the survival outcomes, responses, and incidences of toxicities between taxane, cisplatin and fluorouracil (TPF) and cisplatin and fluorouracil (PF) ICT regimens plus CCRT in LA-NPC.

METHODS

A systematic review and meta-analysis of the literature was conducted to compare the efficacy and safety of TPF versus PF followed by CCRT with cisplatin every 3 weeks or weekly cisplatin and intensity-modulated radiotherapy in LA-NPC.

RESULTS

Three studies with 2482 patients met the inclusion criteria. ICT with the TPF regimen plus CCRT resulted in a significantly improved progression-free survival (hazard ratios [HR] 0.84 [95% CI 0.73-0.96], P = .01), overall survival (HR 0.83 [95% CI 0.71-0.97], P = .02), and 3-year locoregional recurrence-free survival (risk ratios [RR] 1.03 [95% CI 1.01-1.06], P = .009) compared with the PF regimen plus CCRT in LA-NPC. However, distant metastasis-free survival was not statistically significant (P = .07). The incidence of grade 3 or 4 neutropenia (RR 2.08 [95% CI 1.84-2.36]) and diarrhea (RR 1.94 [95% CI 1.07-3.52]) during ICT was higher in the TPF group than in the PF group.

CONCLUSIONS

In terms of progression-free survival, overall survival, locoregional recurrence-free survival, in the era of intensity-modulated radiotherapy, the TPF plus CCRT with cisplatin is superior to PF plus CCRT with cisplatin in LA-NPC. Thus, the TPF plus CCRT regimen appears to be a reasonable treatment option, and further confirmation by prospective studies is needed.

Failure patterns of locoregional recurrence after reducing target volumes in patients with nasopharyngeal carcinoma receiving adaptive replanning during intensity-modulated radiotherapy: a single-center experience in China

BACKGROUND

Previous researches have demonstrated that adaptive replanning during intensity-modulated radiation therapy (IMRT) could enhance the prognosis of patients with nasopharyngeal carcinoma (NPC). However, the delineation of replanning target volumes remains unclear. This study aimed to evaluate the feasibility of reducing target volumes through adaptive replanning during IMRT by analyzing long-term survival outcomes and failure patterns of locoregional recurrence in NPC.

METHODS

This study enrolled consecutive NPC patients who received IMRT at our hospital between August 2011 and April 2018. Patients with initially diagnosed, histologically verified, non-metastatic nasopharyngeal cancer were eligible for participation in this study. The location and extent of locoregional recurrences were transferred to pretreatment planning computed tomography for dosimetry analysis.

RESULTS

Among 274 patients, 100 (36.5%) received IMRT without replanning and 174 (63.5%) received IMRT with replanning. Five-year rates of locoregional recurrence-free survival (LRFS) were 90.1% (95%CI, 84.8% to 95.4%) and 80.8% (95%CI, 72.0% to 89.6%) for patients with and without replanning, P = 0.045. There were 17 locoregional recurrences in 15 patients among patients with replanning, of which 1 (5.9%) was out-field and 16 (94.1%) were in-field. Among patients without replanning, 19 patients developed locoregional recurrences, of which 1 (5.3%) was out-field, 2 (10.5%) were marginal, and 16 (84.2%) were in-field.

CONCLUSIONS

In-field failure inside the high dose area was the most common locoregional recurrent pattern for non-metastatic NPC. Adapting the target volumes and modifying the radiation dose prescribed to the area of tumor reduction during IMRT was feasible and would not cause additional recurrence in the shrunken area.

Concurrent chemoradiotherapy with or without neoadjuvant chemotherapy in pediatric patients with stage III-IVa nasopharyngeal carcinoma: a real-world propensity score-matched cohort study

OBJECTIVES

To compare neoadjuvant chemotherapy (NAC) plus concurrent chemoradiotherapy (CCRT) to CCRT alone in children and adolescents (age ≤ 18 years) with locoregionally advanced nasopharyngeal carcinoma (CA-LANPC, stage III-IVA).

MATERIALS AND METHODS

195 CA-LANPC patients who were treated through CCRT with or without NAC between 2008 and 2018 were enrolled in this study. A matched cohort composed of CCRT patients and NAC-CCRT patients was generated by propensity score matching (PSM) at a 1:2 ratio. Survival outcomes and toxicities were compared between the CCRT group and NAC-CCRT group.

RESULTS

Of the 195 patients, 158 (81%) received NAC plus CCRT, and 37 (19%) received CCRT alone. The NAC-CCRT group had higher EBV DNA levels (≥ 4000 copy/mL), more advanced TNM stage (stage IV disease), and lower incidence of a high radiation dose (> 6600 cGy) than the CCRT group. To avoid bias in treatment selection within retrospectively analysis, 34 patients from the CCRT group were matched with 68 patients from the NAC-CCRT group. In the matched cohort, the 5-year DMFS rate was 94.0% in the NAC-CCRT group versus 82.4% in the CCRT group, with marginal statistical significance (HR = 0.31; 95%CI 0.09-1.10; P = 0.055). During treatment, the accumulate incidence of severe acute toxicities (65.8% vs 45.9%; P = 0.037) in the NAC-CCRT group was higher than the CCRT group. However, the CCRT group had significantly higher accumulate incidence of severe late toxicities (30.3% vs 16.8%; P = 0.041) than the NAC-CCRT group.

CONCLUSIONS

Addition of NAC to CCRT tended to improve long-term DMFS in CA-LANPC patients with acceptable toxicity. However, relative randomized clinical trial is still needed in the future.

Lessons and Opportunities for Biomarker-Driven Radiation Personalization in Head and Neck Cancer

Head and neck cancer is notoriously challenging to treat in part because it constitutes an anatomically and biologically diverse group of cancers with heterogeneous prognoses. While treatment can be associated with significant late toxicities, recurrence is often difficult to salvage with poor survival rates and functional morbidity.^1,2 Thus, achieving tumor control and cure at the initial diagnosis is the highest priority. Given the differing outcome expectations (even within a specific sub-site like oropharyngeal carcinoma), there has been growing interest in personalizing treatment: de-escalation in selected cancers to decrease the risk of late toxicity without compromising oncologic outcomes, and intensification for more aggressive cancers to improve oncologic outcomes without causing undue toxicity. This risk stratification is increasingly accomplished using biomarkers, which can represent molecular, clinicopathologic, and/or radiologic data. In this review, we will focus on biomarker-driven radiotherapy dose personalization with emphasis on oropharyngeal and nasopharyngeal carcinoma. This radiation personalization is largely performed on the population level by identifying patients with good prognosis via traditional clinicopathologic factors, although there are emerging studies supporting inter-tumor and intra-tumor level personalization via imaging and molecular biomarkers.

Optimizing induction chemotherapy regimens for radiotherapy in patients with locoregionally advanced nasopharyngeal carcinoma

BACKGROUND AND PURPOSE

The optimal number of cycles of induction chemotherapy (IC) in locoregionally advanced nasopharyngeal carcinoma (LANPC) remains unresolved. This study aimed to quantitatively assess the changes in gross tumor volumes (GTVs) and to select the most optimal number of IC cycles.

METHODS

We analyzed 54 patients who received a three-cycle IC before commencing radiotherapy, with the tumor and nodal responses assessed by a CT scan before IC and after each IC cycle. The gross tumor volumes of the nasopharynx primary lesion (GTV_T), involved retropharyngeal lymph node (GTV_RP), and involved cervical lymph node (GTV_N) were contoured on each scan. The volume change following each IC cycle was evaluated with Wilcoxon signed-rank test. The three-dimensional vector displacements of target centers were also calculated and compared.

RESULTS

The volume reductions of GTVs following IC varied across different patients and showed different trends for the three GTV types. GTV_T and GTV_RP did not display further volume reduction after two IC cycles, whereas GTV_N showed monotonic volume decreases. For GTV_T and GTV_RP following the three IC cycles, the total volume reduction relative to the initial volume before IC was 12.0%, 22.5%, and 20.1% and 26.0%, 44.1%, and 42.2%, respectively. In contrast, for GTV_N, continuing volume reduction was observed with a total reduction of 25.3%, 43.2%, and 54.7% following the three cycles, and the reductions were all significant. Average displacements of the GTVs were <1.5 mm in all directions; their average three-dimensional displacements were 2.6, 4.0, and 1.7 mm, respectively. Acceptable toxicity was observed in most patients.

CONCLUSION

This study supports two cycles of IC before radiotherapy for patients with LANPC if the initial metastatic cervical lymph node volume is not dominating. Otherwise, three cycles of IC is recommended to further reduce the cervical node volume.

Characteristics of local extension based on tumor distribution in nasopharyngeal carcinoma and proposed clinical target volume delineation

OBJECTIVES

To summarize the characteristics of local extension of eccentric and central nasopharyngeal carcinoma (NPC) by magnetic resonance imaging (MRI) and to improve clinical target volume (CTV) delineation.

METHODS

MRI of 870 newly diagnosed NPC patients were reviewed. According to tumor distribution features, the NPCs were divided into eccentric and central lesions.

RESULTS

All local invasions presented as continuous invasion from gross lesions and structures adjacent to the nasopharynx were more likely to be invaded. There were 240 (27.6%) and 630 (72.4%) cases with central and eccentric lesions, respectively. The spread of eccentric lesions was centered on the ipsilateral Rosenmüller's fossa; and most anatomic sites had significantly higher invasion rates in the ipsilateral side than the contralateral side (P < 0.05). However, they were at low risk of concurrent bilateral tumor invasion (<10%), except the prevertebral muscle (15.4%) and nasal cavity (13.8%). The extension of central NPCs was centered on the nasopharyngeal superior-posterior wall and was more common in the superior-posterior direction. Furthermore, bilateral tumor invasion into the anatomical sites was common.

CONCLUSION

Local invasion of NPC was characterized by continuous invasion from proximal to distal sites. The eccentric and central lesions showed different invasion features. Individual CTV delineation should be based on the distribution characteristics of tumors. The eccentric lesions had a very low probability of invasion into the contralateral tissue; thus routine prophylactic radiation of contralateral parapharyngeal space and skull base foramina may not be necessary.

Post-induction lymph node delineation in nasopharyngeal cancer: A single-center experience

BACKGROUND

We routinely delineate the gross tumor volume (GTV) for the lymph nodes (LN) based on post-induction chemotherapy (IC) MRI in nasopharyngeal carcinoma (NPC). Herein, we investigated the sufficiency of this method, particularly in high-risk LNs.

METHODS

Eighty-one LNs with a high-risk of clinical extranodal extension and/or ≥3-cm diameter in 58 patients were evaluated. A new GTV covering the pre-IC LN volume was delineated for each LN.

RESULTS

The median volume reduction was 72.5% for the GTV and 53.1% for the planning target volume. After a median 43 months, the overall LN local control rate was 97.5%. The 2- and 5-year LN recurrence-free survival, overall survival, and disease-free survival rate was 88.3% and 84.4%, 92.5% and 85.1%, and 86.8% and 79.2%, respectively.

CONCLUSION

IC yields a significant reduction in nodal target volumes, and post-IC nodal volume-based radiotherapy provides excellent LC in NPC, even in high-risk LNs.

Tumor volume reduction after induction chemotherapy with gemcitabine plus cisplatin in nasopharyngeal carcinoma

OBJECTIVES

To evaluate the tumor volume reduction after induction chemotherapy (IC) with gemcitabine plus cisplatin (GP) and to build prediction models for tumor volume reduction in nasopharyngeal carcinoma (NPC).

METHODS

NPC patients who received GP IC were retrospectively enrolled. The gross tumor volume of the nasopharynx and lymph nodes (GTVnx and GTVnd) were contoured before and after IC. Univariate and multivariate analyses were performed to identify associated factors. Nomogram models were constructed to predict the possibility of tumor volume reduction.

RESULTS

A total of 192 patients were enrolled. The mean relative volume reduction for GTVnx and GTVnd was 29.66% and 31.75%, respectively. The volume reduction of GTVnx and GTVnd had a weak association (r = 0.229, p < 0.001). For GTVnx volume reduction, pre-treatment neutrophil count (p = 0.043), lymphocyte count (p = 0.026), LDH level (p = 0.005), and BMI (p = 0.020) were independently associated factors. For GTVnd volume reduction, pre-treatment EBV-DNA (p = 0.029), GTVnd volume (p < 0.001), eosinophil count (p = 0.043), NLR (p = 0.039), LDH level (p = 0.026), and serum potassium level (p = 0.027) were independently associated factors. For the GTVnx nomogram model, areas under the receiver-operating characteristic curve (AUC) were 0.702 and 0.698 for the training and validation cohorts, respectively. For the GTVnd nomogram model, the AUC was 0.872 and 0.758 for the training and validation cohorts, respectively.

CONCLUSIONS

Tumor volumes reduce significantly after GP induction chemotherapy. Nomogram models for predicting the possibility of tumor volume reduction are built.

Gemcitabine Versus Docetaxel Plus Cisplatin as Induction Chemotherapy in Nasopharyngeal Carcinoma

OBJECTIVES

To compare tumor volume reduction after induction chemotherapy (IC) with gemcitabine plus cisplatin (GP) and docetaxel plus cisplatin (DP) and to evaluate the influence on subsequent radiotherapy in locoregionally advanced nasopharyngeal carcinoma (NPC).

STUDY DESIGN

Retrospective clinical study.

METHODS

Patients who received GP or DP IC followed by concurrent chemoradiotherapy (CCRT) were retrospectively enrolled. Propensity score matching (PSM) was adopted to control the balance between the GP and DP groups.

RESULTS

A total of 41 patients treated with GP and 53 patients treated with DP were enrolled. After matching, 33 sub-pairs of 66 patients were generated in the post-PSM cohort. As compared with DP, GP was superior in its gross tumor volume of the nasopharynx (GTVnx) reduction (28.88% vs. 18.73%; P = .014) but equivalent in its gross tumor volume of the lymph nodes (GTVnd) reduction (37.58% vs. 29.79%; P = .229). Univariate and multivariate analyses confirmed that the chemotherapy regimen was an independent factor associated with the reduction in GTVnx (P = .011). The GP group exhibited advantages in the dosimetric parameters of the planning target volume of high-risk volume and low-risk volume (PTV1 and PTV2), lenses, temporal lobes, and parotid glands. Univariate and multivariate analyses confirmed that chemotherapy regimen was an independent factor associated with the dosimetric parameters of PTV1, PTV2, lenses, temporal lobes, and parotid glands.

CONCLUSION

GP regimen achieves a greater GTVnx reduction than DP regimen and has an advantage in the dosimetry of subsequent CCRT.

LEVEL OF EVIDENCE

3 Laryngoscope, 132:2379-2387, 2022.

Long-term results of the phase II dose and volume de-escalation trial for locoregionally advanced nasopharyngeal carcinoma

OBJECTIVE

Patients with locoregionally advanced nasopharyngeal carcinoma (LANPC) were assigned to dose and volume de-escalated intensity-modulated radiation therapy (IMRT) based on response to induction chemotherapy (IC) to limit treatment related toxicity while preserving efficacy.

METHODS AND MATERIALS

A single-arm de-escalated phase II trial was performed in this study. Patients with LANPC received two cycles of IC with docetaxel 60 mg/m² d1, cisplatin 25 mg/m²/day d1-3 and 5-fluorouracil 500 mg/m²/day d1-5 q21d, followed by IMRT. The gross tumor volume of the primary intracavity nasopharyngeal tumor and involved lymph nodes were delineated based on the post-IC tumor extension. Part of the prescribed doses were reduced from 70.4 Gy to 66 Gy for T3-4 diseases. The primary end point was 5-year progression-free survival (PFS) in stage III and IVA-B NPC compared with historical controls of 50% and 35%.

RESULTS

Between January 2010 and November 2013, 48 and 83 eligible patients with stage III and IVA-B NPC were accrued to this trial. With a median follow-up of 92 months, the 5-year and 8-year estimated PFS were 89.6% and 76.0%, 63.9% and 58.0% for patients with stage III and IVA-B disease, which were all improved in comparison with historical controls. Grade 3 acute mucositis were developed in 27.5% patients. Cranial neuropathy and asymptomatic temporal lobe necrosis were found in 2.3% and 1.5% patients.

CONCLUSION

Dose and volume de-escalated IMRT was associated with high PFS and mild late neurological toxicities for IC responders. Further exploration of de-escalation strategies in appropriate patients is needed.

CLINICAL TRIAL REGISTRATION

Clinical trials.gov identifier: NCT03389295.

Is a high-risk clinical target volume required? Evaluation of the dosimetric feasibility based on T staging

Background

Clinical target delineation is a primary focus in the field of radiotherapy. This study aimed to investigate whether high-risk clinical target volume can be removed in nasopharyngeal carcinoma patients with different T stages.

Materials and methods

We designed a test plan without the high-risk clinical target volume for 111 nasopharyngeal carcinoma patients and further compared the test plans with the treatment plans in the parameters of planning target volumes and the radiation dose to normal organs.

Results

Our data showed that when high-risk clinical target volume was abnegated, target coverage, conformity indices, and homogeneity indices of planning target volumes and doses of normal organs were not influenced in the T4 nasopharyngeal carcinoma patients, and more than 95% of the high-risk planning target volume area could still be covered by the 60 Gy dose line. However, only some T1–3 patients achieved the ideal dose coverage, and even fewer after induction chemotherapy (62.8% vs. 41.2%, p = 0.018). Gross tumor volume was positively correlated with the target coverage of the original high-risk planning target volume in the test-plan (p = 0.0001). Gross tumor volume can be used to predict whether the target coverage of high-risk planning target volume is more than 95% (area under the curve = 0.868).

Conclusion

Omitting high risk clinical target volume can be considered in patients with T4 nasopharyngeal carcinoma according to physical evaluations. However, this approach is only suitable for a specific subset of T1–3 patients.

Volumetric modulated arc therapy versus tomotherapy for late T-stage nasopharyngeal carcinoma

Purpose

To compare the dosimetric parameters and clinical outcomes between volumetric modulated arc therapy (VMAT) and tomotherapy for treating late T-stage nasopharyngeal carcinoma (NPC).

Methods

Patients with non-metastatic late T-stage NPC who received definitive radiotherapy with tomotherapy or VMAT were selected. 1:1 propensity score matching (PSM) was used to control the balance of confounding factors. The dosimetric parameters and clinical outcomes were compared.

Results

A total of 171 patients were enrolled before matching, with 61 patients in the VMAT group and 110 patients in the tomotherapy group. In the post-PSM cohort, 54 sub-pairs of 108 patients were included after matching. Tomotherapy was superior to VMAT in the dosimetric parameters of planning target volumes, brainstem, spinal cord, lenses, and parotid glands but inferior in the optic nerves and optic chiasm. The tomotherapy group had a lower incidence of grade ≥ 3 acute mucositis (22.2% vs. 40.7%, p = 0.038) and a higher rate of complete response (83.3% vs. 66.7%, p = 0.046) after radiotherapy. However, there were no significant differences in locoregional failure-free survival (p = 0.375), distant metastasis-free survival (p = 0.529), or overall survival (p = 0.975) between the two groups.

Conclusion

Tomotherapy is superior to VMAT in terms of most dosimetric parameters, with less acute mucositis and better short-term efficacy. There are no significant differences in the survival outcomes between the VMAT and tomotherapy groups.

Individualized clinical target volume delineation and efficacy analysis in unilateral nasopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT): 10-year summary

PURPOSE

To evaluate the long-term local control, failure patterns, and toxicities after individualized clinical target volume (CTV) delineation in unilateral nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT).

METHODS

Unilateral NPC was defined as a nasopharyngeal mass confined to one side of the nasopharynx and did not exceed the midline. From November 2003 to December 2017, 95 patients were retrospectively included. All patients received IMRT. The CTVs were determined based on the distance from the gross tumor. The contralateral para-pharyngeal space and skull base orifices were spared from irradiation.

RESULTS

There were three local recurrences and eight regional recurrences in 10 patients during an 84-month follow-up. All local recurrences were within PGTVnx, and all in-field recurrences. No recurrences were found in traditional high-risk areas including contralateral the para-pharyngeal space and skull base orifices. The 10-year local-recurrence-free survival, regional-recurrence-free survival and overall survival were 96.2%, 90.5% and 84.7%, respectively. The dosimetry parameters of the tumor-contralateral organs were all lower than the values of the tumor-ipsilateral side (P < 0.05). The late toxicities occurred mainly in the tumor-ipsilateral organs, including radiation-induced temporal lobe injury, impaired visuality, hearing loss and subcutaneous fibrosis.

CONCLUSION

Individualized CTV delineation in unilateral NPC could yield excellent long-term local control with limited out-of-field recurrences, reduced dose to tumor- contralateral organs and mild late toxicities, which is worthy of further exploration.

Local control and failure patterns after intensity modulated radiotherapy with reduced target volume delineation after induction chemotherapy for patients with T4 nasopharyngeal carcinoma

•

Induction chemotherapy combined with radiotherapy achieved excellent local control.

•

In-field recurrence is major local failure pattern for T4 nasopharyngeal carcinoma.

•

Radiotherapy with reduced target volume after induction chemotherapy is feasible.

Background

The delineation of target volume after induction chemotherapy(IC) for nasopharyngeal carcinoma(NPC) is currently controversial. In this study, we aimed to analyze the long-term local control(LC) and failure patterns of T4 NPC treated with reduced target volume radiotherapy after IC.

Methods

From September 2007 to January 2013, 145 patients with T4 NPC were retrospectively reviewed. All patients received at least 1 cycle of IC followed by intensity modulated radiotherapy(IMRT). The gross tumor volume(GTV) was delineated according to the post-IC images for intracavity tumors and lymph nodes. The LC and overall survival (OS) rates were calculated using the Kaplan-Meier method. The location and extent of local failures were transferred to the pretreatment planning computed tomography (CT) for dosimetric analysis.

Results

With a median follow-up time of 95 months (range, 16–142 months), 23 local failures were found. The estimated 10-year LC and OS rates were 81.1%and 54.8% respectively. Among the 20 local failures with available diagnostic images, 18(90%) occurred within the 95% isodose lines and were considered in-field failures and 2(10%) were marginal. There was no outside-field failure.

Conclusions

In-field failure was the major pattern of local failure for T4 NPC. IMRT with reduced target volume after IC seems to be feasible. Further researches exploring optimal volume and radiation dose for local advanced NPC in the era of IC are warranted.

Clinical target volume design of postoperative intensity-modulated radiotherapy for major salivary gland tumours according to surgical principles: an innovative method

BACKGROUND

No international consensus has been reached regarding delineation of postoperative intensity-modulated radiotherapy (PO-IMRT) clinical target volumes (CTV) for major salivary gland carcinoma (SGC). The purpose of this article was to report our experience according to surgical principles.

METHODS

Between June 2010 and June 2018, 54 consecutive patients were enrolled. Reserved tissues around the margin of resection that were less than 5 mm from the invasive tumour edge before surgery were defined as high-risk clinical target volumes (CTV-HD), those less than 10 mm away were defined as medium-risk CTV (CTV1), and those 10-20 mm away were defined as low-risk CTV (CTV2), and were irradiated with 63-65 Gy, 59.5-61 Gy, and 45-54 Gy, respectively. Target volume distributions of reserved tissues were analysed and actuarial estimates of overall survival (OS), recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) were obtained with the Kaplan-Meier method.

RESULTS

In parotid gland tumours, the percentages of defined CTV-HD in the styloid process, mandibular ramus, posterior venter of the digastric muscle, carotid sheath and stylomastoid foramen reached 34.29%, 25.71%, 54.29%, 40.00%, and 37.10%, respectively. The median follow-up was 33 months (range, 5-98 months). The 3-year and 5-year Kaplan-Meier estimates of OS, RFS and DMFS were 85.4% and 77.8%, 97.4%, and 97.4%, and 82.0% and 82.0%, respectively.

CONCLUSIONS

It is feasible to delineate CTVs according to distances between various reserved tissues and the primary tumour edge before operation.

The change in tumor volume after induction chemotherapy with docetaxel plus cisplatin in 259 nasopharyngeal carcinoma patients

PURPOSE

To assess the tumor volume change after induction chemotherapy with docetaxel plus cisplatin (DP) in nasopharyngeal carcinoma (NPC).

METHODS

A total of 259 non-metastatic NPC patients who received DP induction chemotherapy were retrospectively reviewed. Gross tumor volume of nasopharynx and lymph nodes (GTVnx and GTVnd) were contoured before and after chemotherapy. Univariate and multivariate analyses were performed to identify factors associated with tumor volume reduction.

RESULTS

For GTVnx, the mean volume before and after chemotherapy were 43.2 cm³ vs 37.4 cm³ (p < 0.001) and the mean relative volume reduction was 12.7%. For GTVnd, the mean volume before and after chemotherapy were 24.6 cm³ vs 17.6 cm³ (p < 0.001) and the mean relative volume reduction was 13.9%. There was a positive linear correlation between the reduction of GTVnx and GTVnd (r = 0.351, p  < 0.001). For GTVnx volume reduction, pretreatment GTVnx volume (≤ 20 cm³ vs > 20 cm³, OR = 4.644, p = 0.001) and chemotherapy cycle (2 cycles vs 3 cycles, OR = 2.418, p = 0.009) were independently associated factors. For GTVnd volume reduction, pretreatment GTVnd volume (≤ 8 cm³ vs > 8 cm³, OR = 7.472, p < 0.001) and chemotherapy cycle (2 cycles vs 3 cycles, OR = 2.621, p = 0.007) were independently associated factors.

CONCLUSION

DP induction chemotherapy reduces tumor volumes moderately in NPC. Larger pre-treatment tumor volumes and three cycles of chemotherapy are associated with higher likelihood of tumor volume reduction.

Impact of tumor volume enlargement after induction chemotherapy on subsequent radiotherapy in locally advanced nasopharyngeal carcinoma: A propensity-score matching analysis

A small proportion of nasopharyngeal carcinoma (NPC) patients show resistance to induction chemotherapy (IC). This study sought to investigate the impact of tumor volume enlargement after IC on the dosimetric parameters of subsequent radiotherapy. The records of a total of 240 locally advanced NPC patients who received IC followed by concurrent chemoradiotherapy were retrospectively reviewed. Patients with a tumor volume enlargement of ≥10% and patients with a tumor volume reduction of ≥10% after induction chemotherapy were classified as the enlargement group and the control group, respectively. The dosimetric parameters of the planning target volumes (PTVs) and the organs at risk (OARs) were compared between the matched groups after propensity score matching (PSM). For the gross tumor volume of nasopharynx (GTVnx), 21 patients and 127 patients were classified as the enlargement group and the control group, respectively. After matching, 20 sub-pairs of 40 patients were generated in the post-PSM cohort. The GTVnx enlargement group exhibited no significant disadvantages in all of the dosimetric parameters, except in the planning organ-at-risk volume (PRV) of contralateral lens (Dmax, 722 cGy vs. 634 cGy, p = 0.041). For the gross tumor volume of lymph nodes (GTVnd), 44 patients and 144 patients were classified as the enlargement group and the control group, respectively. After matching, 39 sub-pairs of 78 patients were generated in the post-PSM cohort. The GTVnd enlargement group exhibited no significant disadvantages in all of the dosimetric parameters. Univariate and multivariate analyses showed that the enlargement of GTVnx and the enlargement of GTVnd were not independently associated with any of the dosimetric parameters. A tumor volume enlargement of ≥10% in GTVnx or GTVnd after induction chemotherapy has no significant impact on the dosimetric parameters of subsequent radiotherapy in locally advanced NPC.

Quality of Life, Toxicity and Unmet Needs in Nasopharyngeal Cancer Survivors

Concerted research efforts over the last three decades have resulted in improved survival and outcomes for patients diagnosed with nasopharyngeal carcinoma (NPC). The evolution of radiotherapy techniques has facilitated improved dose delivery to target volumes while reducing dose to the surrounding normal tissue, improving both disease control and quality of life (QoL). In parallel, clinical trials focusing on determining the optimal systemic therapy to use in conjunction with radiotherapy have been largely successful, resulting in improved locoregional, and distant control. As a consequence, neoadjuvant chemotherapy (NACT) prior to definitive chemoradiotherapy has recently emerged as the preferred standard for patients with locally advanced NPC. Two of the major challenges in interpreting toxicity and QoL data from the published literature have been the reliance on: (1) clinician rather than patient reported outcomes; and (2) reporting statistical rather than clinical meaningful differences in measures. Despite the lower rates of toxicity that have been achieved with highly conformal radiotherapy techniques, survivors remain at moderate risk of persistent and long-lasting treatment effects, and the development of late radiation toxicities such as hearing loss, cranial neuropathies and cognitive impairment many years after successful treatment can herald a significant decline in QoL. Future approaches to reduce long-term toxicity will rely on: (1) identifying individual patients most likely to benefit from NACT; (2) development of response-adapted radiation strategies following NACT; and (3) anticipated further dose reductions to organs at risk with proton and particle therapy. With increasing numbers of survivors, many in the prime of their adult life, research to identify, and strategies to address the unmet needs of NPC survivors are required. This contemporary review will summarize our current knowledge of long-term toxicity, QoL and unmet needs of this survivorship group.

Is Surgery an Inevitable Treatment for Advanced Salivary Lymphoepithelial Carcinoma? Three Case Reports

Lymphoepithelial carcinoma (LEC) of the salivary gland is a rare malignancy which is identical to undifferentiated nasopharyngeal carcinoma. However, most patients are treated with surgery as primary treatment, which is impossible for some very locoregionally advanced patients. And there are few reports of patients treated by an induction chemotherapy (IC) and concurrent chemoradiotherapy (CCRT) approach. This report describes 3 cases of advanced stage LEC of the salivary gland. All patients presented with a palpable mass of variable duration and underwent induction CCRT. All cases were positive for Epstein-Barr virus-encoded small RNAs. After IC, all cases had reached partial response and all achieved complete response after CCRT. All patients remained local-regional recurrence-free after 6-month follow-up for case 1, 50-month for case 2, and 14-month for case 3 up to our last follow-up. No serious adverse events were found.

Nutritional outcomes after radiotherapy target volume reduction for nasopharyngeal cancer: a Phase III trial

Aim: This study aimed to assess the nutritional status of patients with locoregionally advanced nasopharyngeal cancer, for whom intensity-modulated radiotherapy (IMRT) was planned using their pre- or post-induction chemotherapy (IC) nasopharyngeal gross tumor volume. Materials & methods: 212 cases of stage III-IVb nasopharyngeal cancer were randomized into groups A (n = 97) and B (n = 115). IMRT was planned for groups A and B using pre-IC and post-IC images, respectively. Results: There was a significant decrease in the nutritional parameters of group B compared with those of group A during radiotherapy. Multivariate analysis indicated that the T stage and nasopharyngeal gross tumor volume IMRT-planning protocol were prognostic factors of poor nutritional status. Conclusion: Decreasing the IMRT target volume through IC can improve nutritional status.

Extensive pelvic and abdominal lymphadenopathy with hepatosplenomegaly treated with radiotherapy-A case report

This is a case report of a 65-year-old female patient diagnosed with Grade II Follicular Lymphoma of the pelvic and abdomen was treated with a combination of R-CHOP chemotherapy and radiotherapy.

Chemotherapy Potentially Facilitates the Occurrence of Radiation Encephalopathy in Patients With Nasopharyngeal Carcinoma Following Radiotherapy: A Multiparametric Magnetic Resonance Imaging Study

Radiation encephalopathy (RE) is deemed to be a disease induced only by radiotherapy (RT), with the effects of chemotherapeutic agents on the brains of nasopharyngeal carcinoma (NPC) patients being largely overlooked. In this study, we investigated structural and functional brain alterations in NPC patients following RT with or without chemotherapy. Fifty-six pre-RT, 37 post-RT, and 108 post-CCRT (concomitant chemo-radiotherapy) NPC patients were enrolled in this study. A surface-based local gyrification index (LGI) was obtained from high resolution MRI and was used to evaluate between-group differences in cortical folding. Seed-based functional connectivity (FC) analysis of resting-state fMRI data was also conducted to investigate the functional significance of the cortical folding alterations. Compared with the Pre-RT group, patients in the Post-CCRT group showed LGI reductions in widespread brain regions including the bilateral temporal lobes, insula, frontal lobes, and parietal lobes. Compared with the Post-RT group, patients in the Post-CCRT group showed LGI reductions in the right insula, which extended to the adjacent frontal lobe. Seed-based FC analysis showed that patients in the Post-CCRT group had lower FC between the insula and the left middle frontal gyrus than patients in the Pre-RT group. The follow-up results showed that patients in the Post-CCRT group had a much higher RE incidence rate (20.4%) than patients in the Post-RT group (2.7%; P = 0.01). These findings indicate that chemotherapy potentially facilitated the occurrence of RE in NPC patients who underwent radiotherapy.