Modern Radiation Therapy for Extranodal Nasal-Type NK/T-cell Lymphoma: Risk-Adapted Therapy, Target Volume, and Dose Guidelines from the International Lymphoma Radiation Oncology Group

Can the radiation dose be safely reduced in the treatment of nk/T cell lymphoma?

The aim of this study is to investigate the feasibility and safety of dose reduction in the radiotherapy of NK/T-cell lymphoma. A retrospective collection of clinical and treatment data was conducted on 41 patients. The analysis aimed to assess whether the reduction in radiation therapy dosage affected patients' local control and survival. Among the 41 patients, all achieved complete remission after the initial treatment. With a median follow-up of 28.4 months, all except one patient demonstrated good control within the irradiated area. In the entire cohort, a total of 6 patients died and none of the deaths were caused by local tumor failure. The 3-year overall survival rate and progression-free survival rate was 83.8%, 94.4%, respectively. The incidence of long-term toxicity was low. It seems safe to reduce the prophylactic radiation dose to 45 Gy and the preliminary treatment results are satisfactory, with further reduction in side effects.

Analysis of the treatment and prognosis of 266 cases of extranodal natural killer/T-cell lymphoma, nasal type in a single medical center

Objective

To assess the impact of different treatment strategies and risk factors on the prognosis of patients with extranodal NK/T-cell lymphoma, nasal type (ENKTL) in a single medical center.

Methods and analysis

The clinical features of 266 patients with ENKTL were retrospectively analyzed, among whom those in stages I and II received sandwich therapy, while those in stages III and IV underwent chemotherapy plus autologous hematopoietic stem cell transplantation. The Kaplan-Meier curves, univariate and multivariate Cox regression analyses were employed for survival and prognosis analysis. Statistical significance was set at P<0.05.

Results

Following treatment, the post-intervention outcomes demonstrated a complete remission (CR) rate of 71.05% and a partial remission (PR) rate of 3.76%. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 70.4% and 70.9%, respectively. In addition, the PFS for patients in stage I/II was 79.8%, with an OS of 81.1%, whereas for those in stage III/IV, the PFS was 41.7% and the OS was 40.9%. Notably, the achievement of CR immediately after treatment was an independent prognostic factor (P<0.001). Patients in stage I/II depicted a favorable 5-year OS rate, while those in stage III/IV manifested a less favorable prognosis.

Conclusion

Stages of the disease and whether CR was achieved following treatment are important factors determining the survival and prognosis of patients with ENKTL. Further researches focusing on disease onset and mechanisms of drug resistance will contribute to better management of ENKTL.

Assessment of Bone Marrow Involvement in Extranodal NK/T-Cell Lymphoma: Positron Emission Tomography versus Bone Marrow Biopsy, and the Significance of Minimal Involvement by EBV+ Cells (KROG 18-09)

PURPOSE

This study aims to investigate the diagnostic significance of positron emission tomography/computed tomography (PET/CT) in assessing bone marrow (BM) involvement through a comparison of PET/CT findings with BM biopsy in extranodal natural killer/T-cell lymphoma.

MATERIALS AND METHODS

The medical records of 193 patients were retrospectively reviewed. Patients were categorized as having early-stage (PET-ES) or advanced-stage (PET-AS) disease based on PET/CT results. The BM involvement was classified into three groups according to BM biopsy: gross BM involvement, minimal BM involvement (defined as the presence of a limited number of Epstein-Barr virus-positive cells in BM), and no involvement. Calculations of the accuracy of PET/CT in detecting BM involvement and analysis of the clinical outcomes (progression-free survival [PFS] and overall survival [OS]) according to the BM biopsy status were performed.

RESULTS

PET/CT exhibited a sensitivity of 64.7% and a specificity of 96.0% in detecting gross BM involvement. For detecting any (both gross and minimal) BM involvement, the sensitivity was 30.4%, while the specificity was 99.0%. Only one patient (0.7%) demonstrated gross BM involvement among the PET-ES group. Survival outcomes of the PET-ES group with minimal BM involvement (3-year PFS, 55.6%; OS, 77.0%) were closer to those of the PET-ES group with no BM involvement (3-year PFS, 62.2%; OS, 80.6%) than to those of the PET-AS group (3-year PFS, 20.1%; OS, 29.9%).

CONCLUSION

PET/CT exhibits high specificity, but moderate and low sensitivity in detecting gross and minimal BM involvement, respectively. The clinical significance of minimal BM involvement for patients in the PET-ES group may be limited.

Primary ophthalmic natural killer/T-cell lymphoma: A population-based study

BACKGROUND

Ophthalmic lymphomas, a subgroup of extra-nodal lymphomas, have seen an increase in incidence in recent decades. Of these, the NK/T-cell lymphoma (NKTL) subtype is particularly aggressive. Though prevalent mostly in Asian patients, data on ophthalmic NKTL is still limited, especially in the western population. This study aimed to provide an additional analysis of primary ophthalmic NKTL using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

A retrospective analysis was performed on the SEER database covering records from 2000 to 2020. Patients diagnosed with extranodal NKTL originating primarily from an ophthalmic structure were identified.

RESULTS

Out of 4540 ophthalmic lymphomas registered in the SEER database between 2000 and 2020, 9 cases (0.2%) corresponded to ophthalmic NKTL, occurring in patients with a median age of 67 years. The majority of these patients underwent chemotherapy (88.8%) and radiotherapy (66.6%). The 6-month overall survival (OS) and cancer-specific survival (CSS) were both at 50.8%, dropping significantly at the 2-year follow-up.

CONCLUSION

Primary orbital NKTL has a notably severe prognosis. An early diagnosis is important due to the aggressive nature of NKTL.

Phase 2 Clinical Trial of Simultaneous Boost Intensity Modulated Radiation Therapy With 3 Dose Gradients in Patients With Stage I-II Nasal Type Natural Killer/T-Cell Lymphoma: Long-Term Outcomes of Survival and Quality of Life

PURPOSE

The aim of this study was to investigate the treatment results and long-term quality of life in patients with early-stage extranodal natural killer/T-cell lymphoma who were prospectively treated with simultaneous boost intensity modulated radiation therapy (SIB-IMRT) with 3 dose gradients.

METHODS AND MATERIALS

Sixty patients with stage I-II nasal cavity natural killer/T-cell lymphoma (NKTCL) and Waldeyer's ring NKTCL were enrolled in a single-arm, prospective, phase 2 clinical trial from August 2011 to April 2015. All patients were treated with definitive radiation therapy combined with short-course induction chemotherapy. A newly designed SIB-IMRT scheme was uniformly adopted, with 54.6 Gy for the gross tumor volume (GTV) of the primary tumor and GTV of the positive lymph nodes, 50.7 Gy for the high-risk clinical target volume (CTV), and 45.5 Gy for the low-risk CTV, all delivered in 26 daily fractions. Before SIB-IMRT, L-asparaginase-based induction chemotherapy was used in 95.0% (57/60) of patients.

RESULTS

With a median follow-up time of 95.8 months, the 5-year locoregional recurrence-free survival, progression-free survival, and overall survival rates were 83.3%, 81.7%, and 88.3%, respectively. Dosimetric analysis in the first 21 patients showed satisfying conformality for planning target volume of GTV, high-risk CTV, and low-risk CTV, while the organs at risk were well protected. The results of long-term quality-of-life investigations in patients without progression were favorable, and nasal discomfort was the most common symptom. No grade 3 or 4 acute or late toxicities were observed.

CONCLUSIONS

The scheme of target volume delineation and dose setting that we designed has favorable clinical effects with mild side effects in treating patients with stage I-II nasal cavity NKTCL and Waldeyer's ring NKTCL.

Tislelizumab and radiation therapy in low-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type: a phase II study protocol

Low-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type has a favorable outcome with radiation therapy alone, and the addition of chemotherapy shows no survival benefit. Nonetheless, a proportion of patients will relapse or progress, with a dismal outcome, highlighting the need for a novel therapeutic strategy. Promising preliminary findings indicate the efficacy of PD-1/PD-L1 inhibitors in extranodal natural killer/T-cell lymphoma, nasal type, with good toxicity profiles. Here we describe the design of a phase II study (CLCG-NKT-2101), which is evaluating the safety and efficacy of adding anti-PD-1 antibody to the current radiation therapy regimen in low-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type patients. Tislelizumab will be added in an inductive and concurrent way to radiation therapy. The primary end point will be the complete response rate after induction immunotherapy. Clinical trial registration: ClinicalTrials.gov (NCT05149170).

Outcome and risk prediction of early progression in patients with extranodal natural killer/T cell lymphoma from the CLCG study

Recently, progression-free survival at 24 months (PFS24) was defined as clinically relevant for patients with extranodal NK/T cell lymphoma. Herein, the clinical data from two independent random cohorts (696 patients each in the primary and validation datasets) were used to develop and validate a risk index for PFS24 (PFS24-RI), and evaluate its ability to predict early progression. Patients achieving PFS24 had a 5-year overall survival (OS) of 95.8%, whereas OS was only 21.2% in those failing PFS24 (P<0.001). PFS24 was an important predictor of subsequent OS, independent of risk stratification. The proportion of patients achieving PFS24 and 5-year OS rates correlated linearly among risk-stratified groups. Based on multivariate analysis of the primary dataset, the PFS24-RI included five risk factors: stage II or III/IV, elevated lactate dehydrogenase, Eastern Cooperative Oncology Group score ≥2, primary tumor invasion, and extra-upper aerodigestive tract. PFS24-RI stratified the patients into low-risk (0), intermediate-risk (1-2), high-risk (≥3) groups with different prognoses. Harrell's C-index of PFS24-RI for PFS24 prediction was 0.667 in the validation dataset, indicating a good discriminative ability. PFS24-RI calibration indicated that the actual observed and predicted probability of failing PFS24 agreed well. PFS24-RI provided the probability of achieving PFS24 at an individual patient level.

Reappraisal of the role of radiation therapy in lymphoma treatment

Radiation therapy (RT) for lymphomas has improved dramatically with modern imaging and treatment techniques, encompassing only the necessary volume with minimal doses to normal structures. Prescribed radiation doses are reduced, and fractionation schedules are under revision. With effective systemic treatment only initial macroscopic disease is irradiated. With no or less effective systemic treatment, possible microscopic disease is also included. Risks of long-term side effects of RT have diminished dramatically and should be weighed against risks from more systemic treatment or increased risk of relapse. Lymphoma patients are often elderly, they tolerate modern limited RT very well. Lymphomas refractory to systemic treatments often remain radioresponsive, and brief, mild RT may offer effective palliation. New roles for RT are emerging with immune therapies. RT for "bridging," keeping the lymphoma under control while waiting for immune therapy, is well established. Enhancement of the immune response to lymphomas, so-called "priming," is being intensively researched.

Etoposide, dexamethasone, and pegaspargase with sandwiched radiotherapy in early-stage natural killer/T-cell lymphoma: A randomized phase III study

Methotrexate, etoposide, dexamethasone, and pegaspargase (MESA) with sandwiched radiotherapy is known to be effective for early-stage extranodal natural killer/T-cell lymphoma, nasal type (NKTCL). We explored the efficacy and safety of reduced-intensity, non-intravenous etoposide, dexamethasone, and pegaspargase (ESA) with sandwiched radiotherapy. This multicenter, randomized, phase III trial enrolled patients aged between 14 and 70 years with newly diagnosed early-stage nasal NKTCL from 27 centers in China. Patients were randomly assigned (1:1) to receive ESA (pegaspargase 2,500 IU/m² intramuscularly on day 1, etoposide 200 mg orally, and dexamethasone 40 mg orally on days 2-4) or MESA (methotrexate 1 g/m² intravenously on day 1, etoposide 200 mg orally, and dexamethasone 40 mg orally on days 2-4, and pegaspargase 2,500 IU/m² intramuscularly on day 5) regimen (four cycles), combined with sandwiched radiotherapy. The primary endpoint was overall response rate (ORR). The non-inferiority margin was -10.0%. From March 16, 2016, to July 17, 2020, 256 patients underwent randomization, and 248 (ESA [n = 125] or MESA [n = 123]) made up the modified intention-to-treat population. The ORR was 88.8% (95% confidence interval [CI], 81.9-93.7) for ESA with sandwiched radiotherapy and 86.2% (95% CI, 78.8-91.7) for MESA with sandwiched radiotherapy, with an absolute rate difference of 2.6% (95% CI, -5.6-10.9), meeting the non-inferiority criteria. Per-protocol and sensitivity analysis supported this result. Adverse events of grade 3 or higher occurred in 42 (33.6%) patients in the ESA arm and 81 (65.9%) in the MESA arm. ESA with sandwiched radiotherapy is an effective, low toxicity, non-intravenous regimen with an outpatient design, and can be considered as a first-line treatment option in newly diagnosed early-stage nasal NKTCL.

Diagnostic and prognostic value of pretreatment PET/CT in extranodal natural killer/T-cell lymphoma: a retrospective multicenter study

PURPOSE

The objective of this research was to assess the utility of positron emission tomography combined with computed tomography (PET/CT) to detect bone marrow invasion (BMI) and the predictive value of PET/CT in extranodal natural killer/T-cell lymphoma (ENKTL) patients.

PATIENTS AND METHODS

This multicentre study enrolled ENKTL patients who underwent pretherapy PET/CT and bone marrow biopsy (BMB). The specificity, sensitivity, negative predictive value (NPV), and positive predictive value (PPV) of PET/CT and BMB for BMI were evaluated. Multivariate analysis was used to identify predictive parameters for constructing a nomogram.

RESULTS

Seven hundred and forty-eight patients were identified from four hospitals, with eighty (10.7%) having focal skeletal lesions on PET/CT and fifty (6.7%) having positive BMB. When BMB is considered as the gold standard, the specificity, sensitivity, PPV, and NPV of PET/CT for diagnosing BMI were found to be 93.8%, 74.0%, 46.3%, and 98.1%, respectively. PET/CT-positive individuals showed significantly worse OS than PET/CT-negative patients in the subgroup of BMB-negative cases. The nomogram model created according to the significant risk factors from multivariate analysis performed well in predicting survival probability.

CONCLUSION

PET/CT offers a superior degree of precision for determining BMI in ENKTL. A nomogram model including the parameters of PET/CT can predict survival probability and may help in applying appropriate personalized therapy.

A novel prognostic model based on ferritin and nomogram-revised risk index could better stratify patients with extranodal natural killer/T-cell lymphoma

BACKGROUND

Extranodal natural killer (NK)/T-cell lymphoma (ENKTCL) is an aggressive lymphoma with marked heterogeneity, resulting in a distinct prognosis even in patients with the same disease stage. The nomogram-revised risk index (NRI) has been proposed to stratify patients with ENKTCL. Numerous reports have revealed the prognostic role of serum ferritin in various cancers.

PURPOSE

We aimed to evaluate the role of NRI in our single cohort of patients with ENKTCL treated uniformly, explore the prognostic value of ferritin, and establish a new prognostic model to better stratify patients with ENKTCL.

METHODS

We included 326 patients with ENKTCL with detailed data regarding clinical characteristics and survival outcomes. All patients were treated with asparaginase-based chemotherapy with or without radiotherapy. Multiple R packages were used to analyze the prognostic factors and derive a novel prognostic model.

RESULTS

In the training cohort comprising 236 patients with ENKTCL, NRI significantly correlated with progression-free survival (PFS) and overall survival (p < 0.0001). Using a ferritin level of 400 μg/L as the cutoff value, patients with high ferritin levels had significantly inferior PFS (p = 0.00028). Integrating the NRI score and four easily accessible clinical parameters, namely ferritin, hemoglobin, albumin, and D-dimer, a new prognostic model was constructed, stratifying patients with ENKTCL into three risk groups. This new prognostic model was independent of disease stage and NRI and performed better than NRI. Furthermore, this model helped to stratify patients within the same NRI risk groups. Finally, the role of this novel prognostic model was validated in the external validation cohort comprising 90 patients with ENKTCL.

CONCLUSIONS

Serum ferritin level could be a novel prognostic factor in patients with ENKTCL. The new prognostic model combining NRI and clinical parameters could better predict the prognosis of ENKTCL, thereby warranting further validation and potentially guiding individualized treatment in future prospective clinical trials.

Risk stratification and prognostic value of multi-modal MRI-based radiomics for extranodal nasal-type NK/T-cell lymphoma

BACKGROUND

Magnetic resonance imaging (MRI) performs well in the locoregional assessment of extranodal nasal-type NK/T-cell lymphoma (ENKTCL). It's important to assess the value of multi-modal MRI-based radiomics for estimating overall survival (OS) in patients with ENKTCL.

METHODS

Patients with ENKTCL in a prospectively cohort were systemically reviewed and all the pretreatment MRI were acquisitioned. An unsupervised spectral clustering method was used to identify risk groups of patients and radiomic features. A nomogram-revised risk index (NRI) plus MRI radiomics signature (NRI-M) was developed, and compared with the NRI.

RESULTS

The 2 distinct type I and II groups of the MRI radiomics signatures were identified. The 5-year OS rates between the type I and type II groups were 87.2% versus 67.3% (P = 0.002) in all patients, and 88.8% versus 69.2% (P = 0.003) in early-stage patients. The discrimination and calibration of the NRI-M for OS prediction demonstrated a better performance than that of either MRI radiomics or NRI, with a mean area under curve (AUC) of 0.748 and 0.717 for predicting the 5-year OS in all-stages and early-stage patients.

CONCLUSIONS

The NRI-M model has good performance for predicting the prognosis of ENKTCL and may help design clinical trials and improve clinical decision making.

Treatment of extranodal NK/T-cell lymphoma: From past to future

Extranodal NK/T-cell lymphoma (ENKTCL) is the most common subtype of T/NK-cell lymphoma in Asia and Latin America, but very rare in North American and Europe. Patient survival has improved significantly over the past two decades. However, standard treatment has not yet been established, although dozens of prospective trials have been conducted. To help understand how the treatment of ENKTCL has evolved in the past and what trends lie ahead, we have comprehensively reviewed the treatment of this aggressive malignancy, with a particular focus on neglected or unanswered issues, such as the optimal staging method, the best partner of asparaginase (Asp), the individualized administration of Asp, the preferred sequence of CT and RT and so on. Overall, the 5-year overall survival (OS) of patients with Ann Arbor stage I/II disease increased from < 50% in the early 20th century to > 80% in recent years, and the median OS of patients with Ann Arbor stage III/IV disease increased from < 1 year to more than 3 years. The improvement in patient survival is largely attributable to advances in radiation technology and the introduction of Asp and anti-PD-1/PD-L1 immunotherapy into practice. Radiotherapy is essential for patients with early-stage disease, while Asp-based chemotherapy (CT) and PD-1/PD-L1 inhibitors significantly improved the prognosis of patients with advanced-stage disease. ENKTCL management is trending toward simpler regimens, less toxicity, and higher efficacy. Novel drugs, such as manufactured T cells, monoclonal antibodies, and small molecule inhibitors, are being intensively investigated. Based on the fact that ENKTCL is highly resistant to cytotoxic drugs except Asp, and aggressive CT leads to higher toxicity rather than better outcomes, we recommend it is unnecessary to expend additional resources to compare different combinations of Asp with cytotoxic agents. Instead, more efforts should be made to optimize the use of Asp and immunotherapy to maximize efficacy and minimize toxicity, explore ways to overcome resistance to Asp and immunotherapy, identify novel treatment targets, and define subpopulations who may benefit more from specific treatments.

High-dose extended-field radiotherapy plus chemotherapy improved survival in extranodal NK/T-cell lymphoma in a real-life setting: results from the multicenter T-Cell Brazil Project

Extranodal natural-killer/T-cell lymphoma (ENKTL) is a rare and aggressive Epstein-Barr virus related mature T-cell and natural-killer malignancy. Although highly prevalent in South America, few studies covering data from this geographic location have been published. Therefore, this study aims to report clinical characteristics, prognostic factors, and outcomes in a multicenter cohort of ENKTL patients from Brazil. This retrospective, observational and multicenter study included 98 ENKTL patients treated during two decades in Brazil. Data were extracted from the T-Cell Brazil Project database. In our cohort, 59/98 patients (60.2%) were male, with a median age of 50 years. Sixty-two patients (63.3%) had B-symptoms, 26/98 (26.5%) had Eastern Cooperative Oncology Group scale ≥ 2; 16/98 (16.3%) presented extranasal disease and 34.7% (34/98) were advanced-stage (Ann Arbor/Cotswolds III/IV). The median follow-up for the whole cohort was 49 months, with an estimated 2-year overall survival (OS) and progression-free survival (PFS) of 51.1% and 17.7%, respectively. In early-stage disease (IE/IIE), the median OS was 21.8 months for patients treated with concurrent radiotherapy plus chemotherapy (CCRT-VIPD [etoposide/vp-16, ifosfamide, cisplatin and dexamethasone), 16.2 months for sequential chemoradiotherapy (SCRT) followed by asparaginase-based regimens, and 56.7 months for SCRT followed by CHOP-like (cyclophosphamide, doxorrubicin, vincristine and prednisone) treatments, p = 0.211. CCRT was associated with higher rates of early-mortality, hematological toxicity, and mucositis. Median OS was 8.2 months for patients with advanced-stage disease receiving regimens containing asparaginase compared to 3.2 months for anthracycline-based therapy, p = 0.851. Chemo-radiotherapy (CRT) regimens demonstrated better OS (p = 0.001) and PFS (p = 0.007) than chemotherapy alone. Multivariate analysis revealed anemia, relapsed/refractory (R/R) disease and radiotherapy omission as poor outcome predictors for OS. Lymphopenia and radiotherapy omission adversely affected PFS. Concerning progression of disease within 24-months (POD-24), clinical stage III/IV was a poor outcome predictor. In this real-life Brazilian cohort, ENKTL presented dismal outcomes. Radiation therapy was an independent factor for increased OS and PFS, but CCRT regimens were associated with higher toxicities. Polychemotherapy based on anti-multi drug resistant agents was not associated with survival benefit in either early or advanced-stage disease in our patient cohort.

Characteristics and prognosis of distant metastasis after primary treatment for early-stage extranodal nasal-type natural killer/T-cell lymphoma from the China Lymphoma Collaborative Group database

This study aimed to investigate the characteristics and prognosis of distant metastasis (DM) after primary treatment for early-stage extranodal nasal-type natural killer (NK)/T-cell lymphoma (ENKTCL). A total of 1619 patients from the China Lymphoma Collaborative Group database were retrospectively reviewed. The cumulative incidence of DM was assessed using Fine and Gray's competing risk analysis. The correlation between DM sites was evaluated using phi coefficients, while DM sites were classified using hierarchical clustering. Regression analysis was used to assess the linear correlation between DM-free survival (DMFS) and overall survival (OS). The 5-year cumulative DM rate was 26.2%, with the highest annual hazard rate being in the first year (14.9%). The most frequent DM sites were the skin and soft tissues (SSTs, 32.4%) and distant lymph nodes (LNs, 31.3%). DM sites were categorized into four subgroups of distinct prognosis - distant LN, SST, extracutaneous site, and lymphoma-associated hemophagocytic lymphohistiocytosis. SST or distant LN, solitary metastasis, and late-onset DM demonstrated a relatively favorable prognosis. Contemporary chemotherapy significantly decreased DM rates and improved DMFS. Decreased DM rates were further associated with increased OS probabilities. Our findings improve the understanding of the variable clinical behaviors of early-stage ENKTCL based on four distinct DM sites and thus provide guidance for future therapeutic decisions, metastatic surveillance, and translational trial design.

The value of routine bone marrow examination in patients with extranodal NK/T-cell lymphoma staged with PET/CT

BACKGROUND

Limited evidence supports the omission of routine bone marrow (BM) examination (biopsy and aspiration) in patients with nasal-type extranodal NK/T-cell lymphoma (ENKTCL). This study was aimed at assessing whether BM examination provides valuable information for positron emission tomography/computed tomography (PET/CT)-based staging in this patient population.

PATIENTS AND METHODS

Patients newly diagnosed with ENKTCL who underwent initial staging with both PET/CT and BM examination between 2013 and 2020 were retrospectively identified in two Chinese institutions. Overall, 742 patients were included; the BM examination was positive in 67 patients.

RESULTS

Compared with BM biopsy alone, the combination of BM biopsy and aspiration assessment did not afford any additional diagnostic value. No patient with a positive BM biopsy was found to have early-stage disease by PET/CT. BM biopsy or PET/CT led to upstaging from stage III to IV as a result of BM involvement in 21 patients. In 135 patients with distant organ involvement, BM involvement was associated with worse overall survival (OS) and progression-free survival (PFS) compared with the corresponding durations in patients without BM involvement (2-year OS: 35.9% vs. 60.4%, p < .001; PFS: 26% vs. 40.7%, p = .003). No difference in survival was noted between groups judged positive based on PET/CT and BM biopsy.

CONCLUSION

Compared with aspiration, BM biopsy led to the detection of more BM lesions. Baseline PET/CT can be safely used to exclude BM involvement in early-stage disease. Overall, routine BM examination affords diagnostic or prognostic value over PET/CT in patients with advanced-stage nasal-type ENKTCL.

Treatment planning with a 2.5 MV photon beam for radiation therapy

PURPOSE

The shallow depth of maximum dose and higher dose fall-off gradient of a 2.5 MV beam along the central axis that is available for imaging on linear accelerators is investigated for treatment of shallow tumors and sparing the organs at risk (OARs) beyond it. In addition, the 2.5 MV beam has an energy bridging the gap between kilo-voltage (kV) and mega-voltage (MV) beams for applications of dose enhancement with high atomic number (Z) nanoparticles.

METHODS

We have commissioned and utilized a MATLAB-based, open-source treatment planning software (TPS), matRad, for intensity-modulated radiation therapy (IMRT) dose calculations. Treatment plans for prostate, liver, and head and neck (H&N), nasal cavity, two orbit cases, and glioblastoma multiforme (GBM) were performed and compared to a conventional 6 MV beam. Additional Monte Carlo calculations were also used for benchmarking the central axis dose.

RESULTS

Both beams had similar planning target volume (PTV) dose coverage for all cases. However, the 2.5 MV beam deposited 6%-19% less integral doses to the nasal cavity, orbit, and GBM cases than 6 MV photons. The mean dose to the heart in the liver plan was 10.5% lower for 2.5 MV beam. The difference between the doses to OARs of H&N for two beams was under 3%. Brain mean dose, brainstem, and optic chiasm max doses were, respectively, 7.5%-14.9%, 2.2%-8.1%, and 2.5%-19.0% lower for the 2.5 MV beam in the nasal cavity, orbit, and GBM plans.

CONCLUSIONS

This study demonstrates that the 2.5 MV beam can produce clinically relevant treatment plans, motivating future efforts for design of single-energy LINACs. Such a machine will be capable of producing beams at this energy beneficial for low- and middle-income countries, and investigations on dose enhancement from high-Z nanoparticles.

How we treat NK/T-cell lymphomas

Natural killer (NK)/T-cell lymphomas are aggressive malignancies with a predilection for Asian and South American populations. Epstein-Barr virus (EBV) infection in lymphoma cells is universal. Predominantly extranodal, NK/T-cell lymphomas are divided clinically into nasal (involving the nose and upper aerodigestive tract), non-nasal (involving the skin, gastrointestinal tract, testes, and other organs), and aggressive leukaemia/lymphoma (involving the marrow and multiple organs) subtypes. Initial assessment should include imaging with positron emission tomography computed tomography (PET/CT), quantification of plasma EBV DNA as a surrogate marker of lymphoma load, and bone marrow examination with in situ hybridization for EBV-encoded small RNA. Prognostication can be based on presentation parameters (age, stage, lymph node involvement, clinical subtypes, and EBV DNA), which represent patient factors and lymphoma load; and dynamic parameters during treatment (serial plasma EBV DNA and interim/end-of-treatment PET/CT), which reflect response to therapy. Therapeutic goals are to achieve undetectable plasma EBV DNA and normal PET/CT (Deauville score ≤ 3). NK/T-cell lymphomas express the multidrug resistance phenotype, rendering anthracycline-containing regimens ineffective. Stage I/II nasal cases are treated with non-anthracycline asparaginase-based regimens plus sequential/concurrent radiotherapy. Stage III/IV nasal, and non-nasal and aggressive leukaemia/lymphoma cases are treated with asparaginase-containing regimens and consolidated by allogeneic haematopoietic stem cell transplantation (HSCT) in suitable patients. Autologous HSCT does not improve outcome. In relapsed/refractory cases, novel approaches comprise immune checkpoint blockade of PD1/PD-L1, EBV-specific cytotoxic T-cells, monoclonal antibodies, and histone deacetylase inhibitors. Future strategies may include inhibition of signalling pathways and driver mutations, and immunotherapy targeting the lymphoma and its microenvironment.

First-line chemoradiation with or without chidamide (tucidinostat) in patients with early stage intermediate- and high-risk early-stage extranodal nasal-type natural killer/T-cell lymphoma: a randomized phase 2 study in China

PURPOSE

We investigated the safety and efficacy profile of intensity-modulated radiation therapy (IMRT) followed by gemcitabine, dexamethasone, cisplatin (GDP), plus chidamide in the first-line setting for intermediate- and high-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type (ENKTCL).

METHODS

This was an open-label, randomized phase 2 trial performed at two centers in China. Patients were eligible if they were newly-diagnosed with intermediate- and high-risk early-stage ENKTCL with at least one risk factor based on a nomogram-revised risk index:> 60 years old, elevated serum lactate dehydrogenase, invasion of the primary tumor, stage II or Eastern Cooperative Oncology Group performance status > 1 or stage II disease. Patients were treated with IMRT followed by GDP, with or without chidamide, in the first-line setting. Two-year progression-free survival (PFS) comprised the primary endpoint. Toxicities, the 2-year overall survival (OS), and the response rate comprised the secondary endpoints.

RESULTS

Eligible patients (n = 74) were enrolled between May 2015 and December 2019. Among them, 37 patients were treated with IMRT+GDP+chidamide (chidamide group), while 37 cases were treated with IMRT+GDP (control group). Follow-up comprised a median of 43.4 months (range, 1.0-74.6 months). The objective response rate was 86.5% in the chidamide group and 78.4% in the control group (P = 0.359) at the end of treatment completion. The 2-year OS and PFS rates were 89.2% and 75.2% in the chidamide group versus 83.8% (P = 0.388) and 70.2% (P = 0.821) in the control group. The main adverse events were hematological toxicities and mucositis, with similar rates in the two groups (P > 0.05).

CONCLUSIONS

The addition of chidamide to IMRT + GDP as first-line treatment achieved similar treatment outcomes and tolerable toxicities in patients with intermediate- and high-risk ENKTCL.

Recent Advances in the Diagnosis and Treatment of Natural Killer Cell Malignancies

Simple Summary

Natural killer (NK)/T-cell lymphomas are aggressive extranodal Epstein–Barr virus (EBV)-positive malignancies. They can be divided into three subtypes: nasal (involving the nose and upper aerodigestive tract), non-nasal (involving skin, gastrointestinal tract, testis and other organs) and disseminated (involving multiple organs). Lymphoma cells are positive for CD3ε, CD56, cytotoxic molecules and EBV-encoded small RNA. There is a predilection for Asian and Central/South American populations. Genome-wide association studies have identified lymphoma susceptibility loci in Asians. Positron emission tomography computed tomography and plasma EBV DNA quantification are crucial at diagnosis and follow-up. Stage I/II patients receive non-athracycline asparaginse-containing regimens, together with sequential/concurrent radiotherapy. Anthracycline-containing regimens are ineffective. Stage III/IV patients receive asparaginase-containing regimens, followed by allogeneic haematopoietic stem cell transplantation (HSCT). Autologous HSCT does not improve outcome. In relapsed/refractory patients, novel approaches include PD1/PD-L1 targeting, EBV-specific cytotoxic T-cells, and monoclonal antibodies. Small molecules including histone deacetylase inhibitors may be beneficial.

Abstract

Natural killer (NK)/T-cell lymphomas are aggressive malignancies. Epstein–Barr virus (EBV) infection in lymphoma cells is invariable. NK/T-cell lymphomas are divided into nasal, non-nasal, and disseminated subtypes. Nasal NK/T-cell lymphomas involve the nasal cavity and the upper aerodigestive tract. Non-nasal NK/T-cell lymphomas involve the skin, gastrointestinal tract, testis and other extranodal sites. Disseminated NK/T-cell lymphoma involves multiple organs, rarely presenting with a leukaemic phase. Lymphoma cells are positive for CD3ε (not surface CD3), CD56, cytotoxic molecules and EBV-encoded small RNA. There is a predilection for Asian and Central/South American populations. Genome-wide association studies have identified lymphoma susceptibility loci in Asian patients. Positron emission tomography computed tomography and plasma EBV DNA quantification are crucial evaluations at diagnosis and follow-up. Stage I/II patients typically receive non-athracycline regimens containing asparaginse, together with sequential/concurrent radiotherapy. Anthracycline-containing regimens are ineffective. Stage III/IV patients are treated with asparaginase-containing regimens, followed by allogeneic haematopoietic stem cell transplantation (HSCT) in suitable cases. Autologous HSCT does not improve outcome. In relapsed/refractory patients, novel approaches are needed, involving PD1/PD-L1 targeting, EBV-specific cytotoxic T-cells, and monoclonal antibodies. Small molecules including histone deacetylase inhibitors may be beneficial in selected patients. Future strategies may include targeting of signalling pathways and driver mutations.

Radiotherapy of sinonasal cancers

We present the update of the recommendations of the French society of radiotherapy and oncology on the indications and the technical methods of carrying out radiotherapy of sinonasal cancers. Sinonasal cancers (nasal fossae and sinus) account for 3 to 5% of all cancers of the head and neck. They include carcinomas, mucosal melanomas, sarcomas and lymphomas. The management of sinonasal cancers is multidisciplinary but less standardized than that of squamous cell carcinomas of the upper aerodigestive tract. As such, patients with sinonasal tumors can benefit from the expertise of the French expertise network for rare ENT cancers (Refcor). Knowledge of sinonasal tumour characteristics (histology, grade, risk of lymph node involvement, molecular characterization, type of surgery) is critical to the determination of target volumes. An update of multidisciplinary indications and recommendations for radiotherapy in terms of techniques, target volumes and radiotherapy fractionation of the French society of radiotherapy and oncology (SFRO) was reported in this manuscript.

GELAD chemotherapy with sandwiched radiotherapy for patients with newly diagnosed stage IE/IIE natural killer/T-cell lymphoma: a prospective multicentre study

Early-stage natural killer/T-cell lymphoma (NK/TCL) patients usually receive a combination of chemotherapy and radiotherapy, but the optimal treatment approach has not yet been established. This study aimed to investigate the efficacy and safety profile of a novel chemotherapy regimen and sandwiched radiotherapy in early-stage NK/TCL. Patients with newly diagnosed stage IE/IIE disease were eligible. Patients were initially treated with two courses of the GELAD regimen (gemcitabine 1·0 g/m² day 1, etoposide 60 mg/m² days 1-3, pegaspargase 2000 units/m² day 4, and dexamethasone 40 mg days 1-4), followed by intensity-modulated radiotherapy (IMRT; 50-56 Gy in 25-28 fractions) and two additional courses of GELAD chemotherapy. A total of 52 patients were enrolled. The overall response rate and complete response rate per Lugano 2014 criteria were 94·2% and 92·3% respectively. With a median follow-up of 32 months, the estimated four-year overall survival rate and progression-free survival rate were 94·2% [95% confidence interval (CI), 83·2% to 93·1%] and 90·4% (95% CI, 78·4% to 95·9%) respectively. The most common adverse events were related to pegaspargase. Haematological toxicities were mild, with grade 3/4 neutropenia in 15·4% of patients. Our study provides a new approach with high activity and improved safety for the treatment of early-stage NK/TCL patients. This study was registered at www.clinicaltrials.gov as NCT02733458.

Outcome-based multiobjective optimization of lymphoma radiation therapy plans

At its core, radiation therapy (RT) requires balancing therapeutic effects against risk of adverse events in cancer survivors. The radiation oncologist weighs numerous disease and patient-level factors when considering the expected risk-benefit ratio of combined treatment modalities. As part of this, RT plan optimization software is used to find a clinically acceptable RT plan delivering a prescribed dose to the target volume while respecting pre-defined radiation dose-volume constraints for selected organs at risk. The obvious limitation to the current approach is that it is virtually impossible to ensure the selected treatment plan could not be bettered by an alternative plan providing improved disease control and/or reduced risk of adverse events in this individual. Outcome-based optimization refers to a strategy where all planning objectives are defined by modeled estimates of a specific outcome's probability. Noting that various adverse events and disease control are generally incommensurable, leads to the concept of a Pareto-optimal plan: a plan where no single objective can be improved without degrading one or more of the remaining objectives. Further benefits of outcome-based multiobjective optimization are that quantitative estimates of risks and benefit are obtained as are the effects of choosing a different trade-off between competing objectives. Furthermore, patient-level risk factors and combined treatment modalities may be integrated directly into plan optimization. Here, we present this approach in the clinical setting of multimodality therapy for malignant lymphoma, a malignancy with marked heterogeneity in biology, target localization, and patient characteristics. We discuss future research priorities including the potential of artificial intelligence.

The optimal timing of radiotherapy in the combination treatment of limited-stage extranodal natural killer/T-cell lymphoma, nasal type: an updated meta-analysis

This study was designed to explore the relative efficacy and toxicity of upfront radiotherapy (RT) and late RT in combination treatments for patients with limited-stage extranodal natural killer/T-cell lymphoma nasal type (LS-ENKTL). We searched for clinical trials in the PubMed database that compared upfront RT with late RT in the combined treatment of patients with LS-ENKTL. We systematically evaluated the differences in survival, treatment response, and treatment-related adverse events (AEs) between these two groups. Ten retrospective studies with a total of 1752 patients were included. Upfront RT significantly prolonged the overall survival (OS) and progression-free survival (PFS) of patients compared to late RT in combination with chemotherapy (CT) (HR = 0.72, 95% CI 0.59-0.88, P = 0.001 for OS; HR = 0.57, 95% CI 0.41-0.79, P = 0.0007 for PFS). The complete remission (CR) rate in the upfront RT group was superior to that in the late RT group (HR = 1.61, 95% CI 1.09-2.37, P = 0.02). Patients experienced similar local recurrence-free survival (LRFS), objective response rates (ORR), and toxicity between these two arms (P > 0.05 for all) in the analysis of each subgroup. The survival benefit of upfront RT was not correlated with the RT dose, concurrent chemoradiotherapy (CCRT) (or not), or the CT regimen (P > 0.05 for all). Without compromises in terms of toxicity, RT dose, and treatment modality, upfront RT can significantly benefit OS, PFS, and CR compared to late RT in combination treatment. These findings verified that the upfront RT regimen is more suitable for patients with LS-ENKTL.

Association of improved overall survival with decreased distant metastasis following asparaginase-based chemotherapy and radiotherapy for intermediate- and high-risk early-stage extranodal nasal-type NK/T-cell lymphoma: a CLCG study

BACKGROUND

This study evaluated the survival benefit of asparaginase (ASP)-based versus non-ASP-based chemotherapy combined with radiotherapy in a real-world cohort of patients with early-stage extranodal nasal-type natural killer/T-cell lymphoma (ENKTCL).

PATIENTS AND METHODS

We identified 376 patients who received combined radiotherapy with either ASP-based (ASP, platinum, and gemcitabine; n = 286) or non-ASP-based (platinum and gemcitabine; n = 90) regimens. The patients were stratified into low-, intermediate-, and high-risk groups using the early stage-adjusted nomogram-revised risk index. Overall survival (OS) and distant metastasis (DM)-free survival (DMFS) between the chemotherapy regimens were compared using inverse probability of treatment weighting (IPTW) and multivariable analyses.

RESULTS

ASP-based (versus non-ASP-based) regimens significantly improved 5-year OS (84.5% versus 73.2%, P = 0.021) and DMFS (84.4% versus 74.5%, P = 0.014) for intermediate- and high-risk patients, but not for low-risk patients in the setting of radiotherapy. Moreover, ASP-based regimens decreased DM, with a 5-year cumulative DM rate of 14.9% for ASP-based regimens compared with 25.1% (P = 0.014) for non-ASP-based regimens. The survival benefit of ASP-based chemotherapy and radiotherapy remained consistent after adjusting the confounding variables using IPTW and multivariate analyses; additional sensitivity analyses confirmed these results.

CONCLUSIONS

The findings provided support for ASP-based chemotherapy and radiotherapy as a first-line treatment strategy for intermediate- and high-risk early-stage ENKTCL.