Pattern Of Extension And Prognostic Factors In Early Stage Extranodal Nasal-Type NK/T-cell Lymphoma Of The Upper Aerodigestive Tract:a Study Based On Magnetic Resonance Imaging

Objective The aim of this study was to determine the patterns of local tumor extension and regional spread in early stage extranodal nasal-type NK/T-cell lymphoma (NKTCL) of the upper aerodigestive tract based on magnetic resonance imaging (MRI).Materials and Methods Between January1988and December2011,107consecutive patients with available pre-treatment MRI and stage Ⅰ and Ⅱ upper aerodigestive tract NKTCL were selected for the present study. Among them,88patients had primary nasal NKTCL, and19patients had primary Waldeyer's ring NKTCLResults The incidence of primary tumor extended into adjacent structures or organs was59%(27cases). According to the incidence rates of local tumor extension in patients with nasal NKTCL, the involved structures or organs surrounding nasal cavity were classified into three subgroups:high risk (>20%):nasopharynx (35%), maxillary sinus (21%) and ethmoid sinus (21%); intermediate risk (5-20%):skin (14%), oropharynx (8%) and hard plate (7%); and low risk (<5%):orbit (5%), soft plate (2%), skull base (2%), pterygoplatine fossa (2%), hypopharynx(l%), infratemporal fossa (1%) and gingiva (1%). Involvement of regional lymph nodes were observed in33(31%) patients. Regional lymph nodal spread in a contiguous fashion in all patients with lymph node involvement, and no patient had skip lymph node involvement in lower neck. Retropharyngeal nodes (RLN) were the most frequently involved region (23%), followed by level II nodes (19%). Compared with NKTCL originating from Waldeyer's ring, nasal NKTCL was less likely to have regional lymph node involvement (26%vs.53%, P=0.023). However, when nasopharynx was involved, the lymph node involvement rates were equally high for patients with nasal and Waldeyer's ring NKTCL (54%vs.53%, P=0.879).Conclusions Local extension was common and most frequent involvement of adjacent structures or organs included the nasopharynx, maxillary sinus and ethmoid sinus in patients with early stage NKTCL of the upper aerodigestive tract. Regional lymph nodal spread in a contiguous fashion. When nasopharynx was involved, the incidence of regional lymph node involvement was more common in patients with nasal NKTCL. Objective The aim of the present study was to assess treatment outcomes of extended involved-field radiotherapy based on tumor extension determined by magnetic resonance imaging (MRI) in patients with early stage extranodal nasal-type NK/T-cell lymphoma (NKTCL) of the upper aerodigestive tract.Materials and Methods Between January1988and December2011,106patients with early stage upper aerodigestive tract NKTCL underwent extended involved-field radiotherapy based on tumor extension determined by MRI scan. There were74cases of stage I and32cases of stage II disease. Among them,57patients received radiotherapy alone, and49patients received radiotherapy plus chemotherapy.Results The overall response rate after treatment was93%, with a complete response rate of91%. With median follow-up periods of24months, the2-year overall survival (OS) and progression-free survival (PFS) rates were82%and69%, respectively. The2-year OS and PFS rates were85%and76%for stage I disease compared with73%and52%for stage II disease, respectively (OS, P=0.123; PFS, P=0.026). Prognosis of stage II patients with isolated retropharyngeal nodes involvement were comparable to those with stage I disease. The2-year OS rates were91%and85%(P=0.956), with the2-year PFS rate of56%and76%(P=0.442), respectively. Thirty patients experienced treatment failure, including local failure in9(8.5%) patients, regional failure in3(3%) patients, and systemic failure in24(23%) patients. Of10patients with local regional failure,5patients developed in field recurrence only.Conclusions For patients with early stage NKTCL of the upper aerodigestive tract, extended involved-field radiotherapy based on tumor extension determined by MRI showed excellent locoregional control and favorable survival. Prognosis of stage Ⅱ patients with isolated retropharyngeal nodes involvement were comparable to those with stage I disease. Objective The aim of this study was to analyse prognostic factors in patients with early stage extranodal nasal-type NK/T-cell lymphoma (NKTCL) of the upper aerodigestive tract treated with primary radiotherapy.Materials and Methods From January1988to December2011, a total of99patients with early stage upper aerodigestive tract NKTCL treated with primary radiotherapy and available pre-treatment magnetic resonance imaging (MRI) were retrospectively reviewed. There were69cases of stage Ⅰ and30cases of stage Ⅱ disease. Among them,55patients received radiotherapy alone, and44patients received radiotherapy plus chemotherapy. The delineation of primary tumor volume was performed on pre-treatment MRI. We analyzed their survival outcomes according to clinical characteristics, primary tumor volume, tumor necrosis grade, Korea prognostic index (KPI) and stage modified international prognostic index (mIPI), and determined the independent prognostic factors affecting survival.Results With median follow-up periods of24months, the2-year overall survival (OS), and progression-free survival (PFS) rates were82%and69%, respectively. In univariate analysis, primary tumor volume≥30cm3and neck lymph node metastases were correlated with OS and PFS. Tumor necrosis grade, KPI and mIPI were not significant factors for survival. By multivariate analysis, primary tumor volume≥30cm3was an independent prognostic factor. The2-year OS rates for patients with primary tumor volume≥30cm3and<30cm3were64%and89%(P=0.004), with the2-year PFS rates of54%and77%(P=0.036), respectively. Furthermore, patients with primary tumor volume≥30cm3were at higher risk of progression disease (PD) after initial treatment and distant failure compared with patients with primary tumor volume<30cm3. The PD rate after initial treatment and crude distant failure rate for patients with primary tumor volume≥30cm3and<30cm3were21%versus3%(P=0.01) and38%versus17% (P=0.036), respectively.Conclusions The primary tumor volume≥30cm3measured by MRI is an independent prognostic factor in patients with early stage upper aerodigestive tract NKTCL treated with primary radiotherapy.