Expert Anal Cancer Consensus Staging

<p>Accurate pre-therapeutic imaging of the tumour and regional lymph nodes, is - in addition to clinical examination and assessment for distant metastases -essential for prognostication and guiding treatment. Nodal staging has been validated as an important independent prognostic factor [EORTC22861; RTOG9811] and the nodal stage as well as the precise location of involved lymph nodes (mesorectum, presacral space, internal iliac lymph nodes, external iliac lymph nodes, ischiorectal fossa, inguinal lymph nodes) informs the planning of radiotherapy treatment especially when using more conformal techniques such as intensity modulated radiotherapy. It is therefore essential to optimize and standardize pre-treatment imaging to provide accurate and reproducible information to guide treatment decision, development of radiotherapy atlases and clinical trial design.</p><p>Whereas there currently exist a lack of consensus as to which staging modality should be considered as the gold standard for local staging of the tumour (T) and detection of lymph node involvement (N), the use of multi-parametric Magnetic Resonance Imaging (MRI) of the pelvis has been endorsed by international guidelines (NCCN, ESMO/ESTRO).</p><p>An expert panel of radiologist and radiation oncologists with expertise in anal cancer diagnosis and treatment identified by the Anal Staging Subgroup of the International Rare Cancer Incentive (IRCI) will be invited to participate. The panelists will be assigned into groups based on the geographical location and local practice. Each panelist will be provided with access to a series of anonymized MRI datasets of patients with newly diagnosed anal cancer and asked to provide a TNM stage as well as to identify sites of involved nodes (using a standardised proforma – Appendix1).  Each case was selected for the presence of MRI sequences like these:</p><ul><li>T2w TSE sagittal [T2-w sagittal turbo spin echo (TSE) sequence covering the pelvis]</li><li>T1w TSE axial [sequence for pelvic nodal detection] </li><li>T2-w TSE axial [sequence of the pelvis]</li><li>T2w TSE sFOV [high-resolution small-field-of-view T2-w TSE sequences perpendicular and parallel to the anal canal]</li><li>DWI [single shot spin echo-echo planar imaging DWI]</li><li>ADC parametric map [apparent diffusion coefficient (ADC) maps]</li></ul>

精准的术前肿瘤及其区域淋巴结的影像学检查，除临床检查及远处转移评估外，对于预后判断及治疗方案的制定至关重要。淋巴结分期已被证实为重要的独立预后因素[欧洲肿瘤研究治疗组织(EORTC)22861;美国放射治疗与肿瘤学协作组(RTOG)9811]，淋巴结分期以及受累淋巴结的确切位置（中直肠、骶前空间、闭孔淋巴结、髂外淋巴结、坐骨直肠窝、腹股沟淋巴结）为放射治疗计划的制定提供了重要信息，尤其是在采用如调强放射治疗等更为精确的技术时。因此，优化并标准化术前影像学检查，以提供准确且可重复的信息，指导治疗决策、放射治疗图谱的开发及临床试验的设计，显得尤为关键。尽管目前对于哪一种分期方式应被视为肿瘤（T）局部分期和淋巴结受累（N）检测的黄金标准尚无共识，但国际指南（NCCN、ESMO/ESTRO）已推荐使用多参数磁共振成像（MRI）进行盆腔扫描。由国际罕见癌症激励计划（IRCI）的肛门癌分期小组认定的放射科专家和放射治疗专家组成的专家小组将被邀请参与。根据地理分布和当地实践，专家将被分为不同小组。每位专家将获得一组新诊断肛门癌患者的匿名MRI数据集，并被要求提供TNM分期，以及识别受累淋巴结的部位（使用标准化的表格——附录1）。每个病例均选择了包含以下MRI序列：
<ul>
<li>T2w TSE 斜位[T2-w 斜位快速自旋回波(TSE)序列，覆盖盆腔]</li>
<li>T1w TSE 冠状位[盆腔淋巴结检测序列]</li>
<li>T2-w TSE 冠状位[盆腔序列]</li>
<li>T2w TSE sFOV[垂直和平行于肛门通道的高分辨率小视野T2-w TSE序列]</li>
<li>DWI[单次回波平面成像DWI]</li>
<li>ADC参数图[表观扩散系数(ADC)图]</li>
</ul>