Department of Radiation Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Unit of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Sci Rep. 2020 Sep 3;10(1):14613. doi: 10.1038/s41598-020-71577-8.
To assess the role of sentinel lymph-node biopsy (SLNB) and FDG-PET in staging and radiation treatment (RT) of anal cancer patients. This retrospective study was performed on 80 patients (male: 32, female: 48) with a median age of 60 years (39-89 years) with anal squamous cell carcinoma who were treated from March 2008 to March 2018 at the IRCCS San Raffaele Hospital. Patients without clinical evidence of inguinal LNs metastases and/or with discordance between clinical evidence and imaging features were considered for SLNB. FDG-PET was performed in 69/80 patients. Patients with negative imaging in inguinal region and negative SLNB could avoid RT on groin to spare inguinal toxicity. CTV included GTV (primary tumour and positive LNs) and pelvic ± inguinal LNs. PTV1 and PTV2 corresponded to GTV and CTV, respectively, adding 0.5 cm. RT dose was 50.4 Gy/28 fractions to PTV2 and 64.8 Gy/36 fractions to PTV1, delivered with 3DCRT (n = 24) or IMRT (n = 56), concomitant to Mitomycin-C and 5-FU chemotherapy. FDG-PET showed inguinal uptake in 21/69 patients (30%) and was negative in 48/69 patients (70%). Lymphoscintigraphy was performed in 11/21 positive patients (4 patients SLNB confirmed inguinal metastases, 6 patients false positive and 1 patient SLN not found), and in 29/48 negative patients (5/29 showed metastases, 23/29 true negative and 1 SLN not found). Sensitivity, specificity, positive and negative predictive value of FDG-PET were 62%, 79%, 40% and 82%, respectively. Median follow-up time from diagnosis was 40.3 months (range: 4.6-136.4 months): 69 patients (86%) showed a complete response, 10 patients (13%) a partial response, 1 patient (1%) a stable disease. Patients treated on groin (n = 54) versus not treated (n = 26) showed more inguinal dermatitis (G1-G2: 50% vs. 12%; G3-G4: 17% vs. 0%, p < 0.05). For patients treated on groin, G3-G4 inguinal dermatitis, stomatitis and neutropenia were significantly reduced with IMRT against 3DCRT techniques (13% vs. 36%, p = 0.10; 3% vs. 36%, p = 0.003; 8% vs. 29%, p = 0.02, respectively). SLNB improves the FDG-PET inguinal LNs staging in guiding the decision to treat inguinal nodes. IMRT technique significantly reduced G3-G4 toxicities when patients are treated on groin.
评估前哨淋巴结活检 (SLNB) 和 FDG-PET 在肛门癌患者分期和放射治疗 (RT) 中的作用。这项回顾性研究共纳入 80 名经病理证实的肛门鳞状细胞癌患者（男 32 例，女 48 例），中位年龄 60 岁（39-89 岁），于 2008 年 3 月至 2018 年 3 月在 IRCCS San Raffaele 医院接受治疗。对于没有腹股沟淋巴结转移临床证据且/或临床证据与影像学特征不符的患者，考虑进行 SLNB。69/80 例患者行 FDG-PET 检查。对于腹股沟区域影像学检查阴性且 SLNB 阴性的患者，可以避免 RT 照射腹股沟以避免腹股沟毒性。CTV 包括 GTV（原发肿瘤和阳性淋巴结）和骨盆/腹股沟淋巴结。PTV1 和 PTV2 分别对应 GTV 和 CTV，分别增加 0.5cm。PTV2 接受 50.4Gy/28 次分割照射，PTV1 接受 64.8Gy/36 次分割照射，采用三维适形放疗（n=24）或调强放疗（n=56），同时给予丝裂霉素 C 和 5-FU 化疗。FDG-PET 显示 69 例患者中有 21 例（30%）腹股沟摄取，48 例（70%）为阴性。对 21 例阳性患者中的 11 例（4 例 SLNB 证实腹股沟转移，6 例假阳性，1 例 SLN 未找到）和 29 例阴性患者中的 29 例（5 例显示转移，23 例为真阴性，1 例 SLN 未找到）进行淋巴闪烁显像。FDG-PET 的灵敏度、特异性、阳性预测值和阴性预测值分别为 62%、79%、40%和 82%。从诊断到随访中位时间为 40.3 个月（范围：4.6-136.4 个月）：69 例（86%）患者完全缓解，10 例（13%）部分缓解，1 例（1%）疾病稳定。接受腹股沟治疗（n=54）与未治疗（n=26）的患者相比，腹股沟皮肤炎（G1-G2：50%比 12%；G3-G4：17%比 0%，p<0.05）更多。对于接受腹股沟治疗的患者，与 3DCRT 技术相比，IMRT 显著降低了 G3-G4 级腹股沟皮肤炎、口腔炎和中性粒细胞减少症的发生率（13%比 36%，p=0.10；3%比 36%，p=0.003；8%比 29%，p=0.02）。SLNB 提高了 FDG-PET 在指导腹股沟淋巴结治疗决策中的腹股沟淋巴结分期作用。当患者接受腹股沟治疗时，IMRT 技术可显著降低 G3-G4 级毒性。
