Seol Ki Ho, Lee Jeong Eun
Department of Radiation Oncology, Kyungpook National University School of Medicine, Daegu, Korea.
Radiat Oncol J. 2014 Mar;32(1):31-42. doi: 10.3857/roj.2014.32.1.31. Epub 2014 Mar 27.
To evaluate the usefulness of positron emission tomography/computed tomography (PET/CT) for field modification during radiotherapy in esophageal cancer.
We conducted a retrospective study on 33 patients that underwent chemoradiotherapy (CRT). Pathologic findings were squamous cell carcinoma in 32 patients and adenocarcinoma in 1 patient. All patients underwent PET/CT scans before and during CRT (after receiving 40 Gy and before a 20 Gy boost dose). Response evaluation was determined by PET/CT using metabolic tumor volume (MTV), total glycolytic activity (TGA), MTV ratio (rMTV) and TGA ratio (rTGA), or determined by CT. rMTV and rTGA were reduction ratio of MTV and TGA between before and during CRT, respectively.
Significant decreases in MTV (MTV2.5: mean 70.09%, p < 0.001) and TGA (TGA2.5: mean 79.08%, p<0.001) were found between before and during CRT. Median rMTV2.5 was 0.299 (range, 0 to 0.98) and median rTGA2.5 was 0.209 (range, 0 to 0.92). During CRT, PET/CT detected newly developed distant metastasis in 1 patient, and this resulted in a treatment strategy change. At a median 4 months (range, 0 to 12 months) after completion of CRT, 8 patients (24.2%) achieved clinically complete response, 11 (33.3%) partial response, 5 (15.2%) stable disease, and 9 (27.3%) disease progression. SUVmax (p = 0.029), rMTV50% (p = 0.016), rMTV75% (p = 0.023) on intra-treatment PET were found to correlate with complete clinical response.
PET/CT during CRT can provide additional information useful for radiotherapy planning and offer the potential for tumor response evaluation during CRT. rMTV50% during CRT was found to be a useful predictor of clinical response.
评估正电子发射断层扫描/计算机断层扫描（PET/CT）在食管癌放疗期间进行靶区调整的实用性。
我们对33例行放化疗（CRT）的患者进行了一项回顾性研究。病理结果显示，32例为鳞状细胞癌，1例为腺癌。所有患者在CRT前及CRT期间（接受40 Gy后及20 Gy增敏剂量前）均接受了PET/CT扫描。通过PET/CT使用代谢肿瘤体积（MTV）、总糖酵解活性（TGA）、MTV比值（rMTV）和TGA比值（rTGA）进行疗效评估，或通过CT进行评估。rMTV和rTGA分别为CRT前和CRT期间MTV和TGA的降低率。
CRT前和CRT期间，MTV（MTV2.5：平均降低70.09%，p < 0.001）和TGA（TGA2.5：平均降低79.08%，p < 0.001）均有显著下降。rMTV2.5的中位数为0.299（范围为0至0.98），rTGA2.5的中位数为0.209（范围为0至0.92）。在CRT期间，PET/CT检测到1例患者出现新的远处转移，这导致了治疗策略的改变。CRT完成后中位4个月（范围为0至12个月）时，8例患者（24.2%）达到临床完全缓解，11例（33.3%）部分缓解，5例（15.2%）病情稳定，9例（27.3%）病情进展。治疗期间PET上的SUVmax（p = 0.029）、rMTV50%（p = 0.016）、rMTV75%（p = 0.023）与临床完全缓解相关。
CRT期间的PET/CT可为放疗计划提供有用的额外信息，并为CRT期间的肿瘤反应评估提供可能。发现CRT期间的rMTV50%是临床反应的有用预测指标。
