Preliminary study of the internal margin of the gross tumor volume in thoracic esophageal cancer

• Published in: Cancer radiothérapie Vol. 16; no. 7; pp. 595 - 600
• Main Authors: Li, Jiancheng, Wang, Linhua, Wang, Xiaoliang, Zhao, Yunhui, Liu, Di, Chen, Cheng, Zhang, He Ping, Pan, Jianji
• Format: Journal Article
• Language: English
• Published: Paris Elsevier SAS 01.10.2012; Elsevier
• Subjects: Anthropometry - methods; Biological and medical sciences; Carcinoma, Small Cell - pathology; Carcinoma, Small Cell - radiotherapy; Carcinoma, Squamous Cell - pathology; Carcinoma, Squamous Cell - radiotherapy; Esophageal Neoplasms - pathology; Esophageal Neoplasms - radiotherapy; Esophageal tumor; Exhalation; Female; Humans; Inhalation; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Motion; Mouvements respiratoires; Pilot Projects; Radiotherapy Planning, Computer-Assisted; Respiratory movement; Tidal Volume; Tomography, Spiral Computed - methods; Tumeur de l’œsophage; Tumor Burden; Tumor target volume; Tumors; Volume cible tumoral; Mouvements respiratoires; Respiratory movement; Tumor target volume; Tumeur de l’œsophage; Volume cible tumoral; Esophageal tumor; Nuclear medicine; Cancerology; Target volume; Esophageal disease; Radiology; Digestive diseases
• ISSN: 1278-3218; 1769-6658
• DOI: 10.1016/j.canrad.2012.05.020

To measure the displacement of the tumor of the gross tumor volume (GTV) of thoracic esophageal cancer in the calm states of end-inspiration and end-expiration for determining the internal margin of the GTV (IGTV). Twenty-two patients with thoracic esophageal cancer who were unable to undergo surgery were identified in our hospital. The patients received radiotherapy. By using 16-slice spiral computed tomography (CT), we acquired the calm states of end-inspiration and end-expiration. The displacement and volume changes in tumor target volume were measured, and the changes were analyzed to determine if these were associated with the tidal volume and the location and length of the target volume V. In the end, we analyzed the displacement of tumor target volume and calculated the internal margin of the GTV by empirical formula. The average tidal volume was 463.6ml. The average GTV at end-inspiration was 33.3ml and at end-expiration was 33.35ml. Three was not any significant between two groups (T=−0.034, P>0.05). The IGTV (X-axis direction) was 3.09mm for the right sector and 4.08mm for the left border; the IGTV (Z-axis direction) was 3.96mm for the anterior border and 2.83mm for the posterior border; and the IGTV (Y-axis direction) was 7.31mm for the upper boundary (head direction) and 10.16mm for the lower boundary (feet direction). The motion of the GTV showed no significant correlation with the tidal volume of patients and the length of the tumor, but in relation to the tumor location, the displacement of the lower thoracic and the middle thoracic target volumes occurred in the direction of the anterior and right, which were not significantly different (T=0.859, 0.229, P>0.05) The significant differences were observed for the other directions (P<0.05). Because of respiratory and organ movements, the displacement of the tumor target volume was different in all directions. Therefore, we recommend that expansion of the planning target volume during clinical radiation treatment needs to include the displacement of the tumor target volume caused by respiratory and organ movements during each radiotherapy session. Mesurer les déplacements du volume tumoral macroscopique (GTV) dans les cancers de l’œsophage thoracique lors l’inspiration forcée et l’expiration forcée pour déterminer la marge interne de ce volume tumoral macroscopique (IGTV). Vingt-deux patients atteints de cancer de l’œsophage thoracique inopérable ont été irradiés après une scanographie hélicoïdale (avec 16 barrettes) en inspiration forcée et expiration forcée. Le déplacement et le volume tumoral ont été mesurés, et les variations analysées pour déterminer si elles étaient liées au volume courant et à l’emplacement et la longueur du volume cible. Enfin, nous avons analysé le déplacement du volume tumoral macroscopique et calculé sa marge interne avec une formule empirique. Le volume courant était de 463,6mL, le volume tumoral macrocopique moyen en inspiration forcée de 33,3mL et celui en expiration forcée de 33,35mL. Il n’y avait pas de différence entre les deux (T=−0,034, p>0,05). La marge du volume tumoral macroscopique était de 3,09mm vers la droite et 4,08mm vers la gauche, 3,96mm vers l’avant et 2,83mm vers l’arrière, 7,31mm vers la tête et 10,16mm vers les pieds. Il n’y avait pas de corrélation significative entre les mouvements du volume tumoral macroscopique et le volume courant et l’emplacement de la tumeur, mais il a été observé un déplacement des volumes thoraciques bas et médians vers l’avant et la droite, quoique non statistiquement significatif (T=0,859, 0,229, p>0,05) et un déplacement statistiquement significatif dans les autres directions (p<0,05). Différents déplacements de la tumeur ont été observés en rapport avec la respiration dans toutes les directions et nous recommandons donc une extension du volume cible prévisionnel.