Stereotactic body radiotherapy for oligo-recurrence within the nodal area from colorectal cancer

Abstract

Recurrence of colorectal cancer (CRC) often presents as solitary metastases, oligometastases or oligo-recurrence. Surgical resection became the preferred treatment for patients with CRC lung and hepatic metastases. However, surgical treatment for oligo-recurrence within nodal area is not a widely accepted treatment due to due to their relative rarity and high postoperative morbidity. Stereotactic body radiotherapy (SBRT) is one of the emerging radiation treatment techniques in which a high radiation dose can be delivered to the tumor. High-dose SBRT can ablate the tumor with an efficacy similar to that achieved with surgery, especially for small tumors. However, there have been very few studies on SBRT for oligo-recurrence within nodal area, although several studies have evaluated the role of SBRT in the treatment of liver and lung metastases from CRC. This article reviews the current clinical status of and treatment methods for oligo-recurrence within nodal area from CRC, with particular emphasis on SBRT.

Keywords: Colorectal cancer; Lymph node; Oligo-recurrence; Oligometastases; Stereotactic radiotherapy.

Figure 1

CyberKnife planning of stereotactic body radiotherapy for paraaortic lymph node metastases from colorectal cancer. A: Axial view 1; B: Sagittal view; C: Coronal view; D: 3D view. Gross tumor volume (red arrow) was defined as the visualized lymph node. The radiation dose, 48 Gy in 3 fractions, was prescribed to the 80% isodose line of the maximum dose in order to cover the planning target volume.

Figure 2

Disease progression free survival in patients with oligo-recurrence within nodal area from colorectal cancer treated with streotactic body radiotherapy or surgical resection. The cohort of Kang and Bae’s studies are mostly composed of nodal metastases but additionally include lung and liver metastases. The cohort of surgical series include not only oligo-recurrence within nodal area but also central recurrence at anastomosis site. Dot size was weighted for number of patients in each cohort. SBRT: Streotactic body radiotherapy.