Correlation of pelvic MRI picture with functional disorders after complex treatment of rectal cancer

BACKGROUND: The number of patients on dispensary registration and treated for rectal cancer (RCC) increases annually. The distinctive feature of surgical method of treatment is that in addition to the main — therapeutic effect, its application is always accompanied by varying degrees of severity of surgical trauma. The quality of life of patients can suffer significantly in the development of low anterior resection syndrome (LARS), de-adapting them in social and labor status. Previous studies have demonstrated the importance of MRI for accurate assessment of rectal cancer at the time of initial diagnosis, but the option of using the original OMT MRI protocol to assess functional impairment in patients of this profile has never been considered.

AIM: Evaluation of MRI-picture of the pelvic region after complex treatment of RPC, variants and terms of formation of scar-fibrotic changes of presacral tissue after anterior resection and inferior anterior resection to predict the development of functional disorders in the form of SNPR.

METHODS: The article presents the results of MRI studies of 40 patients after complex treatment of locally advanced forms of RCC T3crm+-4N0-2M0 with inclusion of neoadjuvant radiotherapy in short-course mode (SOD 25 Gy) with two radiomodifiers and systemic cytotoxic therapy with capecitabine, a drug of fluoropyrimidine series. The next stage after 3-4 months was sphincter-preserving surgical treatment in the volume of “anterior resection” or “lower anterior resection” of the rectum. Changes in the pelvic region after complex treatment of RPC in the form of presacral fibrosis and the degree of relaxation of pelvic organs in correlation with the severity of SNPR according to the validated questionnaire Low anterior resection syndrome score (LARS Score) are described.

RESULTS: The severity of the cicatricial process in the presacral space has a positive correlation (0.912) with significant disorders according to the LARS questionnaire. A moderate inverse correlation is associated with the location of the tumor from the anal verge at a distance of less than 5 cm (-0.329) and the period after surgical treatment up to 6 months (-0.356).

CONCLUSIONS: The knowledge of variants of post-radiation and postoperative MRI-picture of the small pelvis and peculiarities of scar changes formation allows predicting the development of functional disorders in the form of lower anterior resection syndrome (LARS). Dynamic observation of patients with scar process in the small pelvis should be individualized with the establishment of optimal intervals between radiological studies for dynamic observation and prediction of functional recovery of the locking apparatus of the rectum.