Unrecognized digestive toxicities of radiation therapy

The aim of this article is to review unrecognized toxicities resulting from radiation therapy of digestive neoplasms. Due to their precocious occurrence, acute toxicities are well-known by radiation oncologist, and their treatment well-established. Thus, acute toxicities will not be described in this review. We will focus on incidence, diagnosis, and management of late and uncommon toxicities occurring in the digestive tract and digestive organs. Prevention, by respecting healthy tissues constraints, is the main tool to reduce incidence of those rare complications. Nonetheless, once installed, late toxicities remain a major burden in terms of quality of life and can even be life threatening. Hence, information and education about their diagnosis and management is important.

[Urinary complications of pelvic exenterations for rectal cancer with urinary invasion]

OBJECTIVE

Pelvic exenteration for rectal cancer is indicated in locally advanced rectal tumors or pelvic recurrence invading adjacent organs. The oncologic goal being a complete R0 resection. Our aim was to study the urinary complications resulting from pelvic exenterations with urinary reconstruction in order to obtain a complete local control of the disease.

METHODS

Between April 2004 and June 2013, 42 patients who underwent pelvic exenteration for primary or recurrent rectal adenocarcinoma with urinary tract reconstruction were included. The urinary reconstruction was performed based on preoperative imaging and intraoperative findings. We studied early (within 30 postoperative days) and late urinary morbidity, as well as postoperative carcinologic control.

RESULTS

Forty-two exenterations were performed for primary rectal cancer (n=15) or pelvic recurrence (n=27). R0 complete resection was achieved in 64% of patients. The resection was incomplete (R1) on the urinary tract in 9.5% of patients. The urinary reconstruction methods used were: 31 transileal ureterostomies after total exenteration (bricker procedure), 6 ureteral reimplantations on psoic bladder, 2 ureteroileoplasties, 2 partial cystectomies and one ureteral resection with simple ligation. The median follow-up was 20 months. The perioperative mortality was 2.3% (n=1) and postoperative overall morbidity was 64%. Early and late urinary morbidity was 23.8% and 21.4% respectively. Six patients developed major urinary complications (≥ Clavien IIIb).

CONCLUSION

Pelvic exenteration with urinary resection resulted in our experience, in a local disease control of 64% (including a 90.5% for the urinary tract) at the price of an acceptable early specific morbidity and a low mortality that seems to justify an aggressive surgical approach.

[Sexual functions after treatment for rectal cancer: impact of doses in autonomic pelvic nerves]

PURPOSE

Prospective evaluation of sexual function after treatment of rectal cancer and identification of predictive factors.

PATIENTS AND METHODS

Thirty-three patients were treated with curative intent by chemoradiation and surgery for localized rectal adenocarcinoma. Sexual toxicity was assessed four times (before treatment and at 2, 6 and 12 months) using validated questionnaires: QLQ C30 and EORTC CR38 for all, simplified IIEF for men and FSFI for women. A correlation was sought between the toxicity and clinical and dosimetric parameters by Fisher and Mann-Whitney tests.

RESULTS

In men, erections and sexual satisfaction decreased significantly from the acute phase and then stabilized (respective scores of 84.5 and 86/100 in the initial phase, 66 and 70.4 at the end of radiotherapy, 70 and 70 at 6 months and 68.5 and 70 at 12 months). For women, the changes were not significant. This study confirms some risk factors for sexual toxicity already mentioned (original function, age, tumor volume) and highlights new (dose to the seminal vesicles and above all, doses to pelvic autonomic plexus).

CONCLUSION

Sexual effects of combined treatment of rectal cancer have only recently been described but remain undervalued and poorly understood. The impact of the autonomic pelvic plexus doses is a completely new data that could be extended in the development of intensity-modulated radiotherapy.

[Preoperative radiotherapy for rectal cancer: target volumes]

Preoperative radiochemotherapy followed by total mesorectal excision is the standard of care for T3-T4-N0 or TxN1 rectal cancer. Defining target volumes relies on the patterns of nodal and locoregional failures. The lower limit of the clinical target volume depends also on the type of surgery. Conformational radiotherapy with or without intensity-modulated radiotherapy implies an accurate definition of volumes and inherent margins in the context of mobile organs such as the upper rectum. Tumoral staging recently improved with newer imaging techniques such as MRI with or without USPIO and FDG-PET-CT. The role of PET-CT remains unclear despite encouraging results and MRI is a helpful tool for a reliable delineation of the gross tumour volume. Co-registration of such modalities with the planning CT may particularly guide radiation oncologists through the gross tumour volume delineation. Acute digestive toxicity can be reduced with intensity modulation radiation therapy. Different guidelines and CT-based atlas regarding the target volumes in rectal cancer give the radiation oncologist a lot of ground for reproducible contours.