Early and Late Toxicity of Radiotherapy for Rectal Cancer

Abstract

With the implementation of total mesorectal excision surgery and neoadjuvant (chemo) radiotherapy, the outcome of rectal cancer patients has improved and a substantial proportion of them have become long-term survivors. These advances come at the expense of radiation- and chemotherapy-related toxicity which remains an underestimated problem. Radiation-induced early toxicity in rectal cancer treatment mainly includes diarrhea, cystitis, and perineal dermatitis, while bowel dysfunction, fecal incontinence, bleeding, and perforation, genitourinary dysfunction, and pelvic fractures constitute the majority of late toxicity. It is now generally accepted that short-course radiotherapy (SCRT) and immediate surgery is associated with less early toxicity compared to conventionally fractionated chemoradiotherapy with delayed surgery. There are no significant differences in late toxicity between both treatment regimens. While there is hardly an increase in early toxicity after preoperative SCRT with immediate surgery, late toxicity is substantial compared to surgery alone. Early toxicity is more frequent when a longer interval between SCRT and surgery is used and is comparable to the toxicity observed with conventionally fractionated radiotherapy except that it occurs after the end of the radiotherapy. So far, randomized phase III trials failed to demonstrate a substantial gain in tumoural response when oxaliplatin or molecular agents are added to the multimodality treatment. Moreover, the addition of these drugs increases toxicity and remains therefore experimental.

Advances and Challenges in Treatment of Locally Advanced Rectal Cancer

“…The added benefit of RT in these patients has been questioned because RT is associated with significant toxicity, including bowel obstruction, hip fractures, sexual and urinary dysfunction, and proctitis. 82,118,119 A growing body of 122 The 30 patients who completed preoperative CT had tumor regression and underwent TME without preoperative CRT. No local recurrences were noted at 4 years, and an 84% DFS was achieved.…”

Acute anal toxicity after whole pelvic radiotherapy in patients with asymptomatic haemorrhoids: identification of dosimetric and patient factors

“…There are a lot of studies about radiation tolerance doses in normal organs. [6][7][8] Intestinal problems are common complications of WPRT, whereas severe complications, such as small bowel perforation, are rare. 9,10 On the other hand, acute anal complications, such as anal pain or bleeding, tend to be ignored because of their lower severities.…”

Increased risk of pelvic fracture after radiotherapy in rectal cancer survivors: A propensity matched study

“…Post‐RT pelvic fracture has been discussed thoroughly for gynecological and prostate cancer, but few studies have discussed it for rectal cancer . The survival rate of rectal cancer has been improved due to advances in treatment, and thus, late side effects among survivors have become extremely important . The morbidity and mortality risks after pelvic fracture are both high.…”

“…Radiotherapy (RT), chemotherapy (C/T), and surgical resection are important treatments for rectal cancer patients. Acute side effects after treatment, such as gastrointestinal and genitourinary toxicities, have been discussed thoroughly in previous studies . However, few studies have discussed late side effects of pelvic irradiation …”