Radiation Therapy and Rectal Cancer (original) (raw)
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Role of Radiation in Intermediate-Risk Rectal Cancer
Annals of Surgical Oncology, 2012
The treatment of rectal cancer has greatly evolved during the last several decades as a result of the understanding of the pathways of cancer spread, natural history of the disease, stages prognosis and prognostic markers. The tendency is clearly to move toward a more personalized approach to these patients based on preoperative staging and response to therapy. Although in the past we have been adding more treatment modalities to surgery to the point that every stage II/III cancer was treated with neoadjuvant chemo and radiotherapy followed by radical surgery by total mesorectal excision with or without sphincter preservation and more chemotherapy to follow, more recently this algorithm has been under discussion and scrutiny. Two of the major topics of controversy are: the use of local excision or even a watch-and-wait approach after a clinical complete response and the need for radiotherapy in the intermediate risk group. In this manuscript we will present the historical perspective that has brought the treatment of rectal cancer to the current standard of care and present the evidence supporting further investigation in the intermediate risk group.
Annals of Surgery, 2007
To determine the risk of small bowel obstruction (SBO) after irradiation (RT) for rectal cancer Background: SBO is a frequent complication after standard resection of rectal cancer. Although the use of RT is increasing, the effect of RT on risk of SBO is unknown. Methods: We conducted a retrospective cohort study using Surveillance, Epidemiology, and End Results cancer registry data linked to Medicare claims data to determine the effect of RT on risk of SBO. Patients 65 years of age and older diagnosed with nonmetastatic invasive rectal cancer treated with standard resection from 1986 through 1999 were included. We determined whether patients had undergone RT and evaluated the effect of RT and timing of RT on the incidence of admission to hospital for SBO, adjusting for potential confounders using a proportional hazards model. Results: We identified a total of 5606 patients who met our selection criteria: 1994 (36%) underwent RT, 74% postoperatively. Patients were followed for a mean of 3.8 years. A total of 614 patients were admitted for SBO over the study period; 15% of patients in the RT group and 9% of patients in the nonirradiated group (P Ͻ 0.001). After controlling for age, sex, race, diagnosis year, type of surgery, and stage, we found that patients who underwent postoperative RT were at higher risk of SBO, hazard ratio 1.69 (95% CI, 1.3-2.1). However, the long-term risk associated with preoperative irradiation was not statistically significant (hazard ratio, 0.89; 95% CI, 0.55-1.46). Conclusions: Postoperative but not preoperative RT after standard resection of rectal cancer results in an increased risk of SBO over time.
British journal of cancer, 2005
To evaluate the feasibility, effectiveness, and long-term bowel function of preoperative hyperfractionated accelerated radiotherapy in primary resectable rectal cancer. A total of 184 consecutive patients (median age 65 years, male : female=2 : 1) with clinical T3Nx rectal adenocarcinoma received preoperative pelvic radiation therapy with single fractions of 2.5 Gy twice daily (interval 6 h between fractions) to a total dose of 25 Gy within 1 week. Surgery was conducted the following week. Postoperative histology revealed UICC stage I in 33%, stage II in 26%, stage III in 34%, and stage IV in 7% of the patients. Median follow-up was 43 months (53 months for surviving patients). The actuarial 4-year-local-recurrence rate was 2.1%, overall recurrence 23%. Disease-specific and disease-free survivals at 4 years (excluding stage IV) were 82 and 69%, respectively. Overall survival for 4 years was 68%. Postoperative mortality was 0.5% (one patient), early anastomotic leakage occurred in 11...
Rectal cancer: preoperative versus postoperative irradiation as a component of adjuvant treatment
Seminars in Radiation Oncology, 2003
The search for improved disease control and survival for resectable but high-risk rectal cancers has led to studies that combine all 3 modalities. For surgically resected, high-risk rectal cancers, postoperative chemoradiation has been shown to improve both disease control (local and distant) and survival (disease free and overall) and was recommended as standard adjuvant treatment at the 1990 National Institute of Health Colorectal Cancer Consensus Conference. Three randomized studies showed improved overall survival (OS) and local control for patients treated with postoperative irradiation and chemotherapy when compared with surgery alone or surgery plus irradiation control arms. These include 2 US trials, Gastrointestinal Tumor Study Group and Mayo/North Central Cancer Treatment Group (NCCTG) and a Norway trial. Although most preoperative external beam radiation trials show reductions in local relapse with the addition of preoperative EBRT to resection, only the large Swedish trial of ϳ1,100 patients showed a survival improvement when compared with a surgery alone control arm for resectable primary rectal cancers. In a recent pooled analysis of 3 postoperative adjuvant rectal cancer trials (NCCTG 794751, NCCTG 864751, and GI Intergroup 0114) survival and disease relapse were dependent on both TN and NT stage of disease (N substage within T stage and T substage within N stage). Even among N2 patients (4 or more positive nodes), T substage influenced 5-year OS (T1-2, 69%; T3, 48%; and T4, 38%; P < .001). Ongoing randomized trials are being conducted for patients with high-risk, resectable primary rectal cancers. The intent is to help define optimal combinations of postoperative chemoradiation (US GI Intergroup), to test sequencing issues of preoperative versus postoperative chemoradiation (Germany trial), and to determine if concurrent and maintenance 5-FU and leucovorin add to the benefits found with preoperative irradiation (European Organization for Research and Treatment of Cancer). For subsequent trials, it may be preferable to perform separate studies, or a planned statistical analysis, for different risk groups of patients (low, intermediate, moderately high, and high), as defined in the rectal cancer pooled analysis.
International Journal of Radiation Oncology*Biology*Physics, 1996
Purpose: To explain a possible association between treatment technique and postoperative mortality after preme radiotherapy of rectal carcinoma, the dose distributions were compared in model experiments. Methods and Mate-Preoperative radiotherapy with a three-beam technique delivered in ftve fractlmts to 25 Gy (5 Gy/daily for 5 or 7 days) was given to patients with primary resectabk rectal carcinoma. The adverse effects of this treatment, both acute and late, have been low. In a parallel trial using an identical fraction&on schedule and total dose but with a two-beam technique, the postoperative mortal@ was higher. Two-, three-. and four-beam techniques were analyzed in 20 patients with computed tomography based, three-dllional dose planning. Dose d&rib&ions and dose-volume histograms in the plan&g target volume (PTV) and in the organs at risk were considered. A numerical "biological" model was used to compare the techulques. Results: The two-beam aud the four-beam box techniques give the most h dosed&t in the PTV, although all techniques result in dose distributions that would be considered adequate, provided 16 MV or higher p&&on energies are used. Three-and four-beam techniques show advantagea over the two-bean teclmique with respect to organs at risk, particularly the small bowel. With the two-beam technique aud the upper beam limit at mid-L4, the volume of the bowel that receives >95% of the prescribed dose, and hence, is irprluded in the treated volume (TV), is more than twice as large as that with three-and four-beam techulques, and that of the total body between 1.5 and 2 times as large. The results of the analyses using the biologleal model indicate that the three-and four-beam techniques result in less small bowel eomplieatlon rates than the two-beam technique. The integral energy to the total body is similar for all treatment mod&ties compared. Conclusions: The volume of bowel in&ded in the TV, rather than the energy imparted to the body, influences postoperative mortality, and emphasizes the importance of precise radiotherapy planning to minimize normal tissue toxicity.
Preoperative Short-Course Radiation Therapy in Rectal Cancer
Journal of US-China Medical Science, 2019
Purpose: To evaluate the benefits of preoperative short-course radiotherapy in locally advanced rectal cancer. Patients and methods: A prospective study of 30 rectal cancer patients at T3-4M0 stage and ECOG 0-2 performed preoperative short-course radiation therapy at Hue Central Hospital Vietnam between June 2016 and July 2018, using pelvic 3D-Conformal Radiation Therapy with the total radiation dose being 25 Gy in 5 fractions over five days. Results: Mean age 57.1 ± 13.6 with 46.7% of patients in the range of 41-60 year-old. Male/female ratio: 2/1. Tumour stage T3 and T4 was 70% and 30%, respectively; stage III and stage IV was 86.7% and 13.3%, respectively. Positive lymph node rates on endoscopic ultrasound were 85.7% in T3 and 77.8% in T4. Downstaging rate for stage III, T4 and T3 was 65.4%, 65.4% and 4.8%, respectively. For upper third of the rectum: 100% of T3 stage patients got no downstaging. For middle rectum: downstaging rate for stage III, T4 and T3 was 55.6%, 57.1% and 7.1%, respectively. For lower rectum: downstaging rate for stage III, T4 was 50.0% and 100.0%, respectively. No acute toxicity was seen, 86.7% of the patients performed laparoscopic sphincter-preserving surgery. Conclusion: For the treatment of locally advanced rectal cancer, neoadjuvant therapy is standard. Preoperative short-course radiation therapy is a reasonable therapeutic option because it demonstrates benefits in tumour downstaging especially for middle and lower rectum. .
High dose preoperative irradiation for cancer of the rectum, 1976–1988
International Journal of Radiation Oncology*Biology*Physics, 1991
and the Comprehensive Rectal Cancer Center Two hundred twenty patients with adenocarcinoma of the rectum have heen treated in a program using high dose (NUIOO cGy) preoperative irradiation followed by radical surgical resection. The patients were staged on the basis of pretreatment clinical mobility of the cancers. Seventy-four patients had mobile cancers, 49 had partial fixation (tethered), 85 patients had total tumor fixation, and 12 patients had a frozen pelvis (unresectable). Patients were treated with high energy photons using a four field box technique with total doses ranging from 4000 to 6000 cGy. The overall incidence of local recurrence was 15% (32/220). Patients with fixed and unresectabte tumors had a higher incidence of local recurrence, 20% (21/97) as compared with patients with mobile and partially fixed tumors, 10% (13/l 23). Local recurrence by pathological stage of disease was 6% for patients with Stages 0, A, Bl versus 20% for patients with Stages B2 and C cancer. Overall S-year survival of the total group was 67%. The 5-year survival by clinical stages of disease was 87% for mobile tumors, 74% for partially fixed tumors, 70% for fixed tumors, and 22% for the unresectable group. The 5-year survival by pathological stages of disease was 90% for those with Stage 0, A, Bl and 71, 75, and 47%. respectively, for Stages B2, Cl, and C2 disease. Rectal cancer, Preoperative radiation therapy, High dose preoperative radiation therapy.
Overview of Radiation Therapy for Treating Rectal Cancer
Annals of Coloproctology, 2014
A major outcome of importance for rectal cancer is local control. Parallel to improvements in surgical technique, adjuvant therapy regimens have been tested in clinical trials in an effort to reduce the local recurrence rate. Nowadays, the local recurrence rate has been reduced because of both good surgical techniques and the addition of radiotherapy. Based on recent reports in the literature, preoperative chemoradiotherapy is now considered the standard of care for patients with stages II and III rectal cancer. Also, short-course radiotherapy appears to pro vide effective local control and the same overall survival as more long-course chemoradiotherapy schedules and, therefore, may be an appropriate choice in some situations. Capecitabine is an acceptable alternative to infusion fluorouracil in those patients who are able to manage the responsibilities inherent in self-administered, oral chemotherapy. However, concurrent administration of oxaliplatin and radiotherapy is not recommended at this time. Radiation therapy has long been considered an important adjunct in the treatment of rectal cancer. Although no prospective data exist for several issues, we hope that in the near future, patients with rectal cancer can be treated by using the best combination of surgery, radiation therapy, and chemotherapy in near future.