Abstract Objective To investigate the three dimensional conformal radiation therapy combined with chemotherapy for cancer recurrence after curative effect. Methods 49 cases of recurrence of rectal cancer were randomly divided into conformal radiotherapy plus chemotherapy group (the conformal Group) 25 cases, 24 cases of conventional radiotherapy plus chemotherapy group (conventional group). Fitness-shaped set of future adoption 6MV X-ray whole pelvic radiotherapy 46 Gy converted into three-dimensional fitness conformal radiation therapy to push the amount to 70 Gy, 6MV X-ray the whole pelvic radiotherapy 46 Gy conventional group; After using two posterior oblique wild into the angle of irradiation push amount to 66 Gy both groups in the first week of radiotherapy and the last week of chemotherapy to 5  fluorouracil 500mg/m2 the calcium folinate 200mg, d1 ~ 5, intravenous infusion. Survival analysis by Kaplan  Meier method. Results 1 -, 2 – and 3-year survival rate of the conformal group and the conventional group were 88.0%, 64.0%, 48.0% and 66.7%, 45.8% and 37.5% (P = 0.08), the median survival time of 35 and 22 months respectively. ; 3-year local tumor control rates were 68.0% and 41.7% (P <0.05), and toxicity of the two groups showed no significant difference. Conclusion three-dimensional conformal radiation therapy combined with chemotherapy is an effective treatment method for the treatment of rectal cancer recurrence, can significantly increase the survival rate of patients with recent.

Key words rectal cancer; tumor recurrence; conformal radiotherapy; chemotherapy

 Clinical Observation of Late Course 3  dimensional Conformal Radiotherapy Combined with Chemotherapy for Rectal Cancer of Postoperative Local Recurrence

    ZHOU Ye  qin, TAN Bang  xian, LI Xian  fu, MA Dai  yuan

    Department of Radiotherapy, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000, ChinaAbstract: Objective To evaluate the effects of the late course 3  dimensional conformal radiotherapy combined with chemotherapy for rectal cancer of postoperative local recurrence. Methods Forty  nine rectal cancer patients of postoperative local recurrence were divided randomly into two groups: 25 cases received 3D  CRT plus chemotherapy (3D  CRT group), 24 cases received conventional radiotherapy plus chemotherapy (conventional group). A total tumor doses of 46 Gy by the 6MVX beam to the all pelvic for conventional radiotherapy in the first course, followed in the 3D  CRT group by 3D  CRT to DT 70 Gy, in the conventional group by two field for conventional radiotherapy to 66 Gy.Two groups were all treated one course by 5  Flu plus CF in the first week, and the last week. Kaplan  Meier method was used for survival analysis.Results The 1,2,3 years survival rates for 3D  CRT group and conventional group were 88.0%, 64.0%, 48.0% and 66.7%, 45.8%, 37.5% (P = 0.08). The 3 years local control rate for two group was 68.0%, 41.7% (P <0.05) respectively. The median survival was 35 and 22 months respectively. The side effects were similar in the two groups.Conclusion 3  dimensional conformal radiotherapy combined with chemotherapy can be considered as an effective and feasible approach to rectal cancer patients of postoperative local recurrence, and may significantly improve the survival rate.

    Key words: Rectal neoplasms; Neoplasm recurrence; Conformal Radiotherapy; Chemotherapy

Colorectal cancer is a common malignancy, surgery is the preferred treatment. But a higher recurrence rate after rectal cancer treated with surgery alone. The most recurrent lesions may no longer reoperation, it is based radiotherapy treatment is the inevitable choice. Three-dimensional conformal radiation therapy (3  dimensional conformal radiotherapy, 3DCRT) theory is a way for the shape of the distribution of the high-dose region in three dimensions and shape of the lesion, treatment technology, three-dimensional conformal radiation therapy for rectal cancer recurrence after can reduce the radiation caused by the reaction of the digestive tract and urinary tract. We retrospectively analyzed 49 cases of rectal cancer patients with recurrence 3DCRT radiotherapy combined with concurrent chemotherapy (conformal Group) and the efficacy of conventional radiotherapy plus chemotherapy (conventional group), aims to explore the treatment of rectal cancer recurrence Patients.

    1 Materials and Methods

    1.1 Clinical data

    70,未合并其他严重疾病,所有病例均为术">December 2001 to December 2003 were treated 49 cases of rectal cancer recurrence after resection patients without distant metastasis, Karnofsky score> 70, and not associated with other serious diseases, all cases were surgery, were enrolled conditions after recurrent rectal cancer, clinical pathology, and has previously never radiotherapy, unwilling to undergo surgery again. Patients, 29 males and 20 females. Median age of 57 years (27 to 72 years old). Tubular adenocarcinoma, 39 cases, 10 cases of mucinous adenocarcinoma. The clinical data are shown in Table 1. Table clinical data of 149 patients with rectal cancer recurrence cases (cases)

    Tab 1 Clinical and pathologic characteristics of the patients

    Clinical characteristics3D  CRT

    groupconventional

    grouppeople numbers2524median age4550Maximun tumor size (cm) 2 ~ 73 ~ 6Operation method Mile1613 Dixon911Pathologic type Tubular adenocarcinoma2118 Mucinous adenocarcinoma46

    1.2 Treatment

    External radiation conformal group and the conventional group simulator under the positioning, the two wild on the set before and after whole pelvic wear irradiation field upper bound: L5 lower edge; located in the lower bound: Dixon surgery obturator lower edge, Miles surgery perineal surgical scars; both sides of the profession: the true pelvis 1.5cm. Conformal group 6MV X-ray irradiation to 46Gy after conversion of three-dimensional conformal radiotherapy the conventional group instead of two posterior oblique wild angled conventional radiotherapy push the amount to 66 Gy. Three-dimensional conformal radiotherapy (3DCRT), stereotactic body radiation therapy Billiton can frame and three-dimensional treatment planning system (TPS), the patient supine on the CT simulator located stereotactic body shelves, Put your hands on your forehead, and negative pressure vacuum pad fixed to the patient’s chest, abdomen and pelvis, with enhanced spiral CT scan, the scan range of pelvic and abdominal thickness of 5mm. Scan data transmitted over the network to the three-dimensional treatment planning system. By radiotherapy competent physicians and CT diagnostician outline target. Gross tumor (GTV), including the primary lesion, the clinical target volume (CTV) on the basis of the GTV, up and down outside the expanding 2.0 ~ 3.0cm, left and right to expand outside 1.5cm planning target volume (PTV) on the basis of the CTV expansion outside the four weeks 1.0cm, a center, 4 to 6 beam irradiation. 90% isodose surrounding the planning target volume (PTV),, and PTV internal dose difference of ± 5% for the most satisfaction. Split dose of 2 Gy / 5 times / week for a total dose of 24Gy, rectal tumors reached 70Gy. The patients were in the first week of radiotherapy and the last week of chemotherapy with 5  fluorouracil 500mg/m2 the calcium folinate 200mg, d1 ~ 5, intravenous infusion. Two cycles of chemotherapy.

    1.3 statistical methods

    SPSS10.0 package, Kaplan  Meier survival analysis, difference test Longrank line. Rest χ2 test.

    1.4 determine the efficacy of the standard

    WHO solid tumor efficacy evaluation criteria are divided into complete remission (CR), partial remission (PR), stable (SD), progress (PD), CR + PR effective. March review of the efficacy of the treatment of CT, MRI assessment. Acute reaction of normal tissue RTOG criteria evaluation.

    2 Results

    2.1 Follow-up

    All patients were followed up to January 2007, follow-up rate was 98%.

    2.2 The short-term effect

    0.05)。">Pain relief appropriate form group and the conventional group was 96.0% (24/25) and 91.6% (22/24), the difference was not statistically significant (P> 0.05). Conformal group and the conventional group tumor response rate (CR + PR) were 92.0% (23/25) and 66.7% (16/24) the difference was statistically significant (P <0.05).

    2.3 survival rate

    Conformal group and the conventional group 1 -, 2 – and 3-year survival rates were 88.0%, 64.0%, 48.0% and 66.7%, 45.8%, 37.5%, with a median survival of 35 and 22 months. Group fitness shaped group than in the conventional group, the difference was statistically significant (P = 0.08), as shown in Figure 1.

    Comparison of survival curves of the two groups in Figure 1

    Fig 1 Overall survival curves of patients in two groups

    2.4 local control rate

    Conformal group and the conventional group 3-year local tumor control rate was 68.0% and 41.7%, respectively. Two groups conformal group than in the conventional group (P <0.05).

    2.5 treatment response

    All patients were successfully completed treatment. Bone marrow suppression, gastrointestinal reactions, radiation proctitis and radioactive cystitis toxicity, as shown in Table 2. Table toxicity after the treatment of the two groups of patients

    2.6 recurrence and cause of death

    Local recurrence in three cases, the conventional group, 5 cases, conformal group 1 patients, and in three cases of distant metastasis and death by conformal group 1 cases, two cases of the conventional group. The difference was not statistically significant.

    3 Discussion

    Although surgical technology continues to improve, the postoperative local recurrence is still the main reason for the failure of rectal cancer treatment. A T1 ~ 2N0M0 of rectal cancer local recurrence rate of less than 10 percent, T3N0M0 cases of recurrence rate rose to 15% to 35% of and T3 ~ 4N1 2M0 postoperative recurrence rate as high as 45% to 65% [1]. Local recurrence were located in the pelvic tumor invasion or compression of peripheral nerve and cause pain, the most common symptoms of relapse patients perineum sacrococcygeal pain, the sense of falling, sometimes with lower extremity radiating pain and blood in the stool secretions and other symptoms. Some patients in the perineum palpable and hard, fixed mass. For this part of the patient, the radiochemical treatment can significantly relieve symptoms. This article, the conformal group and the conventional group rate of pain relief were 96.0%, 91.6%, and significantly improve the quality of life of patients.

    Local recurrence after surgery for rectal patients re-resection is difficult, post-operative complications. The mid-1990s, some scholars had recurrent patients to take a positive attitude of the surgery, to adopt a more radical surgical resection such as whole pelvic, abdominal sacral resection surgery, but again locoregional recurrence rate of 77%, indicating extensive pelvic broadcast the bulk is unable to rely on surgery to achieve the purpose of the elimination of tumor [2]. Therefore, surgical resection is not cancer recurrence after treatment of the patients, the majority of the need for radiation therapy. The chemotherapy alone rectum local tumor control was not superior to radiotherapy or of put resynchronization therapy [3]. Some studies have shown that rectal cancer after radical at the same time put the chemotherapy can reduce the rate of local recurrence and distant metastasis and improve survival, suggesting that rectal cancer postoperative chemotherapy based program 5  Fu concomitant radiotherapy is the conventional treatment [ 4,5]. Some studies have shown that concurrent chemoradiotherapy for locally advanced rectal cancer before surgery can improve the rate of surgical resection and local control rate [6  8]. Radiotherapy and chemotherapy in combination can be made to improve efficiency, sensitizing complementary role. Most clinical studies based on 5  Fu continuous intravenous infusion or radiation therapy in the radiotherapy of the whole first week or the last week of intravenous injection of [9,10]. 5  Fu and leucovorin (CF) is used in this article as concurrent chemotherapy drugs, radiation therapy in the first week or the last week of each chemotherapy, radiotherapy did not significantly increase the toxicity. Conformal group and the conventional group of bone marrow suppression, gastrointestinal reaction probabilities are similar, the two groups were not interrupted or delayed treatment due to acute toxicity. Of local recurrence of rectal carcinoma primary tumor bed and pelvic lymph node recurrence conventional radiotherapy to improve tumor dose, increasing the dose of the rectum, bladder, and other normal tissues, increased radiation cystitis, radiation proctitis incidence This is one of the major pelvic irradiation dose restricted. Three-dimensional conformal radiotherapy are coplanar and non-coplanar incident direction, focused irradiation to the tumor tissue, the radiation dose is highly consistent with the target in three dimensions by the high dose in the tumor at the same time, maximize the protection of the surrounding normal tissue , thereby to create the conditions for the increment of the target volume. The imaging studies are not yet fully determined subclinical lesions in order to avoid leakage according to us in the first phase of conventional pelvic radiotherapy to 46Gy to control subclinical lesions after line of three-dimensional conformal radiotherapy for local tumor pushing the amount of To cure amount. To reduce late responding tissue damage, conformal radiotherapy with conventional fractionation 2Gy / F, 5F / w-. Our results show that the conformal group of 3-year local control rate, the 3-year survival rate is higher than the conventional group, similar to the reported in the literature [11,12]. Toxicity of radiation proctitis and cystitis is slightly lower than the control group, but not statistically significant. Pelvic organ dose-volume histograms rectal cancer patients with three-dimensional conformal radiotherapy postural this paper, supine, Koelbl [13] with a three-dimensional treatment planning system analysis of rectal cancer patients treated with radiation therapy in different body postures found in the prone position with A device than supine pelvic organs such as the small intestine, bladder by the amount and the total irradiation volume significantly reduced abdominal vacant. It is worth to learn radiotherapy positioning in the future.

    In summary, the three-dimensional conformal radiotherapy in combination with chemotherapy is the treatment of rectal cancer recurrence after effective treatment can relieve symptoms and improve long-term survival, but how to be more reasonable to arrange a comprehensive treatment of the treatment of locally recurrent rectal cancer, such as best chemotherapy drugs and chemotherapy, the timing of radiotherapy and chemotherapy, the use of chemotherapy drugs, radiation therapy program and technical applications, need further study.