ABSTRACT
Objective To assess the impact of respiratory motion on the displacement of target area and to analyze the discrimination between free breathing and active breathing control (ABC) in patients with gastric cancer treated with post-operative radiotherapy. Methods From January 2005 to November 2006, 22 patients with post-operatively confirmed gastric cancer were enrolled in this study. All diseases were T_3/ N +, staging Ⅱ - Ⅳ. Patients were CT scanned and treated by radiation with the use of ABC. Image J software was used in image processing, motion measurement and data analysis. Surgical clips were implanted as fiducial marks in the tumor bed and lymphatic drainage area. The motion range of each clip was measured in the resultant-projection image. Motions of the clips in superior-inferior (S-I), right-left (R-L) and anterior-posterior (A-P) directions were determined from fluoroscopy movies obtained in the treatment position. Results The motion ranges in S-I, R-L and A-P directions were 11.1 mam, 1.9 mm and 2.5 mm (F = 85.15, P = 0. 000) under free breathing, with 2.2 mm, 1.1 mm and 1.7 nun under ABC (F = 17.64, P = 0. 000), and the reduction of motion ranges was significant in both S-I and A-P directions (t = 4.36, P = 0. 000;t = 3.73,P = 0.000). When compared with under free-breathing, the motion ranges under ABC were kept unchanged in the same breathing phase of the same treatment fraction, while significant increased in different breathing phase in all three directions (t = - 4.36, P = 0. 000; t = - 3.52, P = 0.000; t =-3.79, P = 0. 000), with a numerical value of 3.7 mm, 1.6 mm and 2.8 mm, respectively (F = 19.46, P = 0. 000) . With ABC between different treatment fractions , the maximum displacements were 2.7 mm, 1.7 mm and 2.5 mm for the centre of the clip cluster (F =4.07,P =0. 019), and were 4.6 mm, 3.1 mm and 4.2 mm for the clips (F =5.17 ,P =0.007). The motion ranges were significant increased in all the three directions (t = - 4.09, P=0.000 ; t =-4.46, P = 0.000 ; t = - 3.45, P =0.000). Conclusions In the irradiation of post-operative gastric cancer, the maximum displacement of organ motions induced by respiration is in S-1 direction and the minimum in R-L direction under free breathing. The use of ABC can reduce the motions significantly in S-I and A-P directions, and the same changes exist in both inter-and intra-fraction treatment.
ABSTRACT
Objective To compare the dose distribution of the target and normal tissues in gastric cancers between three-dimension conformal radiation therapy (3DCRT) and intensity modulated radiation therapy (IMRT) plan when respiratory motion factors integrated in the plan. Methods From January 2005to November 2006, 10 patients with post-operatively radiation of gastric cancer were enrolled in this study.Planning CT were acquired conventionally with free-breath mode and the static treatment plans of the 3DCRT and IMRT were designed respectively. Probability distribution functions (PDF) were generated and convoluted with the static dose distributions from 3DCRT and IMRT plans to obtain the integrated plans. The dose distributions of the target and normal tissues were compared between 3DCRT and IMRT integration treatment plans, such as V45 of clinical target volume, V4o of liver and V15, V18 of left and right kidney.Results In the respiratory integrated treatment planning, the target volume coverage and homogeneity with IMRT are superior to those with 3DCRT ( ( V45 98%∶ 87% (t = -3. 35 ,P =0. 010) ,mean dose 46. 81 Gy ±0. 75 Gy∶45.99 Gy ± 1.12 Gy (t = -0. 31 ,P=0. 020) ). The V40 of teh liver in IMRT are smaller than those in 3DCRT ( 12%∶ 16% ;t=3.75,P=0.010). For the left kidney, the V15 and V18 in IMRT are smaller than those in 3DCRT ( (34%∶ 50% (t = 2. 17 ,P = 0. 050) and 27%∶46% (t = 3. 11 ,P = 0. 020) ),but for the right kidney, V15 and V18 in 3DCRT are smaller than those in IMRT ( ( 15%∶ 21% (t = - 2. 42,P=0.040) and 11%∶15% (t= -2.71,P=0.030)). Conclusions When respiratory motion factor integrated in the treatment plan, IMRT showed advantage both in target coverage and normal tissue sparing in the high dose region of liver and left kidney.
ABSTRACT
Objective To estimate the operative risk and outcomes of colorectal cancer patients 80 years of age and older. Methods Colorectal cancer resection was performed in 99 patients 80 years of age and older between Dec. 1987 and June 2005. The informations about clinical data, co-morbidity,complications, operative mortality and survival were retrospectively analyzed. The patients were followed-up for 45.12 months (range 1-136) months. Results Of 99 patients, co-morbidity was found in 43 patients (43.4% ) and complication in 10 patients (10.1%). No patient died of operation.Eighty patients completed the follow-up study. The overall 3-year survival rate and disease-free survival rate were 64.3% and 61.1%, respectively. Whereas the overall 5-year survival rate and disease-free survival rate were 52.8% and 52.1%, respectively. In univariate analysis, curative or palliative operation, tumor differentiation, cancer embolism in the vasculature, tumor staging and complications were proved to be significant prognostic factors. Multivariate survival analysis,however, showed that only the curative or palliative operation was independent factor for survival.Conclusions The high risk of co-morbidity for patients 80 years of age and older is not the obstacle to cancer resection.These patients will have satisfactory outcomes via optimal treatment and operation.
ABSTRACT
Objective To evaluate the toxicity and efficacy of post-operative chemoradiotherapy for gastric cancer. Methods Forty-five gastric cancer patients treated with post-operative radiation ± concurrent chemotherapy were retrospectively analyzed. Among them, 14 were female and 31 were male. The median age was 54 (30-72) years. Pathology stages were IB-IV. Radiotherapy of doses from 45 Gy/25fx to 55 Gy/30fx was delivered to the tumor bed and regional lymph nodes with 3D conformal or IMRT technology.Concurrent chemotherapy agent was fluorouracil or capacitabine. Results All patients except 2 (4%)completed radiotherapy as planned. The most common acute toxicities were hematologic and gastrointestinal effects. The incidence of the patients was 56% with mild nausea/vomiting,71% and 7% with grade Ⅰ / Ⅱ and Ⅲ leucopenia, and 38% with grade Ⅰ/Ⅱ hypodynamia and anepithymia. The 1-year overall survival,relapse-free survival and local control rates were 87% ,82% and 95%, respectively. Conclusions Postoperative chemoradiation for patients with locally advanced gastric cancer is tolerable. Our study shows the advantage of post-operative chemoradiation for local control. However,further prospective randomized trial is needed to validate the efficacy.
ABSTRACT
PURPOSETo introduce how to reconstruct defects after resection for locally advanced carcinoma of externa-lia in man. METHODS In 11 male patients after radical resection of the primary lesion and clearance of lymph nodes, fascial flap, rectus abdominis myocutaneous flap or combined myocutaneous flap of musculus gluteus max-imus and musculus tensor fasciae latae are used to reconstruct the large defects. Reconstruction with rectus abdominis myocutaneous flap is explained in detail. RESULTS In 11 male patients. 10 were healed by first intention, one was healed by granulation. CONCLUSION The key to successful operation is to select the suitable myocutaneous flap according to the degree of defects. Indication and key points of the operation are explained.
ABSTRACT
ObjectiveTo assess the diagnostic value of preoperative lymphoscintigraphy for lateral lymph node metastasis in low rectal cancer. MethodsFrom May 1999 to March 2001, pelvic and lower abdominal lymphoscintigraphy with 99mTc sulfur colloid was performed on 32 patients with proven colorectal cancer one day prior to operation. Among these patients were 27 rectal cancers, 3 sigmoid cancers and 2 colon cancers. Fifteen cases of rectal cancer with the tumor located at or below the peritoneal reflection received extended lymphadenectomy with lateral dissection (D3 lymphadenectomy). The result of lymphoscintigrams was correlated with histologic lateral node examination. Results The image ratio of pararectal nodes, obturator nodes, and internal iliac aorti lymph trains was 69%, 91%, and 100% respectively. In 15 patients receiving D3 lymphadenectomy, 10 had negative lymphoscintigrams whereas 5 had positive image, and the lateral pathology positive rate was 13%(2/15). Analysis of these results revealed the sensitivity (100%), specificity (77%) and accuracy (80%) of this diagnostic method. ConclusionPelvic and lower abdominal lymphoscintigraphy with 99mTc sulfur colloid could demonstrate the lateral lymph node drainage of low rectal cancer, and the correlation with postoperative histologic lateral node examination was high enough to enable surgeons to adopt an individualized surgical approach.