Small bowel displacement system-assisted intensity-modulated radiotherapy for cervical cancer

2004 ◽  
Vol 93 (2) ◽  
pp. 400-406 ◽  
Author(s):  
S HUH ◽  
M KANG ◽  
Y HAN
2021 ◽  
Author(s):  
Gong-yi ZHANG ◽  
ZHANG Rong ◽  
Ping BAI ◽  
Shu-min LI ◽  
Yuan-yuan ZHANG ◽  
...  

Abstract Background Although the prognosis of locally advanced cervical cancer has improved dramatically, survival for those with stage ⅢB-ⅣA disease or lymph nodes metastasis remains poor. It is believed that the incorporation of intensity-modulated radiotherapy into the treatment of cervical cancer might yield an improved loco-regional control, whereas more cycles of more potent chemotherapy after the completion of concurrent chemotherapy was associated with a diminished distant metastasis. We therefore initiated a non-randomized prospective phaseⅡ study to evaluate the feasibility of incorporating both these two treatment modality into the treatment of high risk locally advanced cervical cancer. Objectives to determine whether the incorporation of intensity-modulated radiotherapy and the addition of adjuvant paclitaxel plus cisplatin regimen into the treatment policy for patients with high risk locally advanced cervical cancer might improve their oncologic outcomes. Study Design: Patients were enrolled if they had biopsy proven stage ⅢA-ⅣA squamous cervical cancer or stage ⅡB disease with metastatic regional nodes. Intensity-modulated radiotherapy was delivered with dynamic multi-leaf collimators using 6MV photon beams. Prescription for PTV ranged from 45.0 ~ 50.0Gy at 1.8Gy ~ 2.0Gy/fraction in 25 fractions. Enlarged nodes were contoured separately and PTV-nodes were boosted simultaneously to a total dose of 50.0–65 Gy at 2.0- 2.6Gy/fraction in 25 fractions. A total dose of 28 ~ 35Gy high-dose- rate brachytherapy was prescribed to point A in 4 ~ 5 weekly fractions using an iridium- 192 source. Concurrent weekly intravenous cisplatin at 30mg/m2 was initiated on the first day of radiotherapy for over 1-hour during external-beam radiotherapy. Adjuvant chemotherapy was scheduled within 4 weeks after the completion of concurrent chemo-radiotherapy and repeated 3 weeks later. Paclitaxel 150 mg/m2 was given as a 3-hour infusion on day1, followed by cisplatin 35 mg/m2 with 1-hour infusion on day1-2 (70 mg/m2 in total). Results Fifty patients achieved complete response 4 weeks after the completion of the treatment protocol, whereas 2 patients had persistent disease. After a median follow-up period of 66 months, loco-regional (including 2 persistent disease), distant, and synchronous treatment failure occurred in 4 ,5, and 1, respectively. The 5-year disease-free survival, loco-regional recurrence-free survival, distant-metastasis recurrence-free survival was 80.5%, 90.3%, and 88.0%, respectively. Four of the patients died of the disease, and the 5-year overall survival was 92.1%. Most of the toxicities reported during concurrent chemo-radiotherapy were mild and transient. The occurrence of hematological toxicities elevated mildly during adjuvant chemotherapy, as 32% (16/50) and 4% (2/50) patients experienced grade 3–4 leukopenia and thrombocytopenia, respectively. Grade 3–4 late toxicities were reported in 3 patients. Conclusions The incorporation of intensity-modulated radiotherapy and adjuvant paclitaxel plus cisplatin chemotherapy were highly effective and well-tolerated in the treatment of high-risk locally advanced cervical cancer. The former yields an improved loco-regional control, whereas distant metastases could be effectively eradicated with mild toxicities when adjuvant regimen was prescribed.


2020 ◽  
Author(s):  
Siyuan Li ◽  
Yanping Gong ◽  
Yongqiang Yang ◽  
Qi Guo ◽  
Jianjun Qian ◽  
...  

Abstract Background The goal of this study was to assess small bowel motion and explore the feasibility of using peritoneal space (PS) to replace bowel loops (BL) via the dose constraint method to spare the small bowel during intensity-modulated radiotherapy (IMRT) for rectal cancer. Methods A total of 24 patients with rectal cancer who underwent adjuvant radiotherapy were selected. Weekly repeat CT scans from pre-treatment to the fourth week of treatment were acquired and defined as Plan, 1W, 2W, 3W, and 4W. BL and PS contours were delineated in all of the scans. Two IMRT plans called P PS and P BL were designed on Plan CT using two dose PS and BL constraint methods, respectively, and then copied to CT 1~4W. The shift%, dose volume, and NTCP of the small bowel in P PS and P BL during treatment were evaluated. Results Overall, 109 sets of CT scans from 24 patients were acquired, and 218 plans were designed and copied. The PS and BL volumes were 1339.28 cc and 250.27 cc. The BL and PS shift% V 15 was 28.48% and 11.79% ( p =0.000), which was less in the prone position than in the supine position (25.24% vs 32.10%, p =0.000; 9.9% vs 14.85%, p =0.000). On all of the CT scans, most P PS small bowel dose volumes were less than from P BL . V 15 was 170.07 cc vs 178.58 cc ( p =0.000), and they had a significant correlation. The NTCP of chronic and acute side effects from P PS was significantly less than P BL (2.80% vs 3.00%, p =0.018; 57.32% vs 58.64%, p =0.000). Conclusions This study indicated that small bowel motion may lead to uncertainties in its dose volume and NTCP evaluation during IMRT for rectal cancer. The BL movements were significantly greater than PS, and the prone position was significantly less than the supine position. Using PS instead of BL can spare the small bowel. V 15 <830 cc is the dose constraint standard.


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