Clinical observation in three-dimensional conformal radiotherapy (3D-CRT) with concurrent chemotherapy in treatment of postoperative cerebral gliomas

Objective:The aim of the study was to investigate the efficacy of three-dimensional conformal radiotherapy (3D-CRT) combined with Temozolomide (TMZ) concurrent chemotherapy in treatment of postoperative cerebral gliomas by prospective randomized controlled trials. Methods: Sixty-two patients with cerebral glioma who had residual tumor were divided into 3D-CRT group (radiotherapy group, n=31) and 3D-CRT with concurrent chemotherapy group (chemoradiotherapy group, n=31) prospectively. All patients received a dose of 50-60 Gy/25-30 F/5-6 weeks by 6 MV-X ray, three-dimensional conformal radiotherapy, 1 f/d, 5 times a week. Chemotherapy regimen was Temozolomide:75 mg/m2/d, concomitantly with radiotherapy, followed by 150-200 mg/m2/d, 5 days, 28 days per cycle, totally 3-6 cycles. Results: The total response rate was 35.3% (11/31) in radiotherapy group. The response rate was 61.3% (19/31) in chemoradiotherapy group. There was significant difference in curative effect (P=0.042). There was no significant difference in survival comparison of two groups (P=0.263). Stratified analysis showed the patients with grade Ⅲ gliomas of chemoradiotherapy group had better prognosis than ones of radiotherapy group (P=0.043). Conclusion: The 3D-CRT with concurrent chemotherapy can improve the survival of cerebral gliomas with pathological grade Ⅲ.

Dosimetric study of five-field intensity-modulated radiotherapy compared with conventional three-dimensional conformal radiotherapy for rectal cancer

Objective： The aim of the study was to compare the difference of dose distribution in clinical target volume and organ at risk （OAR） between five-field intensity-modulated radiotherapy （IMRT） and conventional three-dimensional conformal radiotherapy （3DCRT） in the radiotherapy of rectal cancer. Methods： Fifteen patients with rectal cancer treated with radio- therapy （RT） were retrospectively analyzed. Among the patients, seven received RT preoperatively and 8 postoperatively. The target volume and the OARs such as the small bowel, bladder and femoral heads were contoured for each patient. 3DCRT-plan and IMRT-plan were performed for each patient respectively, with the prescribed dose covering at least 95% of the planning target volume （PTV）. The conformity index （CI） and homogeneity index （HI） were used for evaluation of the dose distribution in the target volume, and the Dx% （the lowest dose to the x% volume of the OARs that received the highest dose of irradiation） and the mean dose were used for evaluation of the dose to OARs. Paired-T test was used for companson of the difference between the two plans. Results： In the IMRT-plan and 3DCRT-plan, the CI were 0.94 and 0.87 （P = 0.000） and the HI were 1.13 and 1.17, respectively （P = 0.001）. For small bowel, the D30%, D50% and the mean dose were 19.67 Gy, 15.13 Gy and 18.81 Gy in the IMRT-plan and 25.20 Gy, 22.20 Gy and 22.89 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For bladder, the D30%, D50%, and the mean dose were 24.80 Gy, 34.20 Gy and 28.70 Gy in the IMRT- plan, and 35.07 Gy, 44.67 Gy and 35.68 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For femoral heads, the D5% in the IMRT-plan and 3DCRT-plan were 40.6 Gy and 40.47 Gy, respectively （P = 0.936）, and the mean dose were 30.14 Gy and 25.57 Gy, respectively （P = 0.001）. Conclusion： Five-field IMRT-plan is better than 3DCRT-plan in the conformity and the dose homogeneity within target volume and also better in sparing the small bowel and bladder.

Evaluation of whole-course three-dimensional conformal radiotherapy combined with late-course accelerated hyperfractionated radiotherapy for esophageal carcinoma patients

Objective： The aim of the study was to evaluate the therapeutic effect and safety of whole-course three-dimensional conformal radiotherapy （3DCRT） combined with late-course accelerated hyperfractionated radiotherapy （LCAFR） on patients with esophageal carcinoma. Methods： one hundred and one patients with esophageal carcinoma were divided into two groups. Observing group （49 cases） were treated by whole-course 3DCRT. Patients in control group （52 cases） were treated by conventional radiotherapy. Clinical efficiencies and radiation toxicities were compared between two groups. Results： The side effects including radiation esophagitis （63.2%） and tracheitis （49.0%） decreased in observing group, but there was no significant difference between two groups （69.2% and 55.7% in controls）. The 1-, 2-and 3-year tumor local control rates and overall survival rates in the observing group were significantly improved compared with the control group, being respectively 87.8%, 75.5%, 63.3% vs 71.2%, 55.8%, 42.3% and 85.7%, 71.4%, 46.7% vs 69.2%, 51.9%, 26.9% （all P 0.05）. Conclusion： The therapeutic effect of whole-course 3DCRT combined with LCAFR for esophageal carcinomas is superior to conventional radiotherapy.

Concurrent gemcitabine and cisplatin combined with 3D conformal radiotherapy for stage III non-small cell lung cancer

Objective： To study the toxicities and efficacy of concurrent gemcitabine plus cisplatin combined with three-dimensional conformal radiotherapy for stage Ⅲ non-small cell lung cancer （NSCLC）. Methods： Thirty-six patients with pathologically diagnosed NSCLC received radiotherapy and concurrent chemotherapy. There were 22 patients with stage Ilia and 14 patients with IIIb. Radiotherapy was given a total of 60-70 Gy in conventional fractionation. Chemotherapy included gemcitabine （600 mg/m^2） and cisplatin （20 mg/m^2）, once per week. Results： Thirty-two patients received a total dose of 60-72 Gy. Two patients received 56 Gy and another two patients received 58 Gy. Thirty-four patients received 4-6 weeks of chemotherapy, while two patients received only 2 weeks of chemotherapy. The overall response rate （CR ＋ PR）, complete response rate （CR）, partially response rate （PR） were 83.3% （30/36）, 11.1% （4/36） and 72.2% （26/36） respectively. The median follow-up duration was 18.4 months. The 1- and 2-year overall survival rates were 77.8% （28/36） and 55.6% （20/36）, respectively. Conclusion： Concurrent gemcitabine and cisplatin combined with three-dimensional conformal radiotherapy for stage III non-small cell lung cancer is effective and well tolerated. Lone-term results need further study.

Late course shrinking gross tumor volume (GTV) and boost radiotherapy for a special left lung cancer patient whose right lung was resected: a case report

We reported a special case of a locally advanced squamous cell carcinoma of the left lung. Due to pulmonary tuberculosis, the patient had underwent a complete right-side pulmonary lobectomy 20 years ago. Left lung supports his life, he is unable to carry on an operation treatment, so he accepted radiotherapy. Firstly, we defined gross tumor volume (GTV1) by CT simulation location, three-dimensional conformal radiotherapy (3D-CRT) was used until tumor dose reached 50 Gy/25 f. Secondly, by repeating the planning CT scan, defined GTV2, continued to radiotherapy by 2.5 Gy/f until the dose was 65 Gy/31 f. Using the same method for third CT scan, defined GTV3, continued to radiotherapy by 3 Gy/f until the total dose was 74 Gy/34 f. After radiotherapy, the patient acquired complete response and he had no obvious side-effect of radiotherapy. There has been no recurrence for 5 years now.

Initial outcome of induction chemotherapy followed by radiotherapy and concurrent weekly paclitaxel for stage Ⅲ non-small cell lung cancer

Objective： The aim of our study was to evaluate the toxicity and efficacy of induction chemotherapy （ICT） followed by three-dimensional conformal radiotherapy （3D CRT） and concurrent weekly paclitaxel on unresectable non-small cell lung cancer （NSCLC）. Methods： Stage III NSCLC patients with favorable conditions were treated with 2 to 4 cycles of carboplatin （AUC = 5-6, dl） combined with paclitaxel （175 mg/m〈 dl）, then followed by weekly paclitaxel （40 mg/m2） and concurrent 3D CRT within 3-4 weeks. The prescription dose was given as high as possible under the condition that V20 〈 31% and spinal cord dose 〈 50 Gy. Results： Thirty-one patients were enrolled. ICT was well tolerated. During the concurrent chemoradiotherapy, the treatment of 3 patients was ended ahead of the schedule because of severe pulmonary and heart toxicities; the treatment of 2 patients was delayed for 7 and 12 days because of fatigue. Myelosuppression was mild （16/31）： all were grade 1-2 except 1 was grade 3. Lymphocytopenia was more obvious （29/31, grade 3 in 21）. Three patients developed grade 3 radiation-induced esophagitis, and 2 developed grades 3-4 radiation-induced pneumonitis. Two developed grade 3 esophageal stricture. No grades 3-4 pulmonary fibrosis was observed. The overall response rate was 74.1%. The 1-, 2-, 3-year overall survival rates were 74.2%, 41.9%, and 34.6%, respectively, with the median survival time of 18.5 months. The 1-, 2-, 3-year local progression-freely survival rates were 64.5%, 32.3%, and 20.5%, respectively, with the median local progression-freely survival time of 14.3 months. Conclusion： The program of ICT followed by weekly paclitaxel and 3D CRT is accomplished in most of the favorable stage III NSCLC patients. The toxicity is tolerable, and the response rate is inspiriting.

The impact of intensity modulated radiotherapy on the skin dose for deep seated tumors

Objective: The purpose of this study was to investigate the impact of intensity modulated radiotherapy (IMRT) on surface doses for brain, abdomen and pelvis deep located tumors treated with 6 MV photon and to evaluate the skin dose calculation accuracy of the XIO 4.04 treatment planning system. Methods: More investigations for the influences of IMRT on skin doses would increase its applications for many treatment sites. Measuring skin doses in real treatment situations would reduce the uncertainty of skin dose prediction. In this work a pediatric human phantom was covered by a layer of 1 mm bolus at three treatment sites and thermoluminescent dosimeter (TLD) chips were inserted into the bolus at each treatment site before CT scan. Two different treatment plans [three-dimensional conformal radiation therapy (3DCRT) and IMRT] for each treatment sites were performed on XIO 4.04 treatment planning system using superposition algorism. Results: The results showed that the surface doses for 3DCRT were higher than the surface doses in IMRT by 1.6%, 2.5% and 3.2% for brain, abdomen and pelvis sites respectively. There was good agreement between measured and calculated surface doses, where the calculated surface dose was 15.5% for brain tumor calculated with 3DCRT whereas the measured surface dose was 12.1%. For abdomen site the calculated surface dose for IMRT treatment plan was 16.5% whereas the measured surface dose was 12.6%. Conclusion: The skin dose in IMRT for deep seated tumors is lower than that in 3DCRT which is another advantage for the IMRT. The TLD readings showed that the difference between the calculated and measured point dose is negligible. The superposition calculation algorism of the XIO 4.04 treatment planning system modeled the superficial dose well.