Curative 3D Conformal Radiotherapy of Non-Operated Prostate Adenocarcinoma at Pointe-a-Pitre University Hospital (Guadeloupe): About 29 Cases

Context: Technological advances have improved the toxicities of radiotherapy. We are evaluating the 3D technique in prostate cancer. Materials and Methods: Retrospective study from January 2015 to December 2015 with 29 files. Survival was calculated by Kaplan-Meier method. Results: We collected 29 patient records over the study period. The median age was 75 years with the following extremes: 54 years and 83 years. The median PSA level was 12 ng/ml with a range of 3.05 to 79 ng/ml. Gleason score analysis showed 6 patients (20.69%) with a score of 6 (3 + 3), 23 patients (79.31%) with a score of 7 including 12 patients (41.38%) with grade 3 and 11 patients (37.93%) with grade 4. The median dose delivered was 74 Gy, with a mean dose of 73.79 Gy and extremes of 70 Gy for the minimum and 76 Gy for the maximum. Hormone therapy was combined with radiotherapy in 17 patients (58.62%). Seven patients (24.14%) had grade 1 acute bladder toxicity and one patient (3.45%) had grade 2 acute toxicity. Late bladder toxicity was grade 1 in 5 patients (17.24%), grade 2 in 3 patients (10.34%) and grade 3 in 1 patient (3.45%). Late rectal toxicity, grade 2 in 3 patients (10.34%), grade 3 in 1 patient, was noted. Overall survival at 2 years was 100% and 89.65% at 5 years. Relapse-free survival at 2 years was 82.76% and 62.07% at 5 years. There were 3 deaths (10.34%) of which only one was related to prostate cancer. Conclusion: Radiotherapy, like surgery, is a fundamental option for the treatment of prostate cancers, particularly those that are locally advanced. It is gaining in importance with the improvement of techniques (IMRT, VMAT…) and new fractionations which contribute to the reduction of toxicities and the comfort of patients (shorter spread).

Effect of intensity-modulated radiotherapy versus three-dimensional conformal radiotherapy on clinical outcomes in patients with glioblastoma multiforme

Background Few studies were reported on the comparison of clinical outcomes between intensity-modulated radiotherapy （IMRT） and three-dimensional conformal radiotherapy （3D-CRT） in the treatment of glioblastoma multiforme （GBM）.This study aimed to determine whether IMRT improves clinical outcomes compared with 3D-CRT in patients with GBM.Methods The records of 54 patients with newly-diagnosed GBM from July 2009 to December 2010 were reviewed.The patients underwent postoperative IMRT or 3D-CRT with concurrent and adjuvant temozolomide.Kaplan-Meier method and log rank test were used to estimate differences of patients＇ survival.Results The median follow-up was 13 months.Of the 54 patients,fifty （92.6%） completed the combined modality treatment.The 1-year overall survival rate （OS） was 79.6%.The pattern of failure was predominantly local.A comparative analysis revealed that no statistical difference was observed between the IMRT group （n=21） and the 3D-CRT group （n=33） for 1-year OS （89.6% vs.75.8%,P=0.795）,or 1-year progression-free survival （PFS） （61.0% vs.45.5%,P=0.867）.In dosimetric comparison,IMRT seemed to allow better sparing of organs at risk than 3D-CRT did （P=0.050,P=0.055）.However,there was no significant difference for toxicities of irradiation between the IMRT group and the 3D-CRT group.Conclusions Our preliminary results suggested that delivering standard radiation doses by IMRT is unlikely to improve local control or overall survival for GBM compared with 3D-CRT.Given this lack of survival benefit and increased costs of IMRT,the utilization of IMRT treatment for GBM needs to be carefully rationalized.

Technical and Dosimetric Study of Four Facio-cervical Fields Conformal Radiotherapy for Nasopharyngeal Carcinoma

Objective: The aim of this study is to establish the methods of four facio-cervical field's conformal radiotherapy(4F-CRT) for nasopharyngeal carcinoma(NPC), and to optimize the methods for clinical practice. Materials and Methods:40 patients with untreated NPC of T1-T4(1997 AJCC Staging System) were rolled into this study.Conventional and four facio-cervical fields conform plans were designed for each patient using Pinnacle 8.0 three-dimension treatment planning system(3D-TPS)as follows: 1. Improved plan, four facio-cervical field's conform plan, anterior, posterior facio-cervical and two lateral opposing facio-cervical fields; 2. Conventional plan, two lateral opposing facio-cervical fields delivered to the target in each plan, only with the same dose dose volume histograms(DVHs) of the targets and normal organs, brain stem,spinal cord, parotid glands, and temporal mandibular joints(TMJs) were compared and the dose distribution were evaluated. Results: 1.The dose distribution of the improved plan could meet the requirements for the target volume. 2. There was not any significant difference in the dose of spinal cord between the two plans.The mean doses of Dmaxfor brain stem in conventional plan were much lower than those in the improved plan,though both were within safety limits. 3. Compared with the conventional plans, the improved plan significantly decreased the hotspot areas in the target volume and had better parotid glands and temporal mandibular joints sparing effect. Conclusion:Compared with the conventional plan, the improved plan provides satisfactory dose coverage to the tumor volume and better sparing of the parotid gland, TMJs and other normal tissues in external beam radiotherapy of NPC.

Adjuvant radiotherapy in central hepatocellular carcinoma after narrow-margin hepatectomy:A 10-year real-world evidence

Objective:A prospective randomized control study investigated the feasibility and efficacy of adjuvant radiotherapy on patients with central hepatocellular carcinoma(HCC)after narrow-margin hepatectomy(<1 cm).This study presents an updated 10-year real-world evidence to further characterize the role of adjuvant radiotherapy.Methods:Patients with central HCC after narrow-margin hepatectomy(<1 cm)were prospectively assigned to adjuvant radiotherapy group and control group.Patients'outcome,adverse events,long-term recurrence and survival rates were investigated.Results:The 1-,5-,and 10-year recurrence-free survival(RFS)rates were 81.0%,43.9%,and 38.7%,respectively in adjuvant radiotherapy group and 71.7%,35.8%,and 24.2%,respectively in control group(log-rank test,P=0.09).The 1-,5-,and 10-year overall survival(OS)rates were 96.6%,54.7%,and 42.8%,respectively in adjuvant radiotherapy group and 90.2%,55.1%,and 30.0%,respectively in control group(log-rank test,P=0.20).The 1-,5-,and 10-year RFS rates for patients with small HCC(≤5 cm)were 91.1%,51.6%,and 48.4%,respectively in adjuvant radiotherapy group and 80.0%,36.6%,and 26.6%,respectively in control group(log-rank test,P=0.03).Landmark analysis demonstrated that patients with small HCC in adjuvant radiotherapy group had a significantly improved OS in second five years after treatment in comparison to patients in control group(log-rank test,P=0.05).Conclusions:Our updated results showed a sustained clinical benefit on reducing recurrence,improving longterm survival for small central HCC by adjuvant radiotherapy after narrow-margin hepatectomy.Long-term survival data also indicated that hepatectomy is an optimal treatment for selected patients with central HCC.

Helical tomotherapy and volumetric modulated arc therapy:New therapeutic arms in the breast cancer radiotherapy

AIM To analyse clinical and dosimetric results of helical tomotherapy(HT) and volumetric modulated arc therapy(VMAT) in complex adjuvant breast and nodes irradiation.METHODS Seventy-three patients were included(31 HT and 42 VMAT). Dose were 63.8 Gy(HT) and 63.2 Gy(VMAT) in the tumour bed, 52.2 Gy in the breast, 50.4 Gy in supraclavicular nodes(SCN) and internal mammary chain(IMC) with HT and 52.2 Gy and 49.3 Gy in IMC and SCN with VMAT in 29 fractions. Margins to particle tracking velocimetry were greater in the VMAT cohort(7 mm vs 5 mm).RESULTS For the HT cohort, the coverage of clinical target volumes was as follows: Tumour bed: 99.4% ± 2.4%; breast: 98.4% ± 4.3%; SCN: 99.5% ± 1.2%; IMC:96.5% ± 13.9%. For the VMAT cohort, the coverage was as follows: Tumour bed: 99.7% ± 0.5%, breast: 99.3% ± 0.7%; SCN: 99.6% ± 1.4%; IMC: 99.3% ± 3%. For ipsilateral lung, Dmean and V20 were 13.6 ± 1.2 Gy, 21.1% ± 5%(HT) and 13.6 ± 1.4 Gy, 20.1% ± 3.2%(VMAT). Dmean and V30 of the heart were 7.4 ± 1.4 Gy, 1% ± 1%(HT) and 10.3 ± 4.2 Gy, 2.5% ± 3.9%(VMAT). For controlateral breast Dmean was 3.6 ± 0.2 Gy(HT) and 4.6 ± 0.9 Gy(VMAT). Acute skin toxicity grade 3 was 5% in the two cohorts.CONCLUSION HT and VMAT in complex adjuvant breast irradiation allow a good coverage of target volumes with an acceptable acute tolerance. A longer follow-up is needed to assess the impact of low doses to healthy tissues.

Influence of Position and Radiation Technique on Organs at Risk in Radiotherapy of Rectal Cancer

The influence of the position and radiation technique on the organs at risk（OARs） in radiotherapy of rectal cancer was evaluated. The relationship between the volume of irradiated small bowel（VSB） and acute bowel toxicity was determined. A total of 97 cases of rectal cancer were retrospectively randomized to receive radiotherapy with the designated treatment positions and radiation plans. Among 64 patients in the supine position, 32 patients were given three-dimensional conformal radiotherapy（3DCR） and 32 patients were subjected to intensity-modulated radiation therapy（IMRT） respectively. The rest 33 patients were treated with 3DCRT in the prone position with a belly board. The VSB was calculated for doses from 5 to 45 Gy at an interval of 5 Gy. With prescription dose in planned target volume（PTV） of 50 Gy, the dose distribution, conformal index for PTV（CIPTV）, dose-volume histogram（DVH） of OARs, the correlation of VSB and the acute toxicity were compared. The results were shown as follows：（1） Among the 3 methods, there were no differences in PTV＇s converge including V95 and D95;（2） For IMRT under a supine position, CIPTV was closest to 1, the mean dose of small bowel decreased（P〈0.05）, and the mean VSB from V30 to V45 significantly decreased（P〈0.05）.（3） For 3DCRT with a belly board under a prone position, the mean dose and the mean VSB from 40 to 45 Gy were less than those for 3DCRT under a supine position（P〈0.05）;（4） Mean proportion of VSB was significantly greater in the patients experiencing diarrhea grade 2-4 than in those with diarrhea grade 0-1 at dose levels from V30 to V45（P〈0.05）. It was concluded that for the radiotherapy of rectal cancer, IMRT technique might decrease the high-dose VSB to reduce the risk of acute injury. 3DCRT with a belly board under a prone position is superior to 3DCRT under a supine position, which could be a second choice for radiation of rectal cancer.

Dosimetric Comparison between Coplanar and Non-Coplanar Fields in Irradiation of Middle and Lower Lobes Lung Tumors

Purpose: To compare between the coplanar and non-coplanar fields regarding planning target volume (PTV) coverage, conformity index and preservation of organs at risk (heart-lungs-esophagus and spinal cord). Materials and Methods: 10 patients presented with stage IIIA or IIIB NSCLC with a tumor located in the middle or lower lobes. Because of this location, the heart is one of the main organs at risk. Two plans, coplanar and non-coplanar 3 dimensional conformal radiotherapy plans are performed for each patient. All treatment plans are created using Xio - Computerized medical system treatment planning system. The prescribed dose is 64 Gy in 32 fractions. Results: For both plans, the maximum dose to the PTV doesn’t exceed 110% of the prescribed dose;the 95% isodose (60.8 Gy) covers at least 95% of the PTV volume and the mean conformity index values are also very similar 0.59 vs 0.61 for coplanar and non-coplanar plans respectively without statistically significant difference (P = 0.1711). Regarding organs at risk, large advantage for adding a non-coplanar field in the preservation of the heart is observed. The mean V30 values for noncoplanar plan are 17.3 Gy versus 28.9 Gy for the coplanar plan with statistically significant difference (P = 0.0060). Also, the mean V40 and V50 values for the non coplanar compared to coplanar plan are 12.6 Gy and 7.9 Gy versus 23.1 Gy and 14.9 Gy respectively, and these differences are statistically significant (P = 0.0162) (P = 0.0084). No statistically significant differences are found between coplanar and non-coplanar plans for lungs, esophagus or the spinal cord. Conclusion: Using non-coplanar beams in the irradiation of middle and lower lung tumors significantly reduces the radiation dose to the heart with the same target volume coverage and conformity index.