Clinical Outcomes of Volumetric Modulated Arc Therapy Following Intracavitary/Interstitial Brachytherapy in Cervical Cancer: A Single Institution Retrospective Experience.
ABSTRACT: Purpose: To evaluate treatment outcomes and toxicity in patients with cervical cancer (CC) treated with volumetric modulated arc therapy (VMAT), followed by three-dimensional high-dose-rate intracavity combined with interstitial brachytherapy (IC/IS BT) compared with intensity-modulated radiation therapy (IMRT) treatment. Materials and Methods: A total of 398 patients with stage IA-IVB CC treated with definitive radiotherapy with or without chemotherapy were retrospectively analyzed (331 VMAT and 67 IMRT). A total prescription dose of 45-50 Gy was delivered to pelvic field with VMAT/IMRT in 25/28 fractions, with five fractions per week. Every patient further received IC/IS BT for four to six 6.0-Gy fractions. Local control (LC), disease-free survival (DFS), overall survival (OS), and distant metastasis-free survival (DMFS) rates were calculated. Acute hematotoxicity and late toxicity were recorded. Results: The median follow-up period was 25.47 (range, 0.93-58.93) months for the VMAT and 35.07 (4.8-90.37) months for IMRT. The 3-year OS, DFS, LC, and DMFS rate were 80.5, 65.4, 88.7, and 78.1% in VMAT group, and 76.2, 76.4, 83.1, and 86.1% in the IMRT group, respectively. No significant differences were found between VMAT and IMRT groups for OS, DFS, LC, and DMFS rate. However, patients in the VMAT group had lower incidence of chronic enterocolitis complication (26.6 vs. 38.8%, p = 0.004). In addition, a total of 3 (0.9%) patients developed grade 3 chronic cystitis, and 7 (2.1%) patients developed grade 3 or greater chronic enterocolitis in VMAT group. Conclusion: VMAT combined with IC/IS BT can result in satisfactory curative outcomes and low incidences of late radiation enterocolitis and cystitis in CC treatment.
Project description:Our objective was to examine whether adding induction chemotherapy to concurrent chemoradiotherapy improved survival in stage III nasopharyngeal carcinoma (NPC) patients, especially in low-risk patients at stage T3N0-1.We retrospectively analyzed 687 patients with stage T3N0-1 NPC treated with intensity-modulated radiation therapy (IMRT) plus concurrent chemotherapy (CC) with or without induction chemotherapy (IC). Propensity score matching (PSM) method was used to select 237 pairs of patients from two cohorts. Overall survival (OS), locoregional relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and progression-free survival (PFS) were assessed by using the Kaplan-Meier method, log-rank test, and Cox regression analysis.No significant survival differences were observed between IC plus CC and CC cohorts with similar 4-year OS (91.7% vs 92.6%, P=0.794), LRFS, (92.7% vs 96.8%, P=0.138), DMFS (93.5% vs 94.3%, P=0.582), and PFS (87.5% vs 91.1%, P=0.223). In a univariate analysis, lower Epstein-Barr virus deoxyribonucleic acid (EBV DNA; <4,000 copies/mL) significantly improved 4-year DMFS (95.5% vs 91.6%, P=0.044) compared with higher EBV DNA (≥4,000 copies/mL). No factors were associated with 4-year OS, LRFS, DMFS, and PFS in a multivariate analysis. IC plus CC group experienced higher rates of grade 3-4 leucopenia (P<0.001) and neutropenia (P<0.001).The addition of IC to CC in stage T3N0-1 NPC patients treated with IMRT did not significantly improve their survival. The IC group experienced higher rates of grade 3-4 hematological toxicities. Therefore, further investigation is required.
Project description:Background:Whole-ventricular radiotherapy (WV-RT) followed by a boost to the tumor bed (WV-RT/TB) is recommended for intracranial germ cell tumors (IGCT). As the critical brain areas are mainly in the target volume vicinity, it is unclear if protons indeed substantially spare neurofunctional organs at risk (NOAR). Therefore, a dosimetric comparison study of WV-RT/TB was conducted to assess whether proton or photon radiotherapy achieves better NOAR sparing. Methods:Eleven children with GCT received 24?Gy(RBE) WV-RT and a boost up to 40?Gy(RBE) in 25 fractions of 1.6?Gy(RBE) with pencil beam scanning proton therapy (PBS-PT). Intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans were generated for these patients. NOAR were delineated and treatment plans were compared for target volume coverage (TVC), homogeneity index (HI), inhomogeneity coefficient (IC) and (N)OAR sparing. Results:TVC was comparable for all three modalities. Compared to IMRT and VMAT, PBS-PT showed statistically significant optimized IC, as well as dose reduction, among others, in mean and integral dose to the: normal brain (-35.2%, -32.7%; -35.2%, -33.0%, respectively), cerebellum (-53.7%, -33.1%; -53.6%, -32.7%) and right temporal lobe (-14.5%, -31.9%; -14.7%, -29.9%). The Willis' circle was better protected with PBS-PT than IMRT (-7.1%; -7.8%). The left hippocampus sparing was higher with IMRT. Compared to VMAT, the dose to the hippocampi, amygdalae and temporal lobes was significantly decreased in the IMRT plans. Conclusions:Dosimetric comparison of WV-RT/TB in IGCT suggests PBS-PT's advantage over photons in conformality and NOAR sparing, whereas IMRT's superiority over VMAT, thus potentially minimizing long-term sequelae.
Project description:BACKGROUND AND PURPOSES:This study compared VMAT and IMRT plans for intact breast radiotherapy for left sided breast cancer and evaluated the irradiated dose of planning target volume and OARs, especially focusing on heart and coronary artery. MATERIALS AND METHODS:Eleven patients with left sided breast cancer whose breast was relatively smaller (the mean volumes is 296 cc) treated with breast-conserving surgery were prescribed radiotherapy of 50 Gy in 25 fractions using two or four-field step and shoot IMRT (2 or 4-F IMRT), and one or two-arc VMAT (1 or 2-arc VMAT). The 10 Gy electron boost to the tumor bed after delivery of 50 Gy was not included in the analysis. Multiple planning parameters for the PTV and the PRV-OARs were measured and analyzed. RESULTS:Treatment plans generated using VMAT had better PTV homogeneity than the IMRT plans. For the PRV-OARs, the 1-arc VMAT had significantly higher Dmean and V5 for left lung and heart, and showed worse Dmean for liver, esophagus, spinal cord, contralateral lung and breast. In contrast, the 2-arc VMAT and the 2-F or 4-F IMRT plans showed better results for the PRV-OARs than the 1-arc VMAT. However, for the heart and coronary artery, the 1-arc VMAT showed better V20 and V40 compared with the other plans. Moreover, the 2 F-IMRT had specially advantage on V5 and V20 for heart and V5 for coronary arteries, the 2-F IMRT also showed a greater MU and treatment times. Using the table of quality score to evaluate the plans, we found that 2-F IMRT had the highest scores of 13, followed by the 2-arc VMAT plan (10 points) and 1-arc VMAT plan (8 points), and finally the 4-F IMRT plan (6 points). Moreover, when a dose comparison for heart minus coronary artery was calculated, the V20 and V40 for the rest of heart in all plans were very small and closed, indicating the dose to the coronary artery contributed dramatically to the high dose volumes for the entire heart. CONCLUSIONS:Compared to other plans, the 2-F IMRT plan with fewer monitor units and shorter delivery time is an appropriate technique for left sided breast cancer, which achieved good PTV coverage and sparing of organs at risk besides for the heart and coronary artery.
Project description:This study was to report the long-term outcomes and toxicities of nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). From 2009 to 2010, 869 non-metastatic NPC patients treated with IMRT were retrospectively enrolled. With a median follow-up of 54.3 months, the 5-year estimated local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) were 89.7%, 94.5%, 85.6%, 76.3%, 84.0%, respectively. In locally advanced NPC, gender, T, N, total dose of cisplatin more than 300 mg/m(2) and radiation boost were independent prognostic factors for DMFS and DFS. Age, T, N and total dose of cisplatin were independent prognostic factors for OS. Radiation boost was an adverse factor for LRFS, RRFS, DMFS and DFS. Concurrent chemotherapy was not an independent prognostic factor for survival, despite marginally significant for DMFS in univariate analysis. Concurrent chemotherapy increased xerostomia and trismus, while higher total dose of cisplatin increased xerostomia and otologic toxicities. In conclusion, IMRT provided satisfactory long-term outcome for NPC, with acceptable late toxicities. Total dose of cisplatin was a prognostic factor for distant metastasis and overall survival. The role of concurrent chemotherapy and radiation boost in the setting of IMRT warrants further investigation.
Project description:Background: Plasma Epstein-Barr virus (EBV) DNA has been determined as a prognostic factor in adult nasopharyngeal carcinoma (NPC) patients. This study was designed to evaluate the prognostic value of plasma pretreatment EBV DNA in children and adolescent NPC patients receiving intensity-modulated radiotherapy (IMRT). Methods: Pretreatment EBV DNA was retrospectively assessed in 147 children with newly diagnosed, non-metastatic NPC. All patients were treated using IMRT. Receiver operating characteristic (ROC) curve was used to identify the optimal EBV DNA cutoff point. Prognostic value was examined using a multivariate Cox proportional hazards model. Results: The median follow-up for the entire cohort was 58 months (range, 10-119 months), and the 5-year survival rates for all patients were as follows: overall survival (OS), 88.7%; locoregional relapse-free survival, 95.2%; distant metastasis-free survival (DMFS), 84.8%; and disease-free survival (DFS), 81.5%. For ROC curve analysis, the optimal cutoff value of pretreatment EBV DNA load for DFS was 40,000 copies/mL. High plasma EBV DNA was significantly associated with poorer 5-year DMFS (70.6 vs. 89.1%, P = 0.003) and DFS (63.9 vs. 86.9%, P < 0.001). In multivariate analysis, high plasma EBV DNA was an independent predictor for DMFS and DFS. Conclusions: Pretreatment EBV DNA level was a powerful prognostic discriminator for DMFS and DFS in children and adolescent NPC patients treated with IMRT.
Project description:Purpose: We used randomized trials of radiotherapy (RT) with or without chemotherapy in non-metastatic nasopharyngeal carcinoma to investigate the survival benefit of chemoradiotherapy regimens between two/three-dimensional radiotherapy (2D/3D RT) and intensity-modulated radiotherapy (IMRT). Methods: Overall, 27 trials and 7,940 patients were included. Treatments were grouped into seven categories including RT alone, induction chemotherapy (IC) followed by RT (IC-RT), RT followed by adjuvant chemotherapy (RT-AC), IC followed by RT followed by AC (IC-RT-AC), concurrent chemo-radiotherapy (CRT), IC followed by CRT (IC-CRT), and CRT followed by AC (CRT-AC). To distinguish between 2D/3D RT and IMRT, three categories in IMRT were newly added, including CRT in IMRT, IC-CRT in IMRT, and CRT-AC in IMRT. The P score was used to rank the treatments. Results: Both fixed- and random-effects frequentist and Bayesian network meta-analysis models were applied, which provided similar results and the same ranking. IC-CRT was the most effective regimen compared with CRT-AC and CRT in the IMRT era for overall survival (OS) (HR, 95% CI, IC-CRT vs. CRT-AC, 0.61 (0.45, 0.82); IC-CRT vs. CRT 0.65 (0.47, 0.91)), progression-free survival (PFS) (0.69 (0.54, 0.88); 0.63 (0.49, 0.80)), and distant metastasis-free survival (DMFS) (0.58 (0.28, 1.21); 0.60 (0.42, 0.85)). CRT-AC achieved the highest survival benefit compared with CRT, and IC-CRT for loco-regional relapse-free survival (LRRFS) (0.44 (0.15, 1.28); 0.72 (0.22, 2.33)). Among these 10 categories, after distinguishing between 2D/3D RT and IMRT, IC-CRT in IMRT ranked first for OS, PFS, and DMFS, and CRT-AC in IMRT ranked first for LRRFS. Conclusion: IC-CRT should be the most suitable regimen for loco-regionally advanced NPC in the IMRT era.
Project description:To effectively treat spine metastases, significant dose must be delivered to regions surrounding the spinal cord. We present a study comparing both step-and-shoot intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques to deliver a concomitant hypofractionated prescription dose to the diseased region and to the involved vertebrae.Seven-field IMRT and a single arc VMAT were inversely planned on five (two cervical and three thoracic) spinal metastatic patients. Planning target volumes PTVm (macroscopic) and PTVe (elective involved vertebrae) and associated organs at risk were localised. Mean doses of 35 Gy to PTVm and 20 Gy to PTVe were prescribed in five fractions. Dose statistics, estimated delivery time and results of verification using Delta(4) (ScandiDos, Uppsala, Sweden) were compared.Deliverable plans were achieved with both IMRT and VMAT. The coverage to PTV was similar for both IMRT and VMAT (p=0.5) and the dose to the regions adjacent to the spinal cord was 1% higher with VMAT (p=0.04). The mean delivery time for VMAT was 3.5 min compared with 10.5 min for IMRT. Fewer monitor units were required to deliver IMRT than to deliver VMAT. The median (range) percentage of measured points with a γ-index <1 with 3%/3 mm was 100 (99.9-100)% for IMRT and 100 (88.5-100)% for VMAT.Both VMAT and IMRT can deliver the concomitant hypofractionated regime proposed, and both offer different benefits in dose delivery. IMRT is currently preferred for its superior pre-treatment verification results and shorter planning times.This study explores the feasibility of delivering tumouricidal doses of radiation to metastatic spine disease in the vicinity of the spinal cord.
Project description:The prognostic value of diabetes remains unknown in nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). We retrospectively reviewed medical records of 1489 patients with non-metastatic, histologically-proven NPC treated using IMRT. 81/1489 (5.4%) patients were diabetic, 168/1489 (11.3%) were prediabetic, and 1240/1489 (83.3%) were normoglycemic. The 4-year disease-free survival (DFS), overall survival (OS), loco-regional relapse-free survival (LRRFS) and distant metastasis-free survival (DMFS) rates were 77.1% vs. 82.4% (P = 0.358), 85.8% vs. 91.0% (P = 0.123), 90.9% vs. 91.7% (P = 0.884), and 85.5% vs. 89.2% (P = 0.445) for diabetic vs. normoglycemic patients, and 82.4% vs. 82.4% (P = 0.993), 88.7% vs. 91.0% (P = 0.285), 90.6% vs. 91.7% (P = 0.832) and 91.5% vs. 89.2% (P = 0.594) for preidabetic vs. normoglycemic patients. Multivariate analysis did not established diabetes as poor prognostic factors in NPC patients treated with IMRT (P = 0.332 for DFS, P = 0.944 for OS, P = 0.977 for LRRFS, P = 0.157 for DMFS), however, triglycerides and low density lipoprotein cholesterol were independent prognostic factors. In conclusion, diabetes does not appear to be a prognostic factor in NPC patients treated with IMRT, and attention should be paid to hyperglycemia-associated hyperlipaemia.
Project description:Concurrent radiotherapy to the pelvis plus a prostate boost with long-term androgen deprivation is a standard of care for locally advanced prostate cancer. IMRT has the ability to deliver highly conformal dose to the target while lowering irradiation of critical organs around the prostate. Volumetric-modulated arc therapy is able to reduce treatment time, but its impact on organ sparing is still controversial when compared to static gantry IMRT. We compared the two techniques in simultaneous integrated boost plans. Ten patients with locally advanced prostate cancer were included. The planning target volume (PTV) 1 was defined as the pelvic lymph nodes, the prostate, and the seminal vesicles plus setup margins. The PTV2 consisted of the prostate with setup margins. The prescribed doses to PTV1 and PTV2 were 54 Gy in 37 fractions and 74 Gy in 37 fractions, respectively. We compared simultaneous integrated boost plans by means of either a seven coplanar static split fields IMRT, or a one-arc (RA1) and a two-arc (RA2) RapidArc planning. All three techniques allowed acceptable homogeneity and PTV coverage. Static IMRT enabled a better homogeneity for PTV2 than RapidArc techniques. Sliding window IMRT and VMAT permitted to maintain doses to OAR within acceptable levels with a low risk of side effects for each organ. VMAT plans resulted in a clinically and statistically significant reduction in doses to bladder (mean dose IMRT: 50.1 ± 4.6Gy vs. mean dose RA2: 47.1 ± 3.9 Gy, p = 0.037), rectum (mean dose IMRT: 44± 4.5 vs. mean dose RA2: 41.6 ± 5.5 Gy, p = 0.006), and small bowel (V30 IMRT: 76.47 ± 14.91% vs. V30 RA2: 47.49 ± 16.91%, p = 0.002). Doses to femoral heads were higher with VMAT but within accepted constraints. Our findings suggest that simultaneous integrated boost plans using VMAT and sliding window IMRT allow good OAR sparing while maintaining PTV coverage within acceptable levels.
Project description:Purpose:Brachytherapy is essential for local treatment in cervical carcinoma, but some patients are not suitable for it. Presently, for these patients, the authors prefer a boost by using intensity-modulated radiation therapy (IMRT). The authors evaluated the dosimetric comparison of proton-modulated radiation therapy versus IMRT and volumetric-modulated arc therapy (VMAT) as a boost to know whether protons can replace photons. Patients and Methods:Five patients who received external beam radiation therapy to the pelvis by IMRT were reviewed. Three different plans were made, including pencil beam scanning (PBS), IMRT, and VMAT. The prescribed planning target volume (PTV) was 20 Gy in 4 fractions. The dose to 95% PTV (D95%), the conformity index, and the homogeneity index were evaluated for PTV. The Dmax, D2cc, and Dmean were evaluated for organs at risk along with the integral dose of normal tissue and organs at risk. Results:The PTV coverage was optimal and homogeneous with modulated protons and photons. For PBS, coverage D95% was 20.01 ± 0.02 Gy (IMRT, 20.08 ± 0.06 Gy; VMAT, 20.1 ± 0.04 Gy). For the organs at risk, Dmax of the bladder for PBS was 21.05 ± 0.05 Gy (IMRT, 20.8 ± 0.21 Gy; VMAT, 21.65 ± 0.41 Gy) while the Dmax for the rectum for PBS was 21.04 ± 0.03 Gy (IMRT, 20.81 ± 0.12 Gy; VMAT, 21.66 ± 0.38 Gy). Integral dose to normal tissues in PBS was 14.17 ± 2.65 Gy (IMRT, 25.29 ± 6.35 Gy; VMAT, 25.24 ± 6.24 Gy). Conclusions:Compared with photons, modulated protons provide comparable conformal plans. However, PBS reduces the integral dose to critical structures significantly compared with IMRT and VMAT. Although PBS may be a better alternative for such cases, further research is required to substantiate such findings.