Hypofractionated versus conventionally fractionated image-guided volumetric-modulated arc radiotherapy for localized prostate cancer: a phase II randomized trial from China.
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ABSTRACT: Purpose
To determine the safety of hypofractionated imaging-guided (IG) volumetric-modulated arc radiotherapy (IG-VMAT; 70 Gy/28 fractions over 5.5 weeks) versus conventionally fractionated regimen (IG-VMAT; 80 Gy/40 fractions over 8 weeks) in Chinese patients with localized prostate cancer.Method
In this randomized non-comparative phase II trial, 92 patients with localized prostate cancer were assigned to receive either hypofractionated IG-VMAT (HFRT; 70 Gy/2.5Gy/28f) or conventionally fractionated IG-VMAT (CFRT; 80 Gy/2Gy/40f). Primary endpoint was grade 2 or higher late gastrointestinal (GI) and genitourinary (GU) toxicity at 2 years. The GI/GU toxicity and biochemical relapse-free survival (bRFS) were compared between the two treatment groups.Results
Median follow-up was 26 months. The incidence of grade 2 or higher late GI/GU toxicity was low in both groups; the 5-year cumulative incidence of Radiation Therapy Oncology Group grade 2 or higher GI/GU toxicity at 2 years was 7.6% with HFRT versus 10.3% with CFRT (P = 0.707). Biochemical control was not significantly different between the two groups; the 2-year bRFS was 94.6% for HFRT versus 95.0% for CFRT (P = 0.704).Conclusion
Hypofractionated IG-VMAT appears to be equivalent to conventionally fractionated IG-VMAT in terms of toxicity in Chinese patients with localized prostate cancer.
SUBMITTER: Zhong QZ
PROVIDER: S-EPMC7993676 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:PurposeHypofractionated radiotherapy delivers larger daily doses of radiation and may increase the biologically effective dose delivered to the prostate. We conducted a randomized trial testing the hypothesis that dose-escalated, moderately hypofractionated intensity-modulated radiation therapy (HIMRT) improves prostate cancer control compared with conventionally fractionated IMRT (CIMRT) for men with localized prostate cancer.Patients and methodsMen were randomly assigned to 75.6 Gy in 1.8-Gy fractions delivered over 8.4 weeks (CIMRT) or 72 Gy in 2.4 Gy fractions delivered over 6 weeks (HIMRT, biologically equivalent to 85 Gy in 1.8-Gy fractions assuming prostate cancer α-to-β ratio of 1.5). Failure was defined as prostate-specific antigen (PSA) failure (nadir plus 2 ng/mL) or initiation of salvage therapy. Modified Radiation Therapy Oncology Group criteria were used to grade late (≥ 90 days after completion of radiotherapy) GI and genitourinary toxicity.ResultsMost of the 206 men (72%) had cT1, Gleason score 6 or 7 (99%), and PSA level ≤ 10 ng/mL (90%) disease. Androgen deprivation therapy was received by 24%. With a median follow-up of 8.5 years, men treated with HIMRT experienced fewer treatment failures (n = 10) than men treated with CIMRT (n = 21; P = .036). The 8-year failure rate was 10.7% (95% CI, 5.8% to 19.1%) with HIMRT and 15.4% (95% CI, 9.1% to 25.4%) with CIMRT. There was no difference in overall survival ( P = .39). There was a nonsignificant increase in late grade 2 or 3 GI toxicity with HIMRT (8-year 5.0% v 12.6%; P = .08). However, GI toxicity was only 8.6% when rectal volume receiving 65 Gy of HIMRT was ≤ 15%. Late genitourinary toxicity was similar ( P = .84). There was no grade 4 toxicity.ConclusionThe results of this randomized trial demonstrate superior cancer control for men with localized prostate cancer who receive dose-escalated moderately hypofractionation radiotherapy while shortening treatment duration.
| S-EPMC6804854 | biostudies-literature
Project description:BackgroundTo compare WBC counts during treatment of localized prostate cancer with either conventionally fractionated (CF) or moderately hypofractionated (HYPO) radiotherapy.MethodsWeekly blood test results were extracted from the charts of patients treated within a phase III study comparing HYPO to CF. In order to compare WBC counts at the same nominal dose in both arms and thus to tease out the effect of fractionation, for each recorded WBC value the corresponding cumulative total dose was extracted as well. WBC counts were binned according to percentiles of the delivered dose and three dose levels were identified at median doses of 16, 34.1 and 52 Gy, respectively. A General Linear Model based on mixed design Analysis Of Variance (ANOVA) was used to test variation of WBC counts between the two treatment arms.ResultsOut of 168 randomized patients, 140 (83.3%) had at least one observation for each one of the selected dose levels and were included in the analysis. Mean counts were lower in the CF than the HYPO arm at all selected dose levels, reaching a statistically significant difference at dose level #3 (5397/mm3 vs 6038/mm3 for CF and HYPO, respectively, p = 0.004). The GLM model confirms that the impact of dose on WBC counts is significantly lower in the HYPO arm over the CF one (Greenhouse-Geisser test, p = 0.04). Interestingly, while WBC counts tend to drop throughout all dose levels in the CF arm, this is the case only in the earlier part of treatment in the HYPO arm.ConclusionThis secondary analysis of a phase III study shows that dose fractionation is correlated to WBC drop during treatment of localized prostate cancer, favoring HYPO over CF.
| S-EPMC6352380 | biostudies-literature
Project description:OBJECTIVE: To test the feasibility of volumetric modulated arc therapy (VMAT) in breast cancer and to compare it with three-dimensional conformal radiotherapy (3D-CRT) as conventional tangential field radiotheraphy (conTFRT). METHODS: 12 patients (Stage I, 8: 6 left breast cancer and 2 right breast cancer; Stage II, 4: 2 on each side). Three plans were calculated for each case after breast-conserving surgery. Breast was treated with 50 Gy in four patients with supraclavicular lymph node inclusion, and in eight patients without the node inclusion. Multiple indices and dose parameters were measured. RESULTS: V95% was not achieved by any modality. Heterogeneity index: 0.16 (VMAT), 0.13 [intensity-modulated radiotherapy (IMRT)] and 0.14 (conTFRT). Conformity index: 1.06 (VMAT), 1.15 (IMRT) and 1.69 (conTFRT). For both indices, IMRT was more effective than VMAT (p=0.009, p=0.002). Dmean and V20 for ipsilateral lung were lower for IMRT than VMAT (p=0.0001, p=0.003). Dmean, V2 and V5 of contralateral lung were lower for IMRT than VMAT (p>0.0001, p=0.005). Mean dose and V5 to the heart were lower for IMRT than for VMAT (p=0.015, p=0.002). CONCLUSION: The hypothesis of equivalence of VMAT to IMRT was not confirmed for planning target volume parameter or dose distribution to organs at risk. VMAT was inferior to IMRT and 3D-CRT with regard to dose distribution to organs at risk, especially at the low dose level. ADVANCES IN KNOWLEDGE: New technology VMAT is not superior to IMRT or conventional radiotherapy in breast cancer in any aspect.
| S-EPMC3856548 | biostudies-other
Project description:PurposeThe aim of the present study was to compare the dose distribution generated from photon volumetric modulated arc therapy (VMAT), intensity modulated proton therapy (IMPT), and intensity modulated carbon ion therapy (IMCIT) in the delivery of hypo-fractionated thoracic radiotherapy.Methods and materialsTen selected patients who underwent thoracic particle therapy between 2015 and 2016 were re-planned to receive a relative biological effectiveness (RBE) weighted dose of 60 Gy (i.e., GyE) in 15 fractions delivered with VMAT, IMPT, or IMCIT with the same optimization criteria. Treatment plans were then compared.ResultsThere were no significant differences in target volume dose coverage or dose conformity, except improved D95 was found with IMCIT compared with VMAT (p = 0.01), and IMCIT was significantly better than IMPT in all target volume dose parameters. Particle therapy led to more prominent lung sparing at low doses, and this result was most prominent with IMCIT (p < 0.05). Improved sparing of other thoracic organs at risk (OARs) was observed with particle therapy, and IMCIT further lowered the D1cc and D5cc for major blood vessels, as compared with IMPT (p = 0.01).ConclusionAlthough it was comparable to VMAT, IMCIT led to significantly better tumor target dose coverage and conformity than did IMPT. Particle therapy, compared with VMAT, improved thoracic OAR sparing. IMCIT, compared with IMPT, may further improve normal lung and major blood vessel sparing under limited respiratory motion.
| S-EPMC5558745 | biostudies-literature
Project description:PurposeTo investigate the incorporation of functional lung image-derived low-attenuation area (LAA) based on 4-dimensional computed tomography (4D-CT) in volumetric modulated arc therapy (VMAT) planning for patients with malignant pleural mesothelioma (MPM) after extrapleural pneumonectomy.Methods and materialsTwelve patients with MPM after extrapleural pneumonectomy were included. The primarily affected side was the right in 6 patients and the left in 6 patients. LAA was generated from 4D-CT data according to CT values with a threshold of less than -860 Hounsfield units (HU). Functional lung image was defined as the area where LAA was excluded from contralateral lung image. Two radiation therapy plans were designed: (1) Plan C, conventional VMAT and (2) Plan F, functional VMAT plan based on the functional lung. Both plans were compared in each patient with respect to the following dosimetric parameters: fV20, V20, fV10, V10, fV5, and V5, the percentages of functional or contralateral lung volumes irradiated with >20 Gy, 10 Gy, or 5 Gy, respectively; functional mean lung dose (fMLD) and mean lung dose (MLD), the mean dose to the functional or contralateral lung, respectively; maximum dose to the cord; mean doses to the liver and heart; and planning target volume homogeneity index.ResultsfV5 and MLD were significantly lower in Plan F (fV5, median 57.5% in Plan C vs 38.5% in Plan F, P < .01; MLD, median 7.0 Gy in Plan C vs 6.4 Gy in Plan F, P = .04). fV10, V5, and fMLD were also significantly lower in Plan F. Compared with Plan C, planning target volume homogeneity index and liver, heart, and cord doses were not significantly elevated in Plan F.ConclusionsSignificant reductions in fV5, fV10, fMLD, V5, and MLD were achieved with the functional image guided VMAT plan without negative effects on other factors. LAA-based functional image guided radiation therapy planning in VMAT is a feasible method to spare the functional lung in patients with MPM.
| S-EPMC5514243 | biostudies-literature
Project description:BackgroundFor several tumor entities, automated treatment planning has improved plan quality and planning efficiency, and may enable adaptive treatment approaches. Whole-pelvic prostate radiotherapy (WPRT) involves large concave target volumes, which present a challenge for volumetric arc therapy (VMAT) optimization. This study evaluates automated VMAT planning for WPRT-VMAT and compares the results with manual expert planning.MethodsA system for fully automated multi-criterial plan generation was configured for each step of sequential-boost WPRT-VMAT, with final "autoVMAT" plans being automatically calculated by the Monaco treatment planning system (TPS; Elekta AB, Stockholm, Sweden). Configuration was based on manually generated VMAT plans (manualVMAT) of 5 test patients, the planning protocol, and discussions with the treating physician on wishes for plan improvements. AutoVMAT plans were then generated for another 30 evaluation patients and compared to manualVMAT plans. For all 35 patients, manualVMAT plans were optimized by expert planners using the Monaco TPS.ResultsAutoVMAT plans exhibited strongly improved organ sparing and higher conformity compared to manualVMAT. On average, mean doses (Dmean) of bladder and rectum were reduced by 10.7 and 4.5 Gy, respectively, by autoVMAT. Prostate target coverage (V95%) was slightly higher (+0.6%) with manualVMAT. In a blinded scoring session, the radiation oncologist preferred autoVMAT plans to manualVMAT plans for 27/30 patients. All treatment plans were considered clinically acceptable. The workload per patient was reduced by > 70 min.ConclusionAutomated VMAT planning for complex WPRT dose distributions is feasible and creates treatment plans that are generally dosimetrically superior to manually optimized plans.
| S-EPMC5869893 | biostudies-literature
Project description:The purpose of this work is to evaluate the volumetric-modulated arc therapy (VMAT) multicriteria optimization (MCO) algorithm clinically available in the RayStation treatment planning system (TPS) and its ability to reduce treatment planning time while providing high dosimetric plan quality. Nine patients with localized prostate cancer who were previously treated with 78 Gy in 39 fractions using VMAT plans and rayArc system based on the direct machine parameter optimization (DMPO) algorithm were selected and replanned using the VMAT-MCO system. First, the dosimetric quality of the plans was evaluated using multiple conformity metrics that account for target coverage and sparing of healthy tissue, used in our departmental clinical protocols. The conformity and homogeneity index, number of monitor units, and treatment planning time for both modalities were assessed. Next, the effects of the technical plan parameters, such as constraint leaf motion CLM (cm/°) and maximum arc delivery time T (s), on the accuracy of delivered dose were evaluated using quality assurance passing rates (QAs) measured using the Delta4 phantom from ScandiDos. For the dosimetric plan's quality analysis, the results show that the VMAT-MCO system provides plans comparable to the rayArc system with no statistical difference for V95% (p < 0.01), D1% (p < 0.01), CI (p < 0.01), and HI (p < 0.01) of the PTV, bladder (p < 0.01), and rectum (p < 0.01) constraints, except for the femoral heads and healthy tissues, for which a dose reduction was observed using MCO compared with rayArc (p < 0.01). The technical parameter study showed that a combination of CLM equal to 0.5 cm/degree and a maximum delivery time of 72 s allowed the accurate delivery of the VMAT-MCO plan on the Elekta Versa HD linear accelerator. Planning evaluation and dosimetric measurements showed that VMAT-MCO can be used clinically with the advantage of enhanced planning process efficiency by reducing the treatment planning time without impairing dosimetric quality.
| S-EPMC5690115 | biostudies-literature
Project description:BACKGROUND:To review a single institutional experience of the Radiation Therapy Oncology Group (RTOG) 8502 "QUAD shot" regimen using volumetric modulated arc radiotherapy (VMAT) for incurable head and neck cancer (HNC). METHODS:Thirty-four consecutive patients with HNC were treated with at least one cycle of the RTOG 8502 regimen. Treatment plans included the use of VMAT with 6 MV photons generated by a linear accelerator. Two daily fractions of 3.7?Gy were delivered with an interval of at least 6?h for 2 consecutive days, totaling 14.8?Gy over 4 fractions. This was repeated every 3-4?weeks for a total of three cycles. No concurrent systemic therapy was performed. RESULTS:The number of completed cycles was 1 in 6 (18%) patients, 2 in 5 (15%), and 3 in 23 (68%). Tumor response was achieved in 29 (85%) patients and symptom relief in 20 (77%) of 26 patients. Overall response (tumor response or symptom relief) was achieved in 32 (94%) patients. All patients who received 2 or more treatment cycles achieved overall response. Median overall survival (OS) was 5.7?months. Multivariate analysis revealed that completion of all three treatment cycles was significantly associated with better OS (P?=?0.002). Grade 2 toxicity was observed in four (12%) patients, but no acute Grade???3 or late toxicity was observed. CONCLUSIONS:The RTOG 8502 "QUAD shot" regimen using VMAT is effective for incurable HNC with highly reduced toxicity. Treatment with multiple cycles is recommended for better treatment response and/or survival.
| S-EPMC7251877 | biostudies-literature
Project description:PurposeTo retrospectively evaluate the cardiac exposure in three cohorts of lung cancer patients treated with dynamic conformal arc therapy (DCAT), intensity-modulated radiotherapy (IMRT), or volumetric modulated arc therapy (VMAT) at our institution in the past seven years.Methods and materialsA total of 140 lung cancer patients were included in this institutional review board approved study: 25 treated with DCAT, 70 with IMRT and 45 with VMAT. All plans were generated in a same commercial treatment planning system and have been clinically accepted and delivered. The dose distribution to the heart and the effects of tumor laterality, the irradiated heart volume and the beam-to-heart distance on the cardiac exposure were investigated.ResultsThe mean dose to the heart among all 140 plans was 4.5 Gy. Specifically, the heart received on average 2.3, 5.2 and 4.6 Gy in the DCAT, IMRT and VMAT plans, respectively. The mean heart doses for the left and right lung tumors were 4.1 and 4.8 Gy, respectively. No patients died with evidence of cardiac disease. Three patients (2%) with preexisting cardiac condition developed cardiac disease after treatment. Furthermore, the cardiac exposure was found to increase linearly with the irradiated heart volume while decreasing exponentially with the beam-to-heart distance.ConclusionsCompared to old technologies for lung cancer treatment, modern radiotherapy treatment modalities demonstrated better heart sparing. But the heart dose in lung cancer radiotherapy is still higher than that in the radiotherapy of breast cancer and Hodgkin's disease where cardiac complications have been extensively studied. With strong correlations of mean heart dose with beam-to-heart distance and irradiated heart volume, cautions should be exercised to avoid long-term cardiac toxicity in the lung cancer patients undergoing radiotherapy.
| S-EPMC4667972 | biostudies-literature
Project description:Hypofractionated treatments generally increase the complexity of a treatment plan due to the more stringent constraints of normal tissues and target coverage. As a result, treatment plans contain more modulated MLC motions that may require extra efforts for accurate dose calculation. This study explores methods to minimize the differences between in-house dose calculation and actual delivery of hypofractionated volumetric-modulated arc therapy (VMAT), by focusing on arc approximation and tongue-and-groove (TG) modeling. For dose calculation, the continuous delivery arc is typically approximated by a series of static beams with an angular spacing of 2°. This causes significant error when there is large MLC movement from one beam to the next. While increasing the number of beams will minimize the dose error, calculation time will increase significantly. We propose a solution by inserting two additional apertures at each of the beam angle for dose calculation. These additional apertures were interpolated at two-thirds' degree before and after each beam. Effectively, there were a total of three MLC apertures at each beam angle, and the weighted average fluence from the three apertures was used for calculation. Because the number of beams was kept the same, calculation time was only increased by about 6%-8%. For a lung plan, areas of high local dose differences (> 4%) between film measurement and calculation with one aperture were significantly reduced in calculation with three apertures. Ion chamber measurement also showed similar results, where improvements were seen with calculations using additional apertures. Dose calculation accuracy was further improved for TG modeling by developing a sampling method for beam fluence matrix. Single element point sampling for fluence transmitted through MLC was used for our fluence matrix with 1 mm resolution. For Varian HDMLC, grid alignment can cause fluence sampling error. To correct this, transmission volume averaging was applied. For three paraspinal HDMLC cases, the average dose difference was greatly reduced in film and calculation comparisons with our new approach. The gamma (3%, 3 mm) pass rates have improved significantly from 74.1%, 90.0%, and 90.4% to 99.2%, 97.9%, and 97.3% for three cases, for calculation without volume averaging and calculation with volume averaging, respectively. Our results indicate that more accurate MLC leaf position and transmission sampling can improve accuracy and agreement between calculation and measurement, and are particularly important for hypofractionated VMAT that consists of large MLC movement.
| S-EPMC4831077 | biostudies-other