Phase II Study of Hemithoracic Intensity-Modulated Pleural Radiation Therapy (IMPRINT) As Part of Lung-Sparing Multimodality Therapy in Patients With Malignant Pleural Mesothelioma.
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ABSTRACT: We conducted a two-center phase II study to determine the safety of hemithoracic intensity-modulated pleural radiation therapy (IMPRINT) after chemotherapy and pleurectomy-decortication (P/D) as part of a multimodality lung-sparing treatment.Patients received up to four cycles of pemetrexed plus platinum. If feasible, P/D was performed. Hemithoracic IMPRINT was administered to a planned dose of 50.4 Gy in 28 fractions. The primary end point was the incidence of grade 3 or greater radiation pneumonitis (RP).A total of 45 patients were enrolled; 18 were not evaluable (because of disease progression before radiation therapy [RT], n = 9; refusal of surgery or RT, n = 5; extrapleural pneumonectomy at time of surgery, n = 2; or chemotherapy complications, n = 2). A total of 26 patients received pemetrexed plus cisplatin, 18 received pemetrexed plus carboplatin, and four received a combination. Thirteen patients (28.9%) had a partial response, 15 patients (33.3%) experienced disease progression, one patient died during chemotherapy, and all others had stable disease. Eight patients underwent P/D or an extended P/D, and 13 underwent a partial P/D. A total of 27 patients started IMPRINT (median dose, 46.8 Gy; range, 28.8 to 50.4 Gy) and were evaluable for the primary end point (median follow-up, 21.6 months). Six patients experienced grade 2 RP, and two patients experienced grade 3 RP; all recovered after corticosteroid initiation. No grade 4 or 5 radiation-related toxicities were observed. The median progression-free survival and overall survival (OS) were 12.4 and 23.7 months, respectively; the 2-year OS was 59% in patients with resectable tumors and was 25% in patients with unresectable tumors.Hemithoracic IMPRINT for malignant pleural mesothelioma (MPM) is safe and has an acceptable rate of RP. Its incorporation with chemotherapy and P/D forms a new lung-sparing treatment paradigm for patients with locally advanced MPM.
Phase II Study of Hemithoracic Intensity-Modulated Pleural Radiation Therapy (IMPRINT) As Part of Lung-Sparing Multimodality Therapy in Patients With Malignant Pleural Mesothelioma.
Journal of clinical oncology : official journal of the American Society of Clinical Oncology 20160620 23
<h4>Purpose</h4>We conducted a two-center phase II study to determine the safety of hemithoracic intensity-modulated pleural radiation therapy (IMPRINT) after chemotherapy and pleurectomy-decortication (P/D) as part of a multimodality lung-sparing treatment.<h4>Patients and methods</h4>Patients received up to four cycles of pemetrexed plus platinum. If feasible, P/D was performed. Hemithoracic IMPRINT was administered to a planned dose of 50.4 Gy in 28 fractions. The primary end point was the in ...[more]
Project description:PurposeWe previously reported our technique for delivering intensity modulated radiation therapy (IMRT) to the entire pleura while attempting to spare the lung in patients with malignant pleural mesothelioma (MPM). Herein, we report a detailed pattern-of-failure analysis in patients with MPM who were unresectable or underwent pleurectomy/decortication (P/D), uniformly treated with hemithoracic pleural IMRT.Methods and materialsSixty-seven patients with MPM were treated with definitive or adjuvant hemithoracic pleural IMRT between November 2004 and May 2013. Pretreatment imaging, treatment plans, and posttreatment imaging were retrospectively reviewed to determine failure location(s). Failures were categorized as in-field (within the 90% isodose line), marginal (<90% and ≥50% isodose lines), out-of-field (outside the 50% isodose line), or distant.ResultsThe median follow-up was 24 months from diagnosis and the median time to in-field local failure from the end of RT was 10 months. Forty-three in-field local failures (64%) were found with a 1- and 2-year actuarial failure rate of 56% and 74%, respectively. For patients who underwent P/D versus those who received a partial pleurectomy or were deemed unresectable, the median time to in-field local failure was 14 months versus 6 months, respectively, with 1- and 2-year actuarial in-field local failure rates of 43% and 60% versus 66% and 83%, respectively (P=.03). There were 13 marginal failures (19%). Five of the marginal failures (38%) were located within the costomediastinal recess. Marginal failures decreased with increasing institutional experience (P=.04). Twenty-five patients (37%) had out-of-field failures. Distant failures occurred in 32 patients (48%).ConclusionsAfter hemithoracic pleural IMRT, local failure remains the dominant form of failure pattern. Patients treated with adjuvant hemithoracic pleural IMRT after P/D experience a significantly longer time to local and distant failure than patients treated with definitive pleural IMRT. Increasing experience and improvement in target delineation minimize the incidence of avoidable marginal failures.
Project description:PurposeTo determine clinically helpful dose-volume and clinical metrics correlating with symptomatic radiation pneumonitis (RP) in malignant pleural mesothelioma (MPM) patients with 2 lungs treated with hemithoracic intensity modulated pleural radiation therapy (IMPRINT).Methods and materialsTreatment plans and resulting normal organ dose-volume histograms of 103 consecutive MPM patients treated with IMPRINT (February 2005 to January 2015) to the highest dose ≤50.4 Gy satisfying departmental normal tissue constraints were uniformly recalculated. Patient records provided maximum RP grade (Common Terminology Criteria for Toxicity and Adverse Event version 4.0) and clinical and demographic information. Correlations analyzed with the Cox model were grade ≥2 RP (RP2+) and grade ≥3 RP (RP3+) with clinical variables, with volumes of planning target volume (PTV) and PTV-lung overlap and with mean dose, percent volume receiving dose D (VD), highest dose encompassing % volume V, (DV), and heart, total, ipsilateral, and contralateral lung volumes.ResultsTwenty-seven patients had RP2+ (14 with RP3+). The median prescription dose was 46.8 Gy (39.6-50.4 Gy, 1.8 Gy/fraction). The median age was 67.6 years (range, 42-83 years). There were 79 men, 40 never-smokers, and 44 with left-sided MPM. There were no significant (P≤.05) correlations with clinical variables, prescription dose, total lung dose-volume metrics, and PTV-lung overlap volume. Dose-volume correlations for heart were RP2+ with VD (35 ≤ D ≤ 47 Gy, V43 strongest at P=.003), RP3+ with VD (31 ≤ D ≤ 45 Gy), RP2+ with DV (5 ≤ V ≤ 30%), RP3+ with DV (15 ≤ V ≤ 35%), and mean dose. Significant for ipsilateral lung were RP2+ with VD (38 ≤ D ≤ 44 Gy), RP3+ with V41, RP2+ and RP3+ with minimum dose, and for contralateral lung, RP2+ with maximum dose. Correlation of PTV with RP2+ was strong (P<.001) and also significant with RP3+.ConclusionsHeart dose correlated strongly with symptomatic RP in this large cohort of MPM patients with 2 lungs treated with IMPRINT. Planning constraints to reduce future heart doses are suggested.
Project description:BackgroundTreatment of malignant pleural mesothelioma (MPM) represents a major challenge for oncologists. Multimodality treatment, which generally involves induction chemotherapy, surgery and radiotherapy have recently shown promising results. The aim of this study was to evaluate the locoregional control and toxicity of intensity modulated radiotherapy (IMRT) after pleurectomy and decortication (P/D) as part of trimodality therapy for patients with locally advanced MPM.MethodsWe prospectively analyzed data from 20 patients with MPM treated at a single tertiary-care institution. Initially every patient received induction chemotherapy with platinum-based chemotherapy. After chemotherapy, patients without progression underwent P/D, and if feasible, hemi-thoracic IMRT was administered at a planned dose of 50.4-54 Gy in 28-30 fractions and treated with 9-11 noncoplanar fields.ResultsA total of 15 of the 20 enrolled patients underwent P/D followed by IMRT to the hemi-thoracic cavity. The median total radiotherapy dose was 48.7 Gy (23.4-54 Gy). Radiation pneumonitis (RP) developed in nine patients (60%), and of these, two patients (13.3%) experienced G3 or G4 RP. The estimated locoregional-relapse-free survival at two years was 75.9%, and the main pattern of recurrence was distant (72.7%). For the entire cohort median follow-up was 22.7 months, median progression-free survival was 18.9 months and median overall survival 23.6 months.ConclusionsPlatinum-based chemotherapy followed by lung-sparing surgery (P/D) and IMRT is a feasible and safe treatment modality that yields acceptable locoregional control in patients with locally advanced MPM; however, these results should be corroborated in larger studies.
Project description:Malignant pleural mesothelioma (MPM) is a rare disease of the pleura and is largely related to asbestos exposure. Despite recent advancements in technologies and a greater understanding of the disease, the prognosis of MPM remains poor; the median overall survival rate is about 6 to 9 months in untreated patients. The main therapeutic strategies for MPM are surgery, chemotherapy, and radiation therapy (RT). The two main surgical approaches for MPM are extrapleural pneumonectomy (EPP), in which the lung is removed en bloc, and pleurectomy/decortication, in which the lung stays in situ. Chemotherapy usually consists of a platinum-based chemotherapy, such as cisplatin, often combined with a folate antimetabolite, such as pemetrexed. More recently, immunotherapy has emerged as a possible therapeutic strategy for MPM. Evidence suggests that single-modality treatments are not an effective therapeutic approach for MPM. Therefore, researchers have started to explore different multimodality treatment approaches, in which often combinations of surgery, chemotherapy, immunotherapy, and RT are investigated. There is still no definitive answer to the question of which multimodality treatment combinations are most effective in improving the poor prognosis of MPM. Research into the effects of trimodality treatment approaches have found that radical approaches such as EPP and hemithoracic RT post-EPP are less effective than was previously assumed. In general, there are still a great number of unanswered questions and unknown factors regarding the ideal treatment approach for MPM. Hopefully, more research into multimodality therapy will provide insight into which combination of treatment modalities is most effective.
Project description:PurposeWhole lung irradiation (WLI) is indicated for certain pediatric patients with lung metastases. This study investigated whether WLI delivered as intensity-modulated proton therapy (IMPT) could significantly spare the heart and breasts when compared with conventional WLI delivered with anteroposterior/posteroanterior photon fields and with intensity-modulated photon therapy (IMRT) WLI.Materials and methodsConventional, IMRT, and IMPT plans were generated for 5 patients (aged 5-22 years). The prescription dose was 16.5 GyRBE in 1.5-GyRBE fractions. Conventional plans used 6-MV photons prescribed to the midline and a field-in-field technique to cover the planning target volume (the internal target volume [ITV] + 1 cm). IMRT plans used 6-MV photons with a 7-beam arrangement with dose prescribed to the planning target volume. IMPT plans used scenario-based optimization with 5% range uncertainty and 5-mm positional uncertainty to cover the ITV robustly. Monte Carlo dose calculation was used for all IMPT plans. Doses were compared with paired Student t test.ResultsThe ITV Dmean was similar for the IMPT, conventional, and IMRT plans, but the IMPT plans had a lower Dmin and a higher Dmax at tissue interfaces than conventional plans (Dmean ratio: 0.96, P > .05; Dmin ratio: 0.9, P < .001; Dmax ratio: 1.1, P = .014). Dmeans for breast and heart substructures were lower with IMPT plans than with conventional/IMRT plans (heart ratios, 0.63:0.73; left ventricle ratios, 0.61:0.72; right ventricle ratios, 0.45:0.57; left atrium ratios, 0.79:0.85; right atrium ratios, 0.81:0.86; left breast ratios, 0.40:0.51; right breast ratio, 0.46:0.52; all P < .05).ConclusionsIMPT resulted in comparable ITV coverage and lower mean doses to the heart and breasts when compared with other techniques. Whole lung irradiation delivered as IMPT warrants prospective evaluation in pediatric patients.
Project description:Malignant pleural mesothelioma (MPM) is an extremely difficult disease to treat. This pilot study investigates the feasibility of using volumetric-modulated arc therapy (VMAT) for malignant pleural mesothelioma (MPM), and compares VMAT to static field intensity-modulated radiotherapy (IMRT) for five patients. To identify the best treatment technique for MPM, in five patients, we made a representative comparative analysis of two kinds of techniques for radiation therapy planning: IMRT and VMAT. The plans were created for an Elekta Synergy linear accelerator with 6 MV photons using Oncentra version 4.3 treatment planning system. Dose prescription was 50 Gy to the average of the planning target volume (PTV). PTV coverage and homogeneity, dose of organs at risk, numbers of segments, MUs, and delivery time were evaluated for all techniques. VMAT allowed better homogeneous and conformity indices compared with IMRT (HI = 0.17 vs. 0.12, CI = 0.64 vs. 0.77, respectively, p < 0.05). VMAT plan had a significantly shorter delivery time (326 s) compared with in IMRT plans (510 s), (p < 0.05). In the dose verification, an average of 93.16% of the detector points passed the 3%/3 mm? criterion for VMAT plans, while in IMRT plans the dose verification was 95.12%.(p > 0.05).
Project description:Background and purposeMinimizing radiation dose exposure to nearby organs is key to limiting clinical toxicities associated with radiotherapy. Several treatment modalities such as split- or whole-field intensity-modulated radiotherapy (SF-IMRT, WF-IMRT) and volumetric modulated arc therapy (VMAT) are being used to treat tonsillar cancer patients with unilateral neck radiotherapy. Herein, we provide a modern dosimetric comparison of all three techniques.Materials and methodsForty patients with tonsillar cancer treated with definitive, ipsilateral neck SF-IMRT were evaluated. Each patient was re-planned with WF-IMRT and VMAT techniques, and doses to selected organs-at-risk (OARs) including the larynx, esophagus, and brainstem were compared.ResultsNo significant differences in target coverage existed between plans; however, the heterogeneity index improved using WF-IMRT and VMAT relative to SF-IMRT. Compared to SF-IMRT, WF-IMRT and VMAT plans had significantly lower mean doses to the supraglottic larynx (31 Gy, 18.5 Gy, 17 Gy; p < 0.01), the MDACC-defined larynx (13.4 Gy, 10.5 Gy, 9.8 Gy; p < 0.01), and RTOG-defined larynx (15.8 Gy, 12.1 Gy, 11.1 Gy; p < 0.01), respectively. Mean esophageal dose was lowest with SF-IMRT over WF-IMRT and VMAT (5.9 Gy, 12.2 Gy, 11.1 Gy; p < 0.01) but only in the absence of lower neck disease. On average, VMAT plans had shorter treatment times and required less monitor units than both SF-IMRT and WF-IMRT.ConclusionIn the setting of unilateral neck radiotherapy, WF-IMRT and VMAT plans can be optimized to significantly improve dose sparing of critical structures compared to SF-IMRT. VMAT offers additional advantages of shorter treatment times and fewer required monitor units.
Project description:ObjectivesThere is a resurgence of interest in lung-sparing extirpative surgery for malignant pleural mesothelioma with recent reports of better survival and fewer adverse consequences than with extrapleural pneumonectomy. However, these operations are not well-characterized and to offer evidence-based clinical recommendations and to plan future trials a summary of what is already known is required.DesignA formal literature search was performed and all recovered titles were sequentially sifted by title, abstract and full-text reading according to prespecified criteria. Papers were selected if they contained data relevant to the area of enquiry. Quantitative synthesis and textual analysis, appropriate to the material, were performed.SettingFollow-up studies of patients undergoing surgery for malignant pleural mesothelioma in specialist thoracic or cardiothoracic units.ParticipantsAmong the operated patients described in these papers, a total of 1270 patients had undergone lung-sparing surgery for mesothelioma.ResultsThere were no randomized trials or other forms of controlled studies. From 464 titles, 26 papers contained sufficient data on 1270 patients to be included in the systematic review. Operative descriptions for all series were extracted and tabulated and variation was found in the nature of surgery within and between series, and the degree of detail with which it was described. There was more operative detail in recent papers. All available numerical data were extracted, tabulated and summarized using quantitative methods. The average survival at 1, 2, 3, 4 and 5 years was 51%, 26%, 16%, 11% and 9%, respectively. There were no data on patients' performance status, symptomatic change, or other patient reported outcomes.ConclusionsIn the absence of any form of control data, no conclusions can be drawn concerning survival differences or symptomatic benefits attributable to surgery. As mesothelioma surgery is restricted to a selected minority of patients who often have multiple therapies, future research will require controlled studies with explicit definitions of the clinical and surgical intent.
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.
