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International Journal of Radiation... Jul 2021To explore the efficacy and toxicity of stereotactic body radiation therapy (SBRT) in high-risk prostate cancer (HRPCa) in a consortium of 7 institutional phase 2 trials... (Clinical Trial)
Clinical Trial
PURPOSE
To explore the efficacy and toxicity of stereotactic body radiation therapy (SBRT) in high-risk prostate cancer (HRPCa) in a consortium of 7 institutional phase 2 trials and prospective registries.
METHODS AND MATERIALS
Individual patient data were pooled for 344 patients with a minimum follow-up of 24 months. Biochemical recurrence-free survival (BCRFS) and distant metastasis-free survival (DMFS) were estimated using a Kaplan-Meier framework. Fine and Gray competing risk and Cox proportional hazards regression models were developed to assess the association between time to BCR and time to distant metastasis and prespecified variables of interest. Logistic regression models were developed to evaluate associations between acute and late grade ≥2 genitourinary and gastrointestinal and the following a priori-specified variables: age, dose per fraction, ADT use, and nodal radiation therapy.
RESULTS
Median follow-up was 49.5 months. Seventy-two percent of patients received ADT, with a median duration of 9 months, and 19% received elective nodal radiation therapy. Estimated 4-year BCRFS and DMFS rates were 81.7% (95% CI, 77.2%-86.5%) and 89.1% (95% CI, 85.3%-93.1%). The crude incidences of late grade ≥3 genitourinary and gastrointestinal toxicity were 2.3% and 0.9%.
CONCLUSIONS
These data support a favorable toxicity and efficacy profile for SBRT for HRPCa. Further prospective studies are needed to evaluate the optimal dose and target volume in the context of SBRT for HRPCa.
Topics: Aged; Aged, 80 and over; Dose Fractionation, Radiation; Humans; Male; Middle Aged; Prospective Studies; Prostatic Neoplasms; Radiosurgery; Treatment Outcome
PubMed: 33493615
DOI: 10.1016/j.ijrobp.2021.01.016 -
Technology in Cancer Research &... Feb 2017To present our clinical workflow of incorporating AlignRT for left breast deep inspiration breath-hold treatments and the dosimetric considerations with the deep...
PURPOSE
To present our clinical workflow of incorporating AlignRT for left breast deep inspiration breath-hold treatments and the dosimetric considerations with the deep inspiration breath-hold protocol.
MATERIAL AND METHODS
Patients with stage I to III left-sided breast cancer who underwent lumpectomy or mastectomy were considered candidates for deep inspiration breath-hold technique for their external beam radiation therapy. Treatment plans were created on both free-breathing and deep inspiration breath-hold computed tomography for each patient to determine whether deep inspiration breath-hold was beneficial based on dosimetric comparison. The AlignRT system was used for patient setup and monitoring. Dosimetric measurements and their correlation with chest wall excursion and increase in left lung volume were studied for free-breathing and deep inspiration breath-hold plans.
RESULTS
Deep inspiration breath-hold plans had significantly increased chest wall excursion when compared with free breathing. This change in geometry resulted in reduced mean and maximum heart dose but did not impact lung V or mean dose. The correlation between chest wall excursion and absolute reduction in heart or lung dose was found to be nonsignificant, but correlation between left lung volume and heart dose showed a linear association. It was also identified that higher levels of chest wall excursion may paradoxically increase heart or lung dose.
CONCLUSION
Reduction in heart dose can be achieved for many left-sided breast and chest wall patients using deep inspiration breath-hold. Chest wall excursion as well as left lung volume did not correlate with reduction in heart dose, and it remains to be determined what metric will provide the most optimal and reliable dosimetric advantage.
Topics: Adult; Aged; Breast Neoplasms; Breath Holding; Dose Fractionation, Radiation; Female; Humans; Mastectomy, Segmental; Middle Aged; Organs at Risk; Radiometry; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Image-Guided; Tomography, X-Ray Computed; Workflow
PubMed: 26755749
DOI: 10.1177/1533034615624311 -
International Journal of Radiation... Jun 2024In this Pediatric Normal Tissue Effects in the Clinic (PENTEC) vision paper, challenges and opportunities in the assessment of subsequent neoplasms (SNs) from radiation... (Review)
Review
PURPOSE
In this Pediatric Normal Tissue Effects in the Clinic (PENTEC) vision paper, challenges and opportunities in the assessment of subsequent neoplasms (SNs) from radiation therapy (RT) are presented and discussed in the context of technology advancement.
METHODS AND MATERIALS
The paper discusses the current knowledge of SN risks associated with historic, contemporary, and future RT technologies. Opportunities for research and SN mitigation strategies in pediatric patients with cancer are reviewed.
RESULTS
Present experience with radiation carcinogenesis is from populations exposed during widely different scenarios. Knowledge gaps exist within clinical cohorts and follow-up; dose-response and volume effects; dose-rate and fractionation effects; radiation quality and proton/particle therapy; age considerations; susceptibility of specific tissues; and risks related to genetic predisposition. The biological mechanisms associated with local and patient-level risks are largely unknown.
CONCLUSIONS
Future cancer care is expected to involve several available RT technologies, necessitating evidence and strategies to assess the performance of competing treatments. It is essential to maximize the utilization of existing follow-up while planning for prospective data collection, including standardized registration of individual treatment information with linkage across patient databases.
Topics: Humans; Child; Cancer Survivors; Neoplasms, Radiation-Induced; Organs at Risk; Proton Therapy; Neoplasms, Second Primary; Dose-Response Relationship, Radiation; Dose Fractionation, Radiation; Age Factors; Adolescent; Radiotherapy; Genetic Predisposition to Disease; Neoplasms
PubMed: 38430101
DOI: 10.1016/j.ijrobp.2024.01.206 -
Technology in Cancer Research &... 2020There are very few studies on noncoplanar radiation in tomotherapy because deformable image registration is not implemented in the TomoTherapy Planning Station, a...
BACKGROUND
There are very few studies on noncoplanar radiation in tomotherapy because deformable image registration is not implemented in the TomoTherapy Planning Station, a treatment planning device used in tomotherapy. This study examined whether noncoplanar radiation can be performed on the head using a tilt-type head and neck fixture and deformable image registration.
METHODS
Planning target volume spheres with diameters of 2, 3, and 4 cm were set on a head phantom, and computed tomography images were taken at 0° and 40° using a tilt-type head and neck fixture. Irradiation plans were created in the Tomotherapy Planning Station. Noncoplanar radiation was simulated, and the dose volume was evaluated by adding the 0° dose distribution and 40° dose distribution using the deformable image registration of the RayStation treatment planning system.
RESULTS
The ratio of the phantom volume to the irradiation dose for 20% to 30% of the planning target volume in noncoplanar radiation was smaller than that for 40% to 90% of the planning target volume in single-section irradiation at 0° or 40°.
CONCLUSIONS
Noncoplanar radiation on the head region using tomotherapy was possible by using a tilt-type head and neck fixture, and the dose distribution could be evaluated using deformable image registration. This method helps reduce the dose of the organ-at-risk region located slightly away from the planning target volume.
Topics: Brain Neoplasms; Dose Fractionation, Radiation; Humans; Phantoms, Imaging; Radiation Dosage; Radiosurgery; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Image-Guided; Radiotherapy, Intensity-Modulated
PubMed: 32734825
DOI: 10.1177/1533033820945776 -
Journal of Neuro-oncology Mar 2020To estimate the rate and magnitude of neurologic symptom change during radiation therapy (RT) and impact of symptom change on survival outcomes in patients with diffuse...
PURPOSE
To estimate the rate and magnitude of neurologic symptom change during radiation therapy (RT) and impact of symptom change on survival outcomes in patients with diffuse intrinsic pontine glioma (DIPG).
METHODS
From 2006 to 2014, 108 patients with newly diagnosed DIPG were treated with conventionally fractionated radiation therapy (RT) to 54 Gy (median) at our institution. The presence and severity of neurologic symptoms related to cranial neuropathy (CN) and cerebellar (CB) and long-tract (LT) signs was reviewed before and weekly during RT for each patient. The rate and magnitude of change for each symptom category was evaluated according to accumulated RT dose. The impact of clinical factors and radiation dose-volume parameters was determined using Cox proportional hazards models.
RESULTS
Median dose to first sign of symptomatic improvement was 16.2 Gy (CN), 19.8 Gy (LT) and 21.6 Gy (CB). Most patients showed an improvement by 20 Gy. Larger uninvolved brainstem volume, alone or normalized to total brain (TB) or posterior fossa volume (PF), was associated with shorter time to LT sign improvement (P = 0.044, P = 0.033, and P = 0.05, respectively). Patients with any improvement in CN experienced significantly, yet modestly, prolonged progression-free survival (PFS) and overall survival (OS) (P = 0.002 and P = 0.008, respectively). Tumor volume, with or without normalization to TB or PF, was not significantly associated with PFS or OS.
CONCLUSIONS
Low cumulative RT doses resulted in neurologic improvement in most patients with DIPG. The volume of brainstem spared by tumor influenced time to symptomatic improvement. Neurologic improvement during RT was associated with superior survival.
Topics: Adolescent; Brain Stem Neoplasms; Child; Child, Preschool; Cohort Studies; Diffuse Intrinsic Pontine Glioma; Dose Fractionation, Radiation; Female; Humans; Kaplan-Meier Estimate; Male; Neuropsychology; Treatment Outcome
PubMed: 32016716
DOI: 10.1007/s11060-020-03415-w -
The British Journal of Radiology Aug 2020This study presents a methodology for voxel-based evaluation of two phase sequential radiotherapy treatment plans having conventional dose scheme in the first phase and...
OBJECTIVE
This study presents a methodology for voxel-based evaluation of two phase sequential radiotherapy treatment plans having conventional dose scheme in the first phase and subsequent hypofractionation dose scheme in the second phase based upon different priority [planning target volume (PTV), clinical target volume (CTV) and organs at risk (OAR)] of display modes.
METHODS
A case of carcinoma prostate was selected for demonstration. Varian Eclipse treatment planning system (TPS) was used for contouring and planning. In the first phase, a dose of 52 Gy in 26 fractions to the PTV and in the second phase, a dose of 19.5 Gy in 3 fractions to the PTV Boost was planned on the same CT data set. Both the plans (Phase 1 and Phase 2) were exported and processed using "Voxel-based radiobiology display (VRb) tool". Plan Sum for Biologically effective dose (BED)-Cube and equivalent dose of 2Gy (EQD)-Cube was reconstructed using a combination of linear quadratic (LQ) and linear quadratic-linear (LQ-L) radiobiological models. Tumor control probability (TCP) and normal tissue complication probability (NTCP) for different target volumes and organs were also calculated using EQD-volume histograms of the Plan Sum.
RESULTS
An in-house graphical user interface (GUI) is developed to present the qualitative and quantitative evaluation of the multiphase treatment plans with different display modes and dose regimens. The voxel based TCP obtained for the combined target volume was 90.56%. NTCP for the bladder and rectum was calculated from the Plan Sum histograms and found to be 0.33% and ~0.0% respectively.
CONCLUSION
The proposed methodology using the VRb tool offers superior plan evaluation for multiphase sequential radiotherapy treatment plans over the existing methods.
ADVANCES IN KNOWLEDGE
PTV, CTV and OAR priority based display modes in VRb tool offers better understanding of radiobiological evaluation of sequential radiotherapy treatment plans.
Topics: Dose Fractionation, Radiation; Humans; Male; Models, Statistical; Prostate; Prostatic Neoplasms; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted
PubMed: 32614607
DOI: 10.1259/bjr.20200197 -
Clinical Lung Cancer Jan 2021At our institution, stereotactic body radiotherapy (SBRT) has commonly been prescribed with 50 Gy in 5 fractions and in select cases, 50 Gy in 10 fractions. We sought to... (Comparative Study)
Comparative Study
INTRODUCTION
At our institution, stereotactic body radiotherapy (SBRT) has commonly been prescribed with 50 Gy in 5 fractions and in select cases, 50 Gy in 10 fractions. We sought to evaluate the impact of these 2 fractionation schedules on local control and survival outcomes.
METHODS
We reviewed patients treated with SBRT with 50 Gy/5 fraction or 50 Gy/10 fraction for early-stage non-small cell lung cancer (NSCLC) and metastatic NSCLC. Cumulative incidence of local failure (LF) was estimated using competing risk methodology. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method only for patients with stage I disease.
RESULTS
Of the 353 lesions, 300 (85%) were treated with 50 Gy in 5 fractions and 53 (15%) with 10 fractions. LFs at 3 years were 6.5% and 23.9% and Kaplan-Meier estimate of median time to LF was 17.5 months and 26.2 months, respectively. Multivariable analysis revealed increasing planning target volume (hazard ratio 1.01, P = .04) as an independent predictor of increased LF, but tumor size, ultracentral location, and 10 fractions were not. Among patients with stage I NSCLC (n = 298), overall median PFS was 35.6 months and median OS was 42.4 months. There was no difference in PFS or OS between the 2 treatment regimens for patients with stage I NSCLC. Low rates of grade 3+ toxicity were observed, with 1 patient experiencing grade 3 pneumonitis after a 5-fraction regimen of SBRT.
CONCLUSION
Dose-fractionation schemes with BED ≥ 100 Gy provide superior local control and should be offered when meeting commonly accepted constraints. If those regimens appear unsafe, 50 Gy in 10 fractions may provide acceptable compromise between tumor control and safety with relatively durable control, and minimal negative impact on long-term survival.
Topics: Adenocarcinoma of Lung; Aged; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Dose Fractionation, Radiation; Female; Follow-Up Studies; Humans; Lung Neoplasms; Lymphatic Metastasis; Male; Neoplasm Recurrence, Local; Prognosis; Radiosurgery; Retrospective Studies; Survival Rate
PubMed: 33046359
DOI: 10.1016/j.cllc.2020.09.008 -
Head & Neck Apr 2016The development of intensity-modulated radiotherapy (IMRT) has played a major role in improving outcomes and decreasing morbidity in patients with head and neck cancer.... (Review)
Review
The development of intensity-modulated radiotherapy (IMRT) has played a major role in improving outcomes and decreasing morbidity in patients with head and neck cancer. This review addresses this vital modality with a focus on the important role of the head and neck surgeon. The technique as well as its benefits and points of caution are outlined, the definitions of tumor and treatment volumes are discussed, and the dose and fractionation are detailed. Following this are several sections dedicated to the role of the head and neck surgeon in the planning of both definitive and postoperative radiotherapy to the primary site and neck. There is a focus throughout on anatomic and surgical considerations; commonly encountered situations are illustrated. With a deeper understanding of this technique and their own pivotal contribution to target delineation, head and neck surgeons will be poised to expand their role and improve cancer care for their patients. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2368-E2373, 2016.
Topics: Dose Fractionation, Radiation; Head and Neck Neoplasms; Humans; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated; Surgeons
PubMed: 26705685
DOI: 10.1002/hed.24338 -
Technology in Cancer Research &... Apr 2017The aim of this study is to determine whether stereotactic body radiotherapy for multiple vertebral metastases treated with a single isocenter results in greater...
The aim of this study is to determine whether stereotactic body radiotherapy for multiple vertebral metastases treated with a single isocenter results in greater intrafraction errors than stereotactic body radiotherapy for single vertebral metastases and to determine whether the currently used spinal cord planning organ at risk volume and planning target volume margins are appropriate. Intrafraction errors were assessed for 65 stereotactic body radiotherapy treatments for vertebral metastases. Cone beam computed tomography images were acquired before, during, and after treatment for each fraction. Residual translational and rotational errors in patient positioning were recorded and planning organ at risk volume and planning target volume margins were calculated in each direction using this information. The mean translational residual errors were smaller for single (0.4 (0.4) mm) than for multiple vertebral metastases (0.5 (0.7) mm; P = .0019). The mean rotational residual errors were similar for single (0.3° (0.3°) and multiple vertebral metastases (0.3° (0.3°); P = .862). The maximum calculated planning organ at risk volume margin in any direction was 0.83 mm for single and 1.22 for multiple vertebral metastases. The maximum calculated planning target volume margin in any direction was 1.4 mm for single and 1.9 mm for multiple vertebral metastases. Intrafraction errors were small for both single and multiple vertebral metastases, indicating that our strategy for patient immobilization and repositioning is robust. Calculated planning organ at risk volume and planning target volume margins were smaller than our clinically employed margins, indicating that our clinical margins are appropriate.
Topics: Cone-Beam Computed Tomography; Dose Fractionation, Radiation; Humans; Magnetic Resonance Imaging; Patient Positioning; Radiosurgery; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Image-Guided; Retrospective Studies; Spinal Neoplasms; Tumor Burden
PubMed: 28279146
DOI: 10.1177/1533034616681674 -
Technology in Cancer Research &... Jan 2019Stereotactic body radiotherapy has been suggested to provide high rates of local control for locally advanced pancreatic cancer. However, the close proximity of highly...
BACKGROUND
Stereotactic body radiotherapy has been suggested to provide high rates of local control for locally advanced pancreatic cancer. However, the close proximity of highly radiosensitive normal tissues usually causes the labor-intensive planning process and may impede further escalation of the prescription dose.
PURPOSE
The present study aims to evaluate the consistency and efficiency of Pinnacle Auto-Planning for pancreas stereotactic body radiotherapy with original prescription and escalated prescription.
METHODS
Twenty-four patients with pancreatic cancer treated with stereotactic body radiotherapy were studied retrospectively. The prescription is 40 Gy over 5 consecutive fractions. Most of patients (n = 21) also had 3 other different dose-level targets (6 Gy/fraction, 5 Gy/fraction, and 4 Gy/fraction). Two types of plans were generated by Pinnacle Auto-Planning with the original prescription (8 Gy/fraction, 6 Gy/fraction, 5 Gy/fraction, and 4 Gy/fraction) and escalated prescription (9 Gy/fraction, 7 Gy/fraction, 6 Gy/fraction, and 5 Gy/fraction), respectively. The same Auto-Planning template, including beam geometry, intensity-modulated radiotherapy objectives and intensity-modulated radiotherapy optimization parameters, were utilized for all the auto-plans in each prescription group. The intensity-modulated radiotherapy objectives do not include any manually created structures. Dosimetric parameters including percentage volume of PTV receiving 100% of the prescription dose, percentage volume of PTV receiving 93% of the prescription dose, and consistency of the dose-volume histograms of the target volumes were assessed. D and D of highly radiosensitive organs were also evaluated.
RESULTS
For all the pancreas stereotactic body radiotherapy plans with the original or escalated prescriptions, auto-plans met institutional dose constraints for critical organs, such as the duodenum, small intestine, and stomach. Furthermore, auto-plans resulted in acceptable planning target volume coverage for all targets with different prescription levels. All the plans were generated in a one-attempt manner, and very little human intervention is necessary to achieve such plan quality.
CONCLUSIONS
Pinnacle Auto-Planning consistently and efficiently generate acceptable treatment plans for multitarget pancreas stereotactic body radiotherapy with or without dose escalation and may play a more important role in treatment planning in the future.
Topics: Automation; Dose Fractionation, Radiation; Humans; Organs at Risk; Pancreatic Neoplasms; Precision Medicine; Radiometry; Radiosurgery; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted
PubMed: 31195891
DOI: 10.1177/1533033819851520