While proton radiation therapy offers substantially better dose distribution characteristics than photon radiation therapy in certain clinical applications, data demonstrating a quantifiable clinical ...advantage is still needed for many treatment sites. Unfortunately, the number of patients treated with proton radiation therapy is still comparatively small, in some part due to the lack of evidence of clear benefits over lower-cost photon-based treatments. This review is designed to present the comparative clinical outcomes between proton and photon therapies, and to provide an overview of the current state of knowledge regarding the effectiveness of proton radiation therapy.
The complex technological processes involved in radiation therapy can be intimidating to patients, causing increased treatment-related anxiety and reduced satisfaction. An intervention was ...implemented to provide direct consultations between patients and medical physicists to reduce patient anxiety and improve patient satisfaction. A randomized clinical trial was conducted to test the intervention's effect on anxiety, distress, treatment adherence, technical understanding, and satisfaction in patients receiving radiation therapy.
Eligible patients were recruited into "intervention" and "standard of care" arms within a phase 2 screening randomized trial. Intervention-arm patients met with a medical physicist who provided technical information and addressed patient questions or concerns at the time of treatment simulation and before the first treatment. In addition to baseline information collected before randomization, participants were surveyed (1) before simulation, (2) before the first treatment, and (3) before the completion of treatment to evaluate the study endpoints. Primary endpoints included patient anxiety and distress. Secondary endpoints included patient treatment adherence, overall satisfaction, and technical understanding of treatment. Patients in the intervention arm were surveyed before and after each physicist meeting.
Participant anxiety was significantly reduced in the intervention arm (difference, -0.29; 95% confidence interval, -0.57 to -0.02; P = .038). No differences in distress or treatment adherence were observed between groups. Although measures of technical understanding and satisfaction were evaluated as exploratory objectives, participants in the intervention group were more likely to feel that technical aspects of treatment were adequately explained (difference, 0.78; 95% confidence interval, 0.03-1.54), and all measures of technical understanding and satisfaction were considerably higher in the intervention group at the time of the first visit.
The establishment of a direct patient-provider relationship with the medical physicist reduced anxiety in patients receiving radiation therapy. In addition, increases in patient understanding of the technical aspects of care and in satisfaction were observed at the initiation of treatment.
This work presents the dosimetric characteristics of Total Body Irradiation (TBI) delivered using a dedicated Co‐60 TBI unit. We demonstrate the ability to deliver a uniform dose to the entire ...patient without the need for a beam spoiler or patient‐specific compensation. Full dose distributions are calculated using an in‐house Monte Carlo treatment planning system, and cumulative dose distributions are created by deforming the dose distributions within two different patient orientations. Sample dose distributions and profiles are provided to illustrate the plan characteristics, and dose and DVH statistics are provided for a heterogeneous cohort of patients. The patient cohort includes adult and pediatric patients with a range of 132–198 cm in length and 16.5–37.5 cm in anterior‐posterior thickness. With the exception of the lungs, a uniform dose of 12 Gy is delivered to the patient with nearly the entire volume receiving a dose within 10% of the prescription dose. Mean lung doses (MLDs) are maintained below the estimated threshold for radiation pneumonitis, with MLDs ranging from 7.3 to 9.3 Gy (estimated equivalent dose in 2 Gy fractions (EQD2) of 6.2‐8.5 Gy). Dose uniformity is demonstrated across five anatomical locations within the patient for which mean doses are all within 3.1% of the prescription dose. In‐vivo dosimetry demonstrates excellent agreement between measured and calculated doses, with 78% of measurements within ±5% of the calculated dose and 99% within ±10%. These results demonstrate a state‐of‐the‐art TBI planning and delivery system using a dedicated TBI unit and hybrid in‐house and commercial planning techniques which provide comprehensive dosimetric data for TBI treatment plans that are accurately verified using in‐vivo dosimetry.
Understanding acute toxicities after whole-breast radiotherapy is important to inform patients, guide treatment decisions, and target supportive care. We evaluated patient-reported outcomes ...prospectively collected from a cohort of patients with breast cancer.
We describe the maximal toxicity reported by 8,711 patients treated between 2012 and 2019 at 27 practices. Multivariable models identified characteristics associated with (1) breast pain, (2) bother from itching, stinging/burning, swelling, or hurting of the treated breast, and (3) fatigue within 7 days of completing whole-breast radiotherapy.
Moderate or severe breast pain was reported by 3,233 (37.1%): 1,282 (28.9%) of those receiving hypofractionation and 1,951 (45.7%) of those receiving conventional fractionation. Frequent bother from at least one breast symptom was reported by 4,424 (50.8%): 1,833 (41.3%) after hypofractionation and 2,591 (60.7%) after conventional fractionation. Severe fatigue was reported by 2,008 (23.1%): 843 (19.0%) after hypofractionation and 1,165 (27.3%) after conventional fractionation. Among patients receiving hypofractionated radiotherapy, younger age (
< .001), higher body mass index (BMI;
< .001), Black (
< .001) or other race (
= .002), smoking status (
< .001), larger breast volume (
= .002), lack of chemotherapy receipt (
= .004), receipt of boost treatment (
< .001), and treatment at a nonteaching center predicted breast pain. Among patients receiving conventionally fractionated radiotherapy, younger age (
< .001), higher BMI (
= .003), Black (
< .001) or other race (
= .002), diabetes (
= .001), smoking status (
< .001), and larger breast volume (
< .001) predicted breast pain.
In this large observational data set, substantial differences existed according to radiotherapy dose fractionation. Race-related differences in pain existed despite controlling for multiple other factors; additional research is needed to understand what drives these differences to target potentially modifiable factors. Intensifying supportive care may be appropriate for subgroups identified as being vulnerable to greater toxicity.
Simple intensity modulation of radiation therapy reduces acute toxicity compared with 2-dimensional techniques in adjuvant breast cancer treatment, but it remains unknown whether more complex or ...inverse-planned intensity modulated radiation therapy (IMRT) offers an advantage over forward-planned, 3-dimensional conformal radiation therapy (3DCRT).
Using prospective data regarding patients receiving adjuvant whole breast radiation therapy without nodal irradiation at 23 institutions from 2011 to 2018, we compared the incidence of acute toxicity (moderate-severe pain or moist desquamation) in patients receiving 3DCRT versus IMRT (either inverse planned or, if forward-planned, using ≥5 segments per gantry angle). We evaluated associations between technique and toxicity using multivariable models with inverse-probability-of-treatment weighting, adjusting for treatment facility as a random effect.
Of 1185 patients treated with 3DCRT and conventional fractionation, 650 (54.9%) experienced acute toxicity; of 774 treated with highly segmented forward-planned IMRT, 458 (59.2%) did; and of 580 treated with inverse-planned IMRT, 245 (42.2%) did. Of 1296 patients treated with hypofractionation and 3DCRT, 432 (33.3%) experienced acute toxicity; of 709 treated with highly segmented forward-planned IMRT, 227 (32.0%) did; and of 623 treated with inverse-planned IMRT, 164 (26.3%) did. On multivariable analysis with inverse-probability-of-treatment weighting, the odds ratio for acute toxicity after inverse-planned IMRT versus 3DCRT was 0.64 (95% confidence interval, 0.45-0.91) with conventional fractionation and 0.41 (95% confidence interval, 0.26-0.65) with hypofractionation.
This large, prospective, multicenter comparative effectiveness study found a significant benefit from inverse-planned IMRT compared with 3DCRT in reducing acute toxicity of breast radiation therapy. Future research should identify the dosimetric differences that mediate this association and evaluate cost-effectiveness.
Visualization and detection of early-stage gynecological malignancies represents a challenge for imaging due to limiting factors including tissue accessibility, device ease of use, and accuracy of ...imaging modalities. In this work, we introduce a miniaturized phased-array ultrasound and photoacoustic endoscopic probe which is capable of providing structural, functional, and molecular data for the characterization of gynecologic disease. The proposed probe consists of a 64-element ultrasound phased-array transducer coupled to a fiber-optic light delivery system for co-registered ultrasound and photoacoustic imaging. The fabricated US and PA imaging endoscope’s diameter is 7.5 mm, allowing for potential passage through the cervical canal and thus an intimate contact with gynecological tissues such as the cervical canal and uterus. The developed endoscopic probe was tested and characterized in a set of tissue-mimicking phantoms. US and PA resolutions were measured experimentally using 200 μm diameter wires, resulting in apparent axial and lateral diameters of 289 μm and 299 μm for US, and 308 μm and 378 μm for PA, respectively. The probe’s abilities to operate in both discrete and integrated illumination/acquisition were tested in gelatin phantoms with embedded optical absorbers with the results demonstrating the ability to acquire volumetric dual-modal US and PA images.
The American Society for Radiation Oncology (ASTRO) Physics Core Curriculum Subcommittee (PCCSC) has updated the recommended physics curriculum for radiation oncology resident education to improve ...consistency in teaching, intensity, and subject matter.
The ASTRO PCCSC is composed of physicists and physicians involved in radiation oncology residency education. The PCCSC updated existing sections within the curriculum, created new sections, and attempted to provide additional clinical context to the curricular material through creation of practical clinical experiences. Finally, we reviewed the American Board of Radiology (ABR) blueprint of examination topics for correlation with this curriculum.
The new curriculum represents 56 hours of resident physics didactic education, including a 4-hour initial orientation. The committee recommends completion of this curriculum at least twice to assure both timely presentation of material and re-emphasis after clinical experience. In addition, practical clinical physics and treatment planning modules were created as a supplement to the didactic training. Major changes to the curriculum include addition of Fundamental Physics, Stereotactic Radiosurgery/Stereotactic Body Radiation Therapy, and Safety and Incidents sections, and elimination of the Radiopharmaceutical Physics and Dosimetry and Hyperthermia sections. Simulation and Treatment Verification and optional Research and Development in Radiation Oncology sections were also added. A feedback loop was established with the ABR to help assure that the physics component of the ABR radiation oncology initial certification examination remains consistent with this curriculum.
The ASTRO physics core curriculum for radiation oncology residents has been updated in an effort to identify the most important physics topics for preparing residents for careers in radiation oncology, to reflect changes in technology and practice since the publication of previous recommended curricula, and to provide practical training modules in clinical radiation oncology physics and treatment planning. The PCCSC is committed to keeping the curriculum current and consistent with the ABR examination blueprint.
Prior surveys suggest almost one-third of chief residents report insufficient exposure to treatment planning. We evaluated the state of treatment planning education among United States residents.
A ...web-based survey was sent to current residents identified using the Association of Residents in Radiation Oncology directory.
The response rate was 33%. Twenty-six percent of residents reported a mandatory treatment planning rotation. Seventy-one percent of residents reported reviewing ≤50% of plans with an attending. Twenty-three percent of respondents were not at all or only slightly comfortable (1 or 2 on a 1-5 scale) evaluating treatment plans. Residents with mandatory treatment planning rotations were more comfortable evaluating plans compared with those without mandatory rotations (P = .045). Overall, 60% reported insufficient exposure to treatment planning. Among postgraduate year 5 residents, this rate was 52%. Ninety-two percent of residents expressed interest in free supplemental treatment planning resources.
A significant proportion of residents surveyed report insufficient exposure to treatment planning. Development of a practical treatment planning curriculum would offer the opportunity to improve resident education, and ultimately quality of care, at the national level.
Hypofractionated radiation therapy is a less burdensome and less costly approach that is efficacious for most patients with early-stage breast cancer. Concerns about racial disparities in adoption of ...medical advances motivate investigation of the use of hypofractionated radiation in diverse populations. The goal of our study was to determine whether hypofractionated whole breast radiation therapy after breast-conserving surgery was being similarly used across racial groups in the state of Michigan.
A prospectively collected statewide quality consortium database from 25 institutions was queried for patients with breast cancer who completed hypofractionated (HF) or conventionally fractionated whole breast radiation therapy from January 2012 to December 2018. We used patient-level multivariable modeling to evaluate associations between HF use and race, controlling for patient and facility factors, and multilevel modeling to account for patient clustering within facilities.
Of 9634 patients analyzed, 81% self-reported race as white, 17% as black, and 2% as Asian, similar to statewide and national distributions. In addition, 31.7% of whites were treated at teaching centers compared with 66.7% of blacks and 64.8% of Asians. In 2018, HF was used in 72.7% of whites versus 56.7% of blacks and 67.6% of Asians (P = .0411). On patient-level multivariable analysis, black and Asian races were significantly associated with a lower likelihood of HF receipt (P < .001), despite accounting for treatment year, age, laterality, body mass index, breast volume, comorbidities, stage, triple-negative status, intensity modulated radiation therapy use, teaching center treatment, and 2011 American Society for Radiation Oncology Hypofractionation Guideline eligibility. On multilevel analysis, race was no longer significantly associated with HF receipt.
We observed that black and Asian patients receive hypofractionated whole breast radiation therapy less often than whites, despite more frequent treatment at teaching centers. Multilevel modeling eliminated this disparity, suggesting that differences in facility-specific HF use appear to have contributed. Further inquiry is needed to determine whether reduction of facility-level variation may reduce disparities in accessing HF treatment.
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