PRECISE: Preoperative Radiotherapy to Elicit Critical Immune Stimulating Effects - A Phase II Clinical Trial.

PURPOSE: Radiotherapy is an under-investigated tool for priming the immune system in intact human breast cancers. We sought here to investigate if a preoperative radiotherapy boost delivered was associated with a significant change in tumor infiltrating lymphocytes in the tumor in estrogen receptor positive, HER2Neu non-amplified breast cancers. METHODS AND MATERIALS: 20 patients were enrolled in a phase II clinical trial and received either 7.5Gy x 1 fraction or 2Gy x 5 fractions, completed 6-8 days prior to surgery. Percent stromal tumor infiltrating lymphocytes (TIL) were evaluated on hematoxylin and eosin-stained samples. Short-term safety was assessed based on time to surgery, toxicities, and cosmesis up to 6 months following boost. RESULTS: Stromal TIL increased 6-8 days following completion of boost radiotherapy (median 3.0 (IQR 1.0-6.5) prior to radiotherapy vs. median 5.0 (IQR 1.5-8.0) post radiotherapy, p=0.0037. Zero grade ≥ 3 toxicities up to 6 months following boost were experienced. 94% (16/17) patients with 6 month follow-up cosmetic assessment following breast conservation had good-excellent cosmesis by physician assessment. CONCLUSION: In this phase II trial, preoperative radiotherapy boost resulted in a short-term increase in stromal TIL with minimal toxicities. Preoperative breast radiotherapy appears to be safe and may be a feasible means for priming the tumor microenvironment.

A method for empirically validating FMEA RPN scores in a radiation oncology clinic using physics QC data.

In failure modes and effects analysis (FMEA), the components of the risk priority number (RPN) for a failure mode (FM) are often chosen by consensus. We describe an empirical method for estimating the occurrence (O) and detectability (D) components of a RPN. The method requires for a given FM that its associated quality control measure be performed twice as is the case when a FM is checked for in an initial physics check and again during a weekly physics check. If instances of the FM caught by these checks are recorded, O and D can be computed. Incorporation of the remaining RPN component, Severity, is discussed. This method can be used as part of quality management design ahead of an anticipated FMEA or afterwards to validate consensus values.

Partial Breast Irradiation for Patients With Early-Stage Invasive Breast Cancer or Ductal Carcinoma In Situ: An ASTRO Clinical Practice Guideline.

PURPOSE: This guideline provides evidence-based recommendations on appropriate indications and techniques for partial breast irradiation (PBI) for patients with early-stage invasive breast cancer and ductal carcinoma in situ. METHODS: ASTRO convened a task force to address 4 key questions focused on the appropriate indications and techniques for PBI as an alternative to whole breast irradiation (WBI) to result in similar rates of ipsilateral breast recurrence (IBR) and toxicity outcomes. Also addressed were aspects related to the technical delivery of PBI, including dose-fractionation regimens, target volumes, and treatment parameters for different PBI techniques. The guideline is based on a systematic review provided by the Agency for Healthcare Research and Quality. Recommendations were created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength. RESULTS: PBI delivered using 3-dimensional conformal radiation therapy, intensity modulated radiation therapy, multicatheter brachytherapy, and single-entry brachytherapy results in similar IBR as WBI with long-term follow-up. Some patient characteristics and tumor features were underrepresented in the randomized controlled trials, making it difficult to fully define IBR risks for patients with these features. Appropriate dose-fractionation regimens, target volume delineation, and treatment planning parameters for delivery of PBI are outlined. Intraoperative radiation therapy alone is associated with a higher IBR rate compared with WBI. A daily or every-other-day external beam PBI regimen is preferred over twice-daily regimens due to late toxicity concerns. CONCLUSIONS: Based on published data, the ASTRO task force has proposed recommendations to inform best clinical practices on the use of PBI.

It's the little THANGS: Recording frequently unreported errors for dosimetry quality improvement.

The reporting of errors resulting in dose deviations are well-studied. Less studied is the amount of inconsequential errors that will not harm the patient but could lead to inefficiency. This paper reports an institutional effort to quantify and reduce these less significant errors. Dosimetry items discovered during physicist plan/record and verify (R&V) check prior to treatment were recorded in a shared document and called Therapy Anomaly Gathering System (THANGS) and individual items were called a "thang." Items were categorized to 1 of 4 types: Treatment Plan, Plan Document, R&V, and Secondary MU. The aggregate numbers were presented to the dosimetry staff at regular staff meetings. It was emphasized to the staff that this was a Quality Improvement (QI) study and would not be used punitively. Thangs were tracked over a 4-year period. In Q1 of year 1 of the study, the average number of errors identified was 179/month. This was reduced to 114/month by Q4 of year 1 and 68/month by the end of year 4, a 62% reduction. The number of errors/plan in Q1 Year 1 was 1.25, and that was reduced by Q4 Year 4 to 0.4, a 68% reduction. The percentage of errors by type did not vary much over the 4 years. By far, R&V errors were the most common, and QI efforts were primarily aimed at them. We have developed a simple method to identify areas in dosimetric work that are vulnerable to minor errors and, through consistent reminders, drastically reduce them. This leads to a seamless throughput for a given plan ultimately resulting in improved physics, therapist, and most importantly patient satisfaction.

MPLA case: I didn't realize those were the expectations!

This work of fiction is part of a case study series developed by the Medical Physics Leadership Academy (MPLA). It is intended to facilitate the discussion of how students and advisors can better communicate expectations and navigate difficult conversations. In this case, a fourth-year Ph.D. student Emma learns that her advisor Dr. So is leaving the institution and has not arranged to bring any students with him. As Emma and Dr. So meet to discuss Emma's next steps, the conversation reveals misunderstandings and miscommunications of expectations, including a specific publication requirement for graduation from Dr. So. Having just learned of Dr. So's publication requirement, Emma realizes that graduating before the lab shuts down is not feasible. The intended use of this case, through group discussion or self-study, is to encourage readers to discuss the situation at hand and inspire professionalism and leadership thinking. This case study falls under the scope of and is supported by the MPLA, a committee in the American Association of Physicists in Medicine (AAPM).

MPLA case: How do you lead as a lead physicist?

This work of fiction is part of a case study series developed by the Medical Physics Leadership Academy (MPLA). It is intended to facilitate the discussion of the managerial and leadership challenges faced by a clinical medical physicist. In this case, a physicist David used to work in a clinic where he thrived and felt like a leader, despite not having the title. After a job change, he is now officially the "Lead Physicist" at a hospital newly affiliated with a large academic healthcare system. He believes he will be equally successful. Yet he struggles to bring about changes and get buy-in from coworkers. In the end, he feels like giving up and considers changing his job. This case is in the scenario of Problem Diagnosis.i The intended use of this case, through group discussion or self-study, is to encourage readers to perform a comprehensive analysis that identifies the root cause of the problem. This case study falls under the scope of and is supported by the MPLA, a committee in the American Association of Physicists in Medicine (AAPM).

Implementation and Evaluation of a TG-275 Key Recommendation: An Additional Early Physics Check.

PURPOSE: We report our experience of performing an extra, earlier physics plan check as recommended by the American Association of Physicists in Medicine Task Group 100 and Task Group 275 reports. We assessed utilization and timing of the extra check as well as the time required in a medium-sized clinic. METHODS AND MATERIALS: We retrospectively extracted and analyzed timestamp data from the record and verify system for the quality checklist (QCL) items related to treatment planning and physics "prechecks" for 3487 patients treated at our institution from February 2017 to February 2021. The dosimetry staff was interviewed for their perception of the value and efficacy of the practice. RESULTS: Physics prechecks were requested for 19.0% of plans. The number of requests declined from 43.9% of cases in 2017 to 18.4% in 2018. The introduction of automated plan-check tools and a dosimetrist checklist further contributed to a drop in number of precheck requests to 3.5% in 2019. For patients who received a physics precheck, the treatment planning process was a median 3.6 hours longer compared with those without (P < .001). A total of 12.9% of the precheck requests were canceled by the dosimetrist after waiting a median time of 5.3 hours. There was a strong positive correlation (0.899) between a precheck being requested and the time remaining until treatment start. Higher complexity plans and plans with a specific concern (eg, possible collision) were more likely to have a precheck requested. CONCLUSIONS: Physics prechecks have become standard practice for certain cases in our clinic. However, the perception in the department was that, as a universal practice, waiting for a precheck was not worth the time saved redoing work on the few cases in which an error was caught. Dosimetrist access to automated checking tools and checklists, which were motivated by the precheck process, contributed to this perception.

MPLA Case 3: Don't criticize me in public!

This work of fiction re-enacts a scenario in which a medical physics resident was not able to address a physics call during patient simulation and was criticized by the supervising faculty physicist in front of the team and the patient. The resident and the faculty agreed to meet afterwards to debrief the situation, in the hope of establishing a better working relationship. The intended use of this case, through group discussion, self-study, or role-play, is to encourage readers to discuss the situation at hand, inspire professionalism and leadership thinking, and allow the practice of conflict management. Facilitator's notes are available upon request to the MPLA Cases Subcommittee. This case study falls under the scope of and is supported by the Medical Physics Leadership Academy (MPLA), a committee in the American Association of Physicists in Medicine (AAPM).

MPLA Case 1: Implementing Cone-Beam CT in a Community Hospital.

This fictional case describes a managerial situation of implementing cone-beam computed tomography faced by a solo medical physicist in a rural community hospital. The intended use of the case study, in either a facilitated learning session or self-study, is to inspire the readers to discuss the situation, analyze the institutional and personal factors, apply relevant leadership skills, and propose action plans. This case study falls under the scope of, and is supported by, the Medical Physics Leadership Academy (MPLA). A sample facilitator's guide or self-study guide is included in the manuscript for reference by users of this case study.

MPLA Case 2: A junior physicist attempts to improve radiotherapy workflow.

This fictional case describes the challenging situation for a junior physicist, who joined her hometown's cancer center as a solo physicist after graduating from residency. She is concerned about providing optimal patient care as well as improving her work/life balance. She wonders how to move forward. The intended use of the case study, in either a facilitated learning session or self-study, is to inspire the readers to discuss the situation, analyze the institutional and personal factors, apply relevant leadership skills, and propose action plans. This case study falls under the scope of, and is supported by, the Medical Physics Leadership Academy (MPLA). A sample facilitator's guide or self-study guide is available upon request to the MPLA Cases Subcommittee.

Improved Dose Conformity for Adjacent Targets: A Novel Planning Technique for Gamma Knife Stereotactic Radiosurgery.

Purpose In the current Gamma Knife (GK) planning system (GammaPlan, version 10.2, Elekta AB, Stockholm, Sweden), multiple adjacent brain metastasis (BMs) had to be planned sequentially if BMs were drawn separately, leading to less conformal target dose in the composite plan due to inter-target dose contribution and fine-tuning of the shots being quite tedious. We proposed a method to improve target dose conformality and planning efficiency for such cases. Methods and Materials Fifteen patients with multiple BMs treated on the Leksell GK Perfexion system were retrospectively replanned in the Institutional Review Board (IRB) approved study. The recruitment criterion was all the BMs should be entirely encompassed within the maximum dose grid allowed in the GammaPlan. The BMs were first planned sequentially as routine clinic cases. The contours of the BMs were then exported to the VelocityAI (Varian, CA, USA) to generate a composite contour after a union operation, and all the BMs were planned again simultaneously using this composite contour in the GammaPlan. The inverse planning (IP) was employed in both methods with the same treatment time allowed for a fair plan comparison. Dose evaluation was performed in the VelocityAI with all planning magnetic resonance (MR) images, structure set and dose were exported to the VelocityAI. The dosimetery parameters, including conformality index (CI), V20Gy, V16Gy, V12Gy, and V5Gy, were compared between the two methods. Results The planning results from both methods were reviewed qualitatively and quantitatively. The proposed method exhibited superior CI, except for an outlier case with very tiny BMs. The mean and standard deviation (std.) of the Paddick CI for all patients were 0.76±0.11 for the proposed method, comparing to 0.69±0.13 for the sequential method. The V20Gy, V16Gy, V12Gy, and V5Gy for the proposed method were 10.9±0.9%, 9.5±10.2%, 6.2±16.4% and 3.3±21.8%, all lower than those from the sequential method. Conclusions The proposed method showed improved target dose conformality for all cases except for very tiny BMs. Planning efficiency is considerably better with the combined target technique. The improved dose conformality will be beneficial to patients in long term with lowered risk of radiation necrosis after GK stereotactic radiosurgery (SRS).

Effect of beam profile measurement on arc therapy plan quality assurance: a case study.

We present an example when profile measurement and modeling of an Elekta Agility multileaf collimator (MLC) had a large effect specifically on arc therapy plan quality assurance (QA) results using ArcCheck. ArcCheck absolute dose measurements of these plans were systematically lower than planned by 3-10%. Failing QA results were seen even with unmodulated static and conformal arcs. Furthermore, the effect was found to be dependent on collimator angle, with worse results associated with near-zero collimator angles. In contrast, step-and-shoot QA results were not affected. Changing the beam model to match steeper profile measurements obtained using a different measurement device resolved the problem. This case study demonstrates that conventional gamma index analysis can be sensitive to small profile modeling changes.

American Brachytherapy Society Task Group Report: Long-term control and toxicity with brachytherapy for localized breast cancer.

PURPOSE: There has been significant controversy regarding the equivalency of accelerated partial breast irradiation to whole-breast irradiation. With the recent publication of a large, randomized trial comparing these two treatment modalities, an update on the current state of knowledge of brachytherapy-based accelerated partial breast irradiation, with respect to local control and toxicities, would be useful to practitioners and patients. METHODS AND MATERIALS: A systematic literature review was conducted examining articles published between January 2000 and April 2016 on the topics "brachytherapy" and "breast." A total of 67 articles met inclusion criteria, providing outcomes on local tumor control and/or toxicity for breast brachytherapy. RESULTS: Reported 5-year local failure rates were 1.4-6.1% for multicatheter interstitial brachytherapy (MIB) and 0-5.7% for single-entry brachytherapy catheters when delivered to patients with standard selection criteria. Toxicity profiles are acceptable, with cosmetic outcomes comparable to whole-breast irradiation. The reported rates of infection were 0-12%. Symptomatic fat necrosis was found in 0-12% and 0-3.2% of patients treated with MIB and single-entry brachytherapy catheters, respectively. Late Grade ≥3 telangiectasias and fibrosis were reported in 0-8% and 0-9.1% of patients treated with MIB, respectively. These side effects were less common with single-entry brachytherapy catheters (0-2.0% and 0%, respectively). CONCLUSIONS: Breast brachytherapy is a treatment technique that provides acceptable rates of local control in select patients, as demonstrated by Level I evidence. The side effect profile of this treatment is well documented and should be shared with patients when considering this treatment modality.