Purpose The purposes of this work are to (a) investigate whether the use of auto‐planning and multiple iterations improves quality of head and neck (HN) radiotherapy plans; (b) determine whether delivery methods such as step‐and‐shoot (SS) and volumetric modulated arc therapy (VMAT) impact plan quality; (c) report on the observations of plan quality predictions of a commercial feasibility tool. Materials and methods Twenty HN cases were retrospectively selected from our clinical database for this study. The first ten plans were used to test setting up planning goals and other optimization parameters in the auto‐planning module. Subsequently, the other ten plans were replanned with auto‐planning using step‐and‐shoot (AP‐SS) and VMAT (AP‐VMAT) delivery methods. Dosimetric endpoints were compared between the clinical plans and the corresponding AP‐SS and AP‐VMAT plans. Finally, predicted dosimetric endpoints from a commercial program were assessed. Results All AP‐SS and AP‐VMAT plans met the clinical dose constraints. With auto‐planning, the dose coverage of the low dose planning target volume (PTV) was improved while the dose coverage of the high dose PTV was maintained. Compared to the clinical plans, the doses to critical organs, such as the brainstem, parotid, larynx, esophagus, and oral cavity were significantly reduced in the AP‐VMAT (P < 0.05); the AP‐SS plans had similar homogeneity indices (HI) and conformality indices (CI) and the AP‐VMAT plans had comparable HI and improved CI. Good agreement in dosimetric endpoints between predictions and AP‐VMAT plans were observed in five of seven critical organs. Conclusion With improved planning quality and efficiency, auto‐planning module is an effective tool to enable planners to generate HN IMRT plans that are meeting institution specific planning protocols. DVH prediction is feasible in improving workflow and plan quality.

Purpose/objectives To report our experience of combining three approaches of an automatic plan integrity check (APIC), a standard plan documentation, and checklist methods to minimize errors in the treatment planning process. Materials/methods We developed APIC program and standardized plan documentation via scripting in the treatment planning system, with an enforce function of APIC usage. We used a checklist method to check for communication errors in patient charts (referred to as chart errors). Any errors in the plans and charts (referred to as the planning errors) discovered during the initial chart check by the therapists were reported to our institutional Workflow Enhancement (WE) system. Clinical Implementation of these three methods is a progressive process while the APIC was the major progress among the three methods. Thus, we chose to compared the total number of planning errors before (including data from 2013 to 2014) and after (including data from 2015 to 2018) APIC implementation. We assigned the severity of these errors into five categories: serious (S), near miss with safety net (NM), clinical interruption (CLI), minor impediment (MI), and bookkeeping (BK). The Mann–Whitney U test was used for statistical analysis. Results A total of 253 planning error forms, containing 272 errors, were submitted during the study period, representing an error rate of 3.8%, 3.1%, 2.1%, 0.8%, 1.9% and 1.3% of total number of plans in these years respectively. A marked reduction of planning error rate in the S and NM categories was statistically significant (P < 0.01): from 0.6% before APIC to 0.1% after APIC. The error rate for all categories was also significantly reduced (P < 0.01), from 3.4% before APIC and 1.5% per plan after APIC. Conclusion With three combined methods, we reduced both the number and the severity of errors significantly in the process of treatment planning.

Purpose: To retrospectively compare clinically treated step-and-shoot intensity modulated radiotherapy (ssIMRT) and volumetric modulated arc therapy (VMAT) spine stereotactic body radiotherapy (SBRT) plans in dosimetric endpoints and pretreatment quality assurance (QA) measurements.Methods: Five single fraction spine SBRT (18 Gy) casesincluding one cervical, two thoracic, and two lumbar spinesclinically treated with ssIMRT were replanned with VMAT, and all plans were delivered to a phantom for comparing plan quality and delivery accuracy. Furthermore, we analyzed 98 clinically treated plans (18 Gy single fraction), including 34 ssIMRT and 29 VMAT for cervical/thoracic spine, and 19 ssIMRT and 16 VMAT for lumbar spine. The conformality index (CI) and homogeneity index (HI) were calculated, and QA measurement records were compared. For the spinal cord/cauda equina, the maximum dose to 0.03 cc (D 0.03cc ) and volume receiving 10 or 12 Gy (V 10Gy /V 12Gy ) were recorded. Statistical significance was tested with the Mann-Whitney U test.Results: Compared to ssIMRT, replanned VMAT plans had lower V 10Gy /V 12Gy and D 0.03cc to the spinal cord/cauda equina in all five cases, and better CI in three out of five cases. The VMAT replans were slightly less homogeneous than those of ssIMRT plans. Both modalities passed IMRT QA with >95% passing rate with (3%, 3 mm) gamma criteria. With the 98 clinical cases, for cervical/thoracic ssIMRT and VMAT plans, the median V 10Gy of spinal cord was 4.15% and 1.85% (P = 0.004); the median D 0.03cc of spinal cord was 10.85 Gy and 10.10 Gy (P = 0.032); the median CI was 1.28 and 1.08 (P = 0.009); the median HI were 1.34 and 1.33 (P = 0.697), respectively. For lumbar spine, no significant dosimetric endpoint differences were observed. The two modalities were comparable in delivery accuracy.Conclusion: From our clinically treated plans, we found that VMAT plans provided better dosimetric quality and comparable delivery accuracy when compared to ssIMRT for single fraction spine SBRT.---

Previous work has suggested improved clinical outcomes with increasing radiation dose for patients with locally advanced pancreatic cancer (PC), but heterogeneous doses and schedules are used across institutions. To evaluate the utility of more uniform standard versus dose-escalated external beam radiation given after modern chemotherapy, we reviewed the outcomes at a single institution among locally advanced PC patients. Materials/Methods: We identified patients with inoperable or borderline resectable (BR) PC treated with conventional or hypofractionated radiation since the routine use of FOLFIRINOX and Gemcitabine/Abraxane began at our institution (2014-2020). Patients were excluded if they had metastatic disease or concurrent malignancy. Patients were stratified into highdose (BED 10 >70) and standard-dose (BED 10 <70) groups. Toxicity was evaluated based on CTCAE v 5.0. Overall survival (OS), freedom from local failure (FFLF), and freedom from distant failure (FFDF) were calculated using the Kaplan-Meier method, and compared using the logrank test. Results: A total of 42 patients, 21 in each dose group, were identified. Median age was 67, with 43% of female subjects. Twenty-nine (71%) subjects had BR disease. Median follow up was 8.5 months. The most common standard dose regimen was 50.4 Gy in 28 fractions (57%), and the dose escalated regimen was 67.5 Gy in 15 fractions (95%). Five (24%) patients in the standard dose and 15 (71%) patients in the escalated dose groups were treated using MR-guided RT. Seven (33.3%) and 6 (28.5%) patients in the standard-and high-dose groups, respectively, underwent pancreaticoduodenectomy following RT. OS was not significantly different between groups (median 8.3 vs 10.0 months, p Z 0.853). FFLP (12.2 vs 12.4 months, p Z 0.42) and FFDF (16.4 vs 9.0, p Z 0.72) were also not different between dose groups. Regardless of dose, patients that underwent resection after radiation had significantly greater OS (7.6 vs 25.7 months, p Z 0.01). Among patients who did not proceed to resection, there was a significant improvement in FFLF (median 4.3 vs. 9.1 months, p Z 0.05) in the dose-escalated group, and a non-significant improvement in OS (median 6.4 vs 10.0 months, p Z 0.10). Three grade 3 GI toxicities occurred (one directly attributable to RT) in the standard dose group, and no grade 3 toxicities occurred in the dose-escalated group. Conclusion: Among a cohort of patients with locally advanced PC, use of a dose-escalated radiation resulted in no improvement in overall clinical outcomes with similar toxicity. In patients that did not receive surgery, there was a clinically significant improvement in FFLF and trend towards improvement in survival suggesting truly unresectable patients may benefit most from dose escalation. Prospective trials are warranted to address the utility of dose-escalation in this setting.

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