Faculty Bibliography

Purpose: Radiation induced interstitial pneumonitis and late renal dysfunction are major concerns for patients undergoing total body irradiation (TBI). The purpose of this work is to evaluate the dosimetry of VMAT-based TBI plans generated using Varian Eclipse scripting.
Method(s): Three full-body CT datasets (two patients, one anthropomorphic CIRS phantom) were used. An in-house Eclipse script was developed to generate optimized field arrangements using the body contour, user origin, and couch longitudinal travel. Plans consisted of a lower-body AP/PA portion and an upper-body VMAT portion (8 full arcs with 4-isocenters). Treatment plans to 1320 cGy (165 cGy x 8fx) were generated with dose directives: [PTV V100% >=90- 95%; Total lung Dmean <900 cGy; Kidneys Dmean <1100 cGy]. All plans used 6MV photons and were calculated using the AAA algorithm. Upperbody VMAT plan dosimetry was evaluated 'in-phantom' placing 12 OSLDs in different key locations (lung, kidneys, bone, and soft tissue). Additionally, dosimetric verification was performed for the three plans using Varian portal dosimetry, PerFraction(SNC) and ArcCheck(SNC) with a global gamma criterion of 2%/2 mm.
Result(s): Planning objectives were met for the three treatment plans with the following averages: PTV V100% = 94.02%, total lung Dmean = 872.9 cGy, and kidneys Dmean = 1075.8 cGy. The dose deviation between Eclipse and the OSLDs (relative to the prescribed dose) averaged 0.98%, with each individual dose deviation within +/-4%. Dose ranged between 52.5 cGy (lung) and 187.5 cGy (bone) for OSLD measurements. The average passing rate for all 24 fields (8 per plan) was 98.0%, 99.76% and 98.6% for portal dosimetry, PerFraction and ArcCheck respectively. The lowest passing rate of any individual field was 95.4%, 99.0% and 91.8% for portal dosimetry, PerFraction and ArcCheck respectively.
Conclusion(s): Eclipse scripting can assist in creating robust multi-isocentric VMATbased TBI treatment plans to block lungs and kidneys without compromising target coverage. Dosimetric accuracy and deliverability was confirmed using in-phantom OSLD dosimetry, Varian portal dosimetry, PerFraction and Arc-Check verification

The therapeutic management of regional lymph nodes in breast cancer has seen a remarkable change in the past 2 decades. Clinical trials have refined our knowledge regarding the biology of the disease including the prognostic significance of disease in the regional lymph nodes. The contemporary management of lymph nodes is also influenced by advances in surgical technique, radiation oncology delivery systems, and effective systemic therapy regimens. This paper describes the role of regional nodal irradiation in the context of the de-escalation of axillary surgery, improved understanding of the molecular and pathologic features, and increasing use of neoadjuvant chemotherapy.

OBJECTIVES/HYPOTHESIS/OBJECTIVE:To assess patterns of care and outcomes with the use of neoadjuvant chemotherapy followed by definitive radiation in local-regionally advanced nasopharyngeal carcinoma. STUDY DESIGN/METHODS:Retrospective database analysis. METHODS:We queried the National Cancer Database for patients with T3-4N2 or T1-4N3 nasopharyngeal carcinoma who received concurrent chemoradiotherapy or neoadjuvant chemotherapy followed by radiation. Overall survival (OS) was analyzed using the Kaplan-Meier method, propensity-score matching, and a Cox proportional hazards model adjusting for demographic and disease-specific prognostic factors. RESULTS:P = .001). At a median follow-up of 36.6 months, patients had 3-year OS of 66% in the neoadjuvant group compared with 70% in those who received concurrent chemoradiotherapy (log rank P = .29). On subgroup analysis by histology, T stage, and N stage, there remained no differences in OS between the two groups. On multivariable analysis, there was no significant survival difference associated with neoadjuvant chemotherapy (adjusted hazard ratio [HR]: 1.05, 95% confidence interval [CI]: 0.89-1.25, P = .54). In a propensity score-matched population of 1,008 patients (504 with neoadjuvant therapy and 504 without), there was no significant survival difference associated with neoadjuvant chemotherapy (H: 1.13, 95% CI: 0.93-1.38, P = .22). CONCLUSIONS:Neoadjuvant chemotherapy was used in over 25% of patients, and its use is increasing. However, neoadjuvant chemotherapy was not associated with any differences in survival compared to concurrent chemoradiotherapy. LEVEL OF EVIDENCE/METHODS:4 Laryngoscope, 2018.