Optimization of autogenerated chest-wall radiation treatment plans developed for postmastectomy breast cancer patients in underserved clinics.

Over the past decade, several strides have been made to improve the management of breast cancer in developing countries; however, there are still obstacles present. In the area of radiation therapy, these hurdles include limited access to radiotherapy treatment and scarcity of oncology specialists. In an effort to reduce inequities in cancer care while improving patient outcomes, our research is focused on developing automated postmastectomy radiation therapy (PMRT) plans for breast cancer patients in these underserved communities that can be further improved upon through treatment planning system (TPS) specific optimization guidelines. The automated planning tool utilized algorithms integrated with Varian's Eclipse TPS. The tool created PMRT plans that used monoisocentric tangents and supraclavicular (SCV) fields with a mix of high and low energy photon beams along with field-in-field (FIF) segments. The completed autogenerated PMRT plans were imported into Phillip's Pinnacle 9.10 and Varian's Eclipse 13.6 TPSs to be further improved through manual optimization; the time required to complete this step was measured and assessed. A senior dosimetrist, physicist, and physician evaluated the optimized plans for clinical acceptability. Guidelines were developed for the planning systems that can be implemented by personnel with either limited experience in radiation treatment planning or those with limited time to produce treatment plans. The autogenerated plans in conjunction with our guidelines have shown to significantly reduce the time required to produce a clinically acceptable PMRT plan from approximately 120 ± 60 minutes to just 13 ± 11 (Pinnacle) and 12 ± 7 (Eclipse) minutes, reducing the total uninterrupted treatment planning time by an average of 108 ± 51 minutes. The results from this research indicate that the autogenerated PMRT plans along with the optimization guidelines are a viable option to provide quality and clinically acceptable PMRT plans that are more efficient and consistent for postmastectomy breast cancer patients in severely underserved communities.

Incidence and predictors of chest wall toxicity after high-dose radiation therapy in 15 fractions.

PURPOSE: Fifteen fraction treatment schedules are increasingly used to deliver high doses of radiation therapy (RT) to both lung and hepatobiliary malignancies. The purpose of our study was to examine the incidence and predictors of chest wall (CW) toxicity in patients treated with this regimen. METHODS AND MATERIALS: We evaluated 135 patients treated with RT to doses ≥52.5 Gy in 15 fractions for thoracic and hepatobiliary malignancies between January 2009 and December 2012. We documented patient characteristics and CW dosimetric parameters for each case. Toxicity was scored using the Common Terminology Criteria for Adverse Events, version 4.0, criteria for radiation dermatitis and CW pain. Patient characteristics and CW dosimetric parameters were evaluated for their association with CW toxicity using proportional hazards regression. RESULTS: Median follow-up was 9 months from the start of RT. Forty-eight patients (36%) developed dermatitis at a median time of 18 days. In multivariable analysis, the absolute volume of CW (in cm3) receiving 40 Gy (V40) ≥120 cm3 was associated with the occurrence of dermatitis (hazard ratio, 3.12; 95% confidence interval, 1.74-5.60; P < .001). Twenty-one patients (16%) developed CW pain (20 grade 1, 1 grade 2) at a median time of 3 months. In multivariable analysis, CW V40 ≥150 cm3 was associated with the occurrence of CW pain (hazard ratio, 2.65; 95% confidence interval, 1.12-6.24; P = .03). The absolute rate of CW pain in patients with V40 <150 cm3 was 11% versus 26% in patients with V40 ≥150 cm3 (P = .03). CONCLUSIONS: Hypofractionated RT with 15 fraction regimens results in an acceptable incidence of CW toxicity, specifically CW pain. We recommend a dose constraint of V40 <150 cm3 to minimize this adverse event.