Kimberly S. Corbin

Initial clinical experience of postmastectomy intensity modulated proton therapy in patients with breast expanders with metallic ports

PURPOSE The feasibility of proton postmastectomy radiation therapy in patients reconstructed with expanders has not been previously reported, limiting treatment options. We analyzed the dosimetric impact of the metallic port contained within expanders on intensity modulated proton therapy (IMPT) and report our techniques and quality control for treating patients in this setting. METHODS AND MATERIALS Twelve patients with the same expander model underwent 2-field IMPT as part of a prospective registry. All planning dosimetry was checked with an in-house graphic processing unit--based Monte Carlo simulation. Proton ranges through the expander were validated using a sample implant. Dosimetric impact of setup metallic port position uncertainty was evaluated. Pre- and posttreatment photographs were obtained and acute toxicity was graded using the Common Terminology Criteria for Adverse Events, version 4.0. RESULTS Nine patients had bilateral skin-sparing mastectomy with bilateral tissue expander reconstruction, and 3 patients had unilateral skin-sparing mastectomy and reconstruction. The left side was treated in 10 patients and the right side in 2. Target coverage and normal tissue dose uncertainties resulting from the expander were small and clinically acceptable. The maximum physician-assessed acute radiation dermatitis was grade 3 in 1 patient, grade 2 in 5 patients, and grade 1 in 6 patients. CONCLUSIONS Postmastectomy IMPT in breast cancer patients with expanders is feasible and associated with favorable clinical target volume coverage and normal tissue sparing, even when taking into account treatment uncertainties; therefore, these patients should be eligible to participate in clinical trials studying the potential role of proton therapy in breast cancer. We caution, however, that institutions should carry out similar analyses of the physical properties and dosimetric impact of the particular expanders used in their practice before considering IMPT.

Carbon fiducial image-guidance increases the accuracy of lumpectomy cavity localization in radiation therapy for breast cancer

PURPOSE We investigated the feasibility and accuracy of using carbon fiducials to localize the lumpectomy cavity with 2-dimensional kV imaging for early stage breast cancer radiation therapy. METHODS AND MATERIALS Carbon fiducials were placed intraoperatively in the periphery of the lumpectomy cavity. Nine patients received whole breast irradiation with a boost, and 2 patients received 3-dimensional conformal partial breast irradiation. A total of 89 fractions were assessed for setup errors relative to a predefined gold standard, cone beam computed tomography (CBCT) match to the lumpectomy cavity, using the following 4 setup methods: (1) Align skin tattoos with lasers; (2) match bone with 2-dimensional-2-dimensional (2D/2D) kV onboard imaging (OBI); (3) match the whole breast with CBCT; and (4) match carbon fiducials with 2D/2D kV OBI. The margin for the planning target volume (PTV) was calculated by 2 standard deviations of the setup errors, and compared among the 4 setup methods. Setup errors for patients treated with free breathing and patients with deep inspiration breath hold were also compared. RESULTS The carbon fiducials were sufficiently visible on OBI for matching and introduced minimal artifacts. Of the 4 alignment methods, 2D/2D OBI match to fiducials resulted in the smallest setup errors. The PTV margin was 12 mm for aligning skin tattoos using lasers, 9.2 mm for matching bone on OBI, 6.5 mm for matching breast on CBCT, and 3.5 mm for matching fiducials on 2D/2D OBI. Compared with free breathing, deep inspiration breath hold generally reduced the standard deviations of the setup errors, but further investigation would be needed. CONCLUSIONS Matching to carbon fiducials increased the localization accuracy to the lumpectomy cavity. This reduces residual setup error and PTV margins, facilitating tissue sparing without diminishing treatment efficacy.

Data collection of patient outcomes: one institution’s experience

Abstract Patient- and provider-reported outcomes are recognized as important in evaluating quality of care, guiding health care policy, comparative effectiveness research, and decision-making in radiation oncology. Combining patient and provider outcome data with a detailed description of disease and therapy is the basis for these analyses. We report on the combination of technical solutions and clinical process changes at our institution that were used in the collection and dissemination of this data. This initiative has resulted in the collection of treatment data for 23 541 patients, 20 465 patients with provider-based adverse event records, and patient-reported outcome surveys submitted by 5622 patients. All of the data is made accessible using a self-service web-based tool.

Gemcitabine-Induced Radiation Recall Myositis: Case Report and Review of the Literature

Gemcitabine-induced radiation recall (GIRR) is a phenomenon wherein the administration of gemcitabine induces an inflammatory reaction within an area of prior radiation. We present the case of a 39-year-old female patient with metastatic breast cancer who experienced GIRR myositis 3 months following postoperative radiotherapy, with additional potential paraspinal myositis following ablative radiotherapy to the thoracic spine. A review of previously published cases of GIRR myositis was performed. The case and literature review describe the clinical course and presentation of GIRR, and highlight the importance of including radiation recall as part of a differential diagnosis when a patient undergoing chemotherapy experiences an inflammatory reaction at a prior site of radiation.

Multi-isocenter hybrid electron and rapid arc photon treatment for reirradiation of extensive recurrent inflammatory breast cancer

Delivering an adequate and homogenous dose to a large volume of recurrent cutaneous disease can be challenging even with modern techniques. Here, the authors describe a 3-isocenter hybrid electron and rapid arc photon radiation treatment plan to provide optimal tumor coverage to an extensive recurrence of inflammatory breast carcinoma. This approach allowed for homogeneous treatment of a large volume while effectively modulating dose to previously irradiated tissue and minimizing dose to the underlying heart, lungs and brachial plexus.

Target Delineation and Contouring

Adjuvant whole breast radiotherapy (RT) reduces the risk of recurrence and improves survival after breast-conserving surgery [1]. Recently, the addition of radiation to the high axillary, supraclavicular, and internal mammary lymph nodes has been shown to result in further reductions in locoregional and distant relapse and improvements in disease-free survival [2, 3]. In women with lymph node-positive breast cancer, postmastectomy RT to the chest wall and regional lymph nodes improves overall survival [4]. These established benefits of breast cancer RT are accompanied by an increased risk of delayed morbidity, such as lymphedema [5], secondary malignancy [6], and major coronary events [7]. Therefore, meticulous treatment planning is needed in order to optimize the therapeutic ratio in patients with indications for RT [8].