A PHASE II TRIAL OF BALLOON-CATHETER PARTIAL BREAST BRACHYTHERAPY OPTIMIZATION IN THE TREATMENT OF STAGE 0, I AND IIA BREAST CARCINOMA.

OBJECTIVES: (a) To prospectively determine if multidwell position dose delivery can decrease skin dose and resultant toxicity over single dwell balloon-catheter partial breast irradiation, and (b) to evaluate whether specific skin parameters could be safely used instead of skin-balloon distance alone for predicting toxicity and treatment eligibility. METHODS: A single-arm phase II study using a Simon two-stage design was performed on 28 women with stage 0-II breast cancer. All patients were treated with multiple dwell position balloon-catheter brachytherapy. The primary endpoint was ≥ grade 2 skin toxicity. Initial entry required a balloon-skin distance ≥ 7 mm. Based on the toxicity in the first 16 patients, additional patients were treated irrespective of skin-balloon distance as long as the Dmax to 1 mm skin thickness was < 130%. RESULTS: Compared to the phantom single dwell plans, multidwell planning yielded superior PTV coverage as per median V90, V95 and V100, but had slightly worse V150, V200 and DHI. Dmax to skin was decreased by multidwell planning at multiple skin thicknesses. The most common acute toxicity was grade 1 erythema (57%), and only two patients (7%) developed acute grade 2 toxicity (erythema). Late grade 1 fibrosis was seen in 32%. No patients experienced grade 3, 4, or 5 toxicity. CONCLUSIONS: Multidwell position planning for balloon-catheter brachytherapy results in lower skin doses with equal to superior PTV coverage and an overall low rate of initial skin toxicity. Our data suggest that limiting the Dmax to < 130% to 1 mm thick skin is achievable and results in minimal toxicity.

Stereotactic body radiotherapy for central lung tumors.

INTRODUCTION: Patients with centrally located lung tumors have been reported to have a higher risk of toxicity when treated with stereotactic body radiotherapy (SBRT) compared with patients with peripheral tumors. The optimal SBRT fractionation schedule for treatment of central tumors is unknown. The primary purpose of this study was to assess toxicity in patients with central lesions treated with SBRT at our institution, the majority of whom were treated with four fractions. METHODS: Forty-seven patients with 51 central lesions, either primary lung cancer or lung metastases, were treated with SBRT at the Department of Therapeutic Radiology, Yale University School of Medicine/Yale Cancer Center from 2007 to 2011. The patients were treated with three to five fractions with the majority of patients receiving 50 Gy in four fractions of 12.5 Gy. Forty of the lesions were located within 2 cm of the proximal tracheobronchial tree whereas 11 were located within 2 cm of other mediastinal structures. Toxicity data were collected and analyzed according to pretreatment and tumor characteristics and dosimetric parameters. Lobar control data were compiled. RESULTS: With a median follow-up of 11.3 months (range, 4.8-40.8), four patients experienced grade 3 dyspnea and one patient developed hemoptysis that contributed to respiratory failure and subsequent death. Grade 2 toxicity included fatigue (n = 3), dyspnea (n = 3), chest-wall pain (n = 1), and cough (n = 1). Patients with grade 3+ toxicity had larger maximum tumor diameters compared with those patients without grade 3+ toxicity (median diameter 4.3 cm versus 2.9 cm, p = 0.02). There were no detectable significant differences between the two groups with respect to baseline pulmonary function tests, distance to tracheobronchial tree, maximum point dose to the tracheobronchial tree, maximum dose to 5 cc of the tracheobronchial tree, mean lung dose, and volume of lung receiving 5 Gy, 10 Gy, and 20 Gy. There were two patients who experienced local recurrences. The median biological equivalent dose (linear quadratic formula, α/ß = 10) for patients with local recurrence was 76 Gy compared with 112.5 Gy for patients without local recurrence (2-tailed t test, p = 0.04). The 2-year actuarial lobar local control for the entire cohort was 94%. The 2-year lobar local-control rate for patients receiving a biological equivalent dose of 100 Gy or more was 100% and for those receiving less than 100 Gy was 80% (log rank, p = 0.02). CONCLUSION: SBRT for central lung tumors seems to be safe, although treatment of larger tumors does carry an increased risk of high-grade toxicity. Efforts to decrease the toxicity risk by decreasing the biologically equivalent dose resulted in increased local failure.

Emergence of rationally designed therapeutic strategies for breast cancer targeting DNA repair mechanisms.

Accumulating evidence suggests that many cancers, including BRCA1- and BRCA2-associated breast cancers, are deficient in DNA repair processes. Both hereditary and sporadic breast cancers have been found to have significant downregulation of repair factors. This has provided opportunities to exploit DNA repair deficiencies, whether acquired or inherited. Here, we review efforts to exploit DNA repair deficiencies in tumors, with a focus on breast cancer. A variety of agents, including PARP (poly [ADP-ribose] polymerase) inhibitors, are currently under investigation in clinical trials and available results will be reviewed.

90Yttrium microspheres for nonresectable liver cancer: the University of Connecticut Health Center experience.

PURPOSE: To determine the outcome of 90Y selective internal radiation therapy (SIRT) for primary and metastatic liver tumors at our institution and compare our results to the published literature. PATIENTS AND METHODS: From July 2004 to November 2005 24 patients initiated SIRT therapy with 90Y microspheres at UCHC. Patient charts were reviewed for background, treatment planning, activity and dose, and toxicity information. Main outcome measures included patient survival, toxicity, and evidence of tumor response as indicated by available CT or PET scan reports. RESULTS: The median survival for the colorectal, hepatocellular carcinoma, and "other" groups were 9.0 months, 3.5 months, and 5.8 months, respectively. Post-treatment CT or PET scans were available for 15 of the 24 patients. Of the patients for whom follow-up imaging was available, 5/15 patients (33%) had a documented response, 5/15 (33%) had stable disease, and 5/15 (33%) had disease progression. CONCLUSION: SIRT with 90Y microspheres had antitumor activity in the majority of patients with primary or secondary liver cancer who had experienced disease progression with previous treatments.