The Role of Radiation Therapy in the Management of Dermatofibrosarcoma Protuberans

Purpose: To evaluate the outcome for dermatofibrosarcoma protuberans treated with conservation surgery and radiation therapy. Methods and Materials: A retrospective review was performed of 19 consecutive patients with pathologically confirmed dermatofibrosarcoma protuberans who received radiation as an adjuvant to surgical resection. Results: The patients ages ranged from 19–76 years (median, 40 years); 12 were men. Lesions were located on the trunk in 8, in the head and neck area in 7, and in an extremity in 4. Tumor size ranged from 1.2 to 15 cm (median, 4 cm). Ten patients had at least 1 prior recurrence following earlier resection. Two patients received preoperative radiation to 50 Gy in 5 weeks. Sixteen patients underwent resection followed by radiation (6 of these had positive resection margins). In another patient, the tumor regrew rapidly after resection and definitive radiation was delivered for gross disease. The 6 patients with positive microscopic margins received a median dose of 60 Gy, as did the 10 with negative margins. The 1 patient with gross disease received 65 Gy. At a median follow-up of 6 years, the only patient to develop local recurrence was treated with definitive radiotherapy for gross disease. Actuarial local control was 95% at 10 years. Conclusion: Dermatofibrosarcoma protuberans is a radioresponsive tumor and radiation to doses of 50–60 Gy should be considered as an adjuvant to resection if margins are positive. Combined conservation resection and postoperative radiation should also be considered for situations where adequate wide excision alone would result in major cosmetic or functional deficits

Desmoid Tumor: Prognostic Factors and Outcome After Surgery, Radiation Therapy, or Combined Surgery and Radiation Therapy

PURPOSE: To evaluate the therapeutic value of resection and the potential benefits of and indications for adjuvant and definitive radiation therapy for desmoid tumors. MATERIALS AND METHODS: We performed a retrospective review of 189 consecutive cases of desmoid tumor treated with surgical resection, resection and radiation therapy, or radiation therapy alone. Treatment was surgery alone in 122 cases, surgery and radiation therapy in 46, and radiation therapy alone in 21. Median follow-up was 9.4 years. RESULTS: Overall, 5- and 10-year actuarial relapse rates were 30% and 33%, respectively. Uncorrected survival rates were 96%, 92%, and 87% at 5, 10, and 15 years, respectively. For the patients treated with surgery, the actuarial relapse rates were 34% and 38% at 5 and 10 years, respectively. Among 78 patients with negative margins, the 10-year recurrence rate was 27%, whereas 40 margin-positive patients had a 10-year relapse rate of 54% (P = .003). Tumors located in an extremity also had a poorer prognosis than did those in the trunk. For patients treated with radiation therapy for gross disease, the 10-year actuarial relapse rate was 24%. For patients treated with combined resection and radiation therapy, the 10-year actuarial relapse rate was 25%. The addition of radiation therapy offset the adverse impact of positive margins seen in the surgical group. CONCLUSION: Wide local excision with negative pathologic margins is the treatment of choice for most desmoid tumors. Function-sparing resection is appropriate because adjuvant radiation therapy can offset the adverse impact of positive margins. Unresectable disease should be treated with definitive radiation therapy

Tumor-treating fields dosimetry in glioblastoma:Insights into treatment planning, optimization, and dose–response relationships

Tumor-treating fields (TTFields) are currently a Category 1A treatment recommendation by the US National Comprehensive Cancer Center for patients with newly diagnosed glioblastoma. Although the mechanism of action of TTFields has been partly elucidated, tangible and standardized metrics are lacking to assess antitumor dose and effects of the treatment.This paper outlines and evaluates the current standards and methodologies in the estimation of the TTFields distribution and dose measurement in the brain and highlights the most important principles governing TTFields dosimetry. The focus is on clinical utility to facilitate a practical understanding of these principles and how they can be used to guide treatment. The current evidence for a correlation between TTFields dose, tumor growth, and clinical outcome will be presented and discussed. Furthermore, we will provide perspectives and updated insights into the planning and optimization of TTFields therapy for glioblastoma by reviewing how the dose and thermal effects of TTFields are affected by factors such as tumor location and morphology, peritumoral edema, electrode array position, treatment duration (compliance), array “edge effect,” electrical duty cycle, and skull-remodeling surgery. Finally, perspectives are provided on how to optimize the efficacy of future TTFields therapy. </p

Survival after Robotic-assisted Prostatectomy for Localized Prostate Cancer: An Epidemiologic Study

Backgrounds:To determine the potential survival benefit associated with robotic-assisted laparoscopic prostatectomy (RALP) compared to open radical prostatectomy (ORP) for prostate cancer.Summary of Background Data:RALP has become the dominant surgical approach for localized disease in the absence of randomized clinical evidence and despite of the factor that RALP is more expensive than ORP.Methods:We performed a cohort study involving patients who underwent RALP and ORP for localized prostate cancer at the Commission on Cancer- accredited hospitals in the United States. Overall survival was analyzed using the Kaplan-Meier method, log-rank test, Cox proportional hazards models, and propensity score-matched analyses. An interrupted time-series analysis using the surveillance, epidemiology, and end results program database was also performed.Results:From 2010 to 2011, 37,645 patients received RALP and 12,655 patients received ORP. At a median follow-up of 60.7 months, RALP was associated with improved overall survival by both univariate [hazard ratio (HR), 0.69; P \u3c 0.001] and multivariate analysis (HR, 0.76; P \u3c 0.001) compared with ORP. Propensity score-matched analysis demonstrated improved 5-year all-cause mortality (3.9% vs 5.5%, HR, 0.73; P \u3c 0.001) for RALP. The interrupted time-series analysis demonstrated the adoption of robotic surgery coincided with a systematic improvement in the 5-year cancer-specific survival rate of 0.17% (95% confidence interval, 0.06-0.25) per year after 2003 (P = 0.004 for change of trend), as compared to the time before adoption of RALP (1998-2003, annual percentage change, 0.01%; 95% confidence interval, -0.06 to 0.08). Sensitivity analysis suggested that the results from the interrupted time-series analysis were consistent with the improvement in the all-cause mortality demonstrated in the survival analysis (P = 0.87).Conclusions:In this epidemiologic analysis, RALP was associated with a small but statistically significant improvement in 5-year all-cause mortality compared to ORP for localized prostate cancer. This is the first time in the literature to report a survival benefit with RALP. Our findings have significant quality and cost implications, and provide assurance regarding a dominant adoption of more expensive technology in the absence of randomized controlled trials