Publications by authors named "David Parda"

Purpose: NRG Oncology (NRG)/NSABP B-39/RTOG 0413 compared whole-breast irradiation (WBI) to accelerated partial-breast irradiation (APBI). APBI was not equivalent to WBI in local tumor control. Secondary outcome was Quality-of-life (QOL).

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Purpose: Preclinical studies report that trastuzumab (T) can boost radiotherapy (RT) effectiveness. The primary aim of the B-43 trial was to assess the efficacy of RT alone vs concurrent RT plus T in preventing recurrence of ipsilateral breast cancer (IBTR) in women with ductal carcinoma in situ (DCIS).

Patients And Methods: Eligibility: Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1, DCIS resected by lumpectomy, known estrogen receptor (ER) and/or progesterone receptor (PgR), and human epidermal growth factor receptor 2 (HER2) status by centralized testing.

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Background: Whole-breast irradiation after breast-conserving surgery for patients with early-stage breast cancer decreases ipsilateral breast-tumour recurrence (IBTR), yielding comparable results to mastectomy. It is unknown whether accelerated partial breast irradiation (APBI) to only the tumour-bearing quadrant, which shortens treatment duration, is equally effective. In our trial, we investigated whether APBI provides equivalent local tumour control after lumpectomy compared with whole-breast irradiation.

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Background: Conventionally fractionated and stereotactic body radiation therapy (SBRT) for thoracoabdominal tumors may utilize breath-hold techniques. However, there are concerns that differential amounts of inspired airflow may result in unplanned tumor dislocation and underdosing. Thus, we investigated tumor localization accuracy associated with lung volume variations during breath-hold treatment via an automated-gating interface.

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Objectives: We report single center experience on the outcome and toxicity of SBRT alone or in combination with surgery for inoperable primary and metastatic liver tumors between 2007 and 2014.

Patients And Methods: Patients with 1-4 hepatic lesions and tumor diameter ≤9 cm received SBRT at 46.8Gy ± 3.

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Purpose: The optimal chemotherapy regimen administered concurrently with preoperative radiation therapy (RT) for patients with rectal cancer is unknown. National Surgical Adjuvant Breast and Bowel Project trial R-04 compared four chemotherapy regimens administered concomitantly with RT.

Patients And Methods: Patients with clinical stage II or III rectal cancer who were undergoing preoperative RT (45 Gy in 25 fractions over 5 weeks plus a boost of 5.

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Merkel's cell carcinoma is a rare cutaneous tumor that can affect a wide variety of sites throughout the body. Commonly, it affects the skin alone and the management of limited disease can be confusing since the natural history of the disease involves distant metastasis. Traditional management has required wide local excision with negative margins of resection.

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Purpose: To compare brachytherapy and three-dimensional (3-D) conformal external beam radiotherapy for breast cancer presenting in the previously irradiated breast.

Methods And Materials: Thirty-six patients with TIS-T2 breast carcinomas received brachytherapy or 3-D conformal radiotherapy (3-D CRT) after lumpectomy in a previously irradiated breast as an alternative to salvage mastectomy. Brachytherapy consisted of low-dose-rate (LDR) interstitial technique in 21 patients, whereas 11 patients were treated using high-dose-rate (HDR) balloon technique.

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Objectives: To retrospectively compare radiation toxicity in patients treated with concurrent anastrozole and whole breast irradiation versus women treated sequentially with whole breast irradiation followed by hormonal suppression.

Methods: The records of 249 consecutive estrogen or progesterone receptor positive breast cancer patients treated with breast-conserving surgery and postoperative whole breast irradiation were reviewed. Of total, 57 patients (the concurrent anastrozole group) received concurrent anastrozole prior to and during radiotherapy.

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Purpose: To update the Allegheny General Hospital experience of high-risk Stage I non-small-cell lung cancer patients treated with sublobar resection and intraoperative (125)I Vicryl mesh brachytherapy.

Methods And Materials: Between January 5, 1996 and February 19, 2008, 145 patients with Stage I non-small-cell lung cancer who were not lobectomy candidates because of cardiopulmonary compromise underwent sublobar resection and placement of (125)I seeds along the resection line. The (125)I seeds embedded in Vicryl suture were attached with surgical clips to a sheet of Vicryl mesh, inserted over the target area, and prescribed to a 0.

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Purpose: Fat necrosis is a well-described and relatively common complication arising from post-lumpectomy irradiation of the breast, most commonly breast brachytherapy. We wish to assess the clinical significance of fat necrosis resulting from post-lumpectomy breast irradiation.

Methods: We reviewed the literature to determine the overall incidence and significance of fat necrosis to determine whether or not fat necrosis poses a significant clinical problem.

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Purpose: Electron or photon boost immediately following whole-breast irradiation performed after conservation surgery for early-stage breast cancer is the accepted standard of care. This regimen frequently results in Grade III dermatitis, causing discomfort or treatment interruption. Herein, we compare patients treated with whole-breast irradiation followed by boost compared with a cohort with a planned intercurrent radiation boost.

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The use of brachytherapy--and to a lesser extent, external-beam radiotherapy--in the management of locally recurrent breast cancer following ipsilateral breast tumor recurrence (IBTR) followed by repeat breast-conservation surgery and irradiation is currently an area of intense study. The current cosmetic scoring system is inadequate to score the outcome resulting from retreatment because it does not account for the cosmetic effect of the initial treatment. We propose a modification of the scale for patients who undergo retreatment--the Allegheny General Modification of the Harvard/NSABP/RTOG scoring scale.

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The application of automated segmentation methods for tumor delineation on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) images presents an opportunity to reduce the interobserver variability in radiotherapy (RT) treatment planning. In this work, three segmentation methods were evaluated and compared for rectal and anal cancer patients: (i) Percentage of the maximum standardized uptake value (SUV% max), (ii) fixed SUV cutoff of 2.5 (SUV2.

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Objective: To evaluate the cosmetic outcome of brachytherapy after lumpectomy in the management of carcinoma of the previously irradiated breast.

Materials And Methods: Between January 1998 and April 2008, 26 patients with TIS or T1 breast carcinoma were offered interstitial or intracavitary brachytherapy after lumpectomy in a previously irradiated breast as an alternative to salvage mastectomy. Twenty-five of 26 patients had prior lumpectomy followed by standard postoperative external beam radiotherapy for early stage carcinoma of the breast [dose range 5000-6040 cGy].

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Techniques for generating simplified IMRT treatment plans for treating non-small cell lung cancer (NSCLC) patients with respiratory motion were investigated. To estimate and account for respiratory motion, 4-dimensional computed tomography (4DCT) datasets from 5 patients were used to design 5-field 6-MV ungated step-and-shoot intensity modulated radiotherapy (IMRT) plans delivering a dose of 66 Gy to the planning target volume (PTV). For each patient, 2 plans were generated using the mean intensity and the maximum intensity of 10 CT datasets from different breathing phases.

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A given outcome of radiotherapy treatment can be modeled by analyzing its correlation with a combination of dosimetric, physiological, biological, and clinical factors, through a logistic regression fit of a large patient population. The quality of the fit is measured by the combination of the predictive power of this particular set of factors and the statistical significance of the individual factors in the model. We developed a genetic algorithm (GA), in which a small sample of all the possible combinations of variables are fitted to the patient data.

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Purpose: To examine the feasibility of using the MammoSite brachytherapy applicator in the retreatment of the previously irradiated breast.

Methods And Materials: Between March 2004 and March 2007, three patients previously treated with external beam radiotherapy were retreated using the MammoSite brachytherapy device. Two patients were treated for an ipsilateral breast tumor recurrence after breast conservation surgery and postoperative irradiation, whereas the third patient developed an in-field breast cancer likely associated with Hodgkin's disease mantle irradiation 27 years before.

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Paragangliomas are usually low-grade neoplasms with a benign natural history. While the treatment of paraganglioma has historically been controversial, surgery and radiotherapy have become standardized as therapies of choice for primary therapy. More recently, stereotactic radiosurgery has been used effectively against this rare tumor.

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Purpose: To measure the interfraction changes of the MammoSite applicator and evaluate their dosimetric effect on target coverage and sparing of organs at risk.

Methods And Materials: A retrospective evaluation of the data from 19 patients who received 10 fractions (34 Gy) of high-dose-rate partial breast irradiation was performed. A computed tomography-based treatment plan was generated for Fraction 1, and a computed tomography scan was acquired just before the delivery of each fraction to ensure a consistent shape of the balloon.

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Purpose: A retrospective review to assess the efficacy and morbidity of surgical resection and (125)I interstitial lung brachytherapy placed in approximation to the aorta.

Methods And Materials: The records and postoperative films of 278 patients who had undergone intrathoracic (125)I brachytherapy at our institution were reviewed. All patients had undergone a gross total resection of a non-small-cell lung cancer using segmental resection, wedge resection, or sublobar resection.

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Accurate daily patient localization is becoming increasingly important in external-beam radiotherapy (RT). Mega-voltage cone-beam computed tomography (MV-CBCT) utilizing a therapy beam and an on-board electronic portal imager can be used to localize tumor volumes and verify the patient's position prior to treatment. MV-CBCT produces a static volumetric image and therefore can only account for inter-fractional changes.

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Purpose: To evaluate lumpectomy followed by interstitial brachytherapy as an acceptable salvage therapy for women who have developed localized recurrence of breast cancer after conservation surgery and postoperative external radiotherapy.

Methods And Materials: Between 1/1998 and 10/2006, 21 patients with T0 or T1 in-breast recurrence of carcinoma were offered interstitial low-dose rate brachytherapy after tumor re-excision as an alternative to salvage mastectomy. All patients had failed lumpectomy followed by standard postoperative external beam radiotherapy (range, 5000-6040cGy) as treatment for the initial breast carcinoma.

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