Biomedical subjects

Daniel Taussky

Publications and source records attributed to Daniel Taussky.

10 recordsLinked to original sources

PubMed2006

Rectal-wall dose dependence on postplan timing after permanent-seed prostate brachytherapy.

PURPOSE: Dose to rectal wall after permanent-seed prostate brachytherapy is dependent on distance between posterior prostatic seeds and anterior rectal wall and is influenced by postimplant periprostatic edema. We analyzed the effect of postplan timing on anterior rectal-wall dose. METHODS AND MATERIALS: Twenty patients received permanent seed 125I brachytherapy as monotherapy (145 Gy). Implants were preplanned by use of transrectal ultrasound (TRUS) and carried out by use of preloaded needles. Postimplant dosimetry was calculated by use of magnetic resonance imaging-computed tomography fusion on Days 1, 8, and 30. The anterior rectal-wall dose is reported as the isodose enclosing 1.0 or 2.0 cc of rectal wall and as the RV100 in cc. RESULTS: The dose to rectal wall increased progressively over time. The median increase in dose to 1.0 cc of rectal wall (RD [1 cc]) from Day 1 to 30 was 39.2 Gy (p < 0.001). RV100 increased from a median of 0.07 cc on Day 1 to 0.67 cc on Day 30. The most significant predictor of rectal-wall dose (RD [1 cc], RD [2 cc], or RV100) was the time of evaluation (p < 0.001). CONCLUSION: Although periprostatic edema cannot be quantified by postimplant imaging, the dose to the anterior rectal wall increases significantly over time as prostatic and periprostatic edema resolve. Critical-organ dose reporting and guidelines for minimizing toxicity must take into account the time of the assessment.

Aged↗

PubMed2006

Treatment of the inguinal regions in penile cancer: a review of the literature and treatment proposal.

Penile cancer is a rare malignancy affecting only 1 per 100,000 men in North America and Western Europe. Although the majority of men present with clinically negative inguinal lymph nodes, node positivity is associated with a very poor prognosis. Both the management of positive nodes, and the management of clinically negative nodes in intermediate- and high-risk patients remain controversial. Experience with penile cancer is often limited as even tertiary referral cancer centers may see only one or two such patients per year. The literature, which consists mainly of retrospective studies of patients treated over several decades, is not conclusive. We undertook a literature review to address this issue and to propose.

Humans↗

PubMed2005

Sequential evaluation of prostate edema after permanent seed prostate brachytherapy using CT-MRI fusion.

PURPOSE: To analyze the extent and time course of prostate edema and its effect on dosimetry after permanent seed prostate brachytherapy. METHODS AND MATERIALS: Twenty patients scheduled for permanent seed (125)I prostate brachytherapy agreed to a prospective study on postimplant edema. Implants were preplanned using transrectal ultrasonography. Postimplant dosimetry was calculated using computed tomography-magnetic resonance imaging (CT-MRI) fusion on the day of the implant (Day 1) and Days 8 and 30. The prostate was contoured on MRI, and the seeds were located on CT. Factors investigated for an influence on edema were the number of seeds and needles, preimplant prostate volume, transitional zone index (transition zone volume divided by prostate volume), age, and prostate-specific antigen level. Prostate dosimetry was evaluated by the percentage of the prostate volume receiving 100% of the prescribed dose (V(100)) and percentage of prescribed dose received by 90% of the prostate volume (D(90)). RESULTS: Prostate edema was maximal on Day 1, with the median prostate volume 31% greater than preimplant transrectal ultrasound volume (range, 0.93-1.72; p < 0.001) and decreased with time. It was 21% greater than baseline at Day 8 (p = 0.013) and 5% greater on Day 30 (p < 0.001). Three patients still had a prostate volume greater than baseline by Day 30. The extent of edema depended on the transition zone volume (p = 0.016) and the preplan prostate volume (p = 0.003). The median V(100) on Day 1 was 93.6% (range, 86.0-98.2%) and was 96.3% (range, 85.7-99.5%) on Day 30 (p = 0.079). Patients with a Day 1 V(100) >93% were less affected by edema resolution, showing a median increase in V(100) of 0.67% on Day 30 compared with 2.77% for patients with a V(100) <93 % on Day 1. CONCLUSION: Despite the extreme range of postimplant edema, the effect on dosimetry was less than expected. Dose coverage of the prostate was good for all patients during Days 1-30. Our data indicate that postimplant dosimetry on the day of implant is sufficient for patients with good dose coverage (Day 1 V(100) >93%).

Aged↗

PubMed2005

Risk factors for developing a second upper aerodigestive cancer after radiotherapy with or without chemotherapy in patients with head-and-neck cancers: an exploratory outcomes analysis.

PURPOSE: The objective was to assess the influence of treatment-related and patient-related factors on the risk of developing a second primary tumor (SPT) of the upper aerodigestive tract (UADT) in patients with locoregionally advanced nonmetastatic carcinomas of the head-and-neck region. METHODS AND MATERIALS: The data of 521 patients with a minimum follow-up of 1 year were pooled: 224 patients from the Swiss Group for Clinical Cancer Research (SAKK) 10/94 trial, treated with 1.2 Gy b.i.d. to 74.4 Gy, and randomized to receive or not to receive simultaneous chemotherapy with cisplatin (excluding nasopharyngeal and maxillary sinus carcinomas); and 297 patients from Geneva, all treated with accelerated radiotherapy with concomitant boost to 69.9 Gy and predominantly cisplatin-based concomitant chemotherapy in 33% of patients (including 21 patients with nasopharyngeal carcinomas). An exploratory analysis using competing risk methodology was performed. RESULTS: A total of 65 SPT of the UADT were observed after a median observation time of 4.7 years. The overall risk of experiencing an SPT of the UADT at 10 years in the presence of all other possible events was estimated to be 33%. There were no SPTs after treatment for nasopharyngeal carcinoma. In a multivariate logistic regression analysis, there was no difference in occurrence of SPT at 3 years with respect to the administration of chemotherapy (p = 0.31), age (p = 0.62), performance status (p = 0.61), gender (p = 0.27), presence of nodal disease (p = 0.51), or T stage (p = 0.72). However, patients treated with concomitant boost had fewer SPTs (p = 0.0093). CONCLUSIONS: Our data do not suggest that addition of chemotherapy to radiotherapy influences the incidence of second cancers in patients with head-and-neck cancer. The difference in the incidence of SPT between the two radiotherapy schedule groups merits further exploration.

Carcinoma, Squamous Cell↗

PubMed2005

Salvage surgery after radical accelerated radiotherapy with concomitant boost technique for head and neck carcinomas.

BACKGROUND: Definitive radiotherapy (RT) for head and neck cancer is increasingly used to preserve organ function, whereas surgery is reserved for treatment failure. However, data are sparse regarding the feasibility of salvage surgery, particularly for unselected patients after accelerated RT. METHODS: From 1991 to 2001, 297 patients, most with stage III to IV cancer (Union Internationale Contre le Cancer) were treated with concomitant boost RT (median dose, 69.9 Gy in 41 fractions) with or without chemotherapy (in 33%, usually cisplatin with or without 5-fluorouracil). The 75 patients seen with local and/or regional failure were studied. We analyzed the factors influencing the decision to attempt surgical salvage, the oncologic outcome, and the associated complications. RESULTS: Seventeen (23%) of the 75 patients had a salvage operation. This included all five patients with laryngeal cancers but only 16% to 20% of patients with tumors in other locations. Most patients could not be operated on because of disease extension (40%) and poor general condition/advanced age (30%). Patients with low initial primary T and N classification were more likely to undergo surgery (p = .002 and .014, respectively). Median post-recurrence survival was significantly better for patients who had salvage operations than for those without surgical salvage treatment (44 vs 11 months, p = .0001). Thirteen patients were initially seen with postoperative complications (mostly delayed wound healing and fistula formation). CONCLUSIONS: After definitive accelerated RT with the concomitant boost technique, only a minority of patients with local or regional recurrence underwent salvage surgery. Disease stage, tumor location, and patient's general condition at the initial diagnosis seemed to be the main factors influencing the decision to attempt surgical salvage. For patients with initially resectable disease who undergo radical nonsurgical treatment, more effective follow-up is needed to favor early detection of treatment failure, which may lead to a timely and effective salvage surgery.

Adult↗

PubMed2004

Can concomitant-boost accelerated radiotherapy be adopted as routine treatment for head-and-neck cancers? A 10-year single-institution experience.

PURPOSE: Accelerated schedules are effective in overcoming repopulation during radiotherapy (RT) for head-and-neck cancers, but their feasibility is compromised by increased toxicity. The therapeutic ratio may be particularly favorable for 5-week regimens. This study reports the 10-year experience of a single institution in the routine use of concomitant boost RT as standard radical treatment in all but the most favorable stage patients. METHODS AND MATERIALS: Between February 1991 and June 2001, 296 patients (mean age, 59 years) were treated with concomitant boost RT either alone (67%) or combined with cisplatin-based chemotherapy (33%), with a median tumor dose of 69.9 Gy. Tumors were located in the oropharynx in 52%, hypopharynx in 20%, larynx in 15%, nasopharynx in 7%, and oral cavity in 6%. International Union Against Cancer Stage III-IV disease represented 77% of tumors. The median follow-up for surviving patients was 55 months (range, 10-138 months). RESULTS: The RT schedule was completed to the prescribed dose in all but 1 patient. Twenty patients (7%) had a treatment interruption (median, 5 days; range, 2-35 days). Grade 3-4 Radiation Therapy Oncology Group acute toxicity was observed in 77% of patients, and nutritional support was required in 110 patients (37%). For all patients, the 5-year actuarial locoregional control and disease-free survival rate was 72% and 61%, respectively. In a multivariate analysis, only T and N stage was significantly associated with locoregional control and disease-free survival. Grade 3-4 late toxicity occurred in 14%, mostly bone and cartilage necrosis. CONCLUSIONS: The present, moderately accelerated, concomitant boost regimen is logistically feasible, causing minimal inconvenience to the technical staff and yielding a high rate of patient compliance. Concomitant chemotherapy administration is feasible provided that patients are carefully selected and supportive care is introduced in a timely fashion. Considering the manageable toxicity and the satisfactory tumor control obtained, this regimen represents a good choice when considering implementation of an altered RT fractionation schedule as standard treatment for head-and-neck cancers.

Adolescent↗

PubMed2004

Factors predicting an increased dose to the penile bulb in permanent seed prostate brachytherapy.

PURPOSE: Erectile dysfunction following permanent seed brachytherapy for prostate cancer may be related to the dose to the penile bulb. We investigated anatomic and dosimetric factors that might contribute to an increased dose to the penile bulb. METHODS AND MATERIALS: One-month CT and MR images were examined for 50 consecutive patients treated with exclusive (125)I permanent seed prostate brachytherapy to a prescribed dose of 145 Gy. Implants were preplanned by transrectal ultrasound (TRUS). Postimplant dosimetry was performed at 1 month using an MRI-CT fusion. Spearman's correlation was used to establish a correlation between dosimetric parameters, anatomical factors, and the dose to the penile bulb. RESULTS: Penile bulb volumes ranged from 1.2-8.5 cc (median, 3.9 cc). The distance from the penile bulb to the prostate apex ranged from 5-33 mm (median, 15.5 mm). D50 of the penile bulb ranged from 13-121 Gy. The range for the V45 (65 Gy) was 0-87%; only 3% of patients had >2 cc covered by this isodose and in 16% of patients the V45 covered more than 50% of the penile bulb. About one-third of the patients received a dose to the bulb that would put them at a high risk of erectile dysfunction after external beam radiation, if the dose were radiobiologically equivalent. There was a significant inverse correlation between the distance between the prostate apex and the penile bulb, and the dosimetric parameters of the bulb: r = -0.548, -0.656, p = < 0.01. The further caudal the apex was from the symphysis, the closer it was to the penile bulb (r = -0.564, p = <0.01). We could not find a correlation between the dose to the prostate or its apex and the dose to the penile bulb. CONCLUSION: When the prostate apex is close to the penile bulb, care should be taken to limit the dose to the penile bulb, if possible. This may reduce the incidence of erectile dysfunction and urinary toxicity after permanent seed prostate brachytherapy.

Brachytherapy↗

PubMed2003

Influence of rectal volume changes during radiotherapy for prostate cancer: a predictive model for mild-to-moderate late rectal toxicity.

PURPOSE: To assess the rectal volume changes during radiotherapy for prostate cancer, to estimate an average rectal dose distribution profile during treatment, and to correlate these parameters with mild-to-moderate late rectal toxicity. MATERIALS AND METHODS: Nine patients with localized prostate cancer underwent virtual CT simulation using a six-field conformal 18-MV photon technique. During treatment, patients underwent weekly pelvic CT scans under simulation conditions. Dosimetries were run with each CT data set using the same beam parameters as in the initial treatment plan. The influence of weekly rectal volume changes on the dose-volume histogram (DVH) profiles was studied. A polynomial function correlating the initial rectal volume with the mean percentage of change in the rectal volume during treatment was used to define a correction factor for rectal DVHs. The model was validated using data from 100 patients treated with 74 Gy according to the same technique. Areas under the curve of the initial rectal DVHs were correlated with toxicity (Radiation Therapy Oncology Group Grade 0 vs. 1-2, Student's t test), with or without the use of the above correction factor. RESULTS: A trend for enlargement of the rectal volume during treatment was observed for most patients in the study with small rectal volumes (<75 cm(3)) at simulation, resulting in an increase in the integral rectal dose by a factor ranging from 1.3 to 2.1. Corrected, but not uncorrected, rectal DVH profiles were strongly predictive of Grade 0 vs. 1-2 late rectal morbidity. CONCLUSIONS: Correcting the area under the curve of the rectal DVH at simulation by a factor that takes into account the projected volume changes during treatment correlates significantly with the probability of mild-to-moderate late rectal toxicity (Grade 1-2). This reliable predictor for mild-to-moderate late rectal morbidity may also be a practical tool for treatment planning.

Algorithms↗

PubMed2003

Patient-reported toxicity correlated to dose-volume histograms of the rectum in radiotherapy of the prostate.

We studied 73 patients treated with 3-dimensional conformal radiotherapy for prostate cancer to determine whether there is a correlation between dose per volume to either the whole rectum, rectal wall, rectal surface, or anal canal and the development of late rectal complications measured with prostate-specific quality-of-life (QOL) questionnaires. Given doses were 66.6 to 72 Gy. The prostate cancer modules used were the UCLA-Prostate Cancer Index module (UCLA-PCI) (5 questions), the Functional Assessment of Cancer Therapy-Prostate module (FACT-P) (1 question), and the European Organization for Research and Treatment of Cancer prostate cancer module (EORTC QLQ-PR25) (4 questions). A Spearman correlation analysis between the total toxicity score and the dose-volume histograms (DVHs) was performed. All statistical tests were 2-sided. Sixty-five (89%) patients returned the questionnaire, and 18 (28%) underwent endoscopy for rectal bleeding. We found that only patients who had had an endoscopy showed a correlation between rectal toxicity and dose per volume, as compared with the other patients who showed none. Correlation between rectal toxicity and dose per volume for all 4 structures was stronger for higher doses. For 70 Gy, all contours, except the anal canal, showed a significant dose-volume correlation. Our results indicate that only in cases of pronounced rectal toxicity is there a dose-volume correlation, especially for doses of 70 Gy or more. DVHs of the whole rectum, wall, or surface, but not the anal canal, are all equivalent in predicting late rectal toxicity.

Aged↗

PubMed2002

Clinical markers of hypoxia and other predictive factors of survival in conservative therapy of squamous-cell carcinoma of the esophagus.

BACKGROUND AND AIMS: Carcinoma of the esophagus is an aggressive cancer with a high failure rate after combined local and systemic treatment modalities. One of the factors that could influence the high rate of locoregional persistence is hypoxia. Hypoxic cancers are known to be more aggressive and less responsive to chemo- and radiotherapy. We investigated the effect of several factors on overall survival and several surrogate markers of hypoxia on survival in squamous-cell esophageal cancer. PATIENTS AND METHODS: We conducted a retrospective analysis of 41 curatively treated patients with squamous-cell esophageal cancer: 30 received combined radio- and chemotherapy (cisplatin and 5-FU) and 11 radiotherapy alone. Cox regression analysis was performed to study the effect of several factors on overall survival. RESULTS: Significantly better survival was shown only in patients who were younger, received more cycles of chemotherapy, or had more proximal tumors or less advanced T stage but not for possible clinical surrogate markers for hypoxia, such as levels of hemoglobin before and during treatment or smoking. CONCLUSION: We found no clinical evidence that hypoxia plays a role in survival with squamous-cell esophageal cancer. Number of chemotherapy cycles was, independently of age, predictive of survival. Measurements of in vivo tumor oxygenation could further help in determining the role of tumor hypoxia in esophageal cancer.

Adult↗