[Show abstract][Hide abstract] ABSTRACT: This study was carried out to determine if markers of nutritional status predict for locoregional failure following intensity-modulated radiation therapy (IMRT) with concurrent chemoradiotherapy (CCRT) for squamous cell carcinoma of the head and neck (SCCHN).
We performed a retrospective chart review of 78 patients with SCCHN who received definitive CCRT. We compared patient factors, tumor characteristics, and nutritional status indicators between patients with and without locoregional failure.
Fifteen of 78 patients (19%) experienced locoregional failure. Median follow-up for live patients was 38 months. On univariate analysis, pretreatment percentage of ideal body weight (%IBW) (p < .01), pretreatment hemoglobin (p = .04), and treatment duration (p < .01) were significant predictors of failure. On multivariate analysis, pretreatment %IBW (p = .04) and treatment time (p < .01) remained statistically significant.
Although treatment time is an accepted risk factor for failure, differences in outcome for patients with head and neck cancer undergoing definitive CCRT based on pretreatment %IBW should be examined further.
[Show abstract][Hide abstract] ABSTRACT: To analyze the effect of tungsten shields present in a Fletcher-Suit-Delclos ovoid by comparing the dose distribution computed by a treatment planning system (TPS) to the delivered dose distribution measured by radiochromic film dosimetry.
Gafchromic/EBT films were carefully wrapped around the caps (diameter 20-25 mm) of shielded as well as unshielded ovoids, including their anterior and posterior ends. The ovoids were irradiated to a dose of 300 cGy using a high-dose rate remote afterloading unit. The films were scanned using Vidar VXR-16 Scanner. The dose distribution in the planes above, below, and on the sides of the ovoid were compared with the dose distribution computed by TPS, which does not account for the presence of shields.
The dose distributions obtained about the unshielded ovoid from film dosimetry was in order of what is computed by TPS (90% measurements ± 5%, maximum 8%). The dose reduction in the anterior part of the shielded ovoid affects maximally the dose to the bladder where a reduction up to 20% was noted. The reduction of dose in the posterior part of the ovoid, which is designed to shield rectum was as high as 23%. Where the shields are not present, insignificant difference in the measured and computed dose values was noticed.
The TPS may substantially overestimate the dose to the bladder and rectum, including regions that lie in the shadow of the solid angle subtended by the shields if it does not account for the presence of tungsten shields.
[Show abstract][Hide abstract] ABSTRACT: Controversy exists regarding optimal management of high risk localized endometrial cancer. Given that vaginal brachytherapy (VB) alone is used routinely at our institution, we retrospectively reviewed our outcomes among high risk patients defined according to the PORTEC, GOG 99, and/or Aalders randomized trials of pelvic radiation versus observation to determine if acceptable rates of locoregional control could be achieved with vaginal brachytherapy alone in this highest risk patient population.
The Roswell Park Cancer Institute hospital tumor registry was used to identify all patients with Stage I or IIA endometrial cancer treated between January 1992 and June 2006. A total of 464 patients were identified. Of 261 patients who received post-operative RT, 225 received VB alone. Of those 225, 87 met the high risk criteria as designated by PORTEC (at least 2 of the following high risk features: age>60, Grade 3, and/or myometrial invasion >or=Occurrences of the mathematical operator' (='were changed to 'OE'. Please check.-->50%), GOG 99 (any age with 3 high risk features: Grade 2-3, >66% myometrial invasion, and/or LVSI; age >or=50 with 2 high risk features; or age >or=70 with 1 high risk feature), and/or Aalders (Stage IC, Grade 3). Descriptive recurrence statistics are provided.
Among 87 high risk patients treated with VB alone, 36, 77, and 14 were high risk per PORTEC, GOG 99, and Aalders respectively. Forty (46%) underwent pelvic lymph node dissection. With a median follow-up of 52 months, 3 (3.4%) pelvic recurrences were observed including 1 vaginal recurrence, 1 pelvic recurrence, and 1 local recurrence involving both the vagina and pelvis. All 3 local recurrences were successfully salvaged with pelvic RT+/-surgery.
This represents one of the largest known series of high risk localized endometrial cancer treated with VB alone. The observed 3.4% locoregional recurrence compares favorably with the 5% locoregional recurrence noted among the highest risk patients receiving pelvic RT in the PORTEC, GOG 99, and Aalders randomized trials. In this single institution experience, the 3 local recurrences were salvaged. Based on these findings, we will continue to use VB alone in the adjuvant setting for patients with high risk localized endometrial cancer.
No preview · Article · Nov 2009 · Gynecologic Oncology
[Show abstract][Hide abstract] ABSTRACT: In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.
No preview · Article · Oct 2009 · Medical dosimetry: official journal of the American Association of Medical Dosimetrists
[Show abstract][Hide abstract] ABSTRACT: Optimal management of early-stage uterine papillary serous carcinoma (UPSC) remains controversial. We reviewed our outcomes in this patient population.
The Roswell Park Cancer Institute (RPCI) tumor registry identified all patients with Stages I and IIA UPSC treated between January 1992 and June 2006. The Fisher's exact test was used to compare recurrence rates by adjuvant therapy received. Overall survival (OS) estimates were made using the Kaplan-Meier method.
Fifty-eight patients with Stage I or IIA UPSC underwent surgery. Thirty-four patients (59%) were surgically staged. Among 21 patients with Stage IA disease, 15 received adjuvant therapy. With a median follow-up of 44.7 months, only one recurrence was observed in a patient who received adjuvant brachytherapy. The 5-year OS was 66%. Among 37 patients with Stages IB-IIA, 30 patients received adjuvant therapy. With a median follow-up of 29 months, there were 7 recurrences. The 5-year OS was 60%. Although there were no significant differences in recurrence by adjuvant therapy received, a significant OS benefit was found in those who received radiation. There was no significant difference in OS distributions of those patients who received Carboplatin/Paclitaxel chemotherapy.
Despite the limitations of our retrospective study, we have shown that even comprehensively staged early-stage UPSC patients are still at risk for recurrence despite adjuvant therapy received. Hence, all patients with this histologic diagnosis should be considered at high risk for recurrence and counseled appropriately regarding the risks and benefits of adjuvant therapy.
No preview · Article · Sep 2009 · Gynecologic Oncology
[Show abstract][Hide abstract] ABSTRACT: To determine whether baseline hemoglobin level and radiation treatment interruptions predict for loco-regional failure after intensity-modulated radiation therapy (IMRT) with concurrent chemotherapy for definitive treatment of squamous cell carcinoma of the head and neck (SCCHN).
This retrospective review identified 78 consecutive patients treated with definitive concurrent chemoradiation for SCCHN. Patients were treated with IMRT to 70 Gy in 35 daily fractions to the high-dose target volume and 56 Gy to the elective target volume.
Median age of the cohort was 62 (37-81). Median follow-up was 12 months. Tumor sites included: oropharynx (54%), larynx (36%), oral cavity (5%), and hypopharynx (5%). Fifteen of 78 patients (19%) experienced loco-regional failure. These included: 6 primary site failures, 5 regional failures, and 4 failures in both the primary site and regional lymph nodes. All but one failure occurred in the high-dose target volume. Only duration of radiation treatment and baseline hemoglobin levels were significant predictors of local control. Loco-regional failure occurred in 6 of 13 patients (46%) with radiation treatment interruptions (>1 week) versus 9 of 65 patients (14%) completing radiation therapy without interruption (P = 0.0148). Loco-regional failure occurred in 7 of 19 patients (37%) whose pretreatment hemoglobin level was <12 g/dL compared with 8 of 59 patients (14%) with hemoglobin levels > or = 12 (P = 0.042).
Overall radiation treatment time and pretreatment hemoglobin level were significant predictors for loco-regional failure after definitive concurrent chemotherapy and IMRT for SCCHN.
No preview · Article · Aug 2009 · American journal of clinical oncology
[Show abstract][Hide abstract] ABSTRACT: Purpose: To evaluate the dose perturbation in bladder and rectal regions caused by tungsten shielding within the ovoids of a Fletch‐Suit Delclos gynecological applicator in Ir‐192 HDR brachytherapy procedures. Method and Materials: A Fletcher‐Suit Delclos (FSD) gynecological applicator, assembled with Tungsten shielded ovoids, was rigidly suspended within a water tank. 28 sheets of gafchromic film were then secured in 6.20 mm increments in regions representative of a patient's bladder and rectum. A treatment plan was created (PLATO) to deliver 650 cGy to a user defined pseudo point A. Each film was scanned and analyzed to ascertain it's dosimetric distribution. The data was arranged into two three‐dimensional matrices based on the physical dimensions of the films and their locations with respect to a pseudo origin (intersection of the central tandem with the ovoids). Dosimetric data was also extracted from the planning system at points corresponding to specific locations on the gafchromic films. The entire process was then repeated for an FSD applicator without shielding in the ovoids. Results: The measured shielded data was compared to the planning system data (computed) that accounted for the tungsten shielding within the ovoids. It was evident that the measured doses in both the bladder and rectal regions were significantly lower than the computed data predicted. The largest reduction was roughly 24% in the bladder region, and 23% in the rectal region. Similar values were noticed in the unshielded comparison, where the unshielded FSD measurements were compared to computed data not accounting for ovoid shielding. This verifies a consistent discrepancy between the computed predictions and the measured doses.Conclusion: With the current dose tolerances for critical organs being estimated using shielded applicators, an accurate assessment of dose is imperative. This study provides a quantitative estimate for adjusting these accepted standards of bladder and rectal dose.
[Show abstract][Hide abstract] ABSTRACT: Adenocarcinoma of the endometrium is the most common malignancy of the female genital tract in the United States. Conversely, uterine sarcomas, also included in these guidelines, are uncommon malignancies. Many physicians believe that adenocarcinoma of the endometrium is a relatively benign disease because of the early symptoms of irregular vaginal bleeding, the often-localized nature of the disease, and the generally high survival rate. However, the estimated number of deaths from endometrial cancer continues to increase, indicating the need for a critical reassessment of the guidelines for managing it. Updates of the uterine neoplasms guidelines for 2009 include expanded recommendations for systemic therapy for recurrent, metastatic, and high-risk endometrial disease; updated recommendations for systemic therapy for uterine sarcoma; and new principles of radiation therapy in both endometrial carcinoma and uterine sarcoma.
No preview · Article · May 2009 · Journal of the National Comprehensive Cancer Network: JNCCN
[Show abstract][Hide abstract] ABSTRACT: In intraoperative high-dose-rate (IOHDR) brachytherapy, a 2-dimensional (2D) geometry is typically used for treatment planning. The assumption of planar geometry may cause serious errors in dose delivery for target surfaces that are, in reality, curved. A study to evaluate the magnitude of these errors in clinical practice was undertaken. Cylindrical phantoms with 6 radii (range: 1.35-12.5 cm) were used to simulate curved treatment geometries. Treatment plans were developed for various planar geometries and were delivered to the cylindrical phantoms using catheters inserted into Freiburg applicators of varying dimension. Dose distributions were measured using radiographic film. In comparison to the treatment plan (for a planar geometry), the doses delivered to prescription points were higher on the concave side of the geometry, up to 15% for the phantom with the smallest radius. On the convex side of the applicator, delivered doses were up to 10% lower for small treated areas (<or= 5 catheters) but, interestingly, the dose error was negligible for large treated areas (>5 catheters). Our measurements have shown inaccuracy in dose delivery when the original planar treatment plan is delivered with a curved applicator. Dose delivery errors arising from the use of planar treatment plans with curved applicators may be significant.
No preview · Article · Mar 2009 · Medical dosimetry: official journal of the American Association of Medical Dosimetrists
[Show abstract][Hide abstract] ABSTRACT: The incidence rate of malignant melanoma has shown a rapid worldwide rise in recent years. The staging and management of head and neck melanoma presents some unique challenges. Surgery remains the cornerstone of treatment, while sentinel node biopsy is the most accurate staging modality for regional disease. The complex regional anatomy and lymphovascular drainage of this region may account for the increased biologic aggressiveness and treatment challenges of this disease. Improved understanding of the radiobiology of melanoma has resulted in new adjuvant radiotherapy approaches, yielding improved control rates. The treatment outcomes of metastatic head and neck melanoma remain disappointing but important progress has been made in the understanding of melanoma biology.
No preview · Article · Apr 2008 · Expert Review of Anti-infective Therapy
[Show abstract][Hide abstract] ABSTRACT: Although cervical cancer is decreasing in the United States, because screening is widely used, it is increasing in developing countries (approximately 270,000 deaths per year), because screening is not available to many women. Effective treatment for cervical cancer (e.g., surgery, concurrent chemoradiation) can yield cures in 80% of women with early-stage disease (stages I and II) and in 60% with stage III disease. The hope is that immunization against HPV (using the new vaccines) will prevent persistent infection with certain types of HPV, and is therefore expected to prevent specific HPV cancer in women.9,69
Full-text · Article · Feb 2008 · Journal of the National Comprehensive Cancer Network: JNCCN