- Browse by Subject
Browsing by Subject "brachytherapy"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Dosimetric Comparison of Treatment Techniques: Brachytherapy, Intensity- Modulated Radiation Therapy, and Proton Beam in Partial Breast Irradiation(2015) Hansen, Tara M.; Bartlett, Gregory K.; Mannina, Edward M. Jr.; Srivastava, Shiv P.; Cox, John A.; Das, Indra J.; Department of Radiation Oncology, IU School of MedicinePurpose: To perform a dosimetric comparison of 3 accelerated partial breast irradiation techniques: catheter-based brachytherapy (BT), intensity-modulated radiation therapy (IMRT), and proton beam therapy (PBT). Patients and Methods: Twelve patients with left-sided breast cancer treated with SAVI (Strut-Adjusted Volume Implant) were selected in this study. The original BT plans were compared with optimum plans using IMRT and PBT for 34 Gy (RBE) with 1.1 RBE in 10 fractions using identical parameters for target and organs at risk. Results: Significant reduction in maximum dose to the ipsilateral breast was observed with PBT and IMRT (mean 108.58% [PBT] versus 107.78% [IMRT] versus 2194.43% [BT], P = .001 for both PBT and IMRT compared to BT). The mean dose to the heart was 0%, 1.38%, and 3.85%, for PBT, IMRT, and BT, respectively (P < .001 and P = .026). The chest wall mean dose was 10.07%, 14.65%, and 29.44% for PBT, IMRT, and BT, respectively (P = .001 and .013 compared to BT). The PBT was superior in reducing the mean ipsilateral lung dose (mean 0.04% versus 2.13% versus 5.4%, P = .025 and P < .001). There was no statistically significant difference in the maximum dose to the ipsilateral lung, chest wall, 3-mm skin rind or in the mean ipsilateral breast V50% among the 3 techniques (P = .168, .405, .067, and .780, respectively). PBT exhibited the greatest mean dose homogeneity index of 4.75 compared to 7.18 for IMRT (P = .001) and 195.82 for BT (P < .001). All techniques resulted in similar dose conformality (P = .143). Conclusion: This study confirms the dosimetric feasibility of PBT and IMRT to lower dose to organs at risk while still maintaining high target dose conformality. Though the results of this comparison are promising, continued clinical research is needed to better define the role of PBT and IMRT in the accelerated partial breast irradiation treatment of early-stage breast cancer.Item Prospective trial comparing intraoperative flexible, rigid, and no cystoscopy after ultrasound-guided transperineal permanent seed prostate brachytherapy(Elsevier, 2015) Sylvester, John; Perry, Matthew; Togerson, Erik; Hinton, Jason; Department of Radiation Oncology, IU School of MedicineObjective This is a prospective trial comparing the impact of intraoperative flexible, rigid, and no cystoscopy on dysuria immediately after permanent seed prostate brachytherapy (PB). It prospectively documents the time course and characteristics of dysuria, as well as the rates of urinary retention post-PB. Furthermore, this study attempts to establish the utility of routine, post-PB cystoscopy, by documenting the incidence of finding significant pathology on cystoscopy. Materials and methods Between January 2003 and January 2007, 225 patients deemed by their physician to be candidates for PB alone were recruited to the study. Patients who had external beam radiation therapy and/or androgen deprivation therapy were excluded. Preimplant International Prostate Symptom Score (IPSS), urinary quality of life score, urine leakage score, Sexual Health Inventory for Men score, and Radiation Therapy Oncology Group Bowel Health Inventory Scores were obtained. Patients were assigned to one of the following three groups: intraoperative rigid cystoscopy, flexible cystoscopy, or no cystoscopy following PB. Patient self-administered questionnaires were given to the patient in the recovery room after PB. These questionnaires evaluated the intensity, type, and duration of urinary symptoms associated with the first four urinations post-PB. All patients were seen on postoperative Day 1 when the surveys were retrieved. Patients were then followed up every 3 months. Acute urinary retention (AUR) was documented in the follow ups. Frequencies of significant pathology (defined as bladder tumor, urethral stricture, or large blood clots) were documented at the time of cystoscopy. AUR rates were also evaluated by the isotope used (I125, Pd103, or Cs131). Results A total of 225 patients were enrolled into this study, but only 194 patients could be analyzed for dysuria. Thirty-one patients were excluded from analysis (6, 13, and 12 patients from the rigid, flexible, and no cystoscopy groups, respectively). These patients did not return the questionnaire, or were in retention, and thus did not have dysuria scores to report. Baseline characteristics for the 194 patients in terms of preimplant IPSS, quality of life, prostate volume, and isotope used were well balanced between all three groups. There were no significant differences in dysuria between the three cystoscopy groups at any time point following PB. The mean dysuria score across all time points was 5.5 of 10, with 0 representing “no pain” and 10 representing “the worst possible pain.” Pain was most often characterized as “burning” (78%), whereas dysuria most commonly was “only during urination” (56%). AUR rates (6.8–9.5%) and duration of catheter dependence (10.5–19 days) were not found to be significantly different between the assigned groups. When results were stratified by isotope, patients treated with I125, Pd103, and Cs131 seeds experienced a 6%, 14%, and 0% retention rate, respectively. The I125 and Pd103 patients had similar pretreatment IPSS and prostate volumes. Seven percent of patients undergoing cystoscopy had significant findings. The most common finding was “clots thought too large to void” (3%). Seeds in the bladder/urethra occurred in 1% of cases. Only 0.7% of patients were found to harbor unsuspected bladder tumors. Conclusion There was no significant difference in dysuria in the first four urinations post-PB between patients in the rigid, flexible, and no cystoscopy groups. Larger blood clots that may have been difficult to void, seeds in the bladder and/or urethra, and other abnormalities were found in 7% of patients who had cystoscopy. This may suggest that cystoscopy may be worthwhile post-PB. The incidence of AUR was not significantly different between the three cohorts.