The cancer journal
-
Comparative Study
Dose/volume relationship of late rectal bleeding after external beam radiotherapy for localized prostate cancer: absolute or relative rectal volume?
The purpose of this study was to analyze predictors of late rectal bleeding after external-beam radiotherapy for localized prostate cancer, with a focus on the volume of rectum irradiated. ⋯ To date, five patients have had grade 1 late rectal toxicity (one CRT case and four SCIM-RT cases), one patient had grade 2 late rectal toxicity (CRT), and three patients had grade 3 late rectal toxicity (all CRT cases). Because of the low number of events, the analysis was performed with all patients experiencing rectal bleeding grouped together. The actuarial rectal bleeding rates at 18 and 24 months were 6% and 8%, respectively. The actuarial rectal bleeding rates at 24 months were identical (8%) for both SCIM-RT and CRT. A multivariate analysis of the following parameters was performed to determine independent predictors of rectal bleeding: age (continuous variable), race (Caucasian vs African American), coverage of seminal vesicles (yes vs no), adjuvant androgen deprivation (yes vs no), technique (CRT vs SCIM-RT), Radiation Therapy Oncology Group acute rectal toxicity score (continuous variable), VrPr (continuous variable in cubic centimeters), and %VrPr (continuous variable). Only the VrPr (cubic centimeter) was an independent predictor of rectal bleeding; %VrPr was not. With different cut-off levels being used, a VrPr of 15 cm3 was significant on univariate analysis; the actuarial rectal bleeding rates at 24 months for patients with a VrPr < or = 15 cm3 versus a VrPr > 15 cm3 were 5% versus 22%, respectively. CONCLUSION> In our study sample, which included both conformal and intensity-modulated radiotherapy patients, the volume of rectum receiving the prescribed radiation dose (the equivalent of 78 Gy) was an independent predictor of late rectal bleeding. The percent of rectal volume receivingthe full dose was not. Using actual volume rather than percent volume also avoids the dependence on the extent of rectal volume contours. We recommend 15 cm3 as the cut-off of the rectal volume not to exceed the prescription dose. The rectal bleeding rate at 2 years for cases with < 15 cm3 receiving the full dose was only 5%.
-
Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
I-125 versus Pd-103 for low-risk prostate cancer: morbidity outcomes from a prospective randomized multicenter trial.
The purpose of this study was to test the hypothesis that the shorter half-life of Pd-103 versus I-125 results in a shorter duration of radiation-related symptoms after prostate brachytherapy. ⋯ Patients treated with Pd-103 recovered from their radiation-induced prostatitis sooner than I-125 patients. It appears that patients with minimal pretreatment urinary obstructive symptoms are the most likely to experience implant-related exacerbations of their symptoms and are the most likely to benefit from the more rapid half-life of Pd-103 rather than I-125.
-
Metastases to the spine are a challenging problem. Percutaneous, image-guided tumor ablation with a thermal energy source, such as radiofrequency, has received increasing attention as a promising technique for the treatment of focal malignant disease. We used radiofrequency ablation for patients with unresectable, osteolytic spine metastases under computed tomographic and fluoroscopic guidance. The purpose of this study was to determine the feasibility, effectiveness, and safety of radiofrequency ablation as a palliative procedure to reduce pain and back pain-related disability in patients with vertebral and paravertebral spine tumors who were not able to benefit from radiotherapy, chemotherapy, or surgery. ⋯ Radiofrequency ablation was successfully performed in all 10 patients. Needles were placed accurately under image guidance, and a controlled lesion was created. Pain- and back pain-related disability was clearly reduced, and neurologic function was preserved or stabilized. When confirmed by further investigation, this therapy may be a new option for patients with unresectable spine tumors that do not respond to radiotherapy and chemotherapy.