My data over the years suggests that Palladium is indeed very effective treating lowgrade prostate tumors. This rarely allows for re-utilization of the isotope. Also, technical accuracy of seed placement with Pd is more demanding and requires greater skill on the part of the brachytherapist. I always recommend brachytherapy newcomers to use I at first since it is far more forgiving of geographical targeting misses than Pd In that regard, I believe that stricter standards need to be set by the medical community to ensure improved technical acumen; a one to two day teaching course will never suffice.
With regard to our combination protocol with external beam radiation therapy and Pd. This change of therapeutic approach is important with virtually every cancer, hence the common utilization of combined modality treatments in contemporary cancer medicine e. It is my hope that with improved implant techniques, results with I and Pd will become generalizable. Only a well-conducted, randomized clinical trial will ultimately settle the controversy, but I think the results I have reported in my published studies are telling.
Other Brachytherapy Isotopes Another isotope, Cesium, is currently being investigated as a permanent implant.
It has a shorter half-life 9. This means that Cesium is likely to deliver a higher dose to surrounding healthy tissue over a shorter period of time; and therefore, there is a an increased risk of complications over time. Like Gold Au , another isotope that was used some years ago, the shorter half-life of these isotopes with 9.
Iridium is an isotope used for temporary brachytherapy implants, known as high dose rate HDR brachytherapy. Ir brachytherapy is often combined with external beam radiation. HDR is a form of hypofractionated radiation, which involves limited, very high dose rate treatment sessions fractions. This form of brachytherapy delivers the highest dose of radiation to the entire body due to the penetrating nature of Ir The best-case protocol utilizes fractions treatment sessions over time , but many patients can only tolerate 2 fractions.
Patients with 3 high-risk factors had a biochemical survival rate of only The study also reported that serious urethral strictures affected A more recent study from UCLA reported on intermediate risk patients treated with 6 fractions of HDR as monotherapy without external radiation or hormonal therapy. Patel S, et al, Brachytherapy, Mar - Apr;16 2 There really is no good argument for Ir HDR, aside from the fact that the procedure reimburses doctors substantially more than Pd or I Functional tests of outcome included best-corrected visualacuity.
Anatomic results included changes in tumor height and subretinal fluiddocumented by ophthalmoscopy, fluorescein angiography, and ultrasonography. Results All patients had complete resolution of subretinal fluid with reattachmentof the retina.
Mean follow-up was Conclusions A single Pd plaque radiation treatment was effective indecreasing tumor height, eliminating subretinal fluid, and improving visualacuity in patients with symptomatic circumscribed choroidal hemangiomas. Circumscribed choroidal hemangioma is a benign vascular tumor that typicallyappears as a subtle, amelanotic, red-orange mass in the posterior pole.
Massive exudation may lead to serous retinal detachment. Various treatment modalities have been described for symptomatic choroidalhemangiomas and have included penetrating diathermy, xenon photocoagulation,argon laser photocoagulation, microwave hyperthermia, external beam radiotherapy,infrareddiode laser thermotherapy, photodynamic therapy, stereotactic radiotherapy,and radioactive plaque therapy.
Laser photocoagulation was previously widely used to treat choroidalhemangiomas. Several researchers have also reported successful treatment of diffuseand circumscribed choroidal hemangiomas with radiation therapy. Most recently, Kivela et al 14 reportedtheir experience with stereotactic radiosurgery for circumscribed choroidalhemangioma. They noted resolution of subretinal fluid in all patients andsuggested that stereotactic therapy be targeted to small and posteriorly locatedcircumscribed choroidal hemangiomas.
In , palladium Pd seeds became available forbrachytherapy. Herein are reported what we believe to be the first visual and anatomicresults of a series of patients with symptomatic choroidal hemangiomas treatedwith Pd ophthalmic plaque radiotherapy. A prospective, nonrandomized clinical study was conducted in 5 consecutivepatients with previously untreated and symptomatic circumscribed choroidalhemangioma.
The diagnosis was made by clinical ophthalmoscopic, fluoresceinangiographic, and ultrasonographic features. Each patient participated ina detailed discussion of the risks and benefits of various therapeutic modalities. All patients signed a statement of informed consent. Institutional reviewboard approval was not considered necessary because of the established useof radiation therapy for choroidal hemangiomas. Ophthalmic evaluations included a best-corrected visual acuity andpupillary, oculomotor, and slitlamp examinations.
Goldmann tonometry was usedto measure intraocular pressure. The basal dimensions of the tumors were determinedby ophthalmoscopy, fluorescein angiography, transillumination, and B-scanultrasonography. A-scan ultrasonography was used to measure the height ofthe tumor and internal reflectivity. B-scan ultrasonography was typicallyused to determine tumor location and shape and evidence of retinal detachments.
Fluorescein angiography and fundus photography were used to evaluate and recordpatterns of tumor circulation, focal leakage, cystoid macular edema, and radiationretinopathy. The clinical data were analyzed with regard to improvement in visualacuity after treatment. The SPSS software package, version The cylindrical titanium-encapsulated Pd seeds measured 0. Because of low energy of x-rays from Pd, the 0. In performing brachytherapy, the doctor places a biplaner ultrasound probe in the rectum to image the prostate.
The biplaner ultrasound, along with fluoroscopy, gives a multidimensional view of the prostate on several TV screens. These images are then used to accurately place the needles and to space the seeds in the prostate gland. No surgical incision is required. Needles are advanced through an area of skin behind the scrotum and in front of the rectum into the prostate with the aid of:.
Radioactive seeds are then deposited through the needle into the prostate gland. The seeds are permanently placed in the prostate gland. Depending on the radioactive seeds that are selected, they give off radiation for 3 months to a year. Both the probe and needles are removed when the procedure is completed. Cystoscope is done to evaluate the urethra and the bladder and to retrieve any seeds found in the bladder.
Internal radiation therapy, also called Interstitial Radiotherapy or Brachytherapy involves implanting radioactive seeds into the prostate gland to treat cancer.
Intraoperative brachytherapy using I pellets was reported to provide significant palliation and meaningful prolongation of life in highly selected patients with unresectable carcinoma of the pancreas. After considering some of the advantages of Pd over I, we designed a phase I-II clinical trial to assess the feasibility of intraoperative Pd in unresectable carcinoma of the pancreas to study the related morbidity when combined with chemotherapy and external beam radiation, and to evaluate the impact on palliation and local control rates.
Between December and December , 15 patients with biopsy-proven unresectable adenocarcinoma of the pancreas were treated with interstitial Pd implants during laparotomy. In 13 patients the lesion was located in the head of the pancreas, in one patient in the uncinate process, and in one patient in the body of the pancreas.
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