What is Dynamic Adaptive Radiotherapy or DART?
Dynamic Adaptive Radiation (DART) is cutting edge arsenal of technologies that uses up-to-the-moment “captured” image data to adapt a patient’s treatment to constantly evolving information which occurs during a treatment course. It is well known that changes such as tumor position, size and shape occur not only during a several week treatment regimen, but also on a daily basis when patients are undergoing treatment. DART allows us to realize the single most important goal ever achieved with radiation therapy: Delivering the exact dose to the exact place at exactly the precise time, every time, even when the target (tumor) moves, shrinks or changes shape – a revolutionary and unprecedented accomplishment in the treatment of prostate cancer!
Will All This New Technology Cost Me More?
No. This is truly one time in your life when the newest and best technology will not cost you more than the older, more common approaches. In fact, in terms of a cure, you'll get more for your money!
How Do You Know If You Are "Cured"?
There has been much discussion of what constitutes a cure, or biochemical freedom of disease. Many physician practices have tried to assign a specific PSA nadir (lowest point) to identify the patient as ”cured”. However while a low PSA is important, the goal is not merely a low number but a cure. Patients must be wary of being over treated just to achieve a low number.
The Dattoli Cancer Center considers a patient “cured” when his PSA is significantly reduced and remains at that reduced level consistently for the remainder of his life. Most patients achieve a PSA of <0.2, although this is not mandatory. For example, a particular patient of Dr. Dattoli”s has had a PSA of 2.0 for 18 years. We certainly do not think his treatment failed! For the purpose of determining our success rate in published studies, we employ a strict nadir cutoff of PSA of <0.2 for the purpose of comparing our results with the published results of other treatment modalities. We hold ourselves to a higher standard than most other centers.
What is the Difference in this Center and Others that Specialize in Prostate Cancer Treatment?
The Dattoli Cancer Center & Brachytherapy Research Institute is the only place in the world where this combination of leading edge technologies and pioneering medical specialists are found. Dr. Dattoli has more experience in brachytherapy than any other radiation oncologist in the world. Dr. Sorace has been at the heart of research and development in this field for over a decade. The breadth of our diagnostic and treatment technology is unmatched anywhere.
The success rates of Team Dattoli are documented and professionally envied. Both doctors are widely published and are in great demand as lecturers. Despite their many obligations, they have maintained their primary mission and focus: to provide the very best cancer care available – one man at a time.
What is 3-Dimension Color Doppler Ultrasound?
The color-flow Doppler prostate ultrasound, introduced to the west coast of Florida by the Dattoli Cancer Center, brought a new perspective to diagnosing prostate cancers. The Doppler technology reveals in brilliant color areas of increased blood flow within the gland, indicating sites of suspected tumor growth. This information is crucial in planning the prostate biopsy, as it gives the physician color “targets” for the biopsy cores. Most biopsies for prostate cancer are performed utilizing transrectal ultrasound equipment which portrays images in hues of grey, resulting in randomly spaced biopsy cores that may often miss a cancer entirely.
With the recent addition of a brand new Sonocubic computer program, physicians at Dattoli Cancer Center can look at suspected tumor growth from 360 degrees, rotating the image on the monitor to view the transparent structure from all sides, and enhancing the information needed to perform the all-important biopsy. Additionally, this same sophisticated technology is used for therapeutic reasons (that is, for patients who have already had a biopsy) allowing for the pinpoint targeting of cancerous lesions using both DART and brachytherapy (seeding).
Why Do You Require Such Extensive Metastatic Workup?
A metabolic workup involves a number of tests that tell us whether or not the cancer has spread beyond the prostate gland. This is crucial in deciding on the type of treatment that will be appropriate for each patient. Prostate cancer has been historically both under staged and under graded, which means that the extent and severity of the disease has often been underestimated, and therefore, not adequately treated. To enhance your opportunity for cure, we believe that we should turn over every stone possible, using the most sophisticated techniques to assess every case, including 3-D color flow Doppler ultrasound, MRI of the prostate with endorectal coil or spectroscopic vs. dynamic MRI, helical scans to evaluate lymph nodes, special blood tests, bone scans, Prostascint/Fusion studies, and Combidex® or Sinerem® MRI as indicated. Remember, even if we find something serious as far as the spread and/or aggressiveness of the disease, this will be addressed with an appropriate form of therapy tailored for each patient. At other centers where the workup is not adequate, where the tests are not as extensive, it is what is not found and not treated which can later come back to haunt the patient. We believe in going the extra mile with all of our patients to avoid that kind of unacceptable outcome.
If I've had External Beam Radiation or Seep Replacement Elsewhere, but I am Not Cured, Can I Try Either Again at Your Center?
As we are dedicated to finding the highest level of cure for each patient, we will certainly be willing to schedule a consult with you to determine what we might be able to do to help you. There are a number of possible options that can be considered if a patient experiences biochemical failure (rising PSA or other indicator) after having been treated at another center with external beam radiation or brachytherapy. As a rule of thumb, the earlier a recurrence is detected, the better the chances that a “salvage therapy” can lead to a cure.
Are Some Cancers "Radio-Resistant" and How Will I Know if Mine is?
“Radio-resistance” is an out-dated term from the early years of conventional radiation therapy, or even 3-D conformal radiation. It’s highly unlikely that any tumor can survive the extraordinary, yet safe, doses delivered by DART combined with pd-103. (Tumors often receive in excess of 20,000 cGy.) In addition, in many cases, hormonal therapy prior to radiation has been shown to enhance the radio-sensitivity of the cancer, making treatment all the more effective.
If the full course external beam radiation failed, can I be a candidate for your treatment if my cancer is still confined to the prostate?
Yes, typically not DART alone, but salvage palladium seeding plus/minus abbreviated DART and seed implantation may well be a viable option for you. Your case will be carefully evaluated to determine your candidacy. Hormones are typically used prior to the seeding. Dr. Dattoli has performed salvage seeding for over 15 years.
If my surgery failed and my PSA is Rising with no Evidence of Cancer Spread to Other Organs, am I Still a Candidate for DART?
YES. DART will provide the least dose to healthy tissue and organs surrounding the prostate, minimizing the risk of side effects, and give you the best shot at a cure. In this type of case we commonly use hormones
along with DART.
If I've had a TURP (commonly called a roto-rooter or reaming), am I a candidate for your procedure?
Drs. Dattoli and Sorace have pioneered unique designs to allow seed implantation even in these difficult situations. Each patient is carefully evaluated to determine their candidacy and to minimize potentially unwanted incontinence.
Why are younger men told that they should have radical surgery and not seeding since there are no long term reports on seeding?
The argument that there is insufficient long-term follow-up of brachytherapy series is patently false. In fact, numerous studies of seed implantation, including Dattoli et al. (J of Urology 2007), Blasko et al (2005), and Killmeir (2003) have mean and medium long-term follow-ups that surpass all surgical series published in the PSA era. In this regard, outstanding results (biochemical outcomes) have been reported for younger patients with brachytherapy and this group has the most to gain (reduced risk of urinary incontinence and/or erectile dysfunction). In our practice, we commonly treat men in their early 40’s (as well as patients in their 50’s, 60’s and older). Younger men, after all, have the most to lose – being impotent and wearing diapers for decades.
My urologist told me that if I have radiation and the cancer returns, I can no longer have surgery. Is this true?
Absolutely not – the opposite is true! Firstly, it is extremely rare for patients to have local relapse when treated initially by our team. If however, the cancer did return in the prostate, patients still have a full menu of options including reseeding, surgical removal (by an expert), cryotherapy, biothermy, HIFU and hormonal therapy, not to mention vaccine therapies are on the way. If you desire surgery, there are many proficient surgeons who we can recommend (and it my not be your local urologist).
The real problem is for the patient who chooses surgery first since there are few options left. For example, following surgery, patients are often faced with a rising PSA. It becomes unclear whether the PSA is rising due to cancer left behind in the prostate bed versus cancer in the blood stream. Patients are typically given the benefit of the doubt and are treated to the prostate area with local radiation (you can’t treat the entire body with radiation!). This may be associated with increased complications with damage to bowels, bladder and urethra while the overall chance of benefiting the patient lies only between 10-30%.
If I choose seeding now, what are my options if treatment isn't successful?
This has become a common scare tactic used by surgeons: “If you have radiation, you can never have surgery.” The question which really should be asked is “what do I do if I undergo prostatectomy and my cancer returns?”
After prostatectomy, “broad beam” rather than tightly tailored radiation is typically offered with only 10-30% (depending on PSA level) of patients being cured, while side effects from the initial surgery are compounded. Otherwise, hormones are offered, which have considerable side effects, and also fail to control cancer after 2 to 3 years because the cancer becomes immune or resistant (like infections becoming resistant to antibiotics over time).
After DART and/or seeding, numerous options are available including but not limited to re-seeding, cryosurgery (freezing), biothermy (combining heating and freezing), HIFU, not to mention salvage prostatectomy by an EXPERIENCED SURGEON.
What are the advantages of seeding over surgery?
As mentioned earlier, the risk of impotence and/or incontinence is greatly reduced with seeding, in comparison to the risks resulting from surgery. The surgical procedure typically requires hospitalization and a lengthy recovery period. Because most surgeries require a major incision, there is an increased risk of infection and other surgical complications. Newer laparoscopic and robotic techniques even increase the length of the procedure, thus increasing potential complications (blood clots to the lungs, infection) and many laparoscopic/robotic procedures are aborted and converted to the more formal open approach when vessels are nicked or the rectum is lacerated. At our center, we have published superior results with combination therapy (brachytherapy and IMRT with or without hormones) with intermediate and high risk patients (Stage T3, PSA >10, Gleason Score 7-10, elevated PAP) compared to surgery — with more than 80% of these patients enjoying successful long-term outcomes.
It should be noted that the limitations of the open radical prostatectomy also apply to laparoscopic and robotic surgical techniques: the operation is necessarily performed “in the blind,” in the sense that the patients’ workup tests do not allow the surgeon to know with any certainty in advance whether or not the cancer has spread beyond the prostate gland. In other words, the risk of having “positive surgical margins” is the same regardless of which surgical technique is used. In our opinion, this means there is an unacceptably high risk of failure with all forms of radical surgery.
Is there sufficient published data to support the choice to have seeing over surgery?
Yes, there is. While there are no randomized studies comparing the different types of treatments, numerous independent studies have contrasted statistical data from both options (seeding and surgery), comparing the results of different specialties as reported by the leading practitioners at centers of excellence. Follow-up studies have been in place since the beginning of our practice in 1990. Other large programs, including the Northwest Tumor Institute and the University of Washington in Seattle report an approximate 80% seeding success rate after 12 years of follow up. Our data, using combination beam and seeds, has demonstrated a greater than 80% success rate after 16 years even in patients having locally advanced high-risk malignancies (Stage T3, PSA > 10, Gleason Score 7-10, elevated PAP) while patients having early or intermediate stage disease have enjoyed a greater than 90% success rate. (Note that the longest surgery data follow-up is only 14 years from Johns Hopkins and the “median follow-up” on our patients is longer than any surgical series).
What is dynamic adaptive radiotherapy or DART?
“Dynamic Adaptive Radiation” (DART) is cutting edge technology for truly “individualized” treatment delivery. This involves using up-to-the-moment “captured” image data to adapt a patient’s treatment to constantly evolving information which occurs during a treatment course utilizing DART. It is well known that changes such as tumor position, size and shape occur not only during a several week treatment regimen, but also on a daily basis when patients are undergoing treatment. DART allows us to realize the single most important goal ever achieved with Radiation Treatment: Delivering the exact dose to the exact place at exactly the precise time, every time, even when the target (tumor) moves, shrinks or changes shape – an extraordinary accomplishment!
Why can't I have external radiation at "home" and then come to you for seeding?
We believe that a “seamless,” coordinated treatment plan, combining external beam radiation and seeding, offers the best results for our patients. The unique configuration of technologies available here is designed to work together, so the external radiation plan (DART) and brachytherapy planning perfectly complement each other. It would be very difficult to integrate another center”s therapy with the combinations we have here. Indeed, most other centers do not have the most advanced diagnostic and treatment technologies that we utilize on a daily basis. Our highest level of confidence rests in our own ability to provide you with the very best treatment available anywhere in the world.
What is HDR?
High Dose Radiation (HDR) commonly refers to temporary catheter insertion into the prostate using Iridium-192, which is a very penetrating isotope (radiation spreads far from the isotope), expending the dose quickly and consequently to all neighboring structures. This is NOT a new form of brachytherapy, although it is currently being promoted as such. In fact, Dr. Claude Henschke at Memorial Sloan-Kettering Cancer Center was using it in 1963, with the only difference being today’s microprocessors and imaging techniques. There is less long term data available on temporary HDR outcomes and side effects compared to the permanent Pallidium-103 seed implants we utilize. There may be greater risk of complications with HDR brachytherapy because of the extremely penetrating high dose of radiation delivered by Iridium-192 (1000 to 2000 cGc in a matter of minutes, affecting the entire body).
Bear in mind that DART is also a form of high dose rate radiation employing micro-beamlets precisely targeting the affected area(-s) in minutes, but without affecting surrounding normal tissues as does HDR brachytherapy. We believe that this degree of pinpoint accuracy with DART and 3D-CFD guided Palladium 103 makes HDR catheters obsolete. Meanwhile, we also believe that the use of both DART coupled with ‘round the clock’ (for 3 months) Pd-103 treatments provides the best of both worlds. Essentially, we are exposing the cancer to two different complementary forms of radiation in order to provide the greatest chance of cure. Cancers don’t like change, which is why we deliver this one-two punch from two different radiation sources!
What About Proton Therapy?
Proton Therapy causes significantly fewer complications than does traditional external radiation therapy (EBRT), but its precision in sparing healthy tissues is now surpassed by DART and/or brachytherapy in the most skilled hands, especially with the inverse treatment planning used with DART utilizing SonArray, Portal Vision electronic On-Board imaging, Portal Dosimetry, cone beam helical CT tomography and respiratory gating which are all state of the art methods of motion management, none of which are not available with proton therapy.
It should be emphasized that the radio-biological effect (RBE) of protons is nearly identical to the high-energy photons that we utilize at our center with DART. This being the case, we strongly favor DART in view of the highly sophisticated beam arrangements which are utilized, state-of-the-art prostate immobilization and far more mature data which has been accrued with high energy photons in general. Published series have already demonstrated advantages of DART to 3-D conformal radiation at high dose levels. Meanwhile, we are not even aware of any proton series utilizing higher doses than 3-D conformal radiation.
The preponderance of data suggests that higher doses equal higher cure rates. It is not possible to safely escalate protons to high doses as those used with IMRT — not to mention DART coupled with a Palladium-103 boost. There is significant evidence demonstrating that it requires far higher doses of radiation to eradicate prostate cancer. This is accomplished with DART and Pd-103 which also has the advantage of maximally sparing adjacent normal tissues while escalating doses to specific tumors within the prostate gland — neither can be achieved with protons.
We believe that the utility for protons resides in the treatment of tiny brain tumors, not prostate cancer — due to the size and location of the latter and the inability to maximize the effect in the prostate of what is called “the Bragg Peak” in Proton Therapy(basically, the characteristic pattern of energy deposition occurring when a charged proton particle moves through matter) with the prostate. Because of the physics, side effects with protons will be much higher even at lower dose levels than high energy photons, the complete opposite of what most patients are currently being told by proponents of Proton Therapy. This is another area where patients are well-advised to do their homework.
Many talk about "simultaneous radiation" using Iodine-125 followed by radiation to give a greater dose. Do you do this?
No, because with Palladium-103 you’re already receiving 3 times the dose that iodine delivers without risking the higher rates of rectal, bladder and urethral injury that have been reported when doing seeds first, followed by radiation.
Do your patients go on hormonal therapy?
It has long been known that prostate cancer is to some extent dependent on and nourished by the male sex hormone, testosterone. This is one of a group of hormones known as androgens. Since testosterone stimulates the growth of prostate cancer cells, depleting or ablating the body”s testosterone tends to shrink the size of many tumors, specifically, those that are hormone-sensitive.
The goal of hormonal therapy is to decrease the production of testosterone in the body, inhibiting the growth and progression of the cancer. Hormonal therapy, also known as Androgen Ablation Therapy (ADT), can shrink a man’s prostate by 50%.
Hormonal treatment is typically optional for patients having intermediate risk features (as indicated by Stage, PSA, Gleason Score, and PAP results) but encouraged for patients having high risk features. With the low-risk or mildly aggressive cancers, unless the size of the gland is markedly large, we don’t normally give the conventional hormonal therapy (combined hormonal blockage using an anti-androgen and an LHRH agonist), since this form of therapy may result in typically temporary although potentially longer lasting unwanted side effects such as erectile dysfunction, hot flashes and potential fatigue.
We often prescribe a milder, modified version of hormones which do not reduce testosterone but rather act as blocking agents (e.g. oral anti-androgens), not allowing the testosterone to bind with the prostate cancer receptors. These are commonly combined with other oral agents (e.g. 5 alpha-reductase inhibitors) which do not allow testosterone to convert to dihydrotestosterone (DHT), a metabolite which is 10 times as potent as testosterone in stimulating prostate cancer growth. This type of hormonal therapy is just enough to arrest the cancer and allow the patient to make a more relaxed decision about treatment, without the side effects associated with formal ADT. Hormonal Therapy is often administered intermittently for 6 to 12 months. With Intermittent Hormonal Therapy, the patient’s testosterone level recovers and his quality of life (QOL) improves dramatically.
Is DART considered experimental?
Absolutely not. This modality is FDA and Medicare approved and is a highly sophisticated by-product of prior radiation delivery systems. Numerous recent studies have already shown that it is possible to escalate doses significantly in order to more effectively eradicate the cancer, while decreasing morbidity (unwanted long term side effects) dramatically.
Is all IMRT the same?
No! Many centers that advertise IMRT, actually have early generation equipment that is already antiquated. It’s one thing for a center to offer IMRT, but it’s another to demonstrate that every microbeam has actually struck the desired target which is moving, and smaller than the size of a dot! Only with the most sophisticated ancillary equipment can such a claim be made. That advanced IMRT technology includes but is not limited to On-Board Imaging, image-guided 3D ultrasound and camera-based SonArray, Exact Couch, Portal Vision, real-time cone beam helical tomography, respiration synchronized image acquisition for motion gating, Portal Dosimetry and real-time 4D physician review can such a claim be made. This is the basis behind true DART.
Why do so many patients choose the combination of DART and seeds?
Brachytherapy can be successfully utilized as the sole treatment for many patients who have been diagnosed with very early stage prostate cancer. After exhaustive research, patients learn that additional DART at our facility doesn’t add to toxicity but provides an umbrella of safety in the event that the cancer has made egress (leaks) into the tissues immediately outside the prostate (which is the case in 15-20% of even the most favorable, low-risk presentations). This is not piling on the radiation or giving a lot of both but rather a little of each (a blend which is more thorough than seeds alone or external radiation alone). For intermediate or advanced stage tumors, brachytherapy is typically prescribed in combination with other kinds of treatment, for example, DART, hormones, etc.
What is the advantage of "combination therapy
Having the availability of each type of therapy at a single center allows the physician to tailor make a treatment plan specifically for each individual case (versus a one-size-fits-all approach). Patients have the advantage of using any combination of hormones, DART and/or brachytherapy to achieve a maximum degree of cure. Note that cure rates have improved with most cancers, e.g. breast, lung and colorectal, etc. when using not one but two or three differing modalities. Cancers don’t like change!
What is DART and why is is better than 3-D conformal therapy?
DART, or Dynamic Adaptive Radiation Therapy, takes 3-D Conformal Radiation Therapy to a new level of precision and control. With this increased level of precision where microbeams are literally striking targets the size of a dot (referred to as a “voxel”), we are able to far reduce the risk of damage to the bowel and bladder while maximally preserving erectile function.
Here are some of the advanced features that make this level of precision possible: SonArray, an ultrasound and camera-based image guided system with intra-fractional motion gating, employed moments before each radiation treatment to make sure the prostate and the tumor are in the exact same location for each beam application (even the simple motion of breathing can shift the position of the prostate, which is tracked and corrected for by special respiratory gating, available at the Dattoli Cancer Center). Any patient movement is sensed by SonArray’s intra-fractional observer function in which case the DART goes safely into default mode; Portal Dosimetry is a computerized checks and balance system. Doctors utilize Portal-Vision® which enables them to watch your 4D treatment in ‘real time’ or later in the day at their work stations. Also, the SonArray image guided target positioning systems allows for daily remote real-time 4D review to the physicians’ personal computers using a wireless network system (the first of its kind); The On-Board image device and Cone Beam helical tomography add yet another layer of checks and balances which ultimately result in a level of precision which only five years ago was thought not to be possible.
How do you localize the prostate, the cancer(s) and its relationship to surrounding structures?
To ensure that the target is covered accurately with each radiation treatment, the patient is immobilized in a custom-made cradle, and a special SonArray Acquisition and Targeting System External 4-D Ultrasound and optimized infrared camera guidance is used to assess and fine-tune the position of the patient and surrounding healthy organs just prior to each daily treatment. Real-time rotational helical Cone Beam CT tomography is utilized along with Portal Vision and an On-Board Imager device is used to capture the location of the target and its relation to immediate surrounding adjacent tissue. Even a video respiratory gating program is employed to synchronize the beam with the patient’s breathing movements. Patients receive DART over several weeks’ time and each treatment is approved by the doctors with the aid of amorphous silicon diodes (Portal Vision), and reviewed by the physician in real-time using a unique in-house wireless network. Immobilization is paramount to success and the above methods maintain a daily tracking accuracy less than or equal to .3 mm/0.3 degrees!
With the above state-of-the-art technology, we can make up-to-the-minute treatment decisions while managing organ motion and dynamically adapting the radiation treatment (DART).
How do I find a real "expert" in brachytherapy?
In selecting a physician (for any type of treatment) you will need to be assertive and do your homework. Don’t be shy about asking the doctor how many cases he or she has done and what their success rate is. Ask to speak to numerous patients who will share their experiences with you, and especially patients who were treated up to a decade ago and beyond.
Dr. Dattoli and Dr. Sorace, over their 20-year partnership, have performed many thousands of prostate brachytherapy procedures… more than any practice in the world. Their success rate using brachytherapy and radiation (which is now DART) is in excess of 90% in intermediate and low-risk prostate cancers and greater than 80% even in the most locally advanced high risk prostate cancer. To quote Dr. Dattoli, “This is cancer. When it comes to the placement of seeds and DART micro-beamlets, you want every shot to be a bulls-eye!”
Our “Making My Decision” section provides additional suggestions.
Why not seed first?
When prostate cancer spreads, it grows microscopic extensions – a good analogy is the palm of your hand representing the tumor, and your fingers representing the “spiders” or extra-capsular extensions of the cancer. Within just a few weeks of receiving radiation treatment, those extensions begin to retreat back into the tumor.
We have learned that by targeting the tumor and its extensions first with DART, with or without hormones, the seeding procedure is more effective and serves as a boost, while not leaving the migrating cells in the regions outside of the prostate untreated. The surrounding field is sterilized by the daily radiation and cancers are rendered non-viable when external beam is used upfront.
Additionally, when seeds are placed in the prostate, they may cause scattering of the external radiation when it collides and is displaced by the seeds, with the possibility of irradiating healthy surrounding tissue. The available published literature using seeds before radiation has reported higher rates of rectal injury. Finally, we are concerned that placing seeds first in intermediate to high-grade cancers may even spread cancer into the blood stream, resulting in clinical failure at other sites within the body. This has been documented in contemporary brachytherapy literature.
For additional information on this topic, you may consult these two publications:
Zeitlin SL, Sherman J, Raboy A, Lederman G, Albert P. High dose combination radiotherapy for the treatment of localized prostate cancer. J Urol 1998; 160:91-96.
Patel J, Worthen R, Abadir R, Weaver DJ, Weinstein S, Ross G. Late results of combined Iodine-125 and external beam radiotherapy in carcinoma of prostate. Urol 1990; 36:27-30.
What are the possible side effects from brachytherapy?
The two major side effects of any aggressive prostate cancer treatment are the risk of erectile dysfunction (impotence) and incontinence. With Palladium-103 seed implants, erectile dysfunction occurs in about 15-20% of cases; incontinence is virtually unheard of following Palladium implants. Meanwhile, 85-90% of the 15-20% of patients regain their erectile function when using erectile aids (Viagra, Levitra, Cialis, etc.). With brachytherapy there is typically a diminished ejaculate. After surgery, there is no ejaculate. In contrast, complete or partial erectile dysfunction is experienced in most cases of surgical removal of the prostate gland. Up to 40% of surgical cases also result in some degree of incontinence.
Are there advantages to Palladium-103 over other isotopes?
Yes, there are several significant advantages and that is why we strongly prefer this isotope. The radiation emitted from Palladium-103 (Pd-103) is high enough to deliver a strong, precisely targeted and continuous ‘round the clock’ dose to the prostate tumor. The cancer killing ability, or radio-biological effectiveness (RBE) is higher for Palladium than other commonly used isotopes, such as Iodine 125 (I-125) or Iridium 192 (Ir-192) and far more thoroughly studied than Cesium 131 (Cs -131). Coupled with Palladium’s short half-life (approximately 17 days) and less penetrating characteristics (steep radial dose fall-off), this makes Pd-103 ideal for greatest tumor eradication with maximal protection of surrounding tissues. In addition, because of Palladium’s short half-life, temporary urinary symptoms after treatment are typically months shorter in duration than with treatments employing other isotopes, such as Iodine.
Explain where and how the seeds are implanted.
Each case is different, requiring a unique brachytherapy treatment plan. Depending on the size and contour of the prostate, and the size, number and location of the tumor(s), a precise seeding map is designed for the patient. The seeds are tiny, less than 4.5mm long and about the width of a mechanical pencil lead. Under an outpatient procedure, the patient is anesthetized and the seeds are implanted through the perineum (the area of the body between the anus and the scrotum) using a patented needle-like device. Sophisticated 3-D color flow Doppler ultrasound imaging technology guides the placement of the seeds into the correct locations while avoiding the neurovascular bundles.
Dr. Dattoli commonly uses different strength seeds per patient and even uses different strength seeds in the same prostate gland. For example, higher energy seeds may be positioned within the tumor, while lesser strength seeds may be placed next to normal adjacent tissue. Comparing number of seeds with other patients may be a comparison of apples and oranges, as the number implanted can vary widely.
What are the long-term results for brachytherapy?
The long-term survival rates for patients who have completed brachytherapy or combination therapy including brachytherapy under the care of a skilled radiation oncologist, are as good or better (typically greater than 90%, depending on the PSA, stage and grade) than those who have had surgical removal of the prostate. The biggest difference is in the quality of life after treatment, with far fewer incidents of erectile dysfunction while incontinence is virtually unheard of following brachytherapy (a skilled radiation oncologist will have completed not hundreds of cases, but thousands, and will have personal statistics supporting successful treatments for many years). So here we have a treatment that not only provides higher quality of life but even greater quantity!