Case Reports: A Roundtable Discussion
Case Reports: A Roundtable Discussion
CASE REPORT 1:
A patient with lumbar pain
· Dr. Porter: A 61-year-old gentleman is diagnosed with prostate
cancer and undergoes a radical prostatectomy and lymph node dissection
in 1983. Six years later, he presents with worsening pain in the
lumbosacral spine and a PSA of 120. Therapeutic choices include:
Hormonal manipulation; hormonal manipulation with radiotherapy
to the lumbar cervical spine; isotope therapy; hemibody irradiation;
or chemotherapy. How would you manage this patient?
Approximately 25% of our audience here would choose hormonal therapy
and 75% would use both hormonal therapy and radiation therapy
to the spine. Dr. Stone, what's your opinion?
· Dr. Stone: This patient has an excellent chance of responding
completely to hormonal therapy. His presentation implies that
he may fit into the category of minimal disease, with metastasis
limited to the axial spine. Since these patients respond well
to complete hormonal therapy, I would reserve radiation therapy
for a relapse after hormonal therapy fails.
· Dr. Poulter: Hormonal therapy would be the obvious choice.
The use of radiation therapy would depend on a number of factors,
including the severity of pain, the risk of fracture or spinal
cord compression, and the rapidity of the response to hormonal
manipulation. PSA could be used to assess therapeutic effectiveness.
My choice would be to start with one therapy because, when treating
pain at a single site with two therapies, you do not know which
one is providing the response.
· Dr. Logothetis: I would use hormonal therapy alone.
CASE REPORT 2:
A patient with spinal cord compression
· Dr. Porter: A patient is referred to you after having received
4 mCi of Sr-89 approximately 5 weeks ago. He now has signs of
spinal cord compression at level T10. There are four treatment
choices: Local field radiotherapy of 3,000 cGy in 10 fractions;
neurosurgery; readminister Sr-89; or chemotherapy. How would you
manager this patient?
Responses from our audience indicate that approximately 75% would
treat with local field radiation therapy to the area causing the
cord compression and 25% would refer the patient to neurosurgery.
This case addresses the concern of an additive toxicity from Sr-89
in the spinal cord and external beam radiation . A frequently
asked question is--How does one account for the dose of Sr-89
previously administered? Dr. McGowan, what would you recommend
in this case?
· Dr. McGowan: I would treat with external beam radiation.
I am not concerned about an additive toxicity with Sr-89 in the
spinal cord, since the isotope is absorbed mainly in bone, with
minimal dosage delivered to the spinal cord. Neurosurgical intervention
could also be considered, however, our community of neurosurgeons
are very reluctant to operate on a patient with spinal cord compression
from prostate cancer.
· Dr. Porter: I agree that there are no additive effects
with Sr-89 and external beam radiation, since Sr-89 is a pure
beta emitter. In fact, the TransCanadian study reported no increase
in additive complications from treating spinal cord compressions
with local field radiation followed by Sr-89 treatment.
· Dr. McGowan: I would like to add that I have actually seen
several patients develop a spinal cord compression after receiving
Sr-89. However, it has usually occurred within a week to 10 days
post-treatment, as opposed to the 5-week interval described in
CASE REPORT 3:
What next for this man who failed leuprolide and flutamide?
· Dr. Porter: A patient with D2 metastatic prostate cancer
is treated with total androgen blockade consisting of leuprolide
(Lupron) and flutamide (Eulexin). After 2 years on this therapy,
he relapses and complains of pain that he describes as "fleeting."
His bone scan is positive and his PSA has risen. Treatment choices
include: Isotope therapy; hemibody radiotherapy; local field radiotherapy
to bone-scan-positive areas; or chemotherapy using estramustine
(Emcyt) and VP-16 (etoposide, VePesid).
The majority of attendees in our audience chose isotope therapy.
· Dr. Logothetis: These patients require discussion in choosing
the appropriate treatment regimen. If you have an 80-year-old
gentleman, there is typically no interest in the inconvenience
associated with investigational therapy. Therefore, strontium
would be the appropriate choice when pain palliation is the main
therapeutic goal. Alternatively, a younger patient or one who
would prefer to explore all available options, would be a candidate
for investigational therapy. Once these patients understand that
these treatment options are unproven, the choices of estramustine,
VP-16, or various combinations can be considered. I know of no
proven advantages among them at this time.
I have a note on one of the question cards submitted by the attendees
inquiring about angiogenesis inhibitors, which we are studying.
One such drug, fumagillin, is currently being tested clinically
for the treatment of prostatic carcinoma.
CASE REPORT 4:
May this man be cremated?
· Dr. Porter: An 84-year-old man was treated with 4 mCi of
Sr-89 5 months ago. His disease progressed and he died. His family
wishes to have him cremated. As the radiation oncologist, should
you advise that the body be stored for two half-lives prior to
cremation and should you advise the crematory about the Sr-89,
or is that not necessary? Is radiation emission from the body
not a concern?
There are few rules governing the cremation of a body containing
a beta emitting substance. One study, by the International Association
of Physicists in Medicine, addressed safety rules concerning Sr-89.
This association is not a legal body in the United States. Nonetheless,
they recommend that a body could be cremated with a dose of 400
MBq of Sr-89 and buried with a dose of 1000 MBq (divide by 37
to convert MBq to mCi). Since 400 MBq is well above the dosage
currently used, a patient could be cremated even if he died the
same day the Sr-89 was administered. The cremating facility should,
of course, be informed. The Nuclear Regulatory Commission met
with us recently and is debating the standards of dose responsibilities
CASE REPORT 5:
Pain in the lumbar spine
· Dr. Porter: A patient with well-controlled primary lung
cancer requires palliative radiotherapy for a painful metastasis
in the lumbar spine. How should this patient be treated in terms
of dose fractionation? On the basis of the data that Colin Poulter
presented (see page 19), would you use: 800 cGy in a single local
field fraction; 2,000 cGy in five fractions; 3,000 cGy in 10 fractions;
or 4,000 cGy in 20 fractions.
Responses from our attendees indicate that 3,000 cGy in 10 fractions
is considered standard in North America. Colin, what are your
thoughts on dose fractionation?
· Dr. Poulter: Our standard treatment dosage is 3,000 cGy
in 10 fractions. However, since numerous factors are considered
in dose determination, we frequently deviate from the standard
protocol. Some patients, for example, would receive a single dose
of 800 cGy.
· Dr. McGowan: My standard treatment regimen is 2,000 cGy
in 5 fractions or 1,000 cGy in a single fraction. The dose is
decreased to 800 cGy in a single fraction for rib metastases.
The single treatment patients are often those who must travel
long distances. In Canada, some patients have to travel 300 or
400 miles for treatment, prompting most Canadian clinicians to
use shorter fractionations for practical reasons.