Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3899_Библиотеки_им_академика_М_И_Перельмана.pdf
months). Poor liver function reserve also repre-
sents a relative contraindication to therapy, given
the potential of locoregional therapy to damage
normal liver. Patients with extrahepatic metastatic
disease are unlikely to benefit from treating only
some of their metastatic burden. Prior biliary
enteric anastomoses or an incompetent sphincter
of Oddi are relative contraindications to percuta-
neous therapy given the high risk of infectious
complications. Uncorrected anemia and leukope-
nia are contraindications to chemotherapy. Platelet
levels should be reviewed to insure they are at lev-
els adequate for hemostasis for both arterial and
solid organ punctures.
10.4 Patient Consideration and
Workup
As in any interventional oncology procedure, ini-
tial patient selection is crucial to success. The ini-
tial workup and treatment planning process are
centered around a meticulous review of the
patient’s medical history, oncological history, and
diagnostic imaging. Oncological clinical decision
making is complex and is best performed in a mul-
tidisciplinary setting combining surgical special-
ists, medical specialists, diagnostic radiologists,
interventional radiologists, and radiation therapy
specialists.
Surgical therapy has demonstrated superior sur-
vival benefit with respect to all other treatment
modalities in the treatment of intrahepatic cholan-
giocarcinoma, and the initial concern is whether
complete resection can be achieved (i.e., R0 resec-
tion). The scope of surgical decision making is
beyond the scope of this text, but the imaging
findings pertinent to surgical planning signifi-
cantly overlap those used in locoregional therapy
planning. Imaging is reviewed, with specific atten-
tion paid to the location of the tumor, proximity
to/encasement of adjacent vascular structures,
centricity/number of tumors, arterial supply, and
possible percutaneous approaches (▶ Fig. 10.1a, b).
The relative conspicuity of the tumor on imaging
modalities can be useful to determine the optimal
method of image guidance for ablation. Determi-
nation of portal venous and biliary patency is
important because these are associated with an
increased risk of complication. Lastly, accurate
determination of the stage is important given that
extrahepatic metastatic disease is a relative con-
traindication to liver-directed therapy.
Laboratory and clinical data are also reviewed
for relevant contraindications. ECOG score is a use-
ful assessment of performance status. Patients
appropriate for therapy typically have an ECOG
score < 3 because patients with higher scores are
less likely to derive benefit from therapy due to
coexisting morbidity. Complete blood counts,
chemistries, and liver function tests are routinely
obtained to evaluate for possible procedural con-
traindications. Elevated bilirubin values in this
Fig. 10.1 (a) Contrast-enhanced computed tomographic image of liver demonstrates low-attenutation masses with
peripheral enhancement on early arterial phase. (b) Contrast-enhanced magnetic resonance image of liver
demonstrates low-attenuation masses with peripheral enhancement on early arterial phase.
Cholangiocarcinoma: Ablation and Intra-arterial Therapies
155
population must be interpreted with caution as
biliary obstruction may falsely give the impression
of poor hepatocyte function. Lastly, baseline tumor
markers (usually CA 19–9 and CA-125) are
obtained and, if initially elevated in a patient with
proven cholangiocarcinoma, they have some value
for following the efficacy of therapy. Caution must
be used because biliary system infection (some-
times subclinical) can spuriously elevate these val-
ues. A complete blood count is obtained to ensure
adequate platelet numbers and cell counts prior to
the patient receiving any chemotherapy.
10.5 Selection of Therapy
The clinical superiority of one percutaneous treat-
ment modality over another has not been deter-
mined in any randomized, controlled clinical trial.
Determining which treatment to pursue focuses
largely on technical considerations, theoretical
considerations, individual patient factors, and
operator/institutional experience.
A comparison of patient factors favoring ablative
or transarterial therapy is shown in ▶ Table 10.2.
Ablative therapy tends to favor smaller, oligocen-
tric disease. The best results have been seen in
tumors < 3 cm and intermediate results in tumors <
5 cm, and emerging literature suggests acceptable
recurrence rates in tumors up to 7 cm.
10
Central
tumors, diffuse/infiltrative morphology, and
mutilfocality are more feasibly treated with trans-
arterial therapy. Despite historical concerns over
arterial chemoembolic therapy in the presence of
portal vein thrombosis, recent data suggest that
this is safe.
11
If downstaging to resectability/trans-
plantation is a consideration, consultation with
the surgical team may also provide insight into
optimal therapy.
10.5.1 Technique
Considerable individual and institutional variation
exists in the particular techniques used for both
hepatic chemoembolization and percutaneous ab-
lation. The techniques described hereafter are giv-
en as examples.
10.5.2 Preprocedure
Informed consent is obtained, with special atten-
tion paid to the risks of the particular procedure at
hand. Prophylactic antibiotics are necessary given
the possibility of bacteremia, infected biloma for-
mation, and systemic sepsis after both transarterial
therapy and ablation, particularly in this patient
population with an increased incidence of prior
biliary instrumentation. Multiple prophylactic anti-
biotic regimens have been described; it is impor-
tant that the selected regimen cover typical skin
flora as well as gram-negative organisms likely to
colonize the biliary tract (see the following list).
12
Continuation of antibiotics is left to the discretion
of the operator after evaluation of individual
patients, with courses of 3 to 7 days being common
and courses up to 14 days used in patients at par-
ticularly high risk. A bowel preparation regimen
may reduce the risk of biliary infection.
13
Possible Prophylactic Antibiotic
Regimens
●
1.5 to 3 g intravenous (IV) ampicillin/sulbactam
●
1 g cefazolin IV + 500 mg metronidazole IV
●
1 gm ceftriaxone IV
●
Levofloxacin 500 mg IV or ciprofloxacin 500 mg
IV + 500 mg metronidazole IV (penicillin allergic)
Drugs Commonly Used to Treat
Postembolization Pain, Nausea,
and Malaise
●
Dexamethasone 10 mg IV every 8 hours (pain
and nausea)
●
Ondansetron (Zofran, GlaxoSmithKline) 4 to
8 mg IV every 4 hours (nausea)
●
Patient-controlled analgesic pumps
●
Ofirmev (Cadence Pharmaceuticals) (acetami-
nophen 1 g) IV—use with caution in liver disease
Preprocedure imaging and laboratory values
are again reviewed. IV hydration is administered
in a standard fashion for the prophylaxis of con-
trast-induced nephropathy, and conscious seda-
tion is administered as necessary. Given the high
incidence of postembolization syndrome (> 80%),
Table 10.2 Ablative versus transarterial therapy
Transarterial therapy Ablation
Multicentric disease Focal disease
Infiltrative tumor type Mass forming type
Central location Peripheral location
Adjacent to diaphragm
Cholangiocarcinoma: Ablation and Intra-arterial Therapies
156
some advocate preprocedural administration of IV
steroids, analgesics, and antiemetics, whereas
others treat symptoms as needed. Refer to the fol-
lowing list for commonly used drugs and dosages
extrapolated from systemic chemotherapeutic
experience.
10.5.3 Transarterial Therapy
The equipment necessary is similar to diagnostic
hepatic angiography and embolization performed
for other tumors (see text box). Before the proce-
dure begins, the team determines a plan of which
liver locations to treat, level of injection (lobar,
superselective, etc.), a drug, and a drug vehicle.
Last-minute review of the patient’s most recent
imaging is invaluable to identify anomalous vessel
origin, accessory arteries, parasitic arterial supply,
and other arterial anomalies.
Equipment List For Hepatic
Chemoembolization
Standard
●
Ultrasound with high-frequency linear trans-
ducer
●
Micropuncture (22 gauge) access set, with
0.018 wire and 3/5F transitional dilator.
●
Power injector and tubing, loaded with low/iso-
osmolar contrast
●
5F vascular sheath with pressurized heparinized
saline flush and tubing (2 U/mL typically)
●
5F angiographic catheters—commonly used
shapes include Cobra 2 (Terumo Manufactur-
ing Corporation), SOS Omni (AngioDynamics)
●
0.035 to 0.038 in guidewires, Amplatz and
Benson are typical choice
●
Separate Mayo stand and tray with color-coded
3 mL injection syringes for chemotherapy
●
Embolic material loaded with appropriate
chemotherapy
Optional
●
Microcatheter and microwire for tortuous hep-
atic arterial anatomy, small parasitic vessels, or
subselective injection
●
Femoral arterial closure device
Lobar versus more subselective injection remains
at the discretion of the operator. The hypovascular
nature, multicentricity, and infiltrative nature of
the disease mean that lobar injection may be pre-
ferred for feasibility reasons in any event.
Transf emoral arterial access is obtained in the
standard fashion, and the proper hepatic artery is
selected with a 5F diagnostic catheter of the opera-
tor’s choice. Microcatheter systems are typically
reserved for more distal embolization or challenging
anatomy. Angiography is performed as needed for
confirmation of proper vessel selection and tumor
identification and to ensure the catheter is placed
beyond any potential sources of nontarget emboli-
zation. If one chooses subselective injection, correla-
tion with preprocedural cross-sectional imaging and
in-room cone beam computed tomography (CT) are
helpful to ensure the appropriate arterial branch has
been selected because lesions are often angiographi-
cally occult. Once the appropriate artery has been
selected and the catheter/microcatheter is appropri-
ately positioned, preparation for injection of chemo-
therapeutic drugs is begun (▶ Fig. 10.2a, b).
No chemotherapeutic agent is specifically
approved by the Food and Drug Administration
(FDA) for intra-arterial therapy of cholangiocarci-
noma; usage of all current dr ugs is off label, and
the optimal chemotherapeutic regimen has not
been determined through randomized, controlled
trials. Operators should refer to the manufacturer’s
instructions and be knowledgeable about the con-
traindications/toxicities regarding each chemo-
therapeutic drug before administration.
A variety of chemotherapeutic agents have been
reported, including platinum agents, 5-fluoroura-
cil (5-FU), gemcitabine, doxorubicin, and others,
often in combination. Drug-eluting beads are a
typical vehicle, with polyvinyl alcohol (PVA) and
Gelfoam also being used. The following list pro-
vides a summary of recently reported drugs and
dosages adapted from Ray et al.
14
Chemotherapeutic Regimens
Previously Described in
Transarterial Therapy
●
Irinotecan 200 mg.
●
Mitomycin C 2 to 15 mg.
●
Cisplatin 50 mg, 45 to 50 mg/m
2
, 2 mg/kg.
●
Oxaliplatin 50 mg, 85 to 100 mg/m
2
.
●
Doxorubicin 50 to 150 mg, 50 mg/m
2
.
●
5-FU 450 mg/m
2
.
●
Gemcitabine 1,000 to 2,250 mg/m
2
.
Adapted from Ray, et al.
Cholangiocarcinoma: Ablation and Intra-arterial Therapies
157
Ideally, if drug-eluting beads are used as a
vehicle, they will have been soaked in the chemo-
therapeutic preparation for at least 2 to 4 hours.
The supernatant is removed, and the beads are
reconstituted with a 50/50 mix of saline and con-
trast to maximize bead suspension. Handling pro-
tocols for chemotherapeutic drugs will vary
institutionally; however, most use a separate tray,
syringe set, and gloves to avoid cross contamina-
tion, with proper disposal of agents in a designated
waste container.
Injection is performed slowly under intermittent
fluoroscopy to avoid reflux and subsequent non-
target embolization. Injection continues until one
of two end points, either complete injection of the
planned chemotherapeutic dose, or 2- to 5-beat
stasis (▶ Fig. 10.2c). Some authors have cautioned
against complete stasis in hepatic chemoemboliza-
tion, due to concern for increased risk of necrosis
and collateral liver damage.
Radioembolization is performed in a similar man-
ner, with pretreatment planning and determination
Fig. 10.2 (a) Catheter-directed angiogram of celiac artery in preparation for subselective-targeted therapy. (b)
Catheter-directed angiogram of replaced left hepatic artery off the left gastric artery demonstrates tumor blush. (c)
Postembolization angiogram after therapy with drug-eluting beads demonstrates relatively gentle embolization
staining.
Cholangiocarcinoma: Ablation and Intra-arterial Therapies
158
of shunt fraction by lobar injection of technetium-
99 m macroaggregated serum albumin (
99m
Tc-MAA)
injection into the hepatic artery, and subsequent
gamma camera imaging. Nontarget embolization
has more serious consequences with radioemboli-
zation, as such collateral branches are typically per-
manently embolized with coils prior to the MAA
study. Radioembolization is typically performed in a
lobar fashion, with bilobar disease being treated in
separate sessions and sequential fashion.
10.5.4 Ablative Therapy
In percutaneous ablative therapy, the target lesion
and the device must both be readily visible to
ensure a complete ablation and avoidance of col-
lateral damage. CT and ultrasound (US) guidance
can both be used. Given the variability, it seems
prudent that the procedure be performed in the
CT suite with an ultrasound machine, so that both
modalities can be used. Multiple methods for
tumor ablation are currently FDA approved,
including radiofrequency, microwave, cryoabla-
tion, and, most recently, irreversible electropora-
tion. No technique has been shown to be superior
to any others; however, the largest experience in
the literature is radiofrequency ablation (RFA).
Regardless of the modality, the operator should be
proficient with the apparatus and probe selection.
A probe or array of probes should be selected that
is sufficient to ablate the tumor itself and an adja-
cent area of at least 0.5 cm, preferably 1 cm adjacent
tissue while avoiding normal structures. After local
anesthesia, conscious sedation, and a skin incision,
the apparatus is advanced to the planned location.
If the tumor and adjacent structures are poorly visi-
ble, using an alternative imaging modality can be
helpful, or under CT a single contrast injection can
be used, assuming minimum subsequent patient
movement. When optimal probe position is
obtained, the device is activated as necessary. Tract
ablation during probe removal is also sometimes
performed as a prophylactic measure against seed-
ing the tract with tumor cells. The latter also helps
preclude bleeding complications. A postprocedure
scan is obtained with a focus on possible complica-
tions and the adequacy of the ablation zone.
10.6 Postprocedure
Management
Routine postsedation recovery followed by over-
night admission in the hospital is standard for
symptomatic management and evaluation for
complications; however, outpatient management
is being proposed with radioembolization.
15
Medi-
cal consultations are obtained as necessary. Bar-
ring any immediate complications, patients are
typically discharged in the next day with clinic fol-
low up in 1 to 2 weeks, with repeat laboratory
work.
Follow-up imaging is typically obtained in 4 to 6
weeks, with imaging typically performed after the
final session, if multiple treatment sessions are
planned. Additional therapy sessions are planned
based on tumor response and patient tolerance of
therapy, with studies showing good tolerance to
subsequent therapy.
10.7 Side Effects and
Complications
Liver-directed therapy has a low morbidity and
mortality rate; nevertheless, complications do
occur, and meticulous preprocedure patient selec-
tion can help to minimize these. Complications
and side effects of liver-directed therapy for chol-
angiocarcinoma are similar to those performed for
other indications.
Abscess formation in patients with preexisting
biliary–enteric anastomoses is high; patient
instructions and vigilant postprocedural care
should reflect this.
16
When they occur, abscesses/
infected bilomas are treated with percutaneous
drainage and systemic antibiotic therapy, typically
with good results.
As with any embolic therapy, nontarget emboliza-
tion is a risk, with postembolization cholecystitis,
pleural effusions resulting from diaphragm emboli-
zation, and gastritis all having been reported.
17
These conditions are typically managed successfully
with conservative measures, but early clinical detec-
tion is paramount. Other complications reported
include arterial dissection, injury, puncture site com-
plications, and, rarely, portal venous thrombosis.
10.8 Clinical Data and
Outcomes
Liver-directed therapy for cholangiocarcinoma is a
relatively new treatment modality, and progress is
constant. Several observational studies of transar-
terial chemotherapy and radioembolization have
been performed, with comparison to historical
survival data.
Cholangiocarcinoma: Ablation and Intra-arterial Therapies
159
10.8.1 Chemoembolization
Chemoembolization for intrahepatic cholangiocar-
cinoma has been the most studied liver-directed
treatment modality. The body of literature is
promising, but studies have been limited to small
enrollments, variable drugs, and varying patient
populations.
A recent meta-analysis by Ray et al included 542
patients from 2005 to 2012, with 76.8% having sta-
ble disease or response by imaging criteria post-
treatment, and conferring an estimated survival
benefit of 2 to 7 months versus historical controls
using only systemic chemotherapy.
14
A multicen-
ter retrospective review from Hyder et al that
included 198 patients from five major hepatobili-
ary centers also demonstrated stable disease or re-
sponse by imaging in about 75% of patients with
an overall survival of 13 months, increased from
historical controls of systemic therapy.
18
10.8.2 Radioembolization
Radioembolization shows promise in the treatment
of intrahepatic cholangiocarcinoma. A recent retro-
spective study included 46 patients with up to 15.6-
month surviv al in certain patient subtypes, with an
additional 11% (5 of 46) becoming resectable.
4
█
Pearls
●
Patient selection is crucial. Careful history, deter-
mination of performance status, and a careful
review of imaging can go a long way toward
determining optimal therapy and minimizing
complications.
●
Set appropriate patient expectations. A variety of
liver-directed therapies have shown promise in
prolonging survival and achieving local tumor
control; however, none has been shown to be a
“magic bullet” or cure.
●
Follow the patient clinically. Clinic visits are cru-
cial to assess for early complications, develop
relationships with patients and providers, and
plan future treatment.
●
Carefully review diagnostic imaging. Variant
anatomy readily visible by cross-sectional imag-
ing can be difficult or impossible to identify an-
giographically.
●
Patients with a biliary enteric anastomosis have
high rates (≥ 25%) of infected biloma formation.
Antibiotic prophylaxis and bowel preparation
may reduce this risk.
10.8.3 Ablation
Various ablative methods have been used as treat-
ment of intrahepatic cholangiocarcinoma. Of the
modalities, the most studied is radiofrequency ab-
lation. Several small (< 10) retrospective studies
have been performed at multiple institutions and
suggest an increased survival, with median surviv-
al up to 33 months.
19
References
[1] Amini N, Ejaz A, Spolverato G, Kim Y, Herman JM, Pawlik
TM. Temporal trends in liver-directed therapy of patients
with intrahepatic cholangiocarcinoma in the United States:
a population-based analysis. J Surg Oncol 2014; 110(2):
163–170
[2] Valle J, Wasan H, Palmer DH et al. ABC-02 Trial Investigators.
Cisplatin plus gemcitabine versus gemcitabine for biliary
tract cancer. N Engl J Med 2010; 362(14): 1273–1281
[3] Okusaka T, Nakachi K, Fukutomi A et al. Gemcitabine alone
or in combination with cisplatin in patients with biliary
tract cancer: a comparative multicentre study in Japan. Br J
Cancer 2010; 103(4): 469–474
[4] Mouli S, Memon K, Baker T et al. Yttrium-90radioemboliza-
tion for intrahepatic cholangiocarcinoma: safety, response,
and survival analysis. J Vasc Interv Radiol 2013; 24(8):
1227–1234
[5] Razumilava N, Gores GJ. Classification, diagnosis, and ma-
nagement of cholangiocarcinoma. Clin Gastroenterol Hepa-
tol 2013; 11(1): 13–21.e1, quiz e3–e4
[6] Khan SA, Davidson BR, Goldin RD et al. British Society of
Gastroenterology. Guidelines for the diagnosis and treat-
ment of cholangiocarcinoma: an update. Gut 2012; 61(12):
1657–1669
[7] Robles R, Sánchez-Bueno F, Ramírez P, Brusadin R, Parrilla P.
Liver transplantation for hilar cholangiocarcinoma. World J
Gastroenterol 2013; 19(48): 9209–9215
[8] Rea DJ, Heimbach JK, Rosen CB et al. Liver transplantation
with neoadjuvant chemoradiation is more effective than re-
section for hilar cholangiocarcinoma. Ann Surg 2005; 242
(3): 451–458, discussion 458–461
[9] Park SY, Kim JH, Won HJ, Shin YM, Kim PN. Radiofrequency
ablation of hepatic metastases after curative resection of ex-
trahepatic cholangiocarcinoma. Am J Roentgenol 2011; 197
(6): W1129–34
[10] Haidu M, Dobrozemsky G, Schullian P et al. Stereotactic ra-
diofrequency ablation of unresectable intrahepatic cholan-
giocarcinomas: a retrospective study. Cardiovasc Intervent
Radiol 2012; 35(5): 1074–1082
[11] Chern M-C, Chuang VP, Liang C-T, Lin ZH, Kuo T-M. Trans-
catheter arterial chemoembolization for advanced hepato-
cellular carcinoma with portal vein invasion: safety, efficacy,
and prognostic factors. J Vasc Interv Radiol 2014; 25(1): 32–
40
[12] Venkatesan AM, Kundu S, Sacks D et al. Society of Interven-
tional Radiology Standards of Practice Committee. Practice
guidelines for ault antibiotic prophylaxis during vascular
and interventional radiology procedures. Written by the
Standards of Practice Committee for the Society of Interven-
tional Radiology and Endorsed by the Cardiovascular Inter-
ventional Radiological Society of Europe and Canadian In-
Cholangiocarcinoma: Ablation and Intra-arterial Therapies
160
terventional Radiology Association [corrected]. J Vasc Interv
Radiol 2010; 21(11): 1611–1630, quiz 1631
[13] Patel S, Tuite CM, Mondschein JI, Soulen MC. Effectiveness of
an aggressive antibiotic regimen for chemoembolization in
patients with previous biliary intervention. J Vasc Interv Ra-
diol 2006; 17(12): 1931–1934
[14] Ray CE, Jr, Edwards A, Smith MT et al. Metaanalysis of sur-
vival, complications, and imaging response following che-
motherapy-based transarterial therapy in patients with un-
resectable intrahepatic cholangiocarcinoma. J Vasc Interv
Radiol 2013; 24(8): 1218–1226
[15] Gates VL, Marshall KG, Salzig K, Williams M, Lewandowski
RJ, Salem R. Outpatient single-session yttrium-90 glass mi-
crosphere radioembolization. J Vasc Interv Radiol 2014; 25
(2): 266–270
[16] Kim W, Clark TW, Baum RA, Soulen MC. Risk factors for liver
abscess formation after hepatic chemoembolization. J Vasc
Interv Radiol 2001; 12(8): 965–968
[17] Clark TWI. Complications of hepatic chemoembolization.
Semin Intervent Radiol 2006; 23(2): 119–125
[18] Hyder O, Marsh JW, Salem R et al. Intra-arterial therapy for
advanced intrahepatic cholangiocarcinoma: a multi-institu-
tional analysis. Ann Surg Oncol 2013; 20(12): 3779–3786
[19] Fu Y, Yang W, Wu W, Yan K, Xing BC, Chen MH. Radiofre-
quency ablation in the management of unresectable intra-
hepatic cholangiocarcinoma. J Vasc Interv Radiol 2012; 23
(5): 642–649
Cholangiocarcinoma: Ablation and Intra-arterial Therapies
161
1
Chapter 11
Bone Tumors: Ablation
11.1 Introduction 164
11.2 Indications 164
11.3 Contraindications 165
11.4 Patient Selection and
Preprocedural Workup
165
11.5 Technique 165
11.6 Postprocedure Management
and Follow-up Evaluation
170
11.7 Side Effects and
Complications
171
11.8 Clinical Data and Outcomes 172
11 Bone Tumors: Ablation
Matthew R. Callstrom, and A. Nicholas Kurup
11.1 Introduction
Approximately 70% of the 1 million people that die
each year in the United States due to cancer have
breast, lung, or prostate cancer, and approximately
one-half of these, or 350,000 people, will die with
bone metastases.
1
Although bone metastases can
indicate a poor prognosis with a median survival
of 3 years or less, many patients now live many
years with metastatic cancer, with 5 to 40% of
patients alive at 5 years, dependent on tumor his-
tology and burden.
2,3
Quality of life is an important
consideration for patients, and unfortunately
bone-related cancer pain is often undertreated,
with nearly 80% of patients experiencing severe
pain before a sufficient palliative treatment plan is
initiated.
4
A multidisciplinary team that can offer optimal
analgesic therapy, radiation therapy (RT), surgery,
hormonal and chemotherapies, and focal image-
guided ablation therapies provides the most effec-
tive management of patients with painful skeletal
metastases. The front-line therapy for treatment of
painful metastatic skeletal disease is external
beam radiation therapy (EBRT). This treatment is
at least partially effective for 50 to 80% of patients,
with complete pain response in 50 to 60%.
5
Although many patients experience complete or
partial relief of pain following RT, the time to pain
relief can be extended, with the median relief of
pain achieved in 3 to 7 weeks.
6
Although RT results
in an initial reduction in pain for the majority of
patients, at least for a period of weeks, 20 to 30%
of patients do not experience pain relief, and a
majority that had complete or partial response
experience pain recurrence.
7,8,9,10,11,12
Retreatment
is possible for many patients, but for many
patients that experience minimal or transient
relief of pain following EBRT, further treatment is
not offered due to lack of response or due to limi-
tations in normal tissue tolerance.
Surgery is generally reserved for lesions at great
risk for fracture or following fracture, or for spinal
metastases causing neurological compromise.
Systemic therapies, including chemotherapy,
hormonal therapy, radiopharmaceuticals, and
bisphosphonates, in combination with opioid and
nonsteroidal analgesics, can be effective treatment
for widespread skeletal metastases. However,
these are not generally offered for focal painful
metastases because pain due to metastatic skeletal
disease is often refractory. Radiopharmaceuticals
are often effective in patients with diffuse painful
bony metastases, but are not considered standard
of care for patients with isolated, painful lesions.
For many patients with focal painful metastatic
disease that have failed EBRT, analgesics remain
the only alternative treatment option that is typi-
cally offered. Many patients will limit their use of
these medications due to significant side effects,
such as constipation, nausea, and sedation.
Increasingly minimally invasive, percutaneous
thermal ablation techniques have found clinical
effectiveness for palliation for patients with lim-
ited skeletal metastases. These treatments use
image guidance to place ablative devices into focal
metastatic tumors. These ablation methods
include the use of radiofrequency ablation (RFA),
cryoablation, laser ablation, microwave ablation,
and magnetic resonance–guided focused ultra-
sound (MRgFUS). In addition, patients at risk for
fracture due to metastases in axially loaded loca-
tions (e.g., vertebral bodies and the periacetabular
region) may benefit from percutaneous cemento-
plasty. Of these minimally invasive methods, RFA
and cryoablation have been the most studied.
More recently, percutaneous ablation has been
used to achieve local tumor control in patients
with limited metastatic disease involving the
musculoskeletal system. These patients with
oligometastatic disease benefit from cost-effective
minimally invasive treatments while avoiding the
morbidity of surgery and, if new disease presents,
retreatment is possible.
13,14,15
11.2 Indications
Patients that benefit from focal ablative therapy
for painful metastatic disease report moderate or
severe pain, typically≥ 4 of 10 for the worst pain in
a 24-hour period. Patients with lower reported
pain scores are not usually treated because it is dif-
ficult to improve on mild pain, and type of pain
can usually be managed by oral analgesics. An
important consideration is that pain should be
limited to one or two sites, and the pain should
correlate with a corresponding abnormality evi-
dent with cross-sect ional imaging. For patients
with multiple painful tumors or otherwise diffuse
disease, identifying critical sites for treatment can
Bone Tumors: Ablation
164