Comprehensive overview of Radiotherapy in Benign diseases

1. RT in Benign diseases
Presenter
Dr Atul Gupta
DM Resident
Radiotherapy & Oncology
AIIMS Jodhpur

2. • Benign diseases generally include a class of localized tumors or growths that
have a low potential for progression and do not invade surrounding tissue or
metastasize to distant sites.
• Pathologically, they are composed of well-differentiated cells that are
considered nonmalignant and usually do not require any treatment.
• However, clinically, not all benign diseases have benign consequences. Some
untreated benign diseases can produce bothersome mass or secretory
effects.
• Others can be locally aggressive and cause secondary debilitating symptoms.
INTRODUCTION-

3. For example-
• Graves ophthalmopathy can lead to local pain and visual impairment without
therapeutic intervention.
• a hormonally active pituitary adenoma may cause growth abnormality in
addition to blindness .
• desmoid tumors can be locally persistent even after surgical resection and
grow uncontrollably similar to their malignant counterparts.

4. • RT is known for its anti-cancer effect but
• It is very effective in many benign conditions also
• Under-utilized in clinical practice due to
1. Fear of radiation induced cancer and other effects
2. Lack of awareness in allied specialties
• Drastic changes in RT over last 2-3 decades
• Modern RT is very safe, accurate, precise and conformal
RATIONALE FOR RT IN BENIGN DISEASES -

5. • Prof. Freund (Vienna) in 1897 treated a hairy mole with X-Ray Therapy
• Initial use of RT was for several benign conditions as
I. Tinea Capitis
II. Acne Vulgaris
III. Osteo-arthritis
IV. Hemangiomas
V. Infections
VI. Others
HISTORICAL ASPECT-

6. • When benign diseases are symptomatic or potentially symptomatic.
• When other methods are unavailable or have failed
• A thorough risk–benefit analysis is always pertinent
• Organ-specific acute and chronic toxicities including potential effects on
fertility and induction of secondary tumors in the future must be explained to
and discussed with patients, especially those who are young and have a long
life expectancy.
• Technique of RT : Precise and Accurate
GENERAL PRINCIPLES FOR RT IN BENIGN DISEASES-

7. • Precise mechanism not well defined.
• Radiation is believed to work through a complex of multicellular interactions
that affect different cell types in our body system.
• Benign lesions triggered by trauma-
. Hyperproliferative process
. Radiotherapy is clinically effective in inhibiting cell
proliferation and suppressing cell differentiation without inducing cell death as
is typically seen with tumoricidal doses of radiation
RADIOBIOLOGY IN BENIGN DISEASES-

8. • Effects on blood vessels-
. vascular endothelial cells respond rapidly to radiation damage
. Low dose radiation (total dose <12Gy using 1Gy or less per fraction)
exerts anti-inflammatory effects on endothelial cells of capillaries.
. At higher single or total doses, endothelial cell damage can lead to
sclerosis and obliteration of blood vessels.
• The Radiation-induced modulation of nitric oxide production and oxidative burst in
activated macrophages and native granulocytes lead to modification of the immune
response and inflammatory process as well as clinical analgesic effects.
Contd….

10. INDICATIONS OF RADIOTHERAPY IN BENIGN DISEASES-

11. 1. Acute/chronic inflammatory disorders, e.g., axillary sweat gland abscess, furuncule,
carbuncule and other infections not responding to antibiotics, etc.;
2. Acute/chronic painful degenerative diseases, e.g., insertion tendinitis and chronic or
acute painful osteoarthritic diseases of various joints (hip, knee, etc.);
3. Hypertrophic (hyperproliferative) disorders of soft tissues, e.g., prophylactic RT in
early stages of Morbus Dupuytren and Ledderhose, and Morbus Peyronie, postoperative prophylaxis of
recurrence for keloids and pterygium;
4. Functional diseases, such as Graves’ orbitopathy, arteriovenous malformations, age-related
macular degeneration, persisting lymphatic fistula;
5. Other indications, such as prophylaxis of heterotopic ossification at various joints, prophylaxis of
neointimal hyperplasia, e.g., after arterial dilatation or stent implant obstruction of hemangiomas and other
vascular disorders of various organs;
6. Dermatologic diseases, e.g., pruritus due to itching dermatoses and eczemas, inaccessible
psoriatic focuses (e.g., subungual focuses), basalioma.

12. • The induction of cancer or genetic defects by radiation exposure is attributed to stochastic
effect where there is no threshold level of radiation exposure below which cancer induction
or genetic effects will not occur.
• Increasing Radiation dose can increase probability of cancer but not severity of cancer.
RISK OF SECOND MALIGNANCY-

13. BENIGN NEOPLASMS OF THE BRAIN, HEAD & NECK

14. • Meningioma
• Pituitary Adenoma
• Craniopharyngioma
• Vestibular Schwannoma (Acoustic Neuroma)
• Chordoma
• Glomus Tumor/Chemodectoma/Paraganglioma
• Juvenile Nasopharyngeal Angiofibroma
• Langerhans Cell Histiocytosis (Histiocytosis X)

15. • Meningiomas are the most common tumors of the CNS.
• The incidence peaks in the seventh decade of life with a 2 to 3:1 female-to-male predominance.
• The majority (>90%, Central Brain Tumor Registry of the United States (CBTRUS) 2008–2012) of
meningiomas are benign and classified by the World Health Organization (WHO) as grade I tumors. They
can be heritable in some genetic syndromes (e.g., neurofibromatosis type 2; SMARCE1-related
meningioma, multiple endocrine neoplasia type 1), which present in childhood but make up a minimal
percentage of these tumors.
• These WHO grade II meningiomas (4.6% by CBTRUS) have a higher tendency for local recurrence,
• and WHO grade III/malignant meningiomas (anaplastic, rhabdoid, papillary) are exceedingly rare.
• The most common presenting symptom is headache, but patients may present with other localizing
symptoms depending on the tumor location.
MENINGIOMA

17. Indications of RT in Meningioma-
 tumors in locations in which complete resection is not feasible (i.e., optic
nerve, cavernous sinus, major venous sinus)
 for patients who are poor surgical candidates
 Adjuvant RT is indicated for patients with STR, recurrent disease, or WHO
grade II/III tumors

18. Radiation Therapy Technique details-
 RT techniques include conventionally fractionated three-dimensional conformal radiotherapy (3DRT),
conventionally fractionated intensity-modulated radiation therapy (IMRT), frame-based or linear accelerator–
based fractionated stereotactic radiotherapy (FSRT), stereotactic radiosurgery (SRS), or protons and heavy ions.
 The MRI sequences that best delineate the gross tumor volume (GTV) should be co-registered with the
treatment planning CT scan for optimal treatment planning and delivery.
 For 3DRT or IMRT treatments, the clinical target volume (CTV) is constructed by adding a symmetric margin (0
to 1 cm for WHO grade I; 1 to 2 cm for WHO grade II/III) around the GTV, respecting normal tissue boundaries
and accounting for the imaging characteristics of the tumor
 An additional 3 to 5 mm is added for the final planning target volume (PTV).
 Dose Prescription- For benign meningiomas, the typical dose prescription to the PTV is 50 to 54 Gy given in 1.8-
to 2-Gy daily fractions.
 For patients with more aggressive histology (WHO grade II/III tumors), a higher dose prescription in the range
of 59.4 to 63 Gy is used.

19. • Reported results with SRS are excellent, with 5-year local control rates as high
as 98% to 100%.

20. • Di-Biase et al demonstrated that male gender, conformity index <1.4 and size
>10 mL predict for worse outcome after SRS.
• In Ferraro et al. additional poor prognosticators included high mitotic rate,
nuclear atypia, spontaneous necrosis, and WHO grade III pathology.
• Because of their physical properties, protons and heavy ions (i.e., carbon) are
attractive choices for the treatment of meningiomas, particularly for those
located near critical structures. Several studies have shown excellent local
control rates with the combination of protons and photons or protons alone

21. • second most common intracranial tumors
• Approximately 65% to 70% of these tumors are functional (secretory), thereby producing
increased amounts of hormones.
• Prolactinomas and growth hormone (GH)–secreting adenomas are the most frequently
encountered.
• Functional adenomas are more common in women, whereas nonfunctioning and GH-
secreting adenomas are more common in men.
• Size classification- pico-adenoma <0.3cm, microadenoma <1cm and macroadenoma >1cm.
• Clinical presentation can vary, but nonfunctional adenomas (mostly consisting of
gonadotrophs) are most commonly with visual symptoms (often bitemporal hemianopsia
from compression of the optic chiasm).
PITUTARY ADENOMA

22. • Patients with functional adenomas present with signs and symptoms that correspond to the excess
hormone:
1. galactorrhea, amenorrhea, diminished libido, and infertility in patients with prolactinomas,
2. acromegaly or gigantism in patients with GH-secreting adenomas,
3. Cushing disease in adrenocorticotropic hormone (ACTH)-secreting adenomas, and
4. hyperthyroidism in patients with thyroid-stimulating hormone (TSH)-secreting adenomas.
• Surgical Management-
Transsphenoidal surgery is generally the treatment of choice for pituitary adenomas, providing
immediate relief of compressive symptoms and potentially decreasing hormone secretion.
In some cases, a more aggressive surgery (i.e., extended transsphenoidal approach, frontal
craniotomy) may be indicated for patients with extensive intracranial and skull-based
involvement.
Overall, local control rates range from 50% to 80% after surgery alone for both functioning and
nonfunctioning adenomas.
In patients that continue to have abnormally elevated hormones after surgical resection, adjuvant
treatment with pharmacotherapy and/or radiation therapy is pursued.

23. INDICATIONS OF RT IN PITUTARY ADENOMA-
 In inoperable patients, as a primary therapy
 Indications for adjuvant RT-
1. recurrent tumor after surgery,
2. persistence of hormone elevation after
surgery,
3. and residual disease after STR/debulking
procedure.
Radiation Therapy Volume delineation-
 3DRT, IMRT, single-fraction SRS, SBRT (or HSRT), and FSRT.
 GTV- Gross tumor
 CTV- Gross tumor plus subclinical extent of tumor)1-
1.5cm)
 PTV- 3-5mm around CTV
DOSE PRESCRIPTION-
 Nonfunctional adenomas are typically prescribed a dose of 45 to 50.4 Gy given in 1.8- to 2.0-Gy daily fractions
 Higher doses in the range of 50.4 to 54 Gy are recommended for secretory adenomas as these are felt to be more
locally aggressive and less radio-responsive.

24. SRS in pituitary adenomas-
• SRS has become the more attractive option for the treatment of pituitary adenomas.
• FSRT is used over SRS for large lesions (i.e., >3 cm) or lesions near critical structures (i.e., <1mm to 2mm
from the chiasm)
• Numerous retrospective studies have demonstrated excellent local control rates of 92% to 100% for
nonfunctional adenomas using doses of 14 to 25 Gy (at the edge of the tumor) in a single fraction.
• Commonly used prescriptions are 16 to 20 Gy in a single fraction for nonfunctional adenomas and 20 to 25
Gy in a single fraction for functional adenomas using a frameless robotic radiosurgery platform.

25. • 6% to 10% of pediatric CNS tumors
• The median age of diagnosis is 5 to 10 years with a second peak in patients >40 years old
• an equal male : female ratio.
• These benign tumors are epithelial, arising from remnants of Rathke pouch (hypophyseal–pharyngeal duct),
and are most commonly located in the suprasellar region, though they may be found in the sella proper.
• Histologically, they are divided into the adamantinomatous and squamous subtypes.
• The adamantinomatous subtype is characterized by a solid and cystic pattern with the well-known description
of “machine oil–like” cystic fluid.
• Presenting signs and symptoms include headache, nausea and vomiting, bitemporal hemianopsia, and
endocrine dysfunction (diabetes insipidus [DI], dwarfism, fat tissue disturbance, adrenal cortical insufficiency).
CRANIOPHARYNGIOMA

26. Surgical Intervention-
• The primary goal of surgery is complete resection.
• However, GTR may be associated with high rates of neurologic sequelae including visual impairment and
panhypopituitarism.
• In order to minimize morbidity, most patients are treated with maximal safe resection followed by adjuvant
RT.
Intracavitary Therapies-
• Intralesional bleomycin may be directly injected into the cyst to decrease the rate of cyst recurrence.
• Cystic craniopharyngiomas may also be managed by the use of intralesional radioactive isotope injection
using a beta emitter (yttrium 90, phosphorus 32).
• Typical prescriptions range from 200 to 250 Gy prescribed to the cyst wall. Optimal results are seen in
patients whose tumors have one cyst and lack a large solid component.

27. Indications-
• Residual tumor after STR
• Recurrence
• In select patients (i.e., <3years old) , observation following STR may be an option as local control rates are
similar with RT at the time of relapse (“salvage” RT) compared with adjuvant RT with no compromise in
overall survival.
Dose Prescription-
• The GTV is the postoperative residual tumor volume, including the cyst wall, if present.
• Dose prescriptions for 3DRT and IMRT are typically at least 54 Gy given in 1.8-Gy daily fractions.
Radiotherapy in Craniopharyngioma-

28. Proton Therapy in Craniopharyngioma-
• Fractionated proton radiotherapy has demonstrated excellent results.
• The Loma Linda series treated 15 patients to a total dose of 50.4 to 59.4 gray equivalents (GyE) given in 1.8
GyE daily fractions. Local control was achieved in 14 out of 15 patients with few long-term complications.
• In a series from the Massachusetts General Hospital (MGH), no failures were seen in 24 patients that received
fractionated proton radiotherapy to a total dose of 52.2 to 54 GyE in 1.8 GyE per fraction.
• It has been well established that cysts may regrow during the several weeks of fractionated treatment.
• The MGH proton study recommends that reimaging (CT or MRI if cyst is not well visualized on CT) be
performed within 2 weeks of the treatment planning scan and every 2 weeks thereafter; for large cysts or
those that demonstrate growth during RT, weekly reimaging is recommended.
• Image-guided radiotherapy techniques now allow for the convenient monitoring of cyst regrowth with cone
beam CT scans while patients are on the treatment table.

29. • derived from the neurilemmal of the vestibulocochlear nerve (CN VIII)
• represent 5% to 8% of primary CNS brain tumors
• The vast majority of cases (90%) are unilateral and sporadic, and when bilateral (10% of
cases), they are associated with neurofibromatosis type II
• Clinical presentation can include symptoms of sensorineural hearing loss, tinnitus, and
vertigo. Hearing loss is correlated with tumor location (intracanalicular) rather than tumor
size.
• In a minority of patients (5%), facial nerve symptoms may be present. As the AN grows, it
may affect the trigeminal nerve (CN V) and brainstem.
Vestibular Schwannoma
(Acoustic Neuroma)

30. Surgical Intervention-
• Surgery is the mainstay of management of vestibular schwannomas, particularly for patients with large,
symptomatic lesions.
• Most patients can undergo a complete resection and have low recurrence risk
• Subtotal resection are associated with an approximately 15% risk of recurrence.
• Hearing preservation is approximately 50% to 60% after surgery, and facial nerve preservation ranges from
80% to 90%.
Active Surveillance-
 Observation is appropriate management for some individuals; indications include age >60, multiple
comorbidities, small tumor size, and risk of hearing loss.
 Serial MRI and audiometry (every 6 to 12 months) should be performed in this patient cohort for
surveillance.
 Treatment is initiated when the lesion demonstrates rapid and significant growth or when the patient
becomes symptomatic.
 Overall, a growth rate of <1mm per year is expected for most patients.

31. Radiotherapy in Acoustic Neuroma-
• RT in the form of SRS or FSRT is an option for the primary treatment of AN, often with higher rates of
hearing preservation and facial nerve presentation compared with surgery.
• SRS doses using frame-based platforms are generally 12 to 13 Gy prescribed to the 50% IDL.
• Common dose prescriptions employing FSRT include 25 Gy in 5 fractions, 30 Gy in 10 fractions, and 50 to 55
Gy in 25 to 30 fractions.
• A nonrandomized, prospective trial compared SRS (10 to 12.5 Gy) to FSRT (20 to 25 Gy in 5 fractions). This
study demonstrated comparable rates of local control, hearing preservation, and CN V and CN VII
preservation between the two groups.

32. • Juvenile nasopharyngeal angiofibroma (JNA) is a rare, benign, vascularized tumor in the head and neck,
affecting mostly male adolescents.
• It originates from the first branchial arch artery. JNAs typically occur in the spheno-ethmoidal suture and
spread from the nasal cavity to the sphenopalatine foramen and pterygopalatine fossa.
• Other routes of local spread include the paranasal sinuses, infratemporal fossa, orbital space, and middle
cranial fossa.
• Symptoms initially include recurrent epistaxis and impaired nose breathing. As local extension occurs,
patients may develop facial swelling, orbital symptoms (blindness), cranial nerve deficits, and headaches
from intracranial extension.
Juvenile Nasopharyngeal Angiofibroma

33. RT in Juvenile Nasopharyngeal Angiofibroma-
INDICATIONS-
1. Tumors with intracranial extension or tumors in
patients that are medically inoperable are
generally treated with RT as the primary
modality.
2. Indications for postoperative RT include relapse
after surgery
RT Technique and dose-
 Fractional IMRT preferred
 30-50Gy/2-3Gy per fraction

34. VASCULAR DISORDERS

35. Vascular disorders are broadly categorized into vascular tumors, most
commonly benign hemangiomas, and vascular malformations, including
arteriovenous malformations (AVMs) and cavernous hemangiomas.
Radiosurgery has emerged as an important and common treatment
option for AVMs.
Although radiation was used commonly in the past to treat
hemangiomas in children, the recognition of late effects associated with
radiotherapy, especially secondary malignancies, has rendered this
practice less common.

36. • Intracranial AVMs are congenital vessel abnormalities consisting of conglomerations of
dilated arteries and veins with a resultant lack of a normal capillary bed.
• The overall prevalence is low, affecting approximately 18 in 100,000 individuals with age at
presentation typically between 20 and 40 years old.
• Clinical concern comes from the high risk of bleeding, estimated to be 2% to 4% per year.
• Approximately 50% of patients present with hemorrhage and 50% present with nonfocal
(headache, nausea) symptoms or incidentally found focal neurologic deficits.
• The risk of death per bleed is up to 10% and approximately 30% have serious morbidity
associated with each bleed.
Arteriovenous Malformations (AVM)

37. • A higher Spetzler-Martin grading scale score correlates with increased risk of surgical morbidity and
neurologic deficits.

38. Surgical Intervention-
• The goal of any therapy for AVM is to completely obliterate the nidus.
• Partial obliteration of the nidus does not decrease the bleeding risk.
• Complete surgical excision provides immediate cure but carries a risk of intraoperative bleeding, ischemic
cerebrovascular accident, infection, and death.
• Surgery is particularly indicated for AVMs in superficial, non-eloquent regions of the brain.
• Endovascular therapy (embolization) is not curative, but may be used to decrease the risk of intraoperative
bleeding or to decrease the size of the nidus before planned radiotherapy. There is a theoretical increased
risk of hemorrhage or neurologic complication postembolization.

39. Radiotherapy in AVM-
• SRS is the radiation modality of choice for the treatment of AVMs.
• SRS is indicated mostly for lesions in deep or eloquent regions of the brain and is particularly safe and
successful for lesions that are <3cm.
• Unlike surgery, the time to obliteration ranges from 1 to 4 years after SRS, so the patient remains at a
continued bleeding risk.
• Typical prescriptions for treatment of AVM are 21 to 22 Gy prescribed to the 50% IDL for frame-based
radiosurgery .
• The prescription should be lowered for AVMs near the brainstem or larger lesions (>3 cm).
• For LINAC-based SRS, prescriptions generally range from 16 to 24 Gy in a single fraction to 20 to 22 Gy in 2
fractions for spinal AVMs .

40. Bleeding Risk post SRS-
• Even with time, Maruyama et al. demonstrated that the bleeding risk is not completely eliminated, but
reduced by approximately 88%.
• Overall, the obliteration rate is 80% by 3 years for lesions that are 3 cm or smaller.
• For larger lesions, the angiographic obliteration for large AVMs is significantly reduced, with a mean
approximating 66%.

41. TRIGEMINAL NEURALGIA

42. • A common problem that affects approximately 15,000 patients each year in the United States.
• There is a slight female predominance (1.5:1).
• Two types- Type 1 & Type 2
• Type 1- sudden shocks of sharp, lancinating facial pain lasting anywhere from a few seconds to minutes
with pain-free intervals, more likely to be pain free and have longer disease control post decompression
• Type 2- constant burning, aching, or throbbing pain, generally of lower intensity
• The classic clinical feature is recurrent episodes of sudden, brief, severe, stabbing, or lancinating pain in
the area of the trigeminal nerve sensory distribution.
• It is most commonly unilateral, but some cases are bilateral.
• Common triggers for attacks include talking, chewing, brushing teeth, and cold air.
• The diagnosis is often suspected on the basis of the above clinical symptoms, but an MRI brain should be
performed to rule out structural abnormalities that may be causing secondary TN.

43. RT in Trigeminal Neuralgia-
• SRS has emerged as a successful and minimally invasive procedure to treat classical TN.
• Typical doses using a frame-based radiosurgery platform range from 70 to 90 Gy, prescribed to an isodose
range varying from 50% to 100% prioritizing low doses to the brainstem for minimal toxicity.
• The median time to treatment response varies from 2 to 4 months with higher doses yielding better
treatment response but increased chances of sensory neuropathy (facial numbness).

44. DISEASES OF CONNECTIVE TISSUE AND SKIN

45. • Desmoid tumors (also called aggressive fibromatosis or deep musculoaponeurotic fibromatosis) are benign
tumors of connective tissue tumors that arise from muscle fascia, aponeuroses, tendons, and scar tissue.
• slightly more predominant in females
• tend to occur during the third and fourth decades of life
• Tumors can develop anywhere in the body, but most commonly involve in the trunk/extremity, abdominal
wall, and intra-abdominal sites, including the bowel and mesentery.
• Although desmoids have no known potential for metastasis or dedifferentiation, they are locally aggressive
and commonly have a high rate of recurrence even after complete resection.
DESMOID TUMORS

46. Radiotherapy in Desmoid tumors-
• Radiation therapy is a viable option for inoperable patients and may also be used in
combination with surgery or chemotherapy.
• Five-year local control rates among surgery, radiation therapy, and combined modality
groups were 69%, 93%, and 72%, respectively.

48. • The general recommended radiation dose for inoperable or recurrent desmoids is 60 to 65 Gy.
• Young age (≤30 years) was also associated with increased late toxicity.
• When an R0 resection is not possible, doses of 50 to 60 Gy postoperatively should be given to improve
local control.
• RT is often not considered for intra-abdominal tumors because of the dose and increased field size
required increased risk of bowel injury

49. • Dupuytren contracture, also known as Morbus Dupuytren (MD) and Morbus Ledderhose (ML) depending
on involvement of the hands or feet, respectively, is a connective tissue disorders that affects the palmar or
plantar fascia.
• Global prevalence of Dupuytren disease to be between 3% and 6%.
• Incidence increases after the age of 40
• affects men more often than women.
• A genetic predisposition along with a number of environmental factors (smoking, alcohol use) can lead to
local ischemia and free radical release, which, in turn, stimulates fibroblast proliferation and cytokine
production, particularly IL-1.
Dupuytren Contracture

50. Role of RT-
• Radiotherapy is currently used in the treatment of Dupuytren’s exclusively for early-stage
patients (who have a <10 degree deformity) and is considered standard of care for
prevention of Dupuytren progression.
• Low-dose radiotherapy hinders fibroblast proliferation and the cascade of inflammatory
markers that induce collagen formation and fibroblast differentiation into fibronectin.

51. • Keloids are an excessive tissue proliferation after scars after skin injury from surgery, heat,
chemical burns, inflammation (e.g., acne), or even spontaneous proliferation.
• Keloids appear mostly in the upper body and in regions with high skin tension (e.g.,
sternum, ear lobes).
• There is a genetic and race-specific predisposition that is already noted during adolescence.
• Keloids at the ear lobe after piercing are typical.
• Recurrence is common after treatment.
Keloids and Hypertrophic Scars

52. Role of RT-
• Radiotherapy should be considered in cases of repeat recurrences postoperatively or
where there is a high-risk of recurrence (e.g., marginal resection, large lesion,
unfavorable location).
• Primary RT can be considered in instances where resection would result in functional
impairment and in actively proliferating disorders within about 6 months after the
triggering trauma.
• Prophylactic RT immediately following excision (within the first 24 hours) is most effective
and reduces the risk of recurrence to 15% to 25% in most series.
• The target volume is limited to the scar plus a 1-cm margin; lead shielding can be
constructed to protect normal tissue.

55. • Heterotopic ossification (HO) is a common complication of total hip arthroplasty, hip trauma, or acetabular
fracture.
• HO occurs when the soft tissues around the hip become ossified. Following trauma, primitive mesenchymal
cells in the surrounding soft tissues are transformed into osteoblastic tissue that then forms mature bone.
• The hip is the most common joint affected; HO typically occurs around the femoral neck and adjacent to the
greater trochanter.
• The risk factors for development of HO are unknown, but the incidence is greater in men and occurs in more
than 80% of patients who have a history of ipsilateral or contralateral HO.
• It is also more common in patients with a known history of osteoarthritis, ankylosing spondylitis, and Paget
disease.
• Hip stiffness is the primary symptom and the diagnosis is made radiographically. Pain is typically not
associated with HO.
HETEROTROPIC OSSIFICATION

56. Role of RT in HO-
• External beam radiation is an effective method for prevention of HO after total hip arthroplasty.
• Prophylactic radiation therapy for the prevention of HO has been used since the 1970s.
• A single fraction of 700 or 800 cGy to the at-risk region is recommended and should be delivered in the
perioperative period, either preoperatively (within 4 hours) or postoperatively (within 72 hours).
This study demonstrated that radiation therapy and
indomethacin are both effective in the prevention of
postoperative HO.

57. Although absolute differences may be small,
postoperative RT is on average more effective
than NSAIDs in preventing HO after major hip
procedures, and its efficacy is dose dependent.
There was no evidence for a statistically significant
or clinically important difference between NSAIDs
or radiation in preventing HO.

58. The meta-analysis suggest that radiation therapy is not cost-
effective when compared to use of NSAIDs.

59. • Typically, an AP-PA field size measures 14 × 14 cm with the cranial field border
approximately 3 cm above the acetabulum and the caudal field border encompassing
two-thirds of the proximal implant.
• The dose is prescribed to the body midplane.

60. Different effects of RT with varying doses are exploited for treatment of
benign diseases
Wide range of benign diseases are treated with RT
Should be used when other methods have failed
Most conformal technique to be used
Usually lower dose required
Risk of radiation carcinogenesis is trivial
SUMMARY

61. THANKS