2. Overview in management of lung cancer:
Intent of treatment depends on: resectability
performance status
associated co-morbidities.
Two different approaches: curative
palliative.
Treatment modalities: surgery (for early stages)
radiotherapy- radical or
palliative. Chemotherapy.
3. RT in Lung Cancer: Issues
NSCLC: a moderately radiosensitive tumor; dose escalation
required.
Surrounded by organs which are dose limiting: heart, opposite
lung, spinal cord, esophagus.
Respiratory motion: a pertinent factor necessitating motion
management in radiation delivery.
4. Treatment options:
Stage I: surgery (TOC) or radiotherapy.
Stage II: surgery or RT.
Stage III: surgery+RT/ CT+RT
Stage IV: palliative RT/ chemotherapy.
5. Resectable Early stage ( I, II ) NSCLC::
Surgery is the treatment of choice.
Types of surgery: lobectomy
pneumonectomy
sleeve resection
wedge resection
segmentectomy
en bloc resection.
6.
7.
8.
9.
10. Resectable Early stage ( I, II ) NSCLC::
Patients are considered suitable for pneumonectomy if their
predicted post-op. FEV1 is > 1.2L; the patient does not suffer
from hypercarbia and cor pulmonale is not present.
Standard of care is surgical resection through either a
lobectomy or pneumonectomy with mediastinal lymph node
dissection.
Lobectomy has been shown to be superior to more limited
surgical resections such as wedge resection or segmentectomy
(acc to the LCSG trial, which showed improved local control
with more extensive resection).
11. Complete mediastinal lymphadenectomy provides the best
possible surgical staging by removing all lymph nodes, which can
then be analyzed pathologically for metastatic involvement.
This can help to identify patients who may require post-operative
adjuvant radiation therapy.
At minimum, lymph node sampling of all the draining areas
should be performed at the time of surgical resection, for
accurate final surgical-pathologic staging.
12. 5-year survival rates following surgical resection are:
73% for stage IA
58% for stage IB
46% for stage IIA
36% for stage IIB.
Patients who fail after surgery, present with-
extrathoracic disease (70%)
local recurrence (20%)
local + distant metastasis (10%).
13. Adjuvant chemotherapy is accepted as the standard of care for
patients with node-positive disease (stages IIA, IIB, IIIA)
Post-op radiotherapy may be beneficial in stage IIIA, but is
not indicated in completely resected stage I and II NSCLC.
14. Thoracoscopic Lobectomy::
Video-assisted thoracoscopic surgery (VATS) or thoracoscopic
lobectomy is a minimally invasive surgical treatment currently
being investigated in all aspects of lung cancer.
Has several advantages over standard thoracotomy:
- Acute and chronic pain is minimal.
- Associated with low post-operative morbidity and mortality.
- Minimal risk of intra-operative bleeding.
- Minimal loco-regional recurrence.
- More rapid return to function than lobectomy by thoracotomy.
15. Inoperable Early-stage (I, II) NSCLC::
For patients who cannot undergo surgery, or decline surgical
treatment, conventional radiation therapy results in survival
rates of approx. 15-30%.
However, conventional RT has inferior local control as compared
with surgery.
Hypofractionation, or delivery of high doses of radiation in a few
fractions, is a means of increasing the biologic effects of RT.
Options now available are:
- SBRT (SABR)/ Cyber Knife
-
Brachytherapy: endoluminal and interstitial.
16. SBRT:
SBRT, or Stereotactic Body Radiotherapy ( stereotactic ablative
radiotherapy) refers to the delivery of large doses of radiation to
a small treatment volume, usually employing multiple beams,
using a small number of fractions (5 or less).
Patient selection criteria are:
- Medically inoperable or do not want surgery
- PS 0-2
- Stage T1-3, N0 following PET
- Maximum tumor size 5cm
- Not adjacent to major structures like great vessels, heart,
esophagus
- Able to lie supine for at least an hour.
17. SBRT systems can either use a frame-based system or it
can be frameless.
Frame-based systems have been developed to control
lung and tumor motion, including compression devices,
breath-hold techniques, automated breathing control or
full body moulds.
For frameless systems, gold fiducial markers can be
placed to allow tumor localization by the treatment
machine, or stereotactic real-time imaging can be
performed to localize the tumor visually prior to
treatment.
Stereotactic methods of tumor localization decrease the
effects of lung and tumor motion, resulting in smaller
treatment fields and margins.
18. SBRT planning involves CT imaging of the patient.
To assess the degree of physical excursion of the tumor during
different phases of the respiratory cycle, 4D-CT imaging
should be performed; or, maximum inspiratory and
expiratory scans will provide some degree of approximation of
the degree of motion.
Margins are 1cm in the superior and inferior dimensions and
5mm radially.
Typically, 6-12 convergent, non-co planar beams are used in a
linac-based system.
19. Commonly used doses for
SABR:
Total dose No. of
fractions
Indications
25-34Gy 1 Peripheral, small (<2cm) tumors,
esp. >1cm from the chest wall
45-60Gy 3 Peripheral tumors and >1cm from
the chest wall
48-50Gy 4 Central or peripheral tumors <4-
5cm, esp. <1cm from chest wall.
50-55Gy 5 Central or peripheral tumors, esp.
<1cm from chest wall.
60-70Gy 8-10 Central tumors.
20. RESULTS:
Timmerman et al reported the results of RTOG 0236, a phase II
trial in medically inoperable patients with T1 or T2 tumors
treated to 54Gy in three 18Gy fractions.
3-year primary tumor control rate 97.6%
Loco-regional control rate 90.6%
3-year distant failure rate 22.1%.
Median OS 48.1 months.
21. Because patients are at risk for a second primary or
mediastinal relapse, close follow-up is required. Imaging
should be obtained at least 2-3 months after completion of
SBRT.
Serial PET scans are not recommended as inflammation can
persist for as long as 6 months to 2 years.
Thus SBRT, with its advantage of patient convenience and
promising local control results, has largely replaced
conventionally fractionated radiotherapy as the standard
approach in the medically inoperable patient.
22. Two international phase III trials for SBRT are underway-
- The Stereotactic Radiotherapy versus Surgery (STARS) Trial,
which compares surgery vs. Cyberknife SRT for stage I
NSCLC;
- The Radiosurgery or Surgery for Operable Early-Stage NSCLC
(ROSEL) study, which compares local control, QOL and
treatment costs of surgery versus SBRT.
23. Brachytherapy in Lung cancer:Brachytherapy in Lung cancer:
is considered a suitable alternate treatment for very early
cancers; localized, large unresectable cancers or as a boost in
combination with EBRT.
Indications include thoracic symptoms ( dyspnea due to
endobronchial tumor or obstructive pneumonia), previous
high dose RT to the chest; and endobronchial or endotracheal
lesions.
May be administered by permanent iodine-125 interstitial
implants performed intra-operatively, removable iridium-192
implants through intra-operative insertion of Teflon catheters
in the tumor, or intra-bronchial LDR or HDR iridium 192
implants.
24. Stage III Non-Small Cell Lung Cancer::
Majority of patients with inoperable locally advanced NSCLC
(stage IIIB) receive definitive thoracic RT as part of their
treatment strategy, with concurrent chemotherapy (standard of
care acc to RTOG 94-10 trial).
Sequential chemoRT or RT alone is appropriate for frail patients
unable to tolerate concurrent therapy.
Accelerated RT regimens may be beneficial ( to improve
therapeutic ratio and survival rates and to decrease local
failures)--- particularly if not concurrent with chemotherapy i.e.
in a sequential or RT-only approach.
RT has a role after surgery; however pre-op. RT has no survival
benefit in management of marginally resectable or unresectable
disease.
25. Stage III Non-Small Cell Lung Cancer (contd.)
Preoperative concurrent chemoRT is an option for patients with
resectable stage IIIA (minimal N2 and treatable with
lobectomy) and is also recommended for resectable superior
sulcus tumors.
Preoperative chemotherapy and postoperative RT is an
alternative for patients with resectable stage IIIA.
In patients with clinical stage I/II upstaged surgically to N2+,
PORT is generally administered after post-op chemotherapy.
For positive resected margins, PORT with concurrent
chemotherapy is recommended.
26. stage III
Resectable Unresectable
Preop chemo or
chemoRT chemoRT RT only
surgery
PORT + adj. CT
27. Modalities of RT:
- 2D conventional planning
- 3D CRT.
- IMRT
- 4D gated RT.
28. RT Techniques:
For 2D planning: 2cm margin around any gross tumor.
1cm margin around regional lymph node
groups.
Upper lobe tumors- I/L supraclav and subcarinal lymph nodes
to be included.
Middle and lower lobe tumors- entire mediastinum from the
thoracic inlet to the diaphragm.
29. Fields: AP-PA portals till spinal cord tolerance (~40Gy).
boost of 20Gy by shrinking field technique after spinal
shielding.
Energy: either Cobalt-60 or Linac.
Dose: 60Gy in 30# over 6 weeks (RTOG 73-01 trial).
31. 3D-CRT::
Treatment simulation:Treatment simulation:
- Goal of simulation is to acquire an image-based representation
of the patient for the purposes of tumor and normal organ
delineation for treatment planning.
- Imaging traditionally performed with CT.
- Slice thickness =< 5mm.
- Anatomic region scanned should include both lungs and
extends from level of cricoid cartilage to L2 vertebra.
32. Management of tumor motion:Management of tumor motion:
- Motion can result in significant distortion of axial or helical CT
scans—confounds the ability to contour the target accurately on
the planning CT data set.
- Motion management strategies should be considered when
range of tumor motion is >5mm in any direction.
- Motion encompassing methods are:
- 4D-CT scans, which contain spatial and temporal information
during the CT acquisition process.
- Slow CT scans (4 seconds per slice) acquired during quiet
respiration.
- Abdominal compression devices
- Techniques as deep-inspiration breath hold, automated
breathing control, respiratory gating and tumor tracking.
33. 3D-CRT
GTV: primary tumor and any gross lymph nodes.
CTV: areas thought to harbor micrometastases
(hilar/mediastinal LN, margin).
PTV: margin for physiologic organ motion during treatment
and setup errors.
Beam energy: 6-10 MV.
34. Gross Tumor Volume (GTV)
Clinically macroscopic disease, as typically identified on any
imaging modality.
Usually derived from a treatment planning CT or a PET-CT
obtained during quiet respiration.
Lung windowing should be used for delineation of the primary
tumor GTV.
Mediastinal extent : mediastinal windows.
Lymph node >1cm in SAD: +ve
When feasible, mediastinum should be pathologically staged
and this information should be incorporated into delineating the
nodal GTV.
35. Clinical Target Volume (CTV)
Represents a volumetric expansion of the GTV to encompass
microscopic disease.
GTV-to-CTV: 6mm for squamous cell ca and 8mm for adenoca, with
95% accuracy.
For others: 9mm.
In the absence of radiographic proof of invasion, CTV of the primary
should not extend into the chest wall or mediastinum.
For nodal disease, a 3mm margin encompasses 95% of the microscopic
extranodal extension of disease in LN <2cm. Larger margins required
for LN >2cm.
CTv expansion of the LNs should not extend into the major airways or
the lung.
In PORT, CTV includes the bronchial stump and high-risk draining
lymph node stations.
36. Internal Target Volume (ITV)
Defined by ICRU 62 as ‘an expansion of the CTV to account
for tumor motion’.
Planning Target Volume (PTV)
Volumetric expansion of the CTV to account for setup
variability.
Individual assessment is recommended.
PTV margin can be decreased by immobilization, motion
management and IGRT techniques.
Typical margins are 5-10mm if daily IGRT employed;
otherwise 10-20mm.
37. Beam arrangements:Beam arrangements:
- Beam arrangements can range from simple two-field, parallel
opposed fields to complex, multiple gantry angle, modulated
beams for more focal treatments.
- Beams are shaped with MLC, which enables conformation of
radiation to the target.
- AP/PA fields are considered when disease is more extensive
and located centrally. Off-cord fields are required beyond 40-
45 Gy (in 1.8-2Gy per #) because of spinal cord tolerance.
39. Normal dose-volume constraints for conventionally
fractionated RT::
organ RT alone ChemoRT
Spinal cord 50Gy 45Gy
lung MLD <20Gy
V20 <40%
MLD <20Gy
V20<35%
V10<45%
V5<65%
heart V40 <50% V40 <50%
esophagus V60 <50% V55 <50%
kidney 20Gy (<50% of combined
both kidneys or <75% of
one kidney if he other one
is not functional)
same
liver 30Gy (40%) same
40. IMRT::
More suitable than 3D-CRT for advanced-stage disease with a
larger GTV.
Median absolute reduction in lung volume irradiated above 10
and 20 Gy are 7% and 10% respectively.
>2Gy less mean total lung dose and 10% decrease in the risk of
radiation pneumonitis.
Dose to the heart, esophagus and thoracic tissue also decreased.
Tumors in the superior sulcus or close to the esophagus or spinal
cord or patients with +ve lymph nodes may benefit more.
41. Image-guided radiation therapy (IGRT) is recommended
when using SABR and 3D-CRT/IMRT :
- with steep dose gradients around the target
- When OARs are in close proximity to high-dose regions
- When using complex motion management techniques.
42. Chemotherapy regimens used with RT::
Concurrent chemoRT regimens:
- Cisplatin 50mg/m2 days 1, 8, 29 and 36; etoposide 50mg/m2
days 1-5 and 29-33 (preferred).
- Cisplatin 100mg/m2 days 1 and 29; vinblastine 5mg/m2
/weekly; x 5 (preferred).
- Carboplatin AUC 5 day 1; pemetrexed 500mg/m2 on day 1
every 21 days for 4 cycles (non-squamous).
- Cisplatin 75mg/m2 day 1; pemetrexed 500mg/m2 on day 1
every 21 days for 3 cycles (non-squamous).
43. Sequential chemoRT regimens:
- Cisplatin 100mg/m2 days 1 and 29; vinblastine 5mg/m2/weekly on
days 1,8, 15, 22, 29; followed by RT.
- Paclitaxel 200mg/m2 over 3hours on day 1; carboplatin AUC 6 over
60 minutes on day 1 every 3 weeks for 2 cycles followed bt RT.
- Concurrent chemoRT followed by chemotherapy:
- Paclitaxel 45-50mg/m2 weekly; carboplatin AUC 2 with RT f/b 2
cycles of paclitaxel 200mg/m2 and carboplatin AUC 6.
- Cisplatin 50mg/m2 days 1, 8, 29, 36; etoposide 50mg/m2 days 1-5,
29-33 with RT f/b cisplatin 50mg/m2 and etoposide 50mg/m2 x 2
cycles (category 2B).
44. Chemotherapy regimens for NACT and adjuvant
therapy::
Cisplatin 50mg/m2 days 1 and 8; vinorelbine 25mg/m2 days 1, 8,
15, 22, every 28 days for 4 cycles.
Cisplatin 100mg/m2 day 1 ; vinorelbine 30mg/m2 days 1, 8, 15,
22, every 28 days for 4 cycles.
Cisplatin 100mg/m2 day 1; etoposide 100mg/m2 days 1-3, every
28 days for 4 cycles.
Cisplatin 75mg/m2 day 1; gemcitabine 1250mg/m2 days 1 and 8,
every 21 days for 4 cycles.
45. Cisplatin 75mg/m2 day 1; docetaxel 75mg/m2 day 1 every 21
days for 4 cycles.
Cisplatin 75mg/m2 day 1; pemetrexed 500mg/m2 day 1 for
adenocarcinoma and large cell carcinoma and NSCLC NOS
(without specific histologic subtype) every 21 days for 4 cycles.
For patients with comorbidities or patients not able to tolerate
cisplatin---- paclitaxel 200mg/m2 day 1, carboplatin AUC 6
day 1, every 21 days.
46. Stage IV NSCLC::
Effective palliation is an important objective.
It is important to intervene before SVCO, obstructive pneumonia or
lobar collapse develops.
EBRT:
Certain symptoms like hemoptysis and pain are more effectively
palliated, whereas dyspnea, hoarseness and poor PS appear to be
more refractory.
Isolated symptomatic lesions such as bone metastasis and spinal cord
compression are also managed with palliative courses of RT (eg. 30Gy
in 10#).
Standard therapy for multiple brain metastases in NSCLC is whole-
brain RT ( with dexamethasone 4mg four times daily before and
during RT and anticonvulsants only if seizures occur).
47. Doses:
Palliative RT Total dose Fraction size Treatment
duration
Obstructive
disease
30-45Gy 3Gy 2-3 weeks
Bone mets with
soft tissue mass
20-30Gy 4-3Gy 1-2 weeks
Bone mets
without soft
tissue mass
8-30Gy 8-3Gy 1 day-2 weeks
Brain mets 30Gy 3Gy 2 weeks
Any mets in
patients with
poor PS
8-20Gy 8-4Gy 1 day-1 week
49. Targeted therapy::
Indicated in patients with advanced NSCLC who have failed
platinum/taxane based chemotherapies.
Rationale: EGFR in epithelial tumors gets activated by binding
of natural ligands TGF.
- Activation of EGFR leads to:
- Increased cell proliferation
- Angiogenesis and metastasis.
- Anti-EGFR agents are: a) monoclonal antibodies
cetuximab and panitumumab.
- b) TKIs- geftinib, erlotinib.
50. Geftinib- 250mg OD (oral);
Erlotinib- 150mg OD (oral).
rash and diarrhoea are the most common side effects.
10-15% 0f tumors show shrinkage, while 30-40%
remain stable.
Bevacizumab:
- Is a VEGF monoclonal antibody.
- Inhibits angiogenesis and metastasis by blocking VEGF
induced increase in capillary permeability and peritumoral
lymph drainage.
- Crizotinib: approved by FDA for patients with locally
advanced or metastatic NSCLC who are positive for
ALK gene rearrangement.
51. First-line therapy:First-line therapy:
Bevacizumab +chemotherapy or chemotherapy alone is
indicated in PS 0-1 patients with advanced or recurrent
NSCLC. Bevacizumab should be given until disease
progression.
Cetuximab + vinorelbine/cisplatin is an option for patients
with PS 0-1 (category 2B).
Erlotinib is recommended as a 1st
line therapy in patients with
sensitizing EGFR mutations and should not be given as 1st
line
therapy to patients negative for EGFR mutations or with
unknown EGFR status.
Crizotinib is indicated for select patients with ALK
rearrangements.
52. First-line therapy:First-line therapy:
Two-drug regimens are preferred; a third cytotoxic drug
increases response rate but not survival.
Single agent therapy or platinum based combinations are a
reasonable alternative in patients with PS2 or the elderly.
Cisplatin or carboplatin are effective in combination with any
of the following agents: paclitaxel, docetaxel, gemcitabine,
etoposide, vinblastine, vinorelbine, pemetrexed or albumin-
bound paclitaxel.
53. Maintenance therapy:Maintenance therapy:
Continuous maintenance refers to the use of at least one of
the agents given in 1st
line, beyond 4-6 cycles, in the absence
of disease progression.
Switch maintenance refers to the initiation of a different
agent, not included as part of the 1st
line regimen, in the
absence of disease progression, after 4-6 cycles of initial
therapy.
54. a) Continuation maintenance:
- Continuation of bevacizumab after 4-6 cycles of platinum
doublet chemotherapy and bevacizumab.
- Continuation of cetuximab after 4-6 cycles of cisplatin,
vinorelbine and cetuximab.
- Continuation of pemetrexed after 4-6 cycles of cisplatin and
pemetrexed chemotherapy (non-squamous).
- Continuation of gemcitabine after 4-6 cycles of platinum
doublet chemotherapy (category 2B).
55. b) Switch maintenance:
- Initiation of pemetrexed after 4-6 cycles of 1st
line platinum-
doublet chemotherapy ( non-squamous ).
- Initiation of erlotinib after 4-6 cycles of 1st
line platinum-
doublet chemotherapy (category 2B).
- Initiation of docetaxel after 4-6 cycles of 1st
line platinum-
doublet chemotherapy, in patients with squamous cell ca
(category 2B).
- Close surveillance of patients without therapy is a reasonable
alternative to maintenance.
56. Second-line therapy:Second-line therapy:
In patients who have experienced disease progression either
during or after 1st
line therapy, single agent docetaxel,
pemetrexed or erlotinib are established 2nd
line agents.
- Docetaxel is superior to vinorelbine or ifosfamide.
- Pemetrexed equivalent to docetaxel with less toxicity in
patients with adeno- or large cell ca.
- Erlotinib is superior to BSC.
- Third-line therapy:Third-line therapy: if not already given, options are docetaxel,
pemetrexed, erlotinib or gemcitabine.
57. Sequelae of therapy::
Acute sequelae:Acute sequelae:
include esophagitis, cough, skin reaction and fatigue.
Acute radiation esophagitis usually begins in the 3rd
week of RT, at
approx. 30Gy.
Treatment includes mucosal anaesthetics (viscous lidocaine) and
agents that coat the irritated surfaces (suspension or liquid antacids).
Cough is common but usually mild. Anti-tussive therapy with or
without codeine phosphate is usually effective.
Treatment of acute phase of radiation pneumonitis includes absolute
bed rest, use of bronchodilators and corticosteroid therapy.
Antibiotics indicated only if associated secondary infection.
Skin reaction is mild to moderate; topical moisturizing creams or
ointments relieve symptoms.
58. Late sequelae:Late sequelae:
Include pneumonitis and pulmonary fibrosis, esophageal
stricture, cardiac sequelae ( pericardial effusion, constrictive
pericarditis, cardiomyopathy), spinal cord myelopathy and
brachial plexopathy.
59. Conclusion::
NSCLC accounts for more than 75% of all cases of lung
cancer
Accurate staging is critical as t/t options depend on
spread of the disease.
Surgery is treatment of choice for early stage NSCLC
Radiation has imp role in all stages, for radical t/t as
well as palliation
However its curative potential in stage III is extremely
poor with 5-yr survival rates of 3–10%