LUNG CANCER Flashcards
- Adverse Prognostic Factors
Age > 65
o Performance status > 2
o Advanced stage
o Presence of mediastinal lymphadenopathy
o Tumor hypercalcemia
o Surgical procedure : Limited resection
o Positive resection margins
o Biological markers
§ COX 2
§ p 53
§ EGFR
§ erbB2
o Investigations to confirm the disease
cytology (sensitivity 65% - 75%)
§ Transthoracic FNAC (sensitivity 87% - 91%)
§ Bronchoscopic biopsy (70% - 80%)
§ TT-FNAC associated with
¨ Pneumothorax (27%)
¨ Hemoptysis (5%)
¨ Local bleeding (11%)
o Investigations to assess the stage
Imaging
¨ Plain X rays
- A tumor visible in a chest X ray has usually completed 75% of it’s natural history.
- Guides local radiotherapy
- Cheap follow-up assessment
¨ CT scans
- Accurate assessment of primary disease.
- Best for detection of mediastinal and chest wall invasion.
- Nodal size < 1 cm : 8% chance of occult nodal metastasis
- Nodal size > 2 cm : 70% chance of occult or overt metastasis
- Assessment of abdominal disease esp. of adrenal involvement.
- Various nodal size criteria exist to predict likelihood of nodal metastases.
- Pitfall: Pneumonitis cant be accurately distinguished.
¨ PET CT has a greater degree of sensitivity for detection of nodal disease that would be missed by size based criteria alone.
Bronchoscopy: Most valuable invasive investigation as it allows:
Confirmation of diagnosis:
- Biopsy and brushings 80% accurate
- Low false positive rates 0.8%
- Transbronchial forceps biopsy positive in 70%
- Visualization of tumor done in 60% - 75%
¨ Staging of the tumor: Extent of bronchial and carinal involvement.
¨ Symptom alleviation:
- Stenting
- Bleeding control
- Importance in brachytherapy
¨ Response assessment
¨ Detection of preinvasive malignancy (screening): Autoflurosecence bronchoscopy.
o Investigations to assess fitness for treatment
Blood tests
§ Renal and liver function tests
§ Pulmonary function tests
STAGING
T1: 3 cm or less, completely covered by pleura, does not involve main bronchus
§ T2:
¨ 3cm size.
¨ Visceral pleura involved.
¨ Main bronchus invasion but > 2cm from carina.
¨ Atelectasis / obstructive pneumonitis that extends to the hilar region but does not involve the entire lung
§ T3:
¨ Chest wall
¨ Diaphragm
¨ Mediastinal pleura
¨ Pericardium
¨ Main bronchus <2cm to carina
¨ Complete atelectasis / obstructive pneumonitis of entire lung
§ T4:
¨ Carina
¨ Vertebrae
¨ Great Vessel
¨ Esophagus
¨ Heart
¨ Separate tumour nodule in same lobe
¨ MALIGNANT pleural / pericardial effusion
§ N0: No regional LN metastases
§ N1: LN mets in ipsilateral peribronchial and/or intrapulmonary (Levels 10, 11, 12, 13, 14)
§ N2: Ipsilateral mediastinal or subcarinal
§ N3: Contralateral mediastinal /hilar or Ipsilateral or contralateral supraclavicular/ scalene nodes
- Prevention & Screening
The most cost effective method of lung cancer prevention is to stop smoking.
Screening of lung cancer was initiated with Chest X-Ray (CXR) and sputum cytology
o Disadvantages:
§ Early detection failed to improve prognosis even in high risk groups.
§ False positive results may be as high as 5% in CXR
Both are relatively insensitive to early stages.
§ The prevalence in the population is not high
enough to justify routine mass screening.
TREATMENT
Radical operation: Pneumonectomy24.
§ Lung Conservation:
¨ Lobectomy.
¨ Sleeve resection.
¨ Wedge resection.
¨ Segmentectomy.
§ Mediastinal lymph node dissection:
¨ Provides complete nodal staging.
¨ Identifies patients who require
adjuvant radiotherapy.
¨ Improves survival.
¨ Improves local control
§ At least nodal sampling should be performed, if not complete
lymphadenectomy
o Lymph node dissection
Lobe specific mediastinal nodal dissection in NSCLC
§ Right Side:
¨ Upper lobe (1,2,3,4,7)
¨ Middle lobe (1,2,3,4,7)
¨ Lower lobe (1,2,3,4,7,8,9)
§ Left Side:
¨ Upper lobe (4,5,6,7)
¨ Lower lobe (4,5,6,7,8,9
o Complete Resection
Free resection margins proved microscopically
§ At least a lobe specific mediastinal nodal dissection with complete
hilar and intrapulmonary nodal dissection.
§ At least 6 nodes should have been removed with 3 from mediastinal nodes.
§ No extracapsular extension in the nodes.
§ Highest mediastinal node removed should be microscopically free.
o Criteria for inoperability
Tumor based criteria:
¨ Cytologically positive effusions.
¨ Vertebral body invasion.
¨ Invasion or in casement of great vessels.
¨ Extensive involvement of Carina or trachea.
¨ Recurrent laryngeal nerve paralysis.
¨ Extensive mediastinal lymph node metastasis.
¨ Extensive N2 or any N3 disease.
RT ROLE
Plays an important role in the management of approx
85% of patients with non small cell lung cancers.
¨ RT can be applied in the following settings:
- With curative intent
- With Palliative intent
¨ RT is the most common treatment modality in
majority of patients in Italy as:
- Majority of the patients present with hilar
or mediastinal disease.
- Disease bulk prevents the use of surgical
techniques.
- Associated comorbidities and poor lung
function make patients not suitable for surgery.
- Advanced age and poor socioeconomic status make RT an attractive treatment option.
RT § Treatment techniques
Treatment for cure
- As definitive treatment alone (or with chemotherapy).
- As adjuvant treatment post surgery.
¨ Treatment for local control with limited probability of survival.
¨ Treatment for relief of symptoms, when the disease is too locoregionally advanced for control.
¨ Treatment in special situations:
- Treatment for superior sulcus tumors.
- Treatment for SVCO.
- Local palliative treatment
- Brachytherapy
RT TECHNOQUES
High energy photons (15MeV, 18MeV, etc) may be preferable when used to treat larger GTV’s (gross tumor volumes)
surrounded by consolidated and/or atelectic lung tissue, bulky lymphadenopathy or large blood vessels, thus achieving a better dose
distribution and also an improved therapeutic ratio.
¨ Patients should be treated in supine position unless indicated otherwise.
¨ Dose: 60-70 Gy in 30-35 fr over 6-7 weeks
¨ 3D or IMRT must to be chosen on individuals.
¨ Energy range is choosen to be 6 – 10 MV
¨ Lung correction factor should be applied during the calculations especially if manual calculation is being done
- 4MV à 4% per cm of lung tissue
- 10 MV à 2% per cm of lung tissue
- 20 MV à 1% per cm lung tissue
¨ Field Selection: 2D era
- Parallel opposed anterior and posterior fields are used.
- The primary disease should be encompassed with the 2 cm margin of normal-appearing lung.
- In upper and middle lobe or hilar disease, the inferior margin is situated 5 to 6 cm below the carina.
- In upper lobar disease the superior margin should cover the ipsilateral supraclavicular fossa.
- In lower lobe disease, inferior margin extends to the vertebral origin of the diaphragm.
- Width of the mediastinal field encompasses the vascular shadow, or the lymphadenopathy, whichever is wider.
- Field margins should be such that, the tumor lies within the field during inspiration and expiration.
¨ Respiratory gating:
- Tumors in lung may move by as much as 5-10 mm during normal quiet breathing.
- The PTV may be effectively doubled if this is taken into account Ø dose escalation impossible
- Two techniques of respiratory gating are
a) Breathhold techniques: Active: Using valves and spirometers/ Passive: Voluntary breath holding
(used in PGI)
b) Synchronized gating technique: Uses free breathing with synchronized beam delivery.
¨ Recent innovations
- 3DCRT
- IMRT
- IGRT
§ Early stage (Stage I-II)
Patient selection:
- proper staging
- adequate pulmonary reserve
- absent or controlled medical problems
¨ Effective treatment: impressive local control (65-90%)
¨ Many early stage pts (30-50%) are potentially resectable but MAY have reasons for being medically inoperable. Comorbidities
preventing surgical resection include
- COPD
- Cardio-vascular Disease
Poor performance status
¨ Doing “nothing” is not good in medically inoperable pts
¨ What is SBRT? Technical
- Multiple convergent beams of RT aimed at target
- Requires rigid patient immobilization
- MUST account OR compensate for organ motion
- Precise localization of target via stereotactic coordinate system
- Size-restriction for target
- Typically few-fraction (1 to 5) RT using large individual fraction doses
- High dose conformality, i.e., “tight around target”
- Rapid dose fall-off from target to surrounding normal tissue.
