Date post: | 22-Jan-2018 |
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Techniques and challenges in
radiotherapy of head and neck
cancersSouthern Medical clinic experience
DR MILIND KUMAR
CONSULTANT ONCOLOGIST
Scope of presentation
Overview of head and neck cancer & Radiotherapy
role
Contouring & radiation planning guidelines followed
at SMOC
SMOC experience (Rapidarc in Head and neck
patients)
Management of head and neck cancers
Early stage (Stage I Stage II)—(Single modality)
Surgery or radiotherapy alone usually suffice
Advanced stage(Stage III Stage IV)– (Multimodal)
Surgery followed by post op RT or concurrent chemoradiation
Radiotherapy vs surgery
Multiple sessions –70Gy/35#/7 weeks vs one OT session
Acute side effects—skin reactions, mucositis, pain, fungal infection
Late side effects– loss of taste, xerostomia, dental caries, skin fibrosis.
Organ preservation—speech, swallowing
Weight loss during RT
Radiotherapy rationale
Ionizing radiation– free radicals damage DNA of tumor
While dividing tumor cells undergo apoptosis and cell death
Differential effect on normal tissues and they are less rapidly dividing as
compared to malignant tissues.
Radiotherapy want to focus on GTV-Gross tumor volume
CTV-Clinical target volume for subclinical disease
PTV-CTV + margin to account for daily set up errors and intra-fraction motion
Chemotherapy in head and neck cancers
It is usually used in combination with radiotherapy (sequential or
concurrent).
It has a role in organ / voice preservation (in laryngeal / hypopharyngeal
cancers) and in oropharyngeal cancers.
In select patients chemotherapy can be used for palliating symptoms.
Techniques and machines for RT
2D RT
3DCRT
IMRT
Rapidarc/ VMAT
Sterotactic body RT
Interstitial brachytherapy
MRI/PET based RT planning
Radiotherapy work flow
Initial diagnosis---tissue diagnosis ---Surgical evaluation—MDT discussion
Oncology consult—Diagnosis, investigations, staging and manangement planning
Radiation Simulation- CT with immobilization mask
Dosimetry—Identification and contouring organ at Risk
Radiation oncologist—Identification and contouring GTV/CTV
Dosimetry and Physicist—Planning, approval with RO, Quality assurance (patient specific checks)
Treatment delivery –Radiation therapists
Image guided verification of treatment delivery (CBCT/KV/MV image correction)
Weekly reviews with RO (Weight/ FBC/ local exam/ analgesia)
Daily reviews with oncology nurse, dietitian, Counsellor as need arises.
Contouring details
OAR marked:
Spinal cord
Parotid
Oral cavity
Lacrimal glands
Orbits/ optic apparatus
Larynx
Contouring notes
Nasopharynx case contouring
Anterior tongue (post op) contouring
Larynx contouring
Dose recommendations
Gross disease
70Gy/33#/7 ½ weeks High risk CTV
60Gy/33#/7 ½ weeks Intermediate risk CTV
54Gy/33#/7 ½ weeks Low risk CTV
Post op radiotherapy
66Gy/33#/6 ½ weeks for close/ positive margin
60Gy/30#/6 weeks if margins clear
Dose constraints achieved
Rapidarc planning and delivery
Recurrent adenoid cystic maxilla with
ethmoid extension
Image guidance-Treatment delivery
CBCT-Weekly CBCT
CBCT on demand if weight loss >10%, if mask is loose/ not fitting well
Kv-Kv imaging Daily done for matching.
Adaptive RT planning—In case of significant weight loss –CBCT –correlated with
planning CT scan and enables to re-CT sim and re-plan.
Ca hypopharynx post 23# CBCT
Radiation toxicities -Management
Radiation induced skin reactions-Saline dressings, do not bandage, povidone –
iodine, flamazine
Radiation induced mucositis- anbesol, magic mouthwash, soda bicarb gargles
Analgesia- Tramacet, liquid morphine
Weight loss- High protein diet sheet, daily monitoring by oncology nurses
SMOC experience
32 patients of head and neck cancers/ radiation
Nov 2015- Aug 2017 experience after commissioning of Rapidarc ix
All patients received VMAT –RA
Post op 60Gy-66Gy/30-33#
Radical 70Gy/35#/7 or 70Gy/33#/7 ½ weeks with SIB technique
60Gy/30# 60Gy/33#
54Gy/33#
SMOC experience
32 patients of head and neck cancers/ radiation
Nov 2015- Aug 2017 experience after commissioning of Rapidarc ix
All patients received VMAT –RA
Post op 60Gy-66Gy/30-33#
Radical 70Gy/35#/7 or 70Gy/33#/7 ½ weeks with SIB technique
60Gy/30# 60Gy/33#
54Gy/33#
Demographics
Females- 12/32 (37.5%)
Males- 20/32 (62.5%)
Age 50 and less: 9/32 (28%)
Age 50-70: 17/32 (53%)
Age 70 and above: 6/32 (19%)
Pie Chart showing ratio from females to males
FemalesMales
37.5%62.5%
Pie Chart showing Age bracket for Head and Neck Patients
Age 50 and lessAge 50 - 70Age 70 and above
28.0%19.0%
53.0%
Site distribution
Carcinoma oral cavity – 9
Carcinoma larynx– 9
Carcinoma oropharynx -4
Nasal cavity/ Nasopharynx/ salivary glands /Acoustic neuroma--2 each
Unknown primary,, hypopharynx-1 each
02468
10
Stage distribution
Clinical Pathological
T1- 1 3
T2- 5 7
T3- 5
T4- 6
N1- 1
N2- 2
N3-3
Recurrence/ residual/ margin positive: 5
Chemotherapy
Neoadjuvant chemo-10
Neoadjuvant and concurrent chemo- 9
Concurrent chemo only: 14
Neo Chemo
Neo and ConChemoCon ChemoOnly
Outcomes –Telephonic FU
NED- 23/32 (72%)
Alive with Local recurrence -3 (9%)
Metastatic disease- 1(3%)
Defaulted RT-1(3%)
Death-4 (13%)
Pie Chart Showing Outcomes
NED
Alive with local
Metastatic
Defaulted RT
Death
Our challenges
Timely diagnosis
Timely referral to higher centre and institution of appropriate treatment
PEG insertion pre-RT
Dental prophylaxis
Weight loss-CBCT-Adaptive RT.
Social issues-compliance
Financial constraints—SMARA charity supportive.
Thank you
Teachers/ patients/ Team @ SMC