Techniques and challenges in radiotherapy of head and neck cancers (Experience from SMOC, Trinidad and Tobago)

1. Techniques and challenges in
radiotherapy of head and neck
cancers
Southern Medical clinic experience
DR MILIND KUMAR
CONSULTANT ONCOLOGIST

2. 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)

3. 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

4. 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

5. 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

6. 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.

7. Techniques and machines for RT
 2D RT
 3DCRT
 IMRT
 Rapidarc/ VMAT
 Sterotactic body RT
 Interstitial brachytherapy
 MRI/PET based RT planning

8. 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.

9. Contouring details
 OAR marked:
 Spinal cord
 Parotid
 Oral cavity
 Lacrimal glands
 Orbits/ optic apparatus
 Larynx

10. Contouring notes

11. Nasopharynx case contouring

12. Anterior tongue (post op) contouring

13. Larynx contouring

14. 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

15. Dose constraints achieved

18. Rapidarc planning and delivery

19. Recurrent adenoid cystic maxilla with
ethmoid extension

20. 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.

21. Ca hypopharynx post 23# CBCT

22. 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

23. 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#

24. 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#

25. 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
Females
Males
37.5%
62.5%
Pie Chart showing Age bracket for Head and Neck Patients
Age 50 and less
Age 50 - 70
Age 70 and above
28.0%
19.0%
53.0%

26. 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
0
2
4
6
8
10

27. 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

28. Chemotherapy
 Neoadjuvant chemo-10
 Neoadjuvant and concurrent chemo- 9
 Concurrent chemo only: 14
Neo Chemo
Neo and Con
Chemo
Con Chemo
Only

29. 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

30. 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.

31. Thank you
Teachers/ patients/ Team @ SMC