radiotherapy for recurrent nasopharyngeal cancer

1. DR :- OMER HASHIM
RADIATION ONCOLOGIST
PORTSUDAN ONCOLOGY
CENTER

2. Clinical
dilemma &
challenge????

3. Limited surgery options
Chemotherapy response ???
High toxicity with re-irradiation

4. Multidisciplinary Team
Radiology
Pathology
Dentistry speech
Otolaryngology
Medical Oncology
Speech Pathology
Nutrition

5. Keratinizing SCC
WHO 1
Associated with
tobacco &alcohol
Non keratinizing
SCC .WHO 111
Undifferentiated
.associated with
EBV

6. Treatment of recurrent NPC
• Palliative
chemotherapy
Metastatic recurrent
• Radiotherapy
• Concurrent
Local recurrent

7. Concurrent
CH+RTX
For locally
advanced cases
Increase OS

8. Re-irradiation

10. Diagnosis
Early diagnosis depend on regular follow up
Examinations
Images
endoscopy
Biopsy

11. Images
 Normal anatomy is altered in re-irradiation due to scaring
due to RTX and or surgery . Difficult to differentiate
between recurrent and post surgery
 &post RTX scare .
 So CT &MRI have limited role
 Biological function image PET scan has important role not
only in differentiation of the scare and recurrence but also
in accurate delineation of the recurrent volume

12. Path- clinical
Presentation with
nasal bleeding or
discharge
Time to
recurrent is
1/12 to 10 yrs

13. Recurrent tumor is
more radioresistant
due to more fibrosis –
hypoxia & contain
radioresistant stem
cell

14. Recurrent occurring in
low dose area or in miss
area the loco-regional
failure most likely due to
internasic radio-resistant
&concurrent chemo-radio
will be more effective
than locoreginal failure at
high dose area

15. Recurrent occurring with short time (less than
1 yr) representing aggressive disease and radio-
resistant .
Recurrent after long period indicated
radiosensitive and allow more chance
Of radiation even normal tissue

16. Conformation of recurrence with
biopsy is gold standard

19. Surgery
Surgery has limited role usually only in
regional (lymph nodes )recurrent & very
small size in accessible area

20. RTX of recurrent
NPC
benefit of re-irradiation
complication of re-irrdiation &
Organs tolerance

21. Radiotherapy
Radiation therapy is the only curative treatment
modality for non-metastatic reNPC. For more locally
advanced cases, the addition of concurrently
administered chemotherapy has significantly improved
outcomes, including and especially overall survival (OS)

23. Toxicity
 Toxicity of reirradiation depend on :-
Target
volume
dose
Time
interval

24. Target
volume
Site of
Recurrence
Pervious RTX
Volume
Pervious
BED
LOW
DOSE
AREA
HIGH
DOSE
AREA
NORMA
L
TISSUES
TOLERN
ACE
ACUTE
REACTED
TISSUES
LATE
REATED
TISSUEA
GOOD
REDIORSISTANT Tolerable
Life expectancy

25. Technology factors
The aims of reirradiation to :-
Delivery of therapist significant dose.
Sparing of sensitive normal organs which have less
radiation tolerance reserve
Modern radiotherapy have made the re- RT more
attractive & faceable for dose escalation. potentially
allowing for better palliation

26. Treatment techniques
3D
Proton therapy

29. Non IMRT
2D &conformal result in
high rate of complication
48% --73% late
complication

31. IMRT
IMRT is stander of care for
patients rNPCof OS range
45%-----65%

33. SRS
Several series have reported satisfactory local control
when stereotactic radiosurgery was used to treat
recurrent NPC, as shown by Chua et al. [31] who
reported a 5-year overall survival rate of 47%. The time
interval from primary radiotherapy, rT stage, prior local
failures and tumor volume were significant
predictive factors for local control and/or survival

34. 3 D & IMRT have better out come by increase
the dose to recurrent tumor mass and decrease
the dose to the surrounding normal tissues
No elective irradiation to normal
tissues
GTV to CTV 3-5 mm
CTV to PTV 3-5
mm

35. Radiobiology of reirrdiaton
Dose
Tissueα/β
ratio
Volume
Calculating Total
Cumulative Dose
Biological effective dose
BED
Tech

36. Doses
The optimal dose for reirradiation has not established .
A total dose of 60 GY is widely accepted by most of
radiation oncologist .
 Other regime include 50 GY +BT .
 STS or FSRT 48 GY/6 Fr
 Dose less than 50 GY have worse out come

37. Studies
In cohort study performed by wang et al
comparing RTX vs CHx & supportive
care found that RTX has better OS .

39. Late toxicities
Complication depend on the site of recurrent
Tumor volume, local treatment techniques, doses (pervious
and current one )and time interval
Most common complication :-
Temporal lobe necrosis
Massive hemorrhage
NP tissues necrosis
Carotid stenosis
Fibrosis

40. Home message
Re-irradiation the most reliable treatment for recurrent
nasopharyngeal cancer
In good logistic support .
Fear of cancer more than fear of late appearing
complications of radiotherapy