Oncology 2003 Copyright (c) By Dr. Tun Ngwe Department of Oral & Maxillofacial Surgery University of Dental Medicine, Yangon

1. Dr. Tun Ngwe
Associate Professor
DOMS, UDM, Ygn
August 3, 2018 1TN

2.  Fundamental of patient management
 It is a precise measured dose of radiation to
a defined tumour volume, with a minimal
damage to surrounding tissue
 It is a highly potent cytotoxic agent
 free radicals damage cellular DNA
August 3, 2018 2TN

3.  cure primary tumour
 reduce bulk of the tumour
 reduce fixation of the tumour to surrounding
structures
 decrease incidence of local recurrence
 eliminate positive tumour margins following
incomplete resection
 reduce incidence of neck recurrence
 Post op radiotherapy is useful if multiple
lymph nodes involved or extracapsular
spread
August 3, 2018 3TN

4.  Produces no physical deformity
 Enables simultaneous treatment of regional
tissues and nodal metastasis ( high possible
lymphatic spread from tongue and FOM
cancer)
 Treatment of multiple primary malignant
lesions
August 3, 2018 4TN

5.  General - performence status , age,
nutritional, financial status, systemic d/s
August 3, 2018 5TN

6.  Radio sensitivity - leukemia, lymphoma etc.
 Tissue sensitivity ( more susceptible )
 Faster the rate of turn over, actively dividing
cells
 Histologically less differentiated the tissues,
the more sensitive
 Indirectly proportionate to volume of cancer
cells
 directly proportionate to tissue oxigenation
and blood supply
 bone - less sensitive to R/T
August 3, 2018 6TN

7.  Cure and local control of disease - probability of
survival after adequate therapy
 Palliative - no hope of survival for an extended
period, prolongation of survival and improve QOL
as well as symptoms relief
 as a curative therapy for stage I and II
 as part of combined modality therapy for stage
III and IV
 as part of palliative regime for persistent
cancer, metastatic disease , locoregional
recurrence - bone pain, spinal cord compression,
raised ICP
August 3, 2018 7TN

8.  Total planning volumes =
 clinical targeted volume ( tumour with minimal
effect on surrounding tissues ) +
 internal margin ( additional margin since the
tongue and mandible are not static structures) +
 set up margin - 2-4 mm ( day to day variation in
the position and alignment of the patient )
 to minimize damage surrounding normal
tissue, this volume has to be kept as small as
possible
August 3, 2018 8TN

9.  External beam ( Teletherapy)
 Kilovoltage/Orthovoltage (200-300kV) - low
energy
 Megavoltage ( 300kV -2MV) - high energy
 Cobalt 60, Caesium
 linear energy transfer (LET) - lesser damage , lesser
influence by concentration of oxygen
 Interstitial (Brachy therapy)
 close proximity to tumour (Tongue, FOM)
 wire, needle, seed ( Iradium, Caesium)
 booster therapy - for larger lesion receiving
external beam therapy
August 3, 2018 9TN

10.  Radical dose
 maximum with acceptable toxicity
 total 6000 to 7000 cGy
 Palliative dose
 - minimizing side effect of R/T, 20 cGy for 5 days
August 3, 2018 10TN

11.  200c Gy daily dose in OSCC
 redistribution of cell population in
radiosensitive phase ( M , S )
 repair of sublethal damage in the normal
cells
 repopulation of normal cells
 reoxygenation of tumour cells is enhanced as
the bulk reduce
 better to provides continuous treatment
August 3, 2018 11TN

12.  Fractionation enhances the therapeutic ratio because of the difference in the shape
of the shoulder between the malignant cells and normal tissue
 Shoulder represent the reversible DNA damage
August 3, 2018 12TN

13.  Should be sufficient to allow max
repair of the sublethally damaged
normal tissue
 Short enough to limit the malignant
cell repair and repopulation
August 3, 2018 13TN

14.  Radiation therapy is a highly potent
cytotoxic, react both normal and malignant
cells
 Explanation of the ( toxic ) side effects -
verbal and typed information
 Reassure that most can be alleviated now
and appropriate remedies are available.
August 3, 2018 14TN

15.  Combined treatment
 S/T and R/T are complementary to each
other and effective methods in treatment of
OSCC
August 3, 2018 15TN

16.  deliver higher dose than pre-op R/T
 greater dose to the vol of high risk or known
residual disease
 eleminate residual tumour in the operated
field
 Disadv;
 - delay in initiation of R/T ( 21 days post-op
usually)
 vascular changes impair R/T affect
 distant metastasis as a result of S/T
August 3, 2018 16TN

17.  diminishes tumour implantation by
decreasing viable cells within operative field
 eradicates microscopic disease beyond the
margin of surgical resection
 sterilizes the lymph nodes outside operative
field
 decrease the potential of dissemination that
might produce distant metastasis
 increase the possibility of resectability
 Disadv; - interfere with healing
August 3, 2018 17TN

18.  In OSCC , regional cervical node treatment
must also be consider
 Prophylactic R/T in N0
 Those who had a neck dissection , post op
R/T to the neck ( within 6 weeks of surgery )
when ;
 incomplete excision of tumour
 involved nodes of more than one level
 evidence of extracapsular node
August 3, 2018 18TN

19.  face mask (shell), shielding , wedging are
made in the mould room
 Protection to reduce the damage spinal cord,
eyes etc.
 Bite blocks
August 3, 2018 19TN

20.  Bite block - custom
made
 protects opposite jaw
and associated
structures
 opens and separates
the jaws and depresses
the tongue
 indicated for use in
treatment to the FOM ,
ant. 2/3 of the tongue ,
lower/upper alveolus ,
maxillary sinus
August 3, 2018 20TN

21. August 3, 2018 21TN

22.  Radio-oncologist
 must work closely with physicist & staffs to
ensure greatest accuracy of treatment and
radiation technology according to the plan.
 takes the ultimate responsibility of
treatment and it’s consequences
August 3, 2018 22TN

23.  Non -stochastic effects (reversible) ;
 mucositis
 mucosal ulceration
 hypo/dys-guesia
 anorexia
 pain
 candidiasis
 dermatitis,
 erythema
 alopecia (low dose)
August 3, 2018 23TN

24. xerostomia
cervicle caries
ORN
epithelial atrophy
dryness
telangiectasia
radiation fibrosis
alopecia ( large dose)
August 3, 2018 24TN

25.  See the patient weekly during the R/T and every
3-4 months after R/T
 for side effect or complications (Emergency
,Problems )
 xerostomia - water, artificial saliva, pilocarpine
 pain – analgesic
 fibrosis - mouth opening exercise
August 3, 2018 25TN

26.  Xerostomia
 Radiation dental caries – result of reduced salivary flow and
direct radiogenic damage to the amelodantinal junction
 keep oral cavity moist and clean
 OHI – soft tooth brush using fluoride containing tooth paste
and flossing daily
 Dietary advice with regard to caries prevention
 M/W – avoid alcohol containing , hot and burning M/W,
Fl rinses – daily
Sodium bicarb – 1 tea spoon of baking soda in a quart of
water – 10- 15 times / day
 Fluoride – custom made carrier and 0.4% stannous fluoride
gel
26 TNAugust 3, 2018

27.  elimination of gross sepsis, potential source of
infection
 caries, teeth with perio. problem, mobile
tooth , sites of trauma / irritation sharp edges
 refer to dentist with experience to cancer
management
 should be scheduled in consultation with
oncologist
27 TNAugust 3, 2018

28.  Pain control
 topical anesthesia
 Tricaine , mucaine
Enziclor – Benzydamine + Chlorhexidine 0.2% ,
Quadrajel – antiseptic , analgesic
 antibiotics moisturizing gel
28 TNAugust 3, 2018

29.  antifungal
 oral - Nystatin suspension or pastilles ,
mycostatin , miconazole cream,
clotrimazole troches (lozenge)
 Systemic - Mycostatin , Amphotericin ,
Ketoconazole , Fluconazole etc.)
 M/W – chlorhexidine, Betadine
29 TNAugust 3, 2018

30.  Post-op ( Partial glossectomy & neck
dissection) R/T August 3, 2018 30TN

31. August 3, 2018 31TN

32.  osteomyelitis in irradiated bone
 failed to heal over the period of 3 weeks in
the absence of primary tumour
 incidence – 2-20%
 risk for ORN continues indefinitely after
radiation therapy
August 3, 2018 32TN

33. - high radiation dosage ( >60 Gy ),radiation
technique (interstitial ) , fraction size and
number , bone involved in the field of radiation
- anatomic site of the primary tumour ( H&N )
- higher risk – mandibular bone is denser and
blood supply poorer than maxilla
- dentulous jaws
- dental status - caries , periodontal , impaction
August 3, 2018 33TN

34. - obliterative end arteritis
- tissue haemostatic deficiency results in ;
- hypovascular
- hypoxic
- hypocellular – osteoblast deficiency resulting from the
damaged marrow and periosteum )
- Trauma induced- extraction or mucosal
breakdown under denture or infection ( pulpal
and periodontal problems )
- continual process of normal remodelling in bone
does not occur and sharp areas on the alveolar
ridges will not smooth themselves
- chronic non-healing wound
- OM
August 3, 2018 34TN

35.  before R/T -dental evaluation is important
 residual dentition
 all teeth with questionable or poor prognosis should be
extracted
 impacted within the bone of the mandible to remain
 patient's dental awareness
 oral hygiene , periodontal status
 radiation location
 involved bone and salivary glands
 radiation dose
 below 50 cGy or above
August 3, 2018 35TN

36.  Extraction is done usually at the time of biopsy to R/T only
cases and at the time of surgery to operable cases
 surgically extracted with alveoplasty and primary closure
 alveolar bone must be evenly trimmed and carefully
smoothed
 Allow epithelization – 1 to 2 wks
 up to 14 or even 21 days
 antibiotics during the healing period to minimize infection
 R/T delay if healing is not satisfactory
August 3, 2018 36TN

37.  Regular recall dental examination
 successful early intervention
 conservative dental care
 timely dental treatment
 promptly with trauma (eg; adjustment or
removal of prosthesis that may contributing
to trauma)
August 3, 2018 37TN

38.  Proper dental care by pt
 Daily fluoride applications - mouth rinses or
gels to minimizing tooth decalcification
 regular professional dental prophylaxis every
6 months at a minimum frequency
 Base on patient hygiene needs
 endodontic procedures are difficult because
of progressive sclerosis of the pulp chamber
in irradiated teeth
August 3, 2018 38TN

39.  Removing the crown of the tooth but leaving
the roots
 No attempt at root canal treatment
August 3, 2018 39TN

40.  is not absolutely contraindicated
 if necessary , extraction can be done
 only when acute oral symptom are subsided
 Although either simple extraction without primary closure
or surgical extraction with alveoplasty and primary closure
yields similar results,
 atraumatic , asespis is critical
 antibiotics (Prophylactic as well as post op)
 LA without vasoconstrictor
August 3, 2018 40TN

41.  recommended to both pre and post tooth
removal for the prevention of ORN
 20 - 30 HBO dives before extraction
 10 more dives immediately after extraction
 to increase the local tissue oxygenation and
vascular in growth into the hypoxic tissues
 limited available units world wide
August 3, 2018 41TN

42. August 3, 2018 42TN

43. August 3, 2018 43TN

44. August 3, 2018 44TN

45. August 3, 2018 45TN

46. August 3, 2018 46TN

47. August 3, 2018 47TN

48. Treatment of ORN
 conservative measures
 diluted hydrogen peroxide (1.5%) and
chlorhexidine (0.02%) oral rinses
 Antibiotics
 Surgical method
 vary from sequestrectomy to
hemimandibulectomy
August 3, 2018 48TN

49.  combined hyperbaric oxygen therapy (HBO) ,
surgery and antibiotics
-revascularization of irradiated tissue
-HBO. 2- 2.5 atmospheres pressure
-for 1.5 - 2 hours per day
-up to 80 sessions
August 3, 2018 49TN

50. Therapeutic ultrasound
 at a frequencies of 3 MHz pulsed 1 in 4 at an
intensity of 1 w/cms sq. applied to the
mandible for 10 minutes daily for 50 days
(Reher, 1998).
August 3, 2018 50TN

51.  General ; performence status , nutritional
status, dental review , eye, ear
 Local ; response - complete, partial, minor
response, no change, progression
August 3, 2018 51TN

52. August 3, 2018 52TN

53.  Medical Oncologist
August 3, 2018 53TN

54.  General - performence status
 Age
 nutritional status
 systemic d/s
 blood CP, PC, renal ( urea, creatinine), liver
( LFT), cardio ( ECG)
 financial status
August 3, 2018 54TN

55.  Local - tumour staging, tumour
characteristic-
 chemo sensitivity - highly sensitive to Ac
myeloid leukemia, Ac lymphocytic leukemia,
Hodgkin and Non - Hogkin lymphoma, Ewing's
sarcoma, testicular cancer, ovarian cancer,
myeloma
 also thought less histologically differentiated
tumours may be more sensitive
to C/T
 adverse effect of blood supply reduce the
response of C/T
August 3, 2018 55TN

56.  Goldie - Coldmen hypothesis - tumour cells
mutate to drug resistance
 begins when cells number reaches between 1000
- 1 million
 clinically detectable amount of cells - 1 cm - 1
billion
 resistant is the problem even with small tumour
 maximum chance for cure when effective drugs
are given simultaneously
August 3, 2018 56TN

57.  Cure and local control of disease
 Paliative - prolongation of survival and
improve QOL
 rarely of curative value for OSCC
 as part of combined modality therapy for stage
III and IV
 as part of pallive regime for persistant cancer,
metastatic disease , locoregional recurrence
August 3, 2018 57TN

58.  Optimal dose is necessary for maximum
killing of tumour cells for complete cure
 Intermittent dosing is scheduled for time
short enough to limit tumour cell for repair
but allow the immune system to recover.
August 3, 2018 58TN

59.  Since chemo has nonspecific in action ( kill
both malignant and normal damage )
 explanation of the ( toxic ) side effects -
verbal and typed informations
 reassure that most can be alleviated now
and appropriate remedies are available

August 3, 2018 59TN

60.  Single agent
 rare complete response
 Combined agent or cocktails( 2 to 5 drugs)
decrease the chance of resistance
synergestic action ( Cisplatin & 5 FU )
different mechanism at different stages of
the cell cycle
BMC, CHOP, CABO , PBF
August 3, 2018 60TN

61.  Induction chemo
 Sandwitch chemo
 Adjuvant chemo
 Concurrent chemo
August 3, 2018 61TN

62.  Induction chemo ( Neo adjuvant )
 prior to S/T &/or R/T
 adv;
 decrease tumour size
 decrease distant metastases
 increase tumour sensitivity to R/T
(radiosensitizer effect )
 disadv;
 altered immune status
 delayed surgery
 imprecise margin for resection
August 3, 2018 62TN

63.  Sandwitch chemo
 S/T - C/T - R/T ( after S/T & before R/T)
 disadv;
 adverse effects of blood supply of previous S/T
August 3, 2018 63TN

64.  Adjuvant chemo
 after S/T and/or R/T
August 3, 2018 64TN

65.  Concurrent chemo
 C/T concurrent with R/T
 R/T by sensitizing tumour cells -
methotraxate
August 3, 2018 65TN

66. Cell kill hypopthesis
 destroys cells that are actively dividing
 cell cycle specific ;
 act only at particular cell cycle phase
 cell cycle nonspecific; can act at several or
all cell cycle phases
 active on either a dividing or a resting state
August 3, 2018 66TN

67. G – resting phase
M - Cell division during the mitosis
S – DNA duplicate
August 3, 2018 67TN

68.  Cancer is believed when one of these escape
normal growth control mechanism
 Not that cell cycle is rapid than normal cell ,
but control of growth is lost
August 3, 2018 68TN

69.  Antimetabolites
 methotraxate , 5FU ( fluouracil ) – interfere for
DNA synthesis , target S phase
 Vinca alkaloid
 vincristine ( oncovin ) - target M phase
August 3, 2018 69TN

70.  Alkylating agent
 cyclophosphamide , cisplatin ( nonclassical
alkylating)
 (prevent saperation of DNA , cross bridging
between DNA strands )
 Antimitotic antibiotics
 doxorubicin , bleomycin
 (intercalating between base pairs , scission of
DNA , block RNA production)
 Hormone and Steroid
 glucocorticoid, oestrogen, androgen
August 3, 2018 70TN

71. August 3, 2018 71TN

72.  Medical-oncologist takes the ultimate
responsibility of treatment and its
consequences
 Emergency
 extravasation of chemo agent, chest pain,
hypotension , tumour lysis S etc.
August 3, 2018 72TN

73.  depression of the bone marrow; anaemia,
leucopenia, thrombocytopenia
 GI tract- nausea and vomiting
 hair follicle cells-loss of hair
 specific toxicities against cardiac,
pulmonary, neural, hepatic and renal tissues
August 3, 2018 73TN

74.  Cisplatin - myelosupression, nausea and
vomiting, renal / GI/ oto toxicity
 Bleomycin - mucositis , pulmonary fibrosis
 Steroid - GI
 Methotraxate - myelosupression, mucositis
 5 FU - myelosupression, mucositis, nausea
and vomiting, cardiotoxicity, alopecia
August 3, 2018 74TN

75.  nausea and vomiting - antiemetic - dexa,
metaclopramide, ondensteron
 cardiotoxic - prophylatic nitrate, calcium
channel blocker
 nephrotoxic - prophylatic hydration
 myelosupression - (anemia, leucopenia,
thrombocytopenia) - blood , antibiotic, anti-
fungal
August 3, 2018 75TN

76.  Pain control
 topical anesthesia
 Tricaine , mucaine
Enziclor – Benzydamine + Chlorhexidine 0.2% ,
Quadrajel – antiseptic , analgesic
 antibiotics moisturizing gel
76 TNAugust 3, 2018

77.  Pre and Post chemo - every cycle
 General ;
 performence status , nutritional status,
 renal ( urea, creatinine ), blood CP, PC recheck
 Local ;
 response - complete, partial, minor response, no
change, progression

August 3, 2018 77TN