13 Head and Neck - Oropharynx

Head and Neck - Oropharynx

21

THE GEC ESTROHANDBOOKOF BRACHYTHERAPY | Part II Clinical Practice Version 1 - 15/02/2021

13. ADVERSE SIDE EFFECTS

Only one of the series has reported tracheostomy dependence in 3/88 patients [37]. This was due to aspiration pneumonia and prophylactic tracheostomy was recommended by these authors. However prophylactic tracheostomy is generally not needed in patients with BOT lesion unless there are possibilities of severe airway compromise. This also depends on the expertise of the treating radiation oncologist and the institutional policy. Based on the reported clinical outcomes and toxicity a dose per fraction of 3-4.5Gy/# is recommended.

The toxicity rates with PDR and HDR BT have been much lower than the LDR BT series [16,18,33,37,47,49] . Various series of PDR BT have reported soft tissue necrosis ranging from 1-12%. These studies have used fraction size ranging from 1.2Gy-4.5Gy. Only one study reported soft tissue necrosis of 29%. They have used 6Gy per fraction which could be the possible cause for higher soft tissue necrosis. The chances of ORN are also much lower than that of the LDR series. These have typically ranged from 0-7%. Use of optimization for reducing the dose to the mandible and use of lead shields or separators for spacing could be the possible reasons for a reduction in the ORN rates.

Normal tissue sparing Brachytherapy results in improved normal tissue sparing as compared to that of EBRT alone. In a study by Mamgani et al

TABLE 6 Studies of brachytherapy using radioactive seeds for treatment of oropharyngeal cancers

Number of patients Site/ Stage Mode of treatment Follow up

Author (year)

Local control Overall survival

Toxicity

Complete regresssion 71%

Serious complications: 5.5%

Vikram B (Cancer 1983) Stannard C (Brachytherapy 2014)

124

Palliation I125 permanent implants

OPX/Oral cavity

I125 seed in plastic tubes

80.7% (5 year) 88% (5 year) 39.9% (5 year)

57.2% (5 year) 72% (5 year) 26.6% (5 year)

112

43 months

STN: 18.4%

Horwitz EM (Cancer 1996)

16

BOT

I125 seed implant

47 months

3 exposed bone Cranial nerve XII palsy

Jiang P (JCB 2019)

I 125 seeds permanent implants 20 months

5/81

Recurrent

TABLE 7 Studies of brachytherapy for recurrent oropharyngeal cancers

Number of patients Site

Overall survival

Author (year)

Mode of treatment

Follow up Local control

Toxicity

LDR (plastic tube technique) (60Gy)

Peiffert D (IJROBP 1994) Mazeron JJ (IJROBP 1987) Strnad V (Brachytherapy 2014) Martinez- Fernandes (Brachytherapy 2017) Hepel JT (IJROBP 2005) Bhalavat R (JCB 2018)

Velotonsillar region

78% (4 yr) 69% (5 yr)

30% (5 yr) 14% (5 yr)

73

STN:14%

LDR (guide gutter/plastic tube) (60Gy) PDR (Brachy+Chemo+/- hyperthermia) (60Gy) Salvage brachy+/- EBRT (HDR-4.5Gy bidx10)

70

OPX

-

STN: 27%

STN:17.7% ORN: 11.8%

20/51

BOT

58 months 57% ( 5 yr) 25.5% (5 yr)

68% (2 yr)

15/25

OPX

25months 75% ( 2yr)

No gr3 and 4

Surgery+Periop brachy(PDR) R0:4Gy/#x 8 R1:4Gy/#x10 HDR Mean dose 34Gy 3-4Gy/#

55% (5yr)

35.6% (5 yr)

15/63

opx

6.8yrs

50%RTOG ≥ 3

37% (2 yr)

11/30

OPX

12 months 67% ( 2yr)

25% ORN, STN

40% Graft failure, fistula, soft tissue necrosis 5 patients Reoperation, delayed healing, bleeding

Surgery + Periopbrachy (PDR) R0:4Gy/#x 8 R1:4Gy/#x10 HDR +/- Periop Post op: 3.4Gy/# x10 Radical: 4Gy/#x10 or EBRT: 45-50Gy + 4Gy/#x5

Martinez-Monge R 8/25

OPX

14 months 84.7% 46.4%

Narayana A (Brachytherapy 2007)

63% (2yr)

5/30

OPX

12months 71% (2yr)