13 Head and Neck - Oropharynx

Head and Neck - Oropharynx

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

Takacsi Nagi et al reported clinical outcomes of 60 patients with base of tongue cancers treated with EBRT andHDR BT [48]. Patient received EBRT to a mean dose of 62Gy which was followed by HDR BT to a dose of 5Gy per fraction bid to 3-4 fractions. They reported 5 year LC rate of 57% and OAS of 47%. Late sequalae in the form of soft tissue ulceration was observed in 12% (n=7) and osteoradionecrosis in 1.5% (n=1). Bhalavat et al reported 58 patients with head and neck cancers of which 23 had oropharyngeal primaries [39]. Patients were treated with either HDR BT alone or in combination with EBRT. The dose per fraction for HDR ranged from 3.5Gy to 4.5Gy. The mean total dose for radical BT was 44.5Gy and for boost BT it was 22.5Gy. At a median follow up of 22 months they reported crude LC rates of 79%. The actuarial 5 year OAS in their series was 85.8%. Very low rates of complication (2 soft tissue necrosis and 1 bone necrosis) have been reported in their series. Rudoltz et al evaluated 55 patients with head neck cancer of which 39 had oropharyngeal primaries [49]. Patients were treated with EBRT to a median dose of 55.2Gy followed by HDR BT to a median dose of 16.2Gy. Fraction size ranged from 1.2Gy to 5Gy in their series. At a median follow up of 2.7 years they observed a 2 year LC rate of 79% and late toxicity in 16%with 4 patients developing ORN and 5 patients developing soft tissue necrosis. All of them responded to conservative management. Figure 29 and 30 show pre RT and post RT clinical photographs of a patient with carcinoma of soft palate and right tonsillar malignancy respectively. One of largest experiences of perioperative BT is fromUniversity of Navarra, Spain (Table 5) [50–53]. Martinez-Monge et al in their multiple studies of perioperative implantation followed by HDR BT showed that both in the upfront and reirradiation settings perioperative BT results in LC rates ranging from 55%-86%. This is however associated with high morbidity with ≥ grade 3

RTOG toxicities in around 27.5%-50% of the patients. The major surgical reoperation rates also appear to be high (25-40%) with this technique when compared to other techniques of BT.

Seed implants Iodine 125 seeds have been used in the literature for treatment of primary and recurrent head neck cancers (Table 6). One of the largest series is by Vikram et al in which they treated 124 patients with palliative intent [54]. Complete regressionwas observed in 71% patients with very less toxicity. Stannard et al treated 112 patients of oral cavity, oropharyngeal cancers with I125 seed implants and observed LC rate of 80.7% [55]. Similar outcomes were also observed in another study [56]. I125 implants have shown very encouraging results in recurrent cases as well [57]. Brachytherapy for recurrence/ re-irradiation Brachytherapy is a treatment of choice for recurrent or second primary tumours in the irradiated area (Table 7). One of the largest datasets of reirradiation with BT is with LDR in which 73 patients with velotonsillar cancers were treated to a median dose of 60Gy [58]. They observed a 4 year LR rate of 78% and 5 year OAS of 30%. Similarly another large study from France evaluated 70 patients with oropharyngeal cancers who were treated with BT for oropharyngeal tumours [59]. In the era of PDR and HDR there have been few series which have treated patients with recurrent oropharyngeal cancers using BT . These have shown LC rates ranging from 65-75% at 2 years. However the OAS remains low in these patients ranging from 25%-65% at 2 years [50,50,60–63]. One of the major concerns with BT is a high risk of soft tissue necrosis which has been reported in 14-40% of the patients and osteoradionecrosis ranging from 11-25%. In patients who are considered for perioperative reirradiation with BT there are extremely high chances of graft failure and wound complications [49].

TABLE 5 Studies of brachytherapy in the perioperative setting in the treatment of oropharyngeal cancers

Number of patients Site/ Stage Mode of treatment Follow up

Local control

Overall survival Single modality: 43.5% Multi- modality: 59.7%

Author (year)

Toxicity

Single modality: 68.6% Multi- modality: 83.3%

38.4 months (Single modality)

>grade 3: 43.5% with single modality, 29.5% with multimodality RTOG >3 events in >50% 3 fatal events RTOG > gr 3-27.5% 10% required major resurgery, 1 death RTOG >3 toxicity in > 40%

Surgery+Periop Brachy wit HDR R0: 32Gy/8# R1:40Gy/10# 4Gy/# Surgery+Periop brachy with HDR R0:32Gy/8# R1:40Gy/10# 4Gy/# Surgery+Periop Brachy wit HDR R0:16Gy/4# R1:24Gy/6# 4Gy/# +EBRT: 45Gy/25# Surgery+Periop brachy with HDR

Martinez-Monge (Brachytherapy 2011)

All HN sites 22OPX

22/103

68 months (Combined modality

Martinez- Fernandes (Radiother Oncol 2017) Martinez -Monge (Bracytherapy 2009)

All sites recurrent. 15 OPX

15/63

6.8 yrs

55% 35.6%

Upfront Oral cav, OPX

12/40

50 months

86% 52.3%

Martinez-Monge (Brachytherapy 2006)

All sites recurrent 6 OPX

85.6% (4 yr)

28% required repeat major surgery for complications

6/25

4Gyx 8-R0 4Gyx10-R1 4Gy/#

14 months

46.4% (4 yr)