This systematic review and meta-analysis compared hemithyroidectomy (HT) to total thyroidectomy (TT) followed by radioactive iodine (RAI) for the treatment of well-differentiated T1-T2 N0 thyroid cancer. The analysis included over 17,000 patients from 10 observational studies. It found that HT was not inferior to TT+RAI, with similar recurrence rates of 2.3% for TT+RAI vs 2.8% for HT and 20-year overall survival rates of 96.8% for TT+RAI vs 97.4% for HT. Complication rates like bleeding, laryngeal nerve injury, and hypoparathyroidism were lower

1. Hemithyroidectomy versus total
thyroidectomy for well differentiated T1–2
N0 thyroid cancer: systematic review and
meta-analysis
P. M. Rodriguez Schaap, M. Botti, R. H. J. Otten, K. M. A. Dreijerink, E. J. M. Nieveen van Dijkum, H. J. Bonjer, A. F. Engelsman and C. Dickhoff
Department of Surgery, Department of Endocrinology and Medical Library, Amsterdam University Medical Centre, Amsterdam, Netherlands
Department of General Surgery, University of Pavia, IRCSS Fondazione Policlinico San Matteo, Pavia, Italy
BJS OPEN, Published on 6th October 2020
Presenter – Dr Eazhisai Chelvan R.A
Moderator - Dr Lancelot Lobo

2. Introduction
• Thyroid cancer
• Increased incidence over the past 3 decades
• Standard of care for well differentiated thyroid cancer –
• Total thyroidectomy and adjuvant radioactive iodine treatment
• 10-year overall survival rates of 96–98 per cent
• Complications
• Contribute to treatment-related morbidity and decreased quality of life
• Lifelong need for thyroid hormone supplementation
• Recurrent laryngeal nerve damage
• Bleeding
• Hypoparathyroidism

3. • Large non-comparative national database cohort studies –
• Neither survival benefit
• Nor difference in recurrence rates between TT followed by RAI and
hemithyroidectomy (HT) for well differentiated, low-risk thyroid cancer
• American Thyroid Association - consideration of HT for selected patients with
low-risk, well differentiated thyroid cancer

4. Aim
• HT as the definitive treatment for patients with a particular focus on recurrence
and overall survival in
• low-risk
• node-negative thyroid cancer of 4 cm or less (T1–2 N0)
• well differentiated (papillary or follicular)

6. TNM classification

7. Methods
• The study was registered in the International Prospective Register of
Systematic Reviews (PROSPERO)
• Literature search was performed based on the PRISMA14 and
MOOSE15 guidelines
• Searches focused on
• differentiated thyroid cancer (papillary and follicular)
• tumour size 0–4 cm
• HT compared with TT ± RAI

8. Inclusion and exclusion criteria
Inclusion criteria Exclusion criteria
• Any English-language original
reports comparing HT with TT ±
RAI for the treatment of 0–4-cm,
well differentiated, low-risk
thyroid cancer
• Low risk was defined as node-
negative (N0), T1 and T2 cancers
• Studies describing recurrent
disease only
• Those including patients under 18
years of age
• Letters, reviews, editorials, case
series with fewer than ten
patients

9. Data extraction
• Characteristics
• Patient demographics (number of patients, age and sex)
• Pathology
• Treatment characteristics
• Tumour size

10. • The primary endpoint –
• Recurrence rate and time to recurrence
• Secondary endpoints –
• overall survival
• Perioperative morbidity
• Including laryngeal nerve damage
• Hypoparathyroidism
• Hypocalcaemia

11. Statistical analysis
• Outcome data for recurrence and overall survival were pooled using
Review Manager version 5.3 (The Nordic Cochrane Centre, The
Cochrane Collaboration, Copenhagen, Denmark)
• Presented as forest plots
• Heterogeneity was assessed by calculating the I2 index
• For low heterogeneity (I2 below 25 per cent), a fixed-effect model was
used for meta-analysis
• For intermediate heterogeneity (I2 ranging from 25 to 75 per cent), a
random-effects model was used for meta-analysis

12. • I2 above 75 per cent was considered substantial, and no meta-analysis
was performed
• Data from matched-pair analysis of low-risk patients were used for
the meta-analysis

13. Results

15. • All ten articles described observational cohorts
• Total of 23 134 patients
• Predominantly women
• 19 069 women (82⋅4 per cent)
• 4065 men (17⋅6 per cent)
• 17 699 patients with low-risk, well differentiated thyroid cancer
• No prospective randomized studies were available
• The reported duration of follow-up ranged from 57⋅3 to 141⋅6 months

16. • Patient characteristics
• Median age ranged from 43 to 49 years
• Seven studies - reported histopathological characteristics
• 13 412 patients PTC and 40 with FTC
• Tumour size ranged from less than 0⋅5 to 1⋅93 cm
• RAI treatment following TT surgery was reported in six studies

18. Recurrence
• Nine studies
• 13 864 patients
• The pooled recurrence rates after TT ± RAI and HT were 2⋅3 and 2⋅8
per cent respectively (odds ratio (OR) 1⋅12, 95 per cent c.i., P = 0⋅48)
• Median time to recurrence was reported in four studies and ranged
from 3⋅58 to 5⋅62 years
• The majority of studies defined recurrence as proven by cytology
and/or pathology

20. • four studies involving 12 321 patients, reported on recurrence in
patients with PTMC
• The pooled recurrence rate after TT ± RAI was 2⋅0 per cent and 2⋅4
per cent for HT (P = 0⋅31)

21. • Three studies, reported recurrence rates after surgery for well
differentiated thyroid cancers of 1–4 cm
• involving 1254 patients
• The pooled recurrence rate after TT ± RAI was 5⋅3 per cent versus 6⋅3
per cent for HT (P =0⋅44)

22. Overall survival
• Only two studies reported overall survival
• Included 1758 patients
• The pooled 20-year overall survival rate after TT ± RAI was 96⋅8 per
cent, compared with 97⋅4 per cent for HT (P = 0⋅40)

23. Complications
• Complications were reported in four studies
• Overall, higher complication rates were found in the TT ± RAI group

24. • Bleeding
• Reported in two studies
• In HT group, bleeding rates were 0 per cent and 0⋅7 per cent, compared with
rates of 0 per cent (P = 1⋅0) and 1⋅0 per cent (P = 0⋅6) in the TT ± RAI group
• Laryngeal nerve injury
• TT ± RAI had a higher rate than HT
• Incidence from 0 per cent to 1⋅6 per cent for HT and from 0⋅6 per cent to 9⋅4
per cent for TT ± RAI

25. • Permanent hypoparathyroidism
• Reported in three studies
• No patients with hypoparathyroidism were reported following HT
• TT ± RAI groups the rate ranged from 1⋅7 per cent to 7⋅7 per cent
• Seroma
• Reported in one study
• 19 (29per cent) and 25 (38 per cent) patients in the HT and TT ± RAI groups
respectively

26. Discussion
• Patients with low-risk, well differentiated thyroid cancer –
• low recurrence rates and high survival can be achieved with both HT and TT ±
RAI treatment
• Reported recurrence and 20-year survival rates were similar
• Active follow-up is warranted after HT so that
• If recurrence or metastasis - completion thyroidectomy followed by RAI
treatment if necessary
• There are no guidelines outlining the duration and method of
such follow-up

27. limitations
• The absence of any randomized comparison - selection biases
• Large proportion of included patients in both HT and TT ± RAI groups
had PTMC
• Data from studies reporting on both PTC and FTC were not presented
separately
• Different definitions of both recurrence and complications used in the
studies
• Only two studies reported survival data

28. Conclusion
• HT was a non-inferior alternative to TT ± RAI for well differentiated T1–2 N0
thyroid cancer
• Possible complications of both treatments need to be taken into account, such as
• Recurrent nerve damage
• Hypoparathyroidism
• Hypothyroidism

29. Is it important?
• Yes

30. Is it new?
• No

33. Should we change?
• No

34. Thank you