Somvilai Mayurasakorn, MD.Division of Therapeutic Radiology and Oncology,

Faculty of Medicine, Chiang Mai University

Helical Tomotherapy

• Smaller field widths, smaller pitches and higher modulation factors

More conformal plans

But increased treatment time !!

Tomotherapy Planning Parameters

Image acquisition and matching• MVCT fan-beam images• In-plane resolution of 0.78 mm at the bore

center ; mean beam energy = 0.75 MeV• Set up slices thickness of 2, 4 or 6 mm

– ‘fine’, ‘normal’ and ‘coarse’ settings

• The scan length is kept as short as possible – always within the region of the PTV

Helical Tomotherapy

Helical Tomotherapy Image matching

Dept. of Radiation Oncology M.D. Anderson Cancer Center Orlando

Dept. of Radiation Oncology M.D. Anderson Cancer Center Orlando

Helical Tomotherapy

Dept. of Radiation Oncology M.D. Anderson Cancer Center Orlando

Helical Tomotherapy

Palma et al. Cancer Treatment Reviews 2010;36 :393–399

Helical Tomotherapy

Helical Tomotherapy

Helical Tomotherapy

Conclusions• Combination of IGRT and IMRT• Use ARC therapy : all angles are available to

deliver radiation to target• Treatment field length up to 160 cm• More conformal and homogeneity while

sparing of OARs than IMRT

Helical Tomotherapy

Daily image guidancePositional correction

Intensity-modulated delivery

Helical Tomotherapy

Tomotherapy Treatment Centers : Asia-Pacific

• South Korea– Incheon St. Mary’s Hospital,

Catholic Medical Center– KangNam St Mary’s Hospital,

Catholic University Hospital– Yonsei Cancer Center, Severance

Hospital (2)– GangNam Severance Hospital– National Cancer Center – Catholic Medical Center,

St.Vincent’s Hospital – Yongdong Severance Hospital – Samsung Medical Center – KyungHee University Medical

Center – Korea University Anam Hospital

• China– PLA General Hospital , Beijing– Airforce Hospital, Beijing– Beijing PLA General Hospital– Chung Shan Hosp , Shanghai

• Hong Kong– Hong Kong Sanatorium and

Hospital– Queen Elizabeth Hosp

Tomotherapy Treatment Centers in Asia-Pacific

• Taiwan– National Taiwan University Hospital – China Medical University Hospital – Shin Kong Wu Ho-Su Memorial Hospital – Yuan General Hospital – Far Eastern Memorial Hospital(2) – Chung Shan Medical University Hospital – Kaoshiung Hospital

• India– Tata Memorial Hospital, Delhi– Tata Memorial Hospital, Calcutta– AIIMS, Delhi– Indo American Hospital, Bangalore

• Singapore– Mount Elizabeth Hospital– National Cancer Center

• Malaysia– Prince Court Medical Center– Sime Darby Medical Center

• Japan– Clinic – C4 Chiba– Fukui Prefecture Saiseikai Hosp– Fukui Saiseikai Hosp– Fukushima Medical Centerl – Towada City Hospital – Koga Hospital 21– Aizawa Hospital– Saiseikai Kumamoto Hospital – Takeda Hospital– Nagoya Daini Red Cross Hospital– Kizawa Memorial Hospital– Hokuto Hospital– Hidaka Hospital– Edogawa Hospital – Aichi Cancer Center Hospital and Research

Institute

• Thailand– Chiang Mai University Hosp

• Australia– Royal Brisbane & Women’s Hospital

Quality Depends on Number of Beams

1 Beam 5 Beams 11 Beams

17 Beams 25 Beams 51 Beams

Dose distribution for one patient of regular deliveryA. 2.5-cm-field width (REG 2.5) B. 5-cm-field width (REG 5)

doses are shown in Gy

Helical Tomotherapy

STERZING et al. Int. J. Radiation Oncology Biol. Phys. 2010;76 (4):1266–1273

• A modulation factor of 2 or 3 is usual• For relatively simple cases, such as the

prostate alone, a value of 2 is normally sufficient

• For cases with more complex, intricate shapes, such as HNC, a modulation factor of 3 is usually selected

University of Cambridge /Burnet et al. Clinical Oncology 2010;22:294–312

Helical Tomotherapy

Gross Tumor Volume (GTV)

GTV contour definition The primary tumor (GTV 1)

A 1 cm peripherally enhancing lymph node (GTV2)

GTV1

GTV2