Radiation Oncology
Introduction
Radiation therapy (RT) plays
an essential role in the care of patients with cancer. It is used as curative
treatment for many patients with malignant disease, as integrated therapy
with chemotherapy and surgery, and as palliative treatment for those in whom
curative treatment is not an option. The dose of radiation delivered to the
tumor must be as high as possible, while being as low as possible to surrounding
normal tissues.
The focus of the Radiation
Oncology Division is to develop, evaluate, and expand the role of RT in cancer
treatment. Establishing optimal irradiation techniques, including proton treatment,
is also an important goal of the division.
Routine Activities
The Radiation Oncology Division
includes five consultant physicians, seven technologists, and two medical
physicists. Treatment is mostly based on three-dimensional planning with isodose
distri-butions, performed by RT-dedicated helical scanning CT, to conform
the dose to the tumor. More than 800 new patients are treated annually, and
more than 15 clinical trials that involve RT as a sole or a combined treatment
modality for various cancers are ongoing.
The conventional (photon-electron)
treatment division is equipped with three treatment machines (a Microtron
with 2 gantries, a linear accelerator, and a high dose rate brachytherapy
unit), a CT-simulator, three treatment planning computer workstations, and
many other devices. The proton treatment division, the first such hospital-based
treatment facility in Japan, is equipped with a cyclotron capable of generating
a 235-MeV proton beam. The proton beam is delivered to three treatment rooms
(two isocentric rotational gantries and one fixed horizontal beam line). Regular
maintenance and calibration of all the division equipment is an ongoing important
activity whose aim is the continual safe and accurate delivery of RT.
Case conferences are held on
Wednesday after-noons, and journal clubs are scheduled on Thursday evenings.
A tele-image conference between the Department of Radiation Therapy at the
National Cancer Center Hospital, Tokyo, and our division was initiated in
1995.
New Developments
(1)Proton treatment was initiated in November 1998
at our hospital. We are now conducting three clinical trials, consisting of
a pilot study for head and neck malignancies, a dose-escalating phase I study
for non-small-cell lung cancer, and a phase II study for hepatocellular carcinoma.
(2)We evaluated the proton beam characteristics
of our gantry treatment room and developed new calculating algorithms for
dose distributions. We evaluated the potential for misalignment of patient
position for the treatment of head and neck malignancies by proton therapy
by using the newly developed system using real-time digital fluoroscopic radiography
technology.
(3)The division proposed several new clinical protocols
and started the clinical trials, including a pilot study of induction chemotherapy
followed by hyperfractionated accelerated radiation therapy (HART) for patients
with stage III non-small-cell lung cancer, a phase II study of concurrent
chemotherapy (Nedaplatin + 5FU) and radiation therapy for patients with unresectable
squamous cell carcinoma of the thoracic esophagus, a multi-institutional phase
II study of radiation therapy (66 Gy) alone for patients 80 years old or older
with squamous cell carcinoma of the thoracic esophagus, and a phase II study
of radiotherapy for squamous cell carcinoma of the larynx and hypopharynx
using delayed accelerated hyperfractionation with concurrent chemotherapy.
|
Number
of Patients Treated with Radiation Therapy |
|||||
|
1995 |
1996 |
1997 |
1998 |
1999 |
|
|
New
patients |
558 |
593 |
631 |
617 |
729 |
|
New
treatments |
810 |
796 |
807 |
771 |
859 |
|
Head
& neck |
134 |
138 |
144 |
144 |
149 |
|
Lung,
mediastinum |
247 |
267 |
237 |
224 |
244 |
|
Breast |
78 |
82 |
94 |
94 |
91 |
|
Gastrointestinal
tract |
128 |
135 |
150 |
133 |
174 |
|
Hepatobiliary
& pancreatic regions |
103 |
85 |
77 |
89 |
108 |
|
Gynecological
regions |
17 |
11 |
11 |
18 |
21 |
|
Urological
regions |
17 |
7 |
12 |
12 |
16 |
|
Bone
& soft tissue |
45 |
29 |
22 |
12 |
2 |
|
Hematological
diseases |
34 |
32 |
46 |
37 |
37 |
|
Others |
6 |
10 |
14 |
7 |
17 |
|
Primary
site |
297 |
312 |
352 |
376 |
508 |
|
Recurrent,
metastatic site |
399 |
367 |
344 |
311 |
280 |
|
Prophylactic
purpose |
114 |
117 |
111 |
84 |
71 |
|
Intraoperative
radiation therapy |
62 |
57 |
55 |
49 |
50 |
|
Brachytherapy |
39 |
27 |
15 |
18 |
10 |
|
Proton
therapy |
- |
- |
- |
1 |
18 |
(T. OGINO)
