(Chest. 1999;116:539S-545S.)
© 1999
American College of Chest Physicians
The Rationale and Use of Three-Dimensional Radiation Treatment Planning for Lung Cancer*
Lawrence B. Marks, MD and
Gregory Sibley, MD
*
From the Department of Radiation Oncology, Duke University Medical Center, Durham, NC.
Correspondence to: Lawrence B. Marks, MD, Box 3085, Duke University Medical Center, Durham, NC 27710; e-mail: marks{at}radonc.duke.edu
 |
Abstract
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Treatment of lung cancer with conventional radiation therapy is
associated with suboptimal local tumor control and poor long-term
survival. Poor local tumor control may result from inaccurate tumor
targeting, failure to satisfactorily conform to dose distribution with
the target volume, and/or inadequate radiation doses. Three-dimensional
treatment planning is a radiotherapy technique that provides more
accurate dose targeting via the direct transfer of three-dimensional
anatomic information from diagnostic scans into the planning process.
This technology can assist treatment planning by providing dose-volume
histograms, an estimation of normal tissue complication probabilities,
and facilitate dose escalation. Preliminary clinical studies suggest
that this is a feasible approach worthy of additional study. The
three-dimensional tools provide new opportunities to better understand
radiation-induced changes in pulmonary function.
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Introduction
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Radiation
therapy plays an important role in the treatment of patients with
non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).
For NSCLC, postoperative radiation is generally recommended for
patients with positive nodes, or if the primary tumor is
adherent/invasive into adjacent structures such as the mediastinum. In
these situations, the addition of radiation clearly improves the
local/regional control rate, and might also have a positive impact on
survival. For patients with unresectable cancer, high-dose external
beam radiation therapy, generally combined with systemic chemotherapy
(either sequentially or concurrently), is typically recommended for
patients with a reasonably good performance status.1
While
cures are relatively infrequent among patients with unresectable
disease, most patients do have a tumor response, symptoms referable to
local/regional tumor are either alleviated or prevented, and a definite
fraction, albeit small, is rendered disease-free.
Radiation therapy is the most common local treatment for locally
advanced NSCLC. However, when local tumor control is carefully
assessed, radiation appears to control < 20% of patients’
intrathoracic tumors.2
Inadequate local control likely
contributes to the poor survival rate. The development and
implementation of more effective radiotherapy techniques may improve
local tumor control, and possibly therefore improve long-term survival.
This paper provides an overview of three-dimensional treatment planning
for lung cancer.
Among patients with limited stage SCLC, treatment is typically
multiagent systemic chemotherapy plus thoracic irradiation. The
addition of thoracic radiation clearly improves intrathoracic control,
and has a modest, although real and significant, beneficial impact on
overall survival.3
4
5
Even with thoracic irradiation,
local control remains a problem in SCLC. Just as for NSCLC,
three-dimensional planning might facilitate higher radiation doses and
improve outcome for SCLC.6
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Rationale For Three-Dimensional Treatment Planning
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Conventional Treatment Planning
The radiation oncologist’s goal is to irradiate the target
structures and minimize incidental irradiation of nontarget tissues
(eg, lung, heart, spinal cord, brachial plexus, etc).
Radiation oncologists typically rely on diagnostic CT images to provide
three-dimensional anatomic information of structures of interest. In
conventional planning, this information is transferred onto simulation
films (plain radiographs obtained in the treatment position) by the
radiation oncologist drawing (with a wax pencil) the volumes of
interest. In this regard, radiation oncologists have been performing
three-dimensional treatment planning and reconstruction for years, but
basically in our heads. The essence of three-dimensional radiation
treatment planning (described below) is to accurately
transfer the three-dimensional information—for example, from CT,
directly into the simulation process.
With conventional planning, radiation fields are generally
limited to conventional directions, such as anterior, posterior,
lateral, or simple oblique orientations. Historically, radiation fields
were oriented in these directions because these were the directions
from which diagnostic radiologists were accustomed to viewing. As
radiation beams are rotated away from these traditional directions, the
relationship between intrathoracic structures becomes more difficult to
understand. The computer-assisted transfer of complex three-dimensional
geometric information facilitates the use of unusual beams and is
essential when very unconventional radiation treatment fields are used.
We now routinely treat patients with radiation beams oriented from very
unusual angles, and three-dimensional treatment planning tools are
required. Nevertheless, it is important to recognize that
three-dimensional planning does provide improved transfer of
three-dimensional anatomic data to the simulation process, even when
conventional beam orientations are used.
Because of the intimate relationship between target and normal
tissue within the thorax, it is incumbent on the radiation oncologist
to accurately delineate the structures that should be irradiated and
minimize incidental irradiation of nontarget structures. Without
three-dimensional planning, radiation oncologists often make the field
larger than it needs to be in order to compensate for uncertainties in
the definition of the target volume. Figures 1 2
3
4
5
6
are from the planning system used at Duke (PLUNC: Plan UNC; University
of North Carolina) and illustrate the key features of three-dimensional
treatment planning. Targets and beams are defined and viewed (Figs 1
2
3)
, unusual beam orientations to spare normal structures
(eg, heart) can be used (Figs 4
, 5)
, and doses can be
accurately calculated (Fig 6)
. The details of the three-dimensional
planning procedure are described below.
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Figure 1. Three-dimensional treatment planning using Plan
UNC treatment planning software for a patient with T3N2 NSCLC of the
right lower lobe. The gross target volume (GTV) and clinical target
volume (CTV) are shown on a CT image. The path of an anterior-posterior
beam that includes the CTV with margin is shown.
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Figure 3. The path of the off-cord boost field that includes
the gross target volume (GTV) is shown on a CT image. This boost field
is a left-anterior-superior oblique. This beam orientation is chosen in
order to reduce the volume of heart that is irradiated (see Fig 5
).
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Figure 4. Digitally reconstructed radiograph of the
left-anterior-superior oblique beam designed to treat the gross target
volume (GTV) with margin while omitting the spinal cord. This beam
orientation is chosen in order to reduce the volume of heart that is
irradiated (see Fig 5
).
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Figure 5. An anterior view of the patient with two off-cord
oblique options shown. The left-anterior oblique field is in the axial
plane and incidentally includes some of the heart. The
left-anterior-superior oblique field used in this patient reduces the
amount of heart irradiated. Furthermore, the field size is smaller for
the superiorly obliqued beam than for the axial beam because the former
is oriented along the long axis of the target.
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Figure 6. Isodose distribution showing the contribution from
the initial and boost fields. The gross target volume (GTV) receives a
full dose (>98% of the prescribed dose), while the clinical taget
volume receives a lesser dose (>60% of the prescribed dose).
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Three-Dimensional Treatment Planning Process
The procedure currently used for three-dimensional treatment
planning at Duke University is described below. This system initially
was conceived, developed, and implemented at the University of North
Carolina at Chapel Hill.7
8
9
We gratefully acknowledge the
university’s gracious support in helping to develop the
three-dimensional treatment planning effort at Duke.
The patient is immobilized in a custom-made cradle device designed
specifically to maintain the patient’s position consistently
throughout treatment. Because radiation is delivered every day over a
several-week period, it is important that use of these immobilization
devices be considered to assure reproducibility of patient position
throughout the prolonged treatment time.10
The
immobilization device serves to keep the patient in a consistent
position, but also provides a place for setup marks to be drawn. When a
cradle is not used, setup marks are limited to the patient’s skin.
Modest alterations in the patient’s position, as well as the arm
position, will move the skin, and therefore the setup marks, relative
to the intrathoracic structures.
Imaging: Three-dimensional imaging, typically CT scanning, is
performed in the treatment position. The patient can go home afterwards
and the staff members proceed, at their own pace, with the following
steps.
Outlining: In the image segmentation or outlining
step, the physician, dosimetrist, or physicist defines all structures
of interest on the multiple CT images, including the gross target,
clinical target (gross target and areas at risk for microscopic spread,
such as electively treated lymph nodes), and normal structures.
Treatment planning: Using three-dimensional treatment planning
software, the structures of interest can be viewed in real time from
any orientation, commonly as a series of wire contours. The planner is
free to consider beams from any direction as the software provides a
continuous display of the "beam’s eye view" of the structures of
interest.11
Desired beam orientations are chosen, and
radiation treatment beams are designed on the three-dimensional image
data set. The computer system provides all of the information generally
provided from the "conventional simulator," including setup
instructions, digitally reconstructed radiographs (in lieu of simulator
films), dose distributions, and dose-volume histograms (DVHs).
Potential Shortcomings and the Role of a Physical Simulation
Prior to starting treatment, the patient is brought to the
physical simulator wherein the computer-planned treatment beams are
implemented on the patient, to test that they are indeed implementable.
Occasionally, radiation beams are designed on the computer but cannot
be delivered because of collisions between the patient/couch and the
treatment gantry. In addition, the physician needs to check that the
treatment beams look clinically appropriate on the patient because the
three-dimensional treatment planning process is sometimes deceiving.
For example, if one forgets to contour a particular structure of
interest (such as a normal structure that should be blocked), one might
forget to exclude this structure from the treatment portal defined on
the computer. Bringing the patient to the physical simulator helps the
physician to assess the clinical appropriateness of the treatment
beams. This last step becomes increasingly difficult as very unusual
treatment beams are used, because it becomes increasingly difficult for
the physician to visualize whether the beam is appropriately shaped
and/or positioned. In these settings, we are relying heavily on the
technology. Extreme care should be taken to assure that beams are
arranged as desired. There is the potential for the users of these
advanced treatment planning tools to become complacent because "it
must be right—the computer said so." There is also a tendency to
make radiotherapy fields relatively small when three-dimensional tools
are used. Organ motion and setup uncertainty might lead to underdosage
at the target edge if margins are inadequate.
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Normal Tissue Considerations
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One of the major advances of three-dimensional treatment planning
is that we now know, for the first time, the accurate dose
distribution throughout normal structures. In the past, radiation
oncologists have relied on their "gut feelings" to determine how
much lung or heart could safely be irradiated. Conventional tolerance
doses/volumes were based on anecdotes and vague clinical
impressions.12
Over the last few years, however, many
investigators have used three-dimensional tools to better understand
the normal tissue consequences of thoracic
irradiation.13
14
15
16
17
For example, in the lung, we and others have prospectively studied
radiation-induced changes in pulmonary function, and related these to
the three-dimensional dose distribution.17
18
19
A
three-dimensional radiation dose distribution is usually complex, and
cumbersome for the physician to assimilate. DVHs have been utilized as
a tool to condense the dose data.20
21
22
DVHs describe what
percent of each organ receives what dose of radiation. Two types of
histograms have been used: differential and cumulative. For the
differential dose distribution, the y-axis represents the percent of
the organ irradiated to whatever dose is shown on the x-axis. For the
cumulative histograms, the y-axis value represents the percent of the
target receiving any dose greater than or equal to the dose on the
x-axis. It is important to recognize that these DVHs discard all
spatial information. This might be important since some regions of the
lung might be more (or less) functionally important.23
We
have been calculating the dose distribution within the perfused
(functioning) portion of the lung and have developed the concept of
functional DVHs.23
24
Empiric models have been derived to relate the DVH to incidences of
pulmonary complications.20
21
22
These models have been
tested in several patient data sets; overall, they are useful in
predicting the relative risk of pulmonary
complication.16
17
25
In a multi-institutional study of
540 patients, the average dose delivered to the lung (a very easy
quantity to calculate) appears also to be related to the relative risk
of radiation-induced pulmonary dysfunction.19
These
approaches do not consider preradiotherapy pulmonary function and
appear to be less predictive in patients with very poor preradiotherapy
pulmonary function.17
24
26
An alternative approach has been to relate the dose delivered to
each region of the lung, with changes in function at that individual
region. Advances in nuclear medicine imaging have led to single-photon
emission CT lung scans that provide a three-dimensional map of relative
perfusion within the lung. These scans are performed before and
sequentially following radiation, and percent reductions in regional
function are correlated with regional radiation dose. These studies
have been conducted for many years at Duke University and at the
Netherlands Cancer Institute.27
28
42
Dose-response curves
for regional radiation-induced reductions in pulmonary function have
been derived. Attempts are currently underway at both institutions to
assess whether the sum of regional effects is correlated with the
changes in pulmonary symptoms or changes in pulmonary function
tests.27
29
30
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Clinical Trials
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Published trials on the use of three-dimensional radiotherapy have
demonstrated feasibility and reported promising outcome results with
limited toxicity. The University of Michigan was one of the pioneering
institutions using three-dimensional radiotherapy. At that institution,
Hazuka et al11
have reported results for 88 consecutive
patients with medically inoperable or locally advanced unresectable
NSCLC treated with radiotherapy alone. Many patients were treated with
conventional fields with conformal planning limited to the boost
fields. The median dose for all patients was 67.6 Gy (range, 60 to 74
Gy). Results are shown in Table 1
Table 2
. The median survival time was 15 months, and the 2- and 3-year overall
actuarial survival rates were 37 and 15%, respectively. The 1- and
3-year local progression-free survivals were 76 and 44%, respectively.
Sixty-two percent of patients developed local failure and no dose
response was seen except in the subset of stage IIIa patients who had
improved local progression-free survival with higher doses. The authors
report a 9% incidence of pneumonitis, with only one patient
experiencing a grade 4 reaction. In summary, local failure was common
while toxicity was acceptable, indicating a need for further dose
escalation.
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Table 1. University of Michigan Results Following High-Dose
Thoracic Radiation Using Beam’s-Eye View in Unresectable NSCLC*
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Table 2. University of Chicago: Results Following Treatment of
Stage III NSCLC Using High-Dose Conformal Radiotherapy*
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Follow-up studies at the University of Michigan have utilized an
elaborate system to group patients into dose escalation "bins"
based on their predicted potential for pulmonary toxicity (normal
tissue complication probability).31
Forty-eight NSCLC
patients receiving 2.1-Gy fractions (corrected for tissue
inhomogeneity) to doses of 
92.4 Gy were evaluated. No elective
nodal treatment was used. No radiation pneumonitis occurred in 30
patients alive with follow-up > 6 months, and no isolated failures
were observed in untreated nodal sites. Three of 10 patients treated to
doses of > 84 Gy failed locally.
At Washington University, Graham et al16
reported a series
of 70 patients with inoperable stage I to IIIB lung cancer (65 with
NSCLC, 5 with SCLC) who received conformal radiotherapy (5 SCLC
patients received additional chemotherapy). Stage I/II cancer was
diagnosed in 20 patients, stage IIIA in 36, and stage IIIB in 14.
Patients were treated to a median dose of 69 Gy (range, 60 to 74 Gy).
The authors found a 15% local failure rate, with no failures observed
in electively untreated nodal sites. The 2-year survival rate was 44%,
with a better survival rate seen in patients with local tumor control
compared with those with local failure (47 and 31%, respectively).
Toxicity included a 6% incidence of fatal pneumonitis, which was
volume-related.
The University of Chicago described results for 37 patients with stage
III NSCLC who received a median dose of 66 Gy (range, 60 to 70
Gy).32
Similar to the University of Michigan series, the
2-year survival rate was 37%, local progression was seen in 64% of
the patients, and no isolated recurrences in the untreated nodal
volumes were observed. The median follow-up time was 19 months (range,
10 to 40 months). Two patients developed radiation pneumonitis that
resolved with corticosteroid therapy.
Leibel et al33
and Armstrong et
al34
43
at Memorial Sloan-Kettering Cancer Center
treated 45 patients with stage I to IIIB NSCLC using three-dimensional
radiotherapy.33
34
Radiation doses ranged from 52.2 to
72.0 Gy (mean, 70.2 Gy). Thoracic progression occurred in 46% of
patients, and the 2-year survival rate was 33%.34
Grade 3
or greater pulmonary toxicity was observed in 9% of patients,
occurring most frequently in patients in whom > 30% of lung volume
received a dose of > 25 Gy.
At Duke University, we recently reviewed 94 patients with stage I to
III NSCLC receiving high-dose three-dimensional conformal radiotherapy
with 
6 months of follow-up. The typical approach was to deliver 45
Gy at 1.25 Gy bid to electively treated sites and 73.6 Gy at 1.6 Gy bid
to sites of gross disease (6-h interval, uncorrected for tissue
inhomogeneity) using a concurrent boost technique.35
36
Toxicity included 20 cases of acute grade 3 toxicity (esophagus,
n = 14; pneumonitis, n = 2; skin, n = 4) and 19 cases of grade 3
to 5 late toxicity (esophagus, n = 4 [one grade 4]; pneumonitis,
n = 12 [one grade 5]; skin, n = 5; pericarditis, n = 2 [both
grade 4]). Analyses relating esophageal and pulmonary toxicity to the
three-dimensional dose distribution are underway.37
A
biological toxicity marker, transforming growth factor ß, is also
being examined.38
The 5-year overall survival rates in
patients with stage I, IIIA, and IIIB disease are 47%, 10%, and 7%,
respectively. In a separate analysis, we prospectively surveyed
treating physicians to assess the impact of three-dimensional planning
in the treatment of 133 patents irradiated for lung cancer from 1995
through 1997 at Duke University. Ninety-two percent had gross
intrathoracic disease. Compared with what would have been done without
it, three-dimensional treatment planning resulted in altered beam
arrangements in 52 and 84% of initial and boost treatment fields,
respectively. The field shapes were altered in > 85% of cases.
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Three-dimensional Planning Issues in SCLC
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Pre- vs Postchemotherapy Tumor Volumes
For patients receiving systemic chemotherapy prior to thoracic
irradiation, there is often a marked shrinkage in the intrathoracic
abnormality. Studies have suggested that the radiation field need only
include the postchemotherapy volume.39
40
However, one
needs to be careful interpreting this clinical data. The
Liengswangwong39
study was retrospective. In the study by
Kies et al40
a group of patients was randomized to
radiotherapy based on the pre- vs postchemotherapy volumes. However,
only patients with stable disease or a partial response were
randomized, and those who were treated to the prechemotherapy volumes
had a field reduction after 18 Gy.
In our opinion, the approach for nodal disease and parenchymal lung
disease should be different. For a tumor within the lung parenchyma
that responds, it seems reasonable to consider residual microscopic
foci of tumor to be present throughout the initially involved region of
the lung. If there is a complete response at the primary site to
chemotherapy, should radiotherapy be omitted because there is no
postchemotherapy abnormality? Conversely, is mediastinal disease that
is extrapleural and displaces the lung laterally more likely to shrink
medially as it regresses? Our policy in patients who have had dramatic
response following chemotherapy is to irradiate previous sites of
intraparenchymal disease, but treat the posttreatment central nodal
mass. This approach is analogous to mediastinal lymphoma cases, in
which consolidative radiation to the postchemotherapy mediastinal
volume appears adequate to improve outcome.
Patients often present to the radiation oncologist after chemotherapy,
and treatment planning scans therefore illustrate only postchemotherapy
volumes. Advanced treatment planning software is available to
"fuse" the prechemotherapy and postchemotherapy images, such that
the prechemotherapy volumes can be seen on the postchemotherapy
scan.41
Multimodality Imaging
Three-dimensional treatment planning tools facilitate the fusion
of different diagnostic images. For example, positron emission
tomography nuclear medicine studies can be used to identify areas of
increased metabolic activity related to the tumor. Similarly,
single-photon emission CT lung perfusion scans have been used to
identify areas of relatively functioning lung so that radiation beams
might be designed to avoid these regions.23
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Conclusion
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In summary, computer-assisted radiotherapy planning enables
radiation oncologists to more accurately irradiate target tissues, and
minimize incidental irradiation of nontarget structures. More accurate
targeting of the radiation beam to the volume at risk should facilitate
the use of higher doses of radiation, which should increase
local/regional control and, we hope, survival. Preliminary clinical
studies suggest that this might be a fruitful approach. The
three-dimensional tools provide new opportunities to better understand
radiation-induced changes in pulmonary function.
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Acknowledgements
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Thanks to G. Bentel for assistance with figures and
to J. Forest for administrative support.
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Footnotes
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Abbreviations: DVH = dose-volume histogram;
NSCLC =non-small cell lung cancer; SCLC = small cell lung cancer
Supported in part by National Cancer Institute grant CA69579.
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References
|
|---|
-
Dillman, RO, Seagren, SL, Propert, KJ, et al (1990) A randomized trial of induction chemotherapy plus high-dose radiation versus radiation alone in stage III non-small-cell lung cancer. N Engl J Med 323,940-945[Abstract]
-
Arriagada, R, Le Chevalier, T, Quoix, E, et al (1991) ASTRO (American Society for Therapeutic Radiology and Oncology) plenary: effect of chemotherapy on locally advanced non-small cell lung carcinoma; a randomized study of 353 patients. Int J Radiat Oncol Biol Phys 20,1183-1190[ISI][Medline]
-
Warde, P, Payne, D (1992) Does thoracic irradiation improve survival and local control in limited-stage small-cell carcinoma of the lung? A meta-analysis. J Clin Oncol 10,890-895[Abstract]
-
Perry, MC, Eaton, WL, Propert, KJ, et al (1987) Chemotherapy with or without radiation therapy in limited small-cell carcinoma of the lung. N Engl J Med 316,912-918[Abstract]
-
Murray, N, Coy, P, Pater, JL, et al (1993) Importance of timing for thoracic irradiation in the combined modality treatment of limited stage small-cell lung cancer. J Clin Oncol 11,336-344[Abstract/Free Full Text]
-
Papac, RJ, Son, Y, Bien, R, et al (1987) Improved local control of thoracic disease in small cell lung cancer with higher dose thoracic irradiation and cyclic chemotherapy. Int J Radiat Oncol Biol Phys 13,993-998[ISI][Medline]
-
Rosenman, J, Sailer, SL, Sherouse, G, et al (1991) Virtual simulation: initial clinical results. Int J Radiat Oncol Biol Phys 20,843-851[ISI][Medline]
-
Sailer, SL, Cheney, EL, Rosenman, JG, et al (1992) Treatment planning at the University of North Carolina. Semin Radiat Oncol 2,267-273[CrossRef][Medline]
-
Sherouse, GW, Chaney, EL (1991) The portable virtual simulation. Int J Radiat Oncol Biol Phys 21,475-482[ISI][Medline]
-
Bentel, GC (1999) Patient positioning and immobilization in radiation oncology. McGraw-Hill New York, NY.
-
Hazuka, MB, Turrisi, AT, III, Lutz, ST, et al (1993) Results of high-dose thoracic irradiation incorporating beam’s eye view display in non-small cell lung cancer: a retrospective multivariate analysis. Int J Radiat Oncol Biol Phys 27,273-284[ISI][Medline]
-
Emami, B, Lyman, J, Brown, A, et al (1991) Tolerance of normal tissue to therapeutic irradiation. Int J Radiat Oncol Biol Phys 21,109-122[ISI][Medline]
-
Emami, B, Graham, MV, Purdy, JA (1994) Three-dimensional conformal radiotherapy in bronchogenic carcinoma: considerations for implementation. Lung Cancer 11(suppl 3),S117-S128
-
Graham, MV, Matthews, JW, Harms, WB, Sr, et al (1994) Three-dimensional radiation treatment planning study for patients with carcinoma of the lung. Int J Radiat Oncol Biol Phys 29,1105-1117[ISI][Medline]
-
Graham, MV, Purdy, JA, Emami, B, et al (1995) Preliminary results of a prospective trial using three dimensional radiotherapy for lung cancer. Int J Radiat Oncol Biol Phys 33,993-1000[CrossRef][ISI][Medline]
-
Martel, MK, Ten Haken, RK, Hazuka, MB, et al (1994) Dose-volume histogram and 3-D treatment planning evaluation of patients with pneumonitis. Int J Radiat Oncol Biol Phys 28,575-581[ISI][Medline]
-
Marks, LB, Spencer, DP, Sherouse, GW, et al (1997) Quantification of radiation-induced regional lung injury with perfusion imaging. Int J Radiat Oncol Biol Phys 38,399-409[CrossRef][ISI][Medline]
-
Ten Haken, RK, Martel, MK, Kessler, ML, et al (1993) Use of Veff and iso-NTCP in the implementation of dose escalation protocols. Int J Radiat Oncol Biol Phys 27,689-695[ISI][Medline]
-
Kwa, SLS, Lebesque, JV, Theuws, JCM, et al (1998) Radiation pneumonitis as a function of mean lung dose: an analysis of pooled data of 540 patients. Int J Radiol Oncol Biol Phys 42,1-9[ISI][Medline]
-
Burman, C, Kutcher, GJ, Emami, B, et al (1991) Fitting of normal tissue tolerance data to an analytic function. Int J Radiat Oncol Biol Phys 21,123-135[ISI][Medline]
-
Kutcher, GJ, Burman, C, Brewster, L, et al (1991) Histogram reduction method for calculating complication probabilities for three-dimensional treatment planning evaluations. Int J Radiat Oncol Biol Phys 21,137-146[ISI][Medline]
-
Lyman, JT, Wolbarst, AB (1987) Optimization of radiation therapy: III. A method of assessing complication probabilities from dose-volume histograms. Int J Radiat Oncol Biol Phys 13,103-109[ISI][Medline]
-
Marks, LB, Prosnitz, LR (1994) Estimation of normal tissue complication probabilities with three dimensional technology. Int J Radiat Oncol Biol Phys 28,777-779[ISI][Medline]
-
Marks, LB, Spencer, DP, Sherouse, GW, et al (1995) The role of 3-dimensional functional lung imaging in radiation treatment planning: the functional DVH. Int J Radiat Oncol Biol Phys 33,65-75[CrossRef][ISI][Medline]
-
Oetzel, D, Schraube, P, Hensley, F, et al (1995) Estimation of pneumonitis risk in three-dimensional treatment planning using dose-volume histogram analysis. Int J Radiat Oncol Biol Phys 33,455-460[CrossRef][ISI][Medline]
-
Abratt, RP, Willcox, PA, Smith, JA (1990) Lung cancer in patients with borderline lung functions: zonal lung perfusion scans at presentation and lung function after high dose irradiation. Radiother Oncol 19,317-322[CrossRef][ISI][Medline]
-
Boersma, LJ, Damen, EMF, de Boer, RW, et al (1994) Dose-effect relations for local functional and structural changes of the lung after irradiation for malignant lymphoma. Radiother Oncol 32,201-209[CrossRef][ISI][Medline]
-
Marks, LB, Munley, MP, Bentel, GC, et al (1997) Physical and biological predictors of changes in whole lung function following thoracic irradiation. Int J Radiat Oncol Biol Phys 39,563-570[CrossRef][ISI][Medline]
-
Theuws, JCM, Kwa, SLS, Wagenaar, AC, et al (1999) Prediction of overall pulmonary function loss in relation to the 3-D dose distribution, for patients with breast cancer and malignant lymphoma. Radiat Oncol 49,233-243
-
Fan, M, Hollis, D, Munley, MT, et al (1999) Can we predict radiation (RT)-induced changes in pulmonary function tests (PFTs) based on the lung dose-volume histogram [abstract]? Int J Radiat Oncol Biol Phys 45(suppl),151-152
-
Robertson, JM, Ten Haken, RK, Hazuka, MB, et al (1997) Dose escalation for non-small cell lung cancer using conformal radiation therapy. Int J Radiat Oncol Biol Phys 37,1079-1085[CrossRef][ISI][Medline]
-
Sibley, GS, Mundt, AJ, Shapiro, C, et al (1995) The treatment of stage III nonsmall cell lung cancer using high dose conformal radiotherapy. Int J Radiat Oncol Biol Phys 33,1001-1007[CrossRef][ISI][Medline]
-
Leibel, SA, Armstrong, JG, Kutcher, GJ, et al (1996) 3-D conformal radiation therapy for non-small cell lung carcinoma: clinical experience at the Memorial Sloan-Kettering Cancer Center. Front Radiat Ther Oncol 29,199-206[Medline]
-
Armstrong, J, Raben, A, Zelefsky, M, et al (1997) Promising survival with three-dimensional conformal radiation therapy for non-small-cell lung cancer. Radiother Oncol 44,17-22[CrossRef][ISI][Medline]
-
King, SC, Acker, JC, Kussin, PS, et al (1996) High-dose, hyperfractionated, accelerated radiotherapy using a concurrent boost for the treatment of nonsmall cell lung cancer: unusual toxicity and promising early results. Int J Radiat Oncol Biol Phys 36,593-599[CrossRef][ISI][Medline]
-
Sibley, GS, Maguire, PD, Anscher, MA, et al (1999) High dose radiation therapy: the Duke experience. Proc Am Soc Ther Radiat Oncol 45(suppl),241
-
Maguire, PD, Sibley, GS, Zhou, SM, et al (1999) Clinical and dosimetric predictors of radiation-induced esophageal toxicity. Int J Radiat Oncol Biol Phys 45,97-103[CrossRef][ISI][Medline]
-
Anscher, MS, Kong, FM, Andrews, K, et al (1998) Plasma transforming growth factor ß1 as a predictor of radiation pneumonitis. Int J Radiat Oncol Biol Phys 41,1029-1035[CrossRef][ISI][Medline]
-
Liengswangwong, V, Bonner, JA, Shaw, EG, et al (1994) Limited-stage small-cell lung cancer: patterns of intrathoracic recurrence and the implications for thoracic radiotherapy. J Clin Oncol 12,496-502[Abstract]
-
Kies, MS, Mira, JG, Crowley, JJ, et al (1987) Multimodal therapy for limited small-cell lung cancer: a randomized study of induction combination chemotherapy with or without thoracic radiation in complete responders; and with wide-field versus reduced-field radiation in partial responders: a Southwest Oncology Group study. J Clin Oncol 5,592-600[Abstract/Free Full Text]
-
Rosenman, JG, Miller, EP, Tracton, G, et al (1998) Image registration: an essential part of radiation therapy treatment planning. Int J Radiat Oncol Biol Phys 40,197-205[CrossRef][ISI][Medline]
-
Levinson, B, Marks, LB, Munley, MT, et al (1998) Regional dose response to pulmonary irradiation using a manual method. Radiother Oncol 48,53-60[CrossRef][ISI][Medline]
-
Armstrong, JG, Zelefsky, MJ, Leibel, SA, et al (1995) Strategy for dose escalation using 3-dimensional conformal radiation therapy for lung cancer. Ann Oncol 6,693-697[Abstract/Free Full Text]
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Abstract
Introduction
