Significant rise in survival rates for elderly lung cancer patients
treated using radiosurgery
21 July 2011
Details of advances in the use of stereotactic body radiotherapy
(SBRT) to treat early stage lung cancer in both high risk operable
and inoperable cases were presented at the biennial World Conference
for Lung Cancer (WCLC) in Amsterdam this month. It included
significant improvements in survival of elderly lung cancer patients
in the Netherlands as a result of more advanced SBRT treatments.
A study into survival rates among lung cancer patients in the
Netherlands between 2003 and 2009 was one of only four, out of
approximately 1900 abstracts, selected for presentation at the WCLC
Presidential Symposium. The study1 was outlined by Dr. Cornelis Haasbeek
from VU University Medical Center in Amsterdam, where patients are
treated on six advanced medical linear accelerators from radiosurgery
world leader Varian Medical Systems (NYSE: VAR). This hospital has
pioneered the use of SBRT in the Netherlands, involving higher doses
being delivered in fewer sessions with greater precision than is usual
with conventional radiotherapy.
The team at VU used the country’s comprehensive population registry
to monitor the survival rates of lung cancer patients aged 75 or older.
Whereas previous population studies in North Holland have shown
increased survival rates of up to seven months through the use of SBRT,
latest research on data from the entire Dutch population of 16 million
shows the average survival rate after SBRT jumps by 9.3 months in this
frail population from 16.8 months to 26.1 months. “This improvement in
survival rates for SBRT patients is nothing short of spectacular for a
disease that is difficult to treat by any method,” says Prof. Senan.
The VU study also showed a slight increase in survival rates for
patients treated surgically in the Netherlands and no difference in
survival rates for untreated patients.
“In the Netherlands, SBRT is now preferable to conventional
radiotherapy for treating lung cancer,” says Prof. Suresh Senan,
professor of clinical experimental radiotherapy at VU. “Conventional
radiotherapy, with its 30 to 35 daily treatments, is often not a viable
option for many frail patients who may not be in any condition to travel
but SBRT, involving far fewer treatment sessions, is now the preferred
option.” In the Netherlands, SBRT is now carried out at 11 of the 21
treatment centers offering radiotherapy.
VU University Medical Center treats over 2500 new cancer patients
each year, of which about 120 are early stage non-small cell lung cancer
patients. To date, more than 750 such patients have been treated using
SBRT at the hospital, which was the only center in the Netherlands
offering the treatment until 2006. VU University Medical Center has
since helped a number of other centers to set up their stereotactic
radiotherapy program and, despite this, the number of cases treated at
VU has remained steady. “This indicates that there is a rise in the use
of SBRT for lung cancer in general,” says Prof. Senan.
Other WCLC presentations in radiation medicine based treatments
VU University Medical Center delivered 13 oral presentations at the
World Conference for Lung Cancer meeting on the use of radiation
medicine to treat lung cancer, more than any other center at this
meeting on that subject.
Among these was one² presented by Dr. Wilko
Verbakel, medical physicist, who outlined the hospital’s experience of
treating more than 1400 patients with Varian’s RapidArc volumetric arc
therapy treatment system, including 500 patients who were treated with
RapidArc SBRT. “Radiation delivery time for a dose of 18 Gray takes less
than six minutes on average and a dose of 7.5 Gray is delivered in less
than three minutes,” explained Verbakel. Fast dose delivery reduces the
extent of patient motion during treatment and enables clinics to conform
doses more closely to the size and shape of the tumors, according to
Verbakel who added that it has enabled his clinic to treat large targets
with less risk to surrounding healthy tissue.
In a related paper,³ Dr. Max Dahele from VU suggests that during the
typical time taken to deliver lung SBRT with high dose rates,
“near-rigid fixation” is not necessary and using a Novalis™ Tx linear
accelerator the hospital’s standard approach is now to treat without
external immobilization. “A simpler and more comfortable approach to
patient set-up and positioning achieves comparable stability to that
reported with near-rigid immobilization devices, without the associated
cost and complexity,” said Dr. Dahele.
Another VU presentation⁴ discussed chest wall toxicity in the
risk-adapted SBRT fractionation scheme that VU university medical center
employs and concluded -- based on a review of 530 tumors -- that severe
chest wall pain is uncommon after risk-adapted fixed-beam SBRT,
particularly in tumors located 5mm or more from the chest wall. They
pointed out that this contrasts with published chronic chest wall
toxicity observed in up to 30% of patients undergoing surgery.
In a paper5 on 177 potentially operable early-stage non-small cell
lung cancer patients who elected to undergo SBRT instead of surgery, the
VU team concluded that such patients receiving SBRT had a median overall
survival rate of more than five years and a local control rate of 93%,
an impressive statistic. The three-year overall survival rate was nearly
85%, which compares favorably with results reported in earlier studies.
“These findings are comparable to results found in surgery and support
ongoing randomized clinical trials that compare surgery and SBRT in such
operable patients,” the paper concludes. “Short-term outcomes were
superior to surgery and long-term outcomes were equivalent to surgery.”
The World Conference on Lung Cancer also included a symposium
entitled “Expanding Options for High-Risk Operable Non Small-Cell Lung
Cancer (NSCLC) Patients,” sponsored by Varian Medical Systems. In this
symposium, attended by more than 150 lung cancer clinicians, surgeons
and radiation oncologists reported on the latest techniques for treating
high-risk early stage lung cancer using either surgical approaches or
non-invasive radiosurgery, depending on a patient’s clinical
characteristics and risk profile.
Professor Harvey Pass of the New York University Medical Center
presented his view of state-of-the-art approaches to tackling
early-stage lung cancer, detailing results of local tumor control after
two and three years in non-operable patients. Dr. Pass also outlined the
latest results of a small phase-2 study that Dr. Robert Timmerman of the
University of Texas Southwestern Medical Center, and Dr. Pass are
leading to investigate whether SBRT is suitable for operable patients.
Dr. Bryan Meyers, a thoracic surgeon, and Dr. Jeff Bradley, a
radiation oncologist, both from the Washington School of Medicine in St.
Louis, detailed several cases involving high-risk early-stage lung
cancer patients at their center, outlining how they collaborate as a
multi-disciplinary team to assess a patient’s risk profile in order to
arrive at a treatment recommendation on whether the patient should
receive SBRT or surgery.
Surgeon Dr. Marinus Paul and radiation oncologist Professor Suresh
Senan from VU University Medical Center also presented the benefits of
collaboration between thoracic surgery and radiation oncology
professionals to determine the optimum treatment for lung cancer
patients.
Lung cancer is the leading cause of cancer related deaths worldwide.
In 2010, there were estimated to be 1,608,055 new cases of lung cancer
worldwide and 1,376,579 deaths, representing 18.2% of all cancer
deaths.[1]² Despite recent improvements in survival for many other types
of cancer, five-year survival rates for lung cancer have remained
relatively poor, mainly because by the time a diagnosis is made, lung
cancer is well advanced and treatment options are limited.
In the last decade, SBRT has been used to treat patients who were
considered inoperable. From 2008 to 2010, there were over 40 published
clinical papers on SBRT for the treatment of early stage lung cancer,
plus approximately 30 review papers. Outcomes of early clinical
experience in medically inoperable patients have been very
encouraging³, including a March 2010 paper in JAMA by Dr. Timmerman,
whose three-year follow-up was reached in a multicenter trial and which
showed a 57 percent three-year survival and 98 percent local control.
These results suggest that high-risk operable lung cancer patients may
have a viable alternative treatment option to surgery.
References
1. “Improvements in survival of elderly patients with stage I
NSCLC in the Netherlands between 2003-2009”, [Publication Page:
PRS.3] C.J. Haasbeek, O. Visser, D. Palma, F.J. Lagerwaard, B.
Slotman, S. Senan
2. “Arc-Therapies and Other Approaches for IMRT”, [Publication
Page: M09.2] W.F.A.R. Verbakel
3. ”Fast delivery of stereotactic ablative radiotherapy for lung
tumors: is rigid patient immobilization necessary?” [Publication
Page: Poster P1.148]” M. Dahele, W.F.A.R Verbakel, B. Slotman, S.
Senan
4. ”Chest wall toxicity following risk-adapted stereotactic
radiotherapy for early stage lung cancer”, [Publication Page:
O02.01] E.M. Bongers, C.J. Haasbeek, F.J. Lagerwaard, B. Slotman, S.
Senan
5. ”Stereotactic ablative radiotherapy (SABR) in potentially
operable stage I non-small cell lung cancer patients”, [Publication
Page: O02.03] F.J. Lagerwaard, N.E. Verstegen, C.J. Haasbeek, B.
Slotman, M.A. Paul, E.F. Smit, S. Senan
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[1]² GLOBOCAN 2008 (IARC) Section of Cancer Information
(10/6/2011).
[1]³ Timmerman R et al. Stereotactic Body Radiation Therapy for
Inoperable Early Stage Lung Cancer. JAMA 2010;303(11):1070-1076.
Dosoretz DE, Katin MJ, Blitzer PH, et al. Radiation therapy in the
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