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Journal Club:
Comparison Of IMRT and 3DCRT
as Adjuvant Therapy for Gastric
Cancer
Yuriko Minn, Annie Hsu et al.
Cancer, 15Aug.2010. 116:3943-3952
Radiation Oncology
Dr BRAIRCH, AIIMS
Moderator : Prof. BK MohantiPresenter : Dr Akhilesh Mishra
Sites of Origin And Histologies
• Antrum and Distal Stomach: ~ 40%
• Body: ~ 25%
• Proximal Stomach and GE Jn. : ~ 35%
• Adenocarcinomas : 90-95%
• Lymphomas (Usually with Unfavourable Histologies) : 4-5%
• Leiomyosarcomas : ~2%
• Rest : Carcinoids, Adenocanthomas, SCCs.
General Anatomy
Japanese Surgical Staging for Ca. Stomach
• S0 No serosal invasion
• S1 Suspected serosal invasion
• S2 Defi nite serosal invasion
• S3 Adjacent organ involvement
• N1 Perigastric lymph nodes
• N2 Lymph nodes around the left gastric artery, common
• hepatic artery, splenic artery, and celiac axis
• N3 Lymph nodes in the hepatoduodenal ligament, posterior
• aspect of pancreas, and root of mesentery
• N4 Periaortic and middle colic lymph nodes
• P0 No peritoneal metastases
• P1 Adjacent peritoneal involvement
• P2 A few scattered metastases to distant peritoneum
• P3 Many distant peritoneal metastases
• H0 No liver metastases
• H1 Metastases limited to one lobe
• H2 A few bilateral metastases
• H3 Numerous bilateral metastases
• STAGE GROUPING
• Stage I S0, N0, P0, H0
• Stage II S1, N0-1, P0, H0
• Stage III S2, N0-2, P0, H0
• Stage IV S3, N3-4, P1-3, H1-3
Prognostic Factors
• Stage is the most important prognostic factor
• Regional nodal involvement adversely affects the prognosis. The number and locations of the affected lymph nodes are both significant.
• According to the Japanese Classification of gastric cancer, numbers of positive level II nodes have more influence on the prognosis.
• The prognosis of proximal cancers is less favorable.
• Diffuse type pathology cases are associated with worse treatment results compared with intestinal type
• No biologic markers routinely utilized.
Genetic Alterations Associated With
Worse Prognosis
• Aneuploidy
• Presence of viral genome (H. pylori)
• Telomerase Reactivation
• P53 gene Inactivation
• Dysfunction of repair genes Hmsh3 & Hmlh1
• Overexpression: Her2Neu, bcl2, c-met, k-sam
• Oestrogenic Receptor Expression
• CD44 Expression
Ca. Stomach: General Guidelines • Surgery – primary curative treatment modality
– Proximal stomach total gastrectomy– Distal stomach distal radical gastrectomy
• Nodal DissectionD2
• Avoid splenectomy if possible.
• Consider placing feeding jejunostomy-tube.
• Aim for 5 cm proximal and distal margins whenever possible.
• Remove minimum of 15 LNs.
Chemo & Radiotherapy used mainly in Adjuvant setting for stage II and onwards
• Indications of adjuvant therapy– Margin positive– Gross residual disease – Transmural infiltration – Serosal involvement– Regional node positivity
Surgery: Important Points
• D1 dissection: removes involved proximal or distal or entire stomach, including the greater and lesser omental LN.
• D2 dissection: Also removes the omentalbursa, the front leaf of the transverse mesocolon, and the corresponding arteries are completely cleared, including the portal, celiac, and splenic LN.
• Sites of LF after surgery: Gastric bed ~50%, LN ~40%, anastomosis or stumps ~25%,
ADJUVANT THERAPY
4 wks
Curative resection (R0)
C1 5FUFA
Inj LV-20 mg/m2 IV D1-D5
Inj FU-425 mg/m2 IV D1-D5
EBRT-45 Gy/25#/5 wks
C2-C3 5FUFA with RT (D1-D4; D23-D25)
Inj LV-20 mg/m2 IV bolus
Inj FU-400 mg/m2 IV bolus*
C4-C5 5FUFA q 4wk
Inj LV-20 mg/m2 IV D1-D5
Inj FU-425 mg/m2 IV D1-D5
4 wks
-Macdonald etal. NEJM 2001; 345: 725-30.
* IRCH modification:1)C2-3 5FUFA-
Inj FU-375mgm2 IV bolus2)EBRT by 3D-CRT instead of
conventional RT
INOPERABLE/METASTATIC GASTRIC
CANCER
• LAGC (inoperable)
– NACT 2-3 cycles (CDDP+ Capecitabine) f/b
assessment for surgery
• Palliative –
– Radiotherapy30Gy/10#/2wks (rarely used)
– Chemotherapy5FUFA / capecitabine+ CDDP
– Surgeryfeeding procedure/ gastric bypass surgery
• Best supportive care
Level and Extent of Surgery
• The Dutch and UK-MRC trials compared D1 versus D2 dissection: No signifi cant differences in 5-year survival but higher postoperative mortality and morbidity rates in the D2 dissection (Bonenkamp et al. 1999; Hartgrink et al. 2004; Cuschieri et al. 1999).
• Wu et al. 2006 ,Taipei: the overall 5-year survival significantly improved in patients receiving D3 surgery than D1.
• The Japanese Research Society for Gastric Cancer (JRSGC) considered surgery without D2 dissection inadequate (Kajitani 1981).
Level and Extent of Surgery
• Japan, which reported a hospital mortality rate of
in D2 suegery:0.8% :JCOG 95-01;Sasako et al.
2006; Sano et al. 2004.
• Italian study similar results on postoperative
mortality:Degiuli et al. 2004.
• Spleenectomy is not routinely recommended.
• Spleen and pancreas-preserving
lymphadenectomies are becoming more popular
(Fenoglio-Preiser et al. 1996).
Latest in Surgery
• Endoscopic mucosal dissection (EMR) has been
increasingly used in selected patients with early
stage gastric cancer. Indications for EMR include :
• Tumor size < 3 cm,
• Absence of ulceration,
• Well differentiated histology,
• Absence of lymph node metastasis,
• And no evidence of invasive findings
(Ono et al. 2001; Hiki et al. 1995; Noda et al.
1997).
Areas Included In Radiation Field
• Based On the likely sites of Locoregional Failure ,
the following are included in Radiation Field:
• Gastric / Tumour Bed
• Anastomosis and Gastric Remnant
• Nodal Chains at lesser and greater curvatures
• Celiac Axis, PancreatoDuodenal, Splenic nodes
• SupraPancreatic, Porta Hepatis
• GastroDuodenal & ParaAortic upto level of L3
Conventional Radiation Portal:IRCH
• Upper Border - The bottom of T8 or T9 to cover celiac axis ,GE Jn fundus and dome of Left hemidiaphragm.
• Lower Border - The Bottom of L3 vertebra for Gastro-Duodenal nodes.
• Left Border- 2/3 to 3/4 of Left Hemidiaphragm for Fundus with Supra-Pancreatic and Splenic nodes.
• Right Border – 3-4 cms lateral to vertebral bodies for Antrum with Porta-Hepatis & Gastro-Duodenal nodes.
• 3DCRT is the preferred modality currently.
3DCRT in Ca. Stomach
Radiation Oncology , IRCH
3DCRT in Ca. Stomach
Radiation Oncology , IRCH
Abstract
• The current study was performed to compare the clinical outcomes and toxicity in patients treated with post-operative chemo-radiotherapy for gastric cancer using intensity-modulated radiotherapy (IMRT) versus 3-dimensional conformal radiotherapy (3D CRT).
• From December 1998 to June 2008, 61 patients with non-metastatic gastric or gastroesophageal (GE) junction cancer were treated with postoperative radiotherapy at Stanford University. Two patients treated with IMRT and 2 patients treated with 3D CRT who did not complete their radiation course were excluded, leaving 57 patients for this analysis.
Methods
• Fifty-seven patients with gastric or gastroesophageal
junction cancer were treated postoperatively: 26 with
3D CRT and 31 with IMRT.
• Earlier patients were treated with 3D CRT; however,
there was a gradual shift of practice toward IMRT
beginning in 2002.
• Concurrent chemotherapy was capecitabine (n = 31),
5-fluorouracil (5-FU) (n = 25), or none (n = 1).
• The median radiation dose was 45 Gy. Dose volume
histogram parameters for kidney and liver were
compared between treatment groups
Methods• For the bowel, the intestinal loops outside the
planning treatment volume (PTV) were contoured, not the whole abdominal space. To account for daily setup error and organ motion, the CTV to PTV expansion was typically 5 to 10 mm. Normal structures were also contoured, including kidneys, liver, spinal cord, and bowel.
• Patients were treated with either a 3 or 4-field technique to 43.2 to 50.4 Gy (median, 45 Gy), 5 days a week.
• The PTV received a median dose of 45Gy(range, 41.4-54 Gy) with a median fraction size of 1.8 Gy(range, 1.8-2.08 Gy).
Methods• Although the median doses were similar between
the treatment groups, more patients received >45 Gy in the IMRT group than in the 3DCRT group (10 vs 2, respectively).
• For the 12 patients who received>45 Gy, the additional 5 to 9 Gy were given a sequential conedown or simultaneous integrated boost.
• Six patients with positive margins and 2 patients with close margins received >45 Gy.
• Twenty-three patients treated with IMRT were treated with respiratory gating while all other patients were treated with free breathing. Beam energies used included 6MV, 10 MV, 15 MV, or a mix of 6 and 15 MV.
Methods
• Dose constraint guidelines used for IMRT planning
included:
• 75% of the liver<15 Gy; mean liver dose<20Gy;
• 70% of each kidney<15 Gy or 2/3 of 1 kidney <18
Gy;
• 95% of the bowel <45Gy.Max dose to the
bowel<54Gy. The bowel space was contoured.
• The spinal cord dose was limited to 45 Gy.
• The IMRT plans were normalized to 95% volume to
get 100% of the dose.
Methods
• All patients underwent routine systemic workup and disease evaluation that included history and physical examination, routine laboratory studies,CT of the chest and abdomen, and esophagogastroduodenoscopywith biopsy.
• Fifty-three patients (93%) received chemotherapy that was FU-based (5-fluorouracil [5-FU] or capecitabine) with or without Carboplatin before the start of radiotherapy, the latter regimen being part of an institutional protocol.
Methods
• The majority of patients received 2 cycles
before radiation. Patients received concurrent
chemotherapy with capecitabine (n ¼ 31), 5-
FU (n ¼ 25), or none (n ¼ 1).
• After the completion of radiotherapy, 45
patients (79%) received 1 to 2 cycles of the
same chemotherapy that was given before
radiation, as directed by their medical
oncologists
RESULTS
RESULTS
RESULTS
RESULTS
Results• The 2-year overall survival rates for 3D CRT versus IMRT were
51% and 65%, respectively (P = .5)
• Four locoregional failures occurred each in the 3D CRT (15%) and
the IMRT (13%) patients
• Median OS & DFS from initiation of RT:5.4 & 4.7 Yrs
respectively
• The 2 Yrs DFS for 3DCRT & IMRT: 60% & 54% respectively
(P=0.8)
• The 2 Yrs Local Control Rates for 3DCRT & IMRT: 83% &
81%(P=0.9) respectively
• The median volume receiving 42.75 Gy (95% of 45Gy) for
3DCRT versus IMRT: 1606ml versus 1282.6ml
respectively(P=0.048)
Results• Grade ≥2 acute gastrointestinal toxicity was found to
be similar between the 3D CRT and IMRT patients (61.5% vs 61.2%, respectively) but more treatment breaks were needed (3 vs 0, respectively)
• Grade ≥2 acute haematological toxicity was found to be 35% in 3D CRT and 29% of IMRT patients respectively
• Grade 3 late toxicity in 3DCRT arm in 3 patients versus 1 in IMRT arm
• 49 Patients had > 6 months F/U.
• A total of 17 patients developed distant metastases,the median time to distant metastases:8.7 months(range 3.9-21.6 months)
Results• The median serum creatinine from before radiotherapy
to most recent creatinine was unchanged in the IMRT group (0.80 mg/dL) but increased in the 3D CRT group from 0.80 mg/dL to 1.0 mg/dL (P = .02)
• The median kidney mean dose was higher in the IMRT versus the 3D CRT group (13.9 Gy vs 11.1 Gy; P = .05). The median kidney V20 was lower for the IMRT versus the 3D CRT group (17.5% vs 22%; P = .17)
• The median liver mean dose for IMRT and 3D CRT was 13.6 Gy and 18.6 Gy, respectively (P = .19). The median liver V30 was 16.1% and 28%, respectively (P < .001)
Discussion
• Although the data are not consistent in
demonstrating an advantage of IMRT over 3D CRT,
there may be some gains in acute toxicities with the
use of IMRT because of generally decreased dose to
normal organs such as bowel, kidney, and liver.
• In addition, IMRT may allow for dose escalation in
the hopes to improve disease control, especially in
cases such as close/positive margins, extranodal
disease spread, or other situations believed to have a
high risk of residual microscopic disease, without
increasing the dose to critical structures.
Discussion
• Adjuvant chemoradiotherapy was well tolerated
with either 3D CRT or IMRT, with similar acute
and late toxicities reported.
• The incorporation of image guidance likely
confers additional improvements.
• Further investigation is required to determine the
true clinical benefit of IMRT for this disease, and
we believe it is highly warranted given the
generally poor outcomes of this disease and the
high rate of treatment morbidity.
Discussion• Despite higher doses used, IMRT provides
sparing to the liver and possibly the kidneys
• Although the dosimetric advantage of IMRT
for the kidneys was not consistent, renal
function appears to be preserved better
• These results need to be validated with longer
follow-up as well as in larger studies
Conclusion• LRC is good with adjuvant
chemoradiotherapy but overall outcomes
for Ca. Stomach remains poor.
Improvement in both systemic & local t/t
is required
• Adjuvant chemoradiotherapy was well
tolerated with either 3D CRT or IMRT,
with similar acute and late toxicities
reported
Conclusion
• The differences in clinical outcomes
were not statistically significant in
3DCRT versus IMRT
• IMRT was found to provide sparing
to the liver and possibly renal
function.
• (Cancer 2010;116:3943–52. VC
2010 American Cancer Society)
REFERENCES AND LANDMARK
TRIALS
• Moertel et al (1969) first time demonstrated
the clinical benefit of combining 5FU to
Radiation in locally advanced unresectable
Ca. Stomach.
• INT0116/-SWOG 9008 (Macdonald et al.
2001, 2004, 2009)
• UK-MRC MAGIC Trial 2006 NEJM.
• Japanese S-1 Trial 2007 NEJM.
• Boige et al. 2007 ASCO
Other Major References
• ECOG-CALGB 80101 Trial,2002-2009
• Ringash J, et al.2005. IJROBP
• Wieland P, et al.2004. IJROBP
• Smalley,Gunderson.2002.IJROBP
• Tepper & Gunderson.2002.SRO
• Boda-Heggemann, Hofheinz et al.
2009.IJROBP
• RTOG 9904 Trial
Other Major References
• Milano et al. 2006.BJR
• Chung et al. 2008.IJROBP
• Alani et al. 2009.IJROBP
• Leong T et al.Radiother Oncol 2005
• van der Geld YG et al.IJROBP 2007
• de la Torre et al. Med. Dosim. 2004
• ICRU-62(supplement to ICRU Report 50)1999
• ICRU-83,VOL-10,No.1,2010
THANKS
Recommended