Radiation Oncology/IMRT/Pelvis

This page is for IMRT topics that apply to any pelvic malignancy.

Dosimetry

• U. Chicago, 2000 - PMID 11121668 — "Intensity-modulated whole pelvic radiation therapy in patients with gynecologic malignancies." Roeske JC et al. Int J Radiat Oncol Biol Phys. 2000 Dec 1;48(5):1613-21.
  • 10 pts (5 cervix, 5 endometrium). LN CTV based on expanding vessel contours by 2 cm. Compared 3D-CRT "4-field box" (based on PTV) vs IMRT.
  • Volume of small bowel > 30 Gy, 17.4% (IMRT) vs 33.8% (3D). Reduced volume of rectum and bladder receiving prescription dose by 23%
  • Conclusion: IMRT reduces volume of small bowel irradiated.

Pelvis + para-aortic

• U. Chicago, 2006 (2002-2005) - PMID 16730136 — "Preliminary outcome and toxicity report of extended-field, intensity-modulated radiation therapy for gynecologic malignancies." Salama JK et al. Int J Radiat Oncol Biol Phys. 2006 Jul 15;65(4):1170-6.
  • 13 pts with gynecologic malignancies. CTV included pelvic and presacral LN + para-aortic LN.
  • Low incidence of acute toxicity.

• UAB, 2005 - PMID 15380585 — "IMRT dose escalation for positive para-aortic lymph nodes in patients with locally advanced cervical cancer while reducing dose to bone marrow and other organs at risk." Ahmad RS et al. Int J Radiat Oncol Biol Phys. 2004 Oct 1;60(2):505-12.
  • 5 cervical ca pts with positive PA LN. Treatment included pelvis + para-aortics. Compare 3 techniques: 1) AP-PA (both regions), 2) 4-field box (both regions), 3) IMRT to PA matched to 4-field box to pelvis.

Bone marrow sparing

See also: Radiation Oncology/Toxicity/Bone marrow

• U. Chicago
  • 2003 PMID 12957265 — "Intensity-modulated radiotherapy as a means of reducing dose to bone marrow in gynecologic patients receiving whole pelvic radiotherapy." Lujan AE et al. Int J Radiat Oncol Biol Phys. 2003 Oct 1;57(2):516-21.
    • 10 pts with gynecologic cancer. Compared 3 plans: 1) standard 4-field, 2) IMRT (sparing normal tissues but not bone marrow), and 3) bone-marrow sparing IMRT.
    • Bone marrow sparing IMRT reduced amount of BM treated to >50% of prescription dose from 87.4% (std) and 75.7% (IMRT) to 60%.
  • 2002 PMID 12459361 — "Impact of intensity-modulated radiotherapy on acute hematologic toxicity in women with gynecologic malignancies." Brixey CJ et al. Int J Radiat Oncol Biol Phys. 2002 Dec 1;54(5):1388-96.
    • 36 pts with gynecologic cancer, treating the pelvis using IMRT (that did not include bone marrow sparing in the cost function). Compared hematologic toxicity to 88 pts treated with standard fields.
    • No S.S. seen in grade 2 or higher WBC, ANC, and Hgb toxicity (19.4%, 9.1%, and 8.6% IMRT; 21.6%, 8.3%, 9.2% std). No grade 2 platelet toxicity. Significant difference in WBC toxicity for pts treated with chemo: 31.2% vs 60% (IMRT vs std).
    • Standard IMRT planning resulted in less bone marrow being irradiated, particularly in the iliac crests.