I found a comparison of Intensity Modulated Radiation Therapy (IMRT) with Conventional Radiotherapy

There was recently some discussion on whether there were any benefits for using the more costly IMRT as opposed to the conventional radiation for external pelvic radiation. Since I started IMRT today, I did some research this afternoon and came across this article that seems to justify seeking IMRT as your external radiation choice if you have an option:

Comparison of Intensity Modulated Radiation Therapy (IMRT) with Conventional Radiotherapy (CRT) for Treatment of Uterine Papillary Serous Carcinoma (UPSC) with Sequential Carboplatin and Paclitaxel

Chemotherapy: A Toxicity Study
J. Vainshtein, S. Mutyala, N. Thawani, R. Hannan, R. Yaparpalvi, S. Kalnicki
Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY

Purpose/Objective(s): Uterine papillary serous carcinoma (UPSC) is an uncommon, aggressive variant of endometrial carcinoma that has a propensity for abdominal and pelvic failures and a poor response to therapy. The combination of chemotherapy with radiation therapy (RT) has improved cure rates in patients with UPSC, although with substantial acute toxicity. The development of IMRT has facilitated the delivery of radiation to tumor while sparing normal organs, allowing for good local control with the potential for reducing toxicity. Our institute has initiated a ‘‘sandwich protocol’’ for the treatment of UPSC, consisting of sequential chemotherapy both before and after RT. We herein report a comparison of the acute toxicities from IMRT and CRT in conjunction with high dose rate brachytherapy and ‘‘sandwich’’ Cisplatin or Carboplatin and Paclitaxel (CT) in the treatment of UPSC.

Materials/Methods: Between January 2000 and March 2008, 52 patients with histologically proven UPSC were accrued to the IRB approved ‘‘sandwich’’ protocol at our institution. All patients underwent surgical staging laparotomy with total abdominal hysterectomy and bilateral salpingoophorectomy, followed by sequential chemotherapy and RT. This consisted of Paclitaxel (175 mg/m2) and either Cisplatin (75 mg/m2) or Carboplatin (AUC=6.0, 6.5, 7.5) every 21 days for 3 cycles, both before and after RT. In October 2005, the protocol was amended to change the RT delivery from CRT to IMRT.

Results: The initial 24 patients were treated with CRT and the subsequent 27 patients were treated with IMRT. Two patients in each group were treated to extended paraaortic lymph node fields per protocol for lymph node involvement. All patients in the IMRT group and 20/23 pts in 3DCRT group received intracavitary HDR brachytherapy. All patients completed their prescribed course of RT. No patients in either group experienced any grade 4 toxicity. Patients treated with IMRT experienced significantly less grade 2 or greater gastrointestinal toxicity (30.4% vs. 3.7%, p = 0.007), as well as less genitourinary toxicity (8.3% vs. 0%, p = 0.13) than did those treated with CRT. No differences in hematologic or skin toxicity between treatment groups were observed.

Conclusions: Radiation in combination with sandwich CT chemotherapy for UPSC had less toxicity when delivered via IMRT compared to CRT. This difference was statistically significant for GI toxicity, and approached statistical significance for GU toxicity.
The reduction in GI toxicity is of particular importance, as GI complications are a common dose limiting toxicity in UPSC patients. Further follow-up and prospective study with dose escalation is warranted.

Author Disclosure: J. Vainshtein, None; S. Mutyala, None; N. Thawani, None; R. Hannan, None; R. Yaparpalvi, None; S. Kalnicki,
None.

( http://download.journals.elsevierhealth.com/pdfs/journals/0360-3016/PIIS0360301608017008.pdf )