Prevention of malignant seeding at drain sites after invasive procedures (surgery and/or thoracoscopy) by hypofractionated radiotherapy in patients with pleural mesothelioma

Figures & data

Table I.  Details about prophylactic radiation therapy in malignant pleural mesothelioma from reported randomized and non-randomized studies and from current study

Author	Procedure	Time interval before RT (days)	EBRT schedule/ energy	N./ type of study	Procedure tract metastases after EBRT	Adverse effects from EBRT
Boutin 1995	Thoracoscopy	10 to 15	21 Gy in 3 fr/from 12.5 to 15 MeV electrons	20 vs. 20*/ randomized	0% vs. 40%	No inflammation or edema
Low 1995	Thoracoscopy	Within 15	21 Gy in 3 fr/ 140 KV or 250 KV photons	19**/ retrospective	0%	No side effects
Cellerin 2004	Aspiration, needle biopsy, chest drain, surgical incision	10 to 123 (median 37)	Several not specified	33 vs. 25*/ retrospective	21% vs. 48%	NR
Bydder 2004	Needle biopsy, FNA, thoracoscopy, thoracic drain	Within 15	10 Gy in 3 fr/9 MeV electrons	43**/ randomized	7% vs. 10%	No patients with RTOG/EORTC Grade 2–4 toxicities
West 2005	Needle biopsy, thoracoscopy, chest drain	6 to 42 (median 26)	21 Gy in 3 fr/10 MeV electrons, 6 MV photons with bolus, 200 KV photons without bolus	37/ retrospective	0%***	NR
O'Rourke 2007	Thoracic drain, thoracoscopy, pleural biopsy	Within 21	21 Gy in 3 fr/9–12 MeV electrons or 250 KV photons	31 vs. 30*/ randomized	13% vs. 10%****	Three patients with erythema/discoloration, one vomiting, one chest discomfort
Current study	Thoracoscopy, pleurectomy, thoracic drain, FNA	11 to 60	21 Gy in 3 fr/ 12 MeV electrons	32/ retrospective	0%	Eleven patients with erithema G1/ no late adverse effects

Notes: EBRT, external beams radiation therapy; fr, fractions; N, number of patients; FNA, fine needle aspiration; NR, non reported; EORTC, European Organisation for Research and Treatment of Cancer; RTOG, Radiation Therapy Oncology Group.

* Number of treated patients vs number of non-treated patients

** Data reported based on the number of procedure sites (Low et al.: 38 sites from 20 patients, 1 lost at follow up; Bydder et al.: 58 procedure sites from 43 patients)

*** No tumour growth within areas that had been treated with prophylactic radiotherapy; in 3 patients there was already tumor invasion of the skin and chest wall at the chest instrumentation site at the time of radiotherapy; 2 patients received a second treatment after developing nodules at the edge of one of the previously treated fields.

**** Tumor nodules associated with baseline drain site: 4/31 patients in the Radiation Treatment (RT) arm vs. 3/30 patients in the Best Supportive Care (BSC) arm. Nodules at other sites associated with subsequent procedures (no prophylactic RT performed) were also observed: 3 in the RT arm, 1 in the BSC arm.

Figure 1.  Thoracoscopy scar site covered by 10×10 cm square radiation field.

Figure 2.  Overall survival for the whole series of 32 patients estimated using the Kaplan-Meier method. Confidence intervals (C.I.) were computed according to Greenwood's formula for the standard error of cumulative survival. Analysis was carried on using SAS statistical software.