PARIS — France is experiencing a public meltdown of Chernobyl proportions in an ever-widening scandal over radiation therapy incidents that may have affected more than 6,000 patients.

The French nuclear safety authority, l’Autorit S ret Nucl aire (ASN), revealed on Sept. 7 that during an investigation of two known incidents affecting 433 patients receiving an overdose of radiation at Centre Hospitalier Jean Monnet d’Epinal, it discovered that another 300 patients treated between 1999 and 2000 were exposed to excessive radiation of around 7%.

ASN went on to report further it had discovered that, as far back as 1989, “inappropriate” software parameters were set for positioning patients undergoing radiation therapy at the Epinal radiation therapy clinic, potentially exposing an additional 4,500 patients to radiation 5.5% greater than required.

Prior to its closure in late February, the Epinal clinic had treated about 700 patients annually.

To date 63 lawsuits have been filed, including five for involuntary homicide. French jurisprudence does not recognize class-action suits, so each plaintiff must file independently. A lawsuit filed earlier this year by the association gave patients a legal standing with insurance companies, which previously had refused to recognize their right to seek a claim.

The meltdown of radiation therapy spread across France with the warning in June from BrainLab (Feldkirchen, Germany) that a mechanical incompatibility could cause a target area “misalignment” for the sterotactic units used for brain cancer therapy in Montpellier, Tours, Nancy and Paris.

An estimated 620 patients treated since 2003 may have been affected, though no complications were immediately reported.

University Hospital Toulouse, also using BrainLab equipment, reported a different problem with the malfunctioning of the unit’s accelerator that potentially exposed 145 patients to excessive radiation.

“We are facing a health issue of exceptional magnitude,” said Rosellyne Bachelot, French minister of health, youth and sport, at an early September press conference.

The health ministry etablished a hot line for affected patients to contact medical staff for examinations. More than 1,500 calls were fielded in the first week.

Bachelot said she is launching a top-to-bottom investigation of all French radiotherapy centers and, significantly, will double the number of radiophysicists over the next five years. Recommendations from a working group commissioned in March are due later this month.

The ministry also said that before the end of 2007 in vivo dosimetry will be required for all patients undergoing radiotherapy. It also issued a requirement that all software interfaces must be in French. Commonly used in the past, English-language interfaces no longer will be permitted.

Bachelot met last week with an association formed by the patients from the Epinal center and assured them they will be compensated “in the best way and in the shortest time.”

G rard Welzer, a lawyer for the Epinal patient association, told the newspaper Le Monde: “All the better that Madame Bachelot is putting the spotlight on this affair. But these patients demand medical treatment and they are coming up against resistance from the insurers to receive compensation.”

In an interview with the newspaper La Depeche du Midi, published earlier this week, Bachelot said she would use her influence to push health insurance companies covering the affected hospitals, “in the event they would like to hide behind a wait-and-see attitude.”

More lawsuits are expected from the widening pool of patients either exposed to overdoses of radiation or targeting errors in six different hospitals for an array of indications, including radiation therapy for breast cancer, brain cancer and significantly, for prostate cancer, where five patients died as a result.

The revelations, which played out across the country’s mass media in June and again in September, have created a crisis of confidence for radiation therapy in France that, except for the glaring mistreatment of patients in Epinal, is disproportionate to the severity of the problems reported.

Some 180,000 patients receive radiation therapy in France each year, and as suggested by the response from the health ministry, a shortage of qualified staff and sufficient training has been called into question as much as any technical issues.

In its report, ASN said “the importance of the ‘organization’ factor in risk prevention is unrecognized,” and that “various links in the healthcare chain, which are supposed to make it possible to avoid crises or to handle them as well as possible, all broke one after the other.”

The incidents at Epinal stand apart from other revelations of radiation errors. Human error, even outright meddling with equipment and protocols, explains the worst of the patient injury experienced at the clinic.

The systematic over-dosage of patients was first noticed in the summer of 2005, but was not reported as required to French authorities until October 2006.

The scandal broke this past March with the revelation that 24 men treated for prostate cancer at Epinal received a radiation dosage an average of 20% greater than specified.

ASN concluded that the cause of the incident for those men was “ignorance or neglect of the basic rules of quality assurance by the person who was in charge.” That individual manipulated the parameters for the dynamic wedge that shapes the delivery of the radiation to the targeted area and calculates the required dosage.

Inappropriate beaming of radiation to the genital and rectal areas of the men undergoing treatment for prostate cancer produced devastating consequences. Five men died as a result, while the others suffer from what is politely described as “a compromised quality of life.”

One of the survivors vividly described his quality of life to Le Monde, saying, “I have one bag to pee in, one bag for my feces, and my butt and penis always hurt.”

This patient group, the most severely burned by the radiation, also was the most recently treated, between May 2004 and August 2005.

According to ASN, a “systematic error in parameters” for the radiation therapy unit traces back to 1989 and potentially has affected 5,200 patients.

Medical equipment used in Epinal is not faulted nor named in the report, except for a CadPlan treatment planning software produced by Varian Medical Systems (Palo Alto, California) that was manipulated by the technician.

Six officials, including the director of the hospital and regional health authority executives, face disciplinary action. Two radiation therapists have been suspended and a radiophysicist has been fired.